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Seasonal Variation in Quality and Quantity of Hyparrhenia Rufa, a Native Grass in Diamphwe Cattle Ranch of Central Malaw...

Permanent Link: http://ufdc.ufl.edu/UFE0045102/00001

Material Information

Title: Seasonal Variation in Quality and Quantity of Hyparrhenia Rufa, a Native Grass in Diamphwe Cattle Ranch of Central Malawi, Africa
Physical Description: 1 online resource (66 p.)
Language: english
Creator: Makondi, Felix G
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2012

Subjects

Subjects / Keywords: forage -- minerals -- quality
Animal Sciences -- Dissertations, Academic -- UF
Genre: Animal Sciences thesis, M.S.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: The objective of the study was to evaluate the seasonal variation in quality and quantity of predominant native pasture forage (hyparrhenia rufa) at Diamphwe cattle ranch, from October 2011 to March 2012 as a vasis for supplementation. Monthly changes in minerals, (CP), (ADF), (NDF), (IVDME), (HM) and (HA) were analyzed.  January, Februaru and March had greater HM, P greater than 0.05 but it was characterized by an increase in ADF and NDF as the season progressed.  Greater IVDMD, P less than 0.05 was observed in the Uplands in October and November but the month with the least digestibility was December. In October and November, Uplands showed greater CP concentration P less than 0.05. CP, Na, S and Cu, did not meet the requirement for beef cattle but Zn only met the requirement in March. Ca, P, K, Mg, CI, Fe, Mo, Mn and Co met the requirement for beef cattle during the study period.  The results also showed the importance of Lowlands for livestock production in the ranch although Lowlands constituted only a small fraction of this landscape, they provided greater levels of herbage mass throughout the study period.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by Felix G Makondi.
Thesis: Thesis (M.S.)--University of Florida, 2012.
Local: Adviser: Arthington, John D.

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2012
System ID: UFE0045102:00001

Permanent Link: http://ufdc.ufl.edu/UFE0045102/00001

Material Information

Title: Seasonal Variation in Quality and Quantity of Hyparrhenia Rufa, a Native Grass in Diamphwe Cattle Ranch of Central Malawi, Africa
Physical Description: 1 online resource (66 p.)
Language: english
Creator: Makondi, Felix G
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2012

Subjects

Subjects / Keywords: forage -- minerals -- quality
Animal Sciences -- Dissertations, Academic -- UF
Genre: Animal Sciences thesis, M.S.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: The objective of the study was to evaluate the seasonal variation in quality and quantity of predominant native pasture forage (hyparrhenia rufa) at Diamphwe cattle ranch, from October 2011 to March 2012 as a vasis for supplementation. Monthly changes in minerals, (CP), (ADF), (NDF), (IVDME), (HM) and (HA) were analyzed.  January, Februaru and March had greater HM, P greater than 0.05 but it was characterized by an increase in ADF and NDF as the season progressed.  Greater IVDMD, P less than 0.05 was observed in the Uplands in October and November but the month with the least digestibility was December. In October and November, Uplands showed greater CP concentration P less than 0.05. CP, Na, S and Cu, did not meet the requirement for beef cattle but Zn only met the requirement in March. Ca, P, K, Mg, CI, Fe, Mo, Mn and Co met the requirement for beef cattle during the study period.  The results also showed the importance of Lowlands for livestock production in the ranch although Lowlands constituted only a small fraction of this landscape, they provided greater levels of herbage mass throughout the study period.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by Felix G Makondi.
Thesis: Thesis (M.S.)--University of Florida, 2012.
Local: Adviser: Arthington, John D.

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2012
System ID: UFE0045102:00001


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1 SEASONAL VARIATION IN QUALITY AND QUANTITY OF HYPARRHENIA RUFA, A NATIVE GRASS IN DIAMPHWE CATTLE RANCH OF CENTRAL MALAWI AFRICA By F ELIX G OODSON M AKONDI A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FL ORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE UNIVERSITY OF FLORIDA 2012

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2 2012 Felix Goodson Makondi

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3 To my family

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4 ACKNOWLEDGMENTS I thank my committee Dr. J. D. Arthington, Dr. Cliff Lamb, Dr. J.Ven dramin and Dr. S.C Malunga for working arduously with me and providing me the necessary guidance in completing this research. I would also like to thank the United States Agency for International Development (USAID) for their support for my studies. Thank s go to the faculty and staff of the Animal Sciences Department University of Florida, Chitedze Research Station Malawi, The Range Cattle Research and Education Center at Ona. And last but not least, thanks to the administrators at the Department of Animal Health and Livestock Development (Malawi) also staff at Diamphwe cattle Ranch and Mrs. Dzinkambani for forage sampling.

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5 TABLE OF CONTENTS page ACKNOWLEDGMENTS ................................ ................................ ................................ .. 4 LIST OF TABLES ................................ ................................ ................................ ............ 7 LIST OF ABBREVIA TIONS ................................ ................................ ............................. 8 ABSTRACT ................................ ................................ ................................ ..................... 9 CHAPTER 1 INTRODUCTION ................................ ................................ ................................ ..... 11 2 LITERATURE REV IEW ................................ ................................ .......................... 14 Diamphwe Cattle Ranch ................................ ................................ ......................... 14 Uplands and Lowlands ................................ ................................ ..................... 14 Constrai nts to Cattle Production ................................ ................................ ....... 15 Hyparrhenia R ufa ................................ ................................ ................................ .... 21 Carbon 4 Plants ................................ ................................ ................................ 22 Nutritive Value of C4 Grasses ................................ ................................ .......... 22 Carbon 4 Grass Quality ................................ ................................ .................... 23 3 MATERIALS AND METHODS ................................ ................................ ................ 26 Pasture Description ................................ ................................ ................................ 26 Pasture Selection and Forage Sampling. ................................ ................................ 26 Herbage Mass a nd Accumulation ................................ ................................ ............ 27 Analysis of Nutrients ................................ ................................ ................................ 28 Statistical Analysis ................................ ................................ ................................ ... 28 4 RESULTS AND DISCUSSION ................................ ................................ ............... 32 Herbage Mass and Accummulation ................................ ................................ ........ 32 Herbage Mass ................................ ................................ ................................ .. 32 Herbage Accumulation ................................ ................................ ..................... 33 ADF, NDF, IVDMD, CP, ................................ ................................ .......................... 34 Acid Detergent Fiber (ADF) ................................ ................................ .............. 34 Neutral Detergent Fiber (NDF) ................................ ................................ ......... 34 Invitro Dry Matter Digestibility (IVDMD) ................................ ............................ 35 Crude P rotein (CP) ................................ ................................ ........................... 36 Macrominerals ................................ ................................ ................................ ........ 37 Calcium (Ca) ................................ ................................ ................................ .... 37 Phosphorus (P) ................................ ................................ ................................ 37

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6 Potassium (K) ................................ ................................ ................................ ... 38 Magnesium (Mg) ................................ ................................ .............................. 38 Sodium (Na) ................................ ................................ ................................ ..... 38 Sulphur (S) ................................ ................................ ................................ ....... 39 Chlorine (Cl) ................................ ................................ ................................ ..... 39 Microminerals ................................ ................................ ................................ ......... 40 Iron (Fe) ................................ ................................ ................................ ............ 40 Copper (Cu) ................................ ................................ ................................ ...... 41 Molybdenum (Mo) ................................ ................................ ............................ 41 Zinc (Zn) ................................ ................................ ................................ ........... 42 Manganese (Mn) ................................ ................................ .............................. 43 Cobalt (Co) ................................ ................................ ................................ ....... 43 Conclusion ................................ ................................ ................................ .............. 44 LIST OF REFERENCES ................................ ................................ ............................... 64 BIOGRAPHICAL SKETCH ................................ ................................ ............................ 66

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7 LIST OF TABLES Table page 3 1 Chemical Composition of Soils from Experimental Site ................................ ...... 29 3 2 Rainfall Data (mm) During th e Experimental Period ................................ ........... 30 3 3 Temperature Date C, During the Experimental Period ................................ ...... 31 4 1 Herbage Mass, kg/ha ................................ ................................ ......................... 45 4 2 Herbage Accumulation, kg/ha daily ................................ ................................ .... 46 4 3 ADF, % of DM ................................ ................................ ................................ ..... 47 4 4 NDF, % of DM ................................ ................................ ................................ .... 48 4 5 In Vitro Dry Matter Digestibility, % ................................ ................................ ...... 49 4 6 Crude Protein, % of DM ................................ ................................ ...................... 50 4 7 Calcium, % of DM ................................ ................................ ............................... 51 4 8 Phosphorous, % of DM ................................ ................................ ....................... 52 4 9 Potassium (K) % of DM ................................ ................................ ...................... 53 4 10 Magnesium (Mg) % of DM ................................ ................................ .................. 54 4 11 Sodium (Na), % of DM ................................ ................................ ........................ 55 4 12 Sulfur (S), % of DM ................................ ................................ ............................. 56 4 13 Chlorine, (Cl) % of DM ................................ ................................ ........................ 57 4 14 Fe, ppm ................................ ................................ ................................ .............. 58 4 15 Copper (Cu), ppm ................................ ................................ ............................... 59 4 16 Molybdenum (Mo), ppm ................................ ................................ ...................... 60 4 17 Zinc (Zn), ppm ................................ ................................ ................................ .... 61 4 18 Manganese (M n), % of DM ................................ ................................ ................. 62 4 19 Cobalt, ppm ................................ ................................ ................................ ........ 63

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8 LIST OF ABBREVIATION S ADF Acid detergent fiber C3 Carbon 3 C4 Carbon 4 Ca Calcium Cl Chlorine Co Colbat CP Crude protein Cu Copper DM Dry matter Fe Iron HA Herbage Accumulation HM Herbage Mass K Potassium Mg Magnesium Mn Manganese Mo Molybdenum Na Sodium NDF Neutral detergent fiber OM Organic matter P Phosphorous PPM Parts Per Million S Sulphur Zn Zinc

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9 Abstract of Thesis Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree o f Master o f Science SEASONAL VARIATION IN QUALITY AND QUANTITY OF HYPARRHENIA RUFA, A NATIVE GRASS IN DIAMPHWE CATTLE RANCH OF CENTRAL MALAWI AFRICA By Felix Goodson Makondi December 2012 Chair: J. D. Arthington Major: Animal Science s The objective of the study was to evaluate the seasonal variation in quality and quantity of predominant native pasture forage (hypar rhenia rufa) at Diamphwe cattle ranch, from October 2011 to March 2012 as a basis for supplementation Monthly changes in minerals, (CP), (ADF), (NDF), (IVDMD), (HM) and (HA) were analyzed. January, February and March had greater HM, P < 0.05 in the Lowlan ds Lowlands had greater HA, P < 0.05 in December to January. There was no difference in ADF in both locations and also NDF did not differ, P > 0.05 but it was characterized by an increase in ADF and NDF as the season progressed Greater IVDMD, P < 0.05 wa s observed in the Uplands in October and November but the month with the least digestibility was December. In October and November, Uplands showed greater CP concentration P < 0.05 CP, Na, S, and Cu did not meet the requirement for beef cattle but Zn onl y met the requirement in March. Ca, P, K, Mg, Cl, Fe, Mo, Mn and Co met the requirement for beef cattle during the study period The results also showed the importance of Lowlands for livestock production in the ranch although Lowlands constituted only a

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10 small fraction of this landscape, they provided greater levels of herbage mass throughout the study period.

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11 CHAPTER 1 INTRODUCTION Diamphwe cattle ranch occupies 32,000 hectares of land and is in the central region of Malawi in the Dzalanyama fores 1650 m and at a distance of 80 kilometers southwest of Lilongwe the capital city of Malawi. There are two seasons in Malawi: The rainy season which extends from October to March and a dry period from April to September. The annual precipitation ranges from 763 1140 mm and temperatures range from This cattle ranch is owned by the government of Malawi and has a population of over four thousand (4,000) cattle The main objective of the ranch is to produce steers for fattening and work oxen and also acts as a reserve for Malawi Zebu cattle genetic material. Native grasses of which hyparrhenia rufa dominates are the primary source of nutrition for these cattle. Unfortunately, forages often do not provide all of the needed nutrients which cattle require throughout the year. Many incidences of mineral inadequacies in forages and soils have been reported which contribute to reproductive failure and low production ra te (Vagas and Mc Dowell 1997). The cyclic gain of cattle body weight with the onset of the rains and the loss of about 30% of this body weight during the dry season continues to be a major limitation to cattle production in Malawi (Mtimuni 1982). Recently solutions to the problem of the long dry season have been attempted with the introduction of improved forages in form of Rhodes grass and use of stored feed such as hay and corn silage. Intensification of livestock production has brought about some nutri tional problems. In spite of frequent dipping to control ticks to avoid tick borne diseases and

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12 application of some improved livestock management techniques, major problems still exist within the ranch. These problems include cyclic body weight gain and lo ss, 50% average calving rate, calf mortality of 20% and herd mortality rate of 5% from unknown causes (10 year average for Diamphwe cattle ranch). Nutrient supplementation of cattle can help to alleviate problems associated with lack of forage quality and quantity (Grunes and Welch 1989). The balance of minerals is of vital consideration for animal health so far as their availability is concerned; the body can tolerate a deficiency of vitamins longer than a mineral deficiency (Grunes and welch 1989). Miner al deficiencies or imbalances in soils and forages have long been held responsible for low production and reproduction problems among grazing animals (Mc Dowell 1985). Mineral deficiencies likely to affect production of grazing livestock in many regi ons of the world include the major elements calcium (Ca), phosphorous (P), magnesium (Mg) sodium(Na) sulphur(S) and the trace elements cobalt(Co), copper(Co) iodine (I), manganese(Mn), selenium(Se), zinc(Zn) and iron (fe) (Little,1982; Judson et al1987;Judson an d Mc Farlane 1998). When nutrients are deficient the producer is justified to supplement. Currently there is a lack of information on the possible deficiencies of all nutrients and also mineral toxicities for pasture grazing animals at Diamphwe cattle ranc h. T his study was conducted to provide an objective basis for efficient and low cost nutrient and mineral supplementation, to identify grazing and supplementation strategies necessary to maintain long term herbage productivity and quality and livestock pro duction within the ranch by; 1) Assessing forage nutrient

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13 concentrations during the rainy season, 2) Quantifying the dynamics of herbage yield and quality in the U pland and L owland

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14 CHAPTER 2 LITERATURE REVIEW Diamphwe Cattle Ranch Diamphwe cattle Ranch was established in 1971 as part of Dzalanyama Forest Reserve within the 100,000 hectares of the forest reserve with a multipurpose form of land use to keep away poachers, bush fires and wood cutters from damaging the fauna and flora of the reserve and for production of good quality beef. (Dowsett and Lemaire 1989) Vegetation of the Ranch varies from Brachystegia or savanna woodland to evergreen forests. It also forms part of Dzalanyama Range, a series of rocky hills running north west south east along the b order with Mozambique, which marks the water shed between Lake Malawi and the Zambezi river system. The eastern side of the Ranch is relatively flat, at about 1,300 m Diamphwe Cattle Ranch is characterized by rolling to flat topography with tropical savanna grassland characterized by short grasses and scattered shrubs and trees. The soil is deep well drained latosols on higher parts with poorly drained sand and clay soils in lowlands (Reynolds 2000) Diamphwe Cattle Ranch practices controlled breeding thus calving season starts in September or October depending on the time the bulls were introduced and it is done to take advantage of the rainy season when pastures are in abundance Uplands and Lowlands In the Uplands where the attitude rise above 1 300 m the soil is deep well drained latosols while in the Lowlands where the attitude is 750 m the soil is poorly drained sand

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15 and clay. Lowlands are shallow and seasonally water logged depressions. (Hodges 1983). The Hyparrhenia rufa pattern of growth is mainly controlled by regular grass fires in the Uplands and in the Lowlands the moisture of lower lying areas maintains a greener and more fire resistant margin to the remaining forest. The grass layer is depressed in the Uplands by relatively light cro wned trees, which have the ability to coppice freely after cutting. The woodland varies in density from tall fairly open woodland to dense shrub. Grasses vary according to habitat, but are generally of medium height with low ground cover. When trees are cl eared, the grasses become more vigorous and a dense vegetative cover results in the Uplands (Mitchell 1987 ). Lowlands are nearly treeless areas dominated by grasses or sedges with a buildup of organic matter with a hydromorphic soil horizon. cat chment also acts as a hydrological store, holding water and releasing it as a base flow to its headwater stream during the dry season. (Roberts 1988) Constraints to Cattle Production A major constraint to cattle production at Diamphwe cattle ranch is the long dry season which extends for six months from April to October. During the dry season, scarcity of grass becomes a problem in Malawi. Consequently nutrition has frequently been cited as the most limiting factor in cattle production in Malawi (Mtimuni, 1982). Absence of legumes in natural pasture and the rapid decline of forage quality of native grasses as the rainy season progresses are factors hampering cattle production. When quality is low, forages alone may not support desired rates of animal perfo rmance (Moore and Sollenberger, 2002).

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16 Low CP content of native grass is often below 7% of the minimum required for microbial activity and this limits intake (Milford and Mirson, 1965). High lignin content of tropical forage and reduced microbial activity caused by low dietary CP increases the retention rate of digesta in the rumen. Forage intake decreases and animals lose body weight because digestibility declines as lignin content increases (Minson, 1974). NDF which constitutes lignin, cellulose and he micellulose is inversely related to digestibility and intake potential of feed as it predicts the extent of biological degradation (Van Soest, 1991.) Concentration of NDF in C4 plants such as hyparrhenia rufa is 70% or higher and requires microbes. Acid De tergent Fiber (ADF) which constitutes lignin and cellulose is used to predict dietary ingredient for many herbivores. Two of the major functions of fiber are to st imulate rumination and salivation and to form a mat that functions as a filtering system and prevents a rapid passage of particles and loss of nutrients (Van Soest et al 1991). This corresponds to NDF which is commonly used to asses forage quality. The ND F is better related to intake and gastrointestinal fill than any other measure of fiber thus expectation that the fiber requirement is better expressed in terms of NDF rather than ADF (Lewis et al, 1991). Ruminants generally and dairy cattle in particular require adequate coarse insoluble fiber for normal rumen function and maintenance of normal milk fat (Robertson et al 1991). Normal rumen function in dairy cattle is associated with adequate rumination and cellulose digestion. These events maintain rumen p H and cellulolytic microorganisms that characteristically produce the high acetate to propionate

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17 ratios needed for normal lipid metabolism in the cow. Daily rumination time is directly proportional to coarse NDF intake and related body size. Animals gain body weight during the rainy season when there is a plentiful supply of forage which provides adequate protein and energy for the level of production for most local Malawi Zebu (Mtimuni, 1992). Animals lose body weight as forage quality progressively decli nes during the dry season. Animals may lose as much as 30% of their peak body weight in the dry season Mtimuni, (1982) severely affecting cowherd productivity. The low calving rate observed at Diamphwe cattle ranch is partially caused by poor feed quality and quantity. On average, animals calve every other year due to low nutrient reserves in their body. Low calving rate (approximately 50%) coupled with an extended length of time to reach slaughter weight, stagnates productivity. The problem of low calving rate in animals is not unique to Diamphwe cattle ranch. Other livestock centers in Malawi experience the same problem indicating that low calving rate is wide spread in Malawi (Livestock and Meat Study 1983). Efforts in livestock production in Malawi have been devoted to solving the problems of forage availability during the dry season. Considering the situation of plentiful low quality forage, Mtimuni, (1982) states that the major factor on such a pasture is the low CP content of grasses, which usually is below 7%, the maximum required for rumen microbial activity. Energy becomes the second limiting factor because of reduced intake of low quality forage.

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18 The gross energy content of forages is about 18 mega joules (MJ) per kg DM. Not all of this is availabl e to the animals. After the forage has been digested, part of the energy is excreted in the urine and in methane that is produced during the fermentation process in the rumen. The animals also produce heat during digestion. Therefore with respect to the en ergy content of forage, a differentiation is made between Gross energy (GE), digestible energy (DE) which is GE minus energy of the undigested parts. Metabolisable energy (ME) which is DE minus energy in urine and methane and Net energy which is ME minus h eat produced. The net energy can be used by the animal to supply its various needs like maintenance of body functions, growth, lactation or gestation. A cow weighing 250 kilograms needs between 30 and 35 MJ metabolisable energy each day for maintenance, de pending how far it walks. For this, it needs forage with about 1% nitrogen content and about 50% digestibility. To produce milk, a cow needs 5 7 MJ metabolisable energy per kg depending on fat content (Bayer 1998). Ruminants differ little with respect to t he energy they need to produce 1 kilogram of milk or to gain 1 kilogram live weight with the same fat content. What can differ however is the basic metabolic rate. The basic metabolic rate differs between animal species, for instance, it is much lower in c amels than cattle of the same weight. It also differs between breeds. The higher, the genetic potential, the higher the basic metabolic rate the more feed is needed of high quality (Bayer 1998) Although the available energy and protein of a feed are of vital importance to any animal, optimal production is only possible if there is an adequate supply of minerals (Mc Dowell 1985, Khan et al 2004).

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19 In general, response to mineral supplementation has been observed during the r ainy season when animals are growing rapidly there by increasing requirements. (Khan et al, 2004).To ensure efficient production, deficient nutrients must be supplied at required level so, thus Identification of deficient nutrients is then the first step i n the management of livestock nutrition. A manifested deficiency of minerals does not present a problem because it can be corrected using existing methods. The major problem is the sub optimal deficiency of minerals which can reduce growth rates and may ca use low calving rate but is not readily apparent due to lack of specific clinical signs (Mtimuni, 1992) Very little is known about the growth characteristics and nutritional status of forage at Diamphwe cattle ranch. Therefore the objective of this study is to characterize the current status of minerals, CP, NDF, ADF, digestibility and growth characteristics of hyparrhenia rufa at Diamphwe cattle ranch during the rainy season. Under nutrition is commonly accepted as one of the most important limitations to grazing livestock production in the tropics. The lack of sufficient energy and protein is often responsible for suboptimum livestock production. However numerous investigations have observed that cattle may deteriorate in spite of abundant feed supply (Mc Dowell and Arthington 2005). Mineral imbalances (deficiency or excesses) in soils and forages have long been held responsible for low production and reproductive problems among grazing ruminants in tropics. Wasting diseases, loss of hair, depigmanted hair skin disorders, non infectious abortion, diarrhea, and anemia, loss of appetite, borne abnormalities, tetany, low fertility, and pica are clinical signs often suggestive of mineral deficiencies

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20 throughout the world (Mc Dowell and Arthington 2005). Minera ls are vital for normal growth, reproduction, health and proper functioning of the animals body (Mc Dowell 1992). Minerals protect and maintain the structural components of the body organs and tissues and are constituents of body fluids and tissues as elec trolytes. Minerals catalyze several enzymatic processes and hormone systems (Underwood and Suttle 1999). They maintain acid base balance, water balance and osmotic pressure in the blood and cerebral spinal fluids. In fact, approximately 5% of the body weig ht of an animal consists of minerals. Adequate intake of forages by grazing ruminants is essential to meet mineral requirements. Factors which greatly reduce forage intake, such as low protein less than 7% of DM and increased degree of lignification, reduce total minerals consumed (Mc Dowell and Arthington 2005). Ruminants on pasture may inadvertently consume large quantities of soil as a natural consequence of grazing (Healey 1974). Deliberate soil consumption on the other hand is classified as a fo rm of pica, which is defined as animals chewing on objects and eating materials not considered to be natural feed stuff. Concentration of mineral elements in forage is dependent upon the interaction of a number of factors including soil, plant species, and stage of maturity, yield, pasture management and climate. The influence of soil chemistry and soil characteristics on the occurrence of mineral problems for grazing ruminants has been reviewed (Reid and Horvath, 1980) and of the total mineral concentrati on in soils, only a frac tion is taken up by plants. Although mineral content of a soil ultimately depends on the parent rock from which the

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21 soil was derived, evidence indicates little relationship between soil chemistry and mineral composition of farm crop s and vegetation growing on it (Underwood, 1981). Consequently mineral intake by animals depends more on the type of plant and level of consumption than on the parent rock (Underwood et al 1981). The most devastating economic effect of phosphorous defic iency is documented to be reproductive failure with phosphorous supplementation drastically increasing fertility levels in grazing cattle in many parts of the world (Mc Dowell 1985). In phosphorus deficient areas cattle are reported to produce a calf every other year or longer (Mc Dowell et al 1983). These animals require longer calving intervals to build up phosphorous reserves. P content of pasture mostly dominated by hyparrhenia rufa species decreases as the rainy season progresses from a high 0.2% P sho rtly after the beginning of the rainy season to as low as 0.05% (Mc Dowell et al 1992). The mineral elements most likely to be lacking under tropical conditions for ruminants are Ca, P, Na, C, Cu, I, S and Zn (Arthington, et al 2005) Hyparrhenia rufa Hypa rrhenia rufa is a common native pasture plant throughout East Africa and Latin America used mainly for beef production. It is also used as coarse thatching grass in Africa. It is a perennial C4 grass commonly known as a yellow spike thatching grass in Sout hern Africa. Hyparrhenia rufa is distributed throughout tropical Africa but it is wide spread in Central and South America. It favors well in a seasonally flooded grassland and open woodland and stands water logging and temporary flooding. The height of th e grass ranges from 60 240 cm with loose and narrow panicles of up to 50 cm long. It has slightly spreading and contiguous racemes with hairy

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22 spikelets of 3.5 5 mm long. Its flowering stems have little leaf and the sheaths of the leaves enclose about hal f the length of each internode. (Napper 1965). Hyparrhenia rufa requires precipitation of about 600 1400mm and it does well on retentive soils and is able to withstand a dry season of six months. It is sensitive to Aluminum soils and does well in black clays and latosols (Spain and Andrew 1977). In terms of photoperiod, hyparrhenia rufa is a short day plant. Growth is retarted when day length is less than 12 hours, 15 minutes during the growing season from October to April Rattry (1973). It stands cl ose grazing if applied rotationally and not continuously and tolerates seasonal burning. Hyparrhenia rufa has a good disease and pest resistance but it is susceptible to frosts but successfully competes with weeds and smothers them but combines well wi th legumes. C arbon 4 Plants Hyparrhenia rufa, the predominant grass for cattle grazing at the ranch is a C arbon 4 (C4 ) grass The C4 grasses grow well under high temperatures. C4 grasses are more efficient in fixing carbon dioxide than other grasses; however, they have a specialized thick walled parenchyma bundle sheath around each vascular bundle and much smaller portion of more compact thin walled mesophyll tissue than C3 grasses (Wilson 1993). These anatomical characteristics results in plants with less concentration of crude protein and soluble carbohydrates and greater concentration of cell wall components such as cellulose and hemicellulose compared to C3 grasses. Nutritive Value of C4 G rasses Forage nutritive value is defined as the chemical comp osition, digestibility, and nature of digested products of forage (Mott and Moore, 1995) and is often expressed

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23 using CP, IVDMD, NDF, ADF and lignin. The nutritive value of C4 grasses can be excellent early in the growing season, but because of their rapid growth and maturity, nutritive value can decrease significantly as the growing season progresses (Coleman et al 2004).The C4 mechanism of photosynthesis allows high Carbon dioxide fixation at relatively low leaf N concentrations and low concentrations of rubsco (Moore et al 2004), which results in plants with smaller CP c oncentrations than C3 species. Averaged across a large number of species, CP concentration of C4 grasses ranged from 4 6% less than C3 grasses and the occurrence of CP deficiency in liv estock fed C4 grasses was greater (Minson, 1990). In addition, high temperature at which C4 plants typically grow also promote lignification and reduce plant tissue and cell wall degradability (Vendramin, 1999). In general, forage quality of C4 grasses de clines with maturity. The decrease in leaf to stem ratio caused by the onset of reproductive stems elongation often decreases Nutritive value. Forage nutritive value is determined according to nutrient concentration, nutrient digestibility, (Mort and Moore 1970). Cell walls (NDF) and their derivatives (ADF) have been used either alone or with other chemical entities to predict both intake and digestibility (Moore et al, 1996). C arbon 4 G rass Q uality Forage quality is expressed in animal performance thus wei ght gain, milk production wool production and work under the conditions that 1) animals used to compare forage have potential for production and are uniform among treatments. 2) Forages are available in quantities adequate for maximum intake and 3) no supp lemental energy and protein are provided (Moore 1994). Forage quality is a function of Nutritive value and intake (Mertens 2009). Animal production is a function of

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24 the daily intake of digestible dry matter and therefore depends on both the quantity of foo d eaten and the digestibility of the feed (Holmer et al, 1966) It is known that increasing forage mass, starting from low levels of mass, is associated with greater bite weight and intake that lead to greater animal performance (Sollenberger and Burns 2000). Likewise, it has been shown that at a similar level of forage mass, increasing forage nutritive value is associated with greater animal performance. In a continuous stocking method, there are no defined periods of grazing and rest and the grazin g period is actually equal to the grazing season. To be sustainable, the system must maintain sufficient herbage mass and herbage accumulation rate at all times to support the number of assigned grazing animals. Under grazing, results in an underestimate o f the carrying capacity and product per acre and possibly an overestimate of the product per animal. Overgrazing may greatly reduce the product per animal and per acre. Every effort should be made to attain optimum utilization of the forage (Burns 1973). I n grazing, there is little or no direct control of the feed supply and must resort to other methods for keeping the feed supply in equilibrium with the requirements of the animals and some of the alternatives are 1) To adjust the cattle numbers on a fixed area of land 2) To adjust the size of the pasture to provide the correct amount of herbage for a fixed number of animals. 3) To harvest a portion of the pasture for silage or hay during flush period of growth. 4) To feed supplementary roughage or concentra tes during periods of low herbage supply and 5) to defer grazing or to under graze in order to provide forage in those periods of season when production is low. Under grazing,

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25 results in an accumulation of forage which is not utilized. Over grazing, result s in a lower plane of nutrition for the livestock and frequently injury to the sward. So it is very important to choose a stocking rate which is near optimum for the species or management system (Burns et al 2002)

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26 CHAPTER 3 MATERIALS AND METHOD S Pasture D escription The study was conducted at Diamphwe cattle ranch in Malawi located between 1,650 m and receives between 763 1140 mm precipitations annually. Almost 90% of rain fall occurs between November to March with little rain between May and October. The average daily minimum temperature is Diamphwe cattle ranch is characterized by rolling to flat topography with t ropical savanna grassland characterized by short grasses and scattered shrubs and trees. Grass which is predominant is hyparrhenia rufa followed by themenda triandra and andropogos. The soil is deep, well drained latosols on higher parts of the catena, wi th poorly drained sand and clay soils in the L owland Soil, rainfall and temperature data during the study period have been presented in Table 3 1, 3 2 and 3 3 respectively Pasture Selection and F orage S ampling Diamphwe cattle ranch was selected for fora ge vegetation sampling and study of forage nutritive value based on its high population of cattle about (four thousand cattle) among all the Malawi government ranches and farms (2010 Malawi Government Livestock Report) and due to its characteristic dry sea son forage shortages. A total of eight grazing pastures representative of the entire ranch (four in the U pland and four in the L owland) were selected randomly and demarcated for the U pland and 4 L owland). Forage samples were harv ested monthly from three sites per pasture from October 2011 to March 2012.

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27 A total of 144 samples (72 U pland and 72 L owland) were collected, resulting from 18 samples per pasture (3 samples per month per pasture) and 24 samples per sampling thus 12 sample s U pland and 12 samples L owland each month were harvested from the eight grazing pastures using plastic gloves and plucked to a height of 20cm from the ground to represent the height that was being grazed. Each of the three places in each pasture had 4 poi nts selected at random for forage harvesting. Each of the composite forage samples came from 4 sub samples of the three places. Forage samples were placed in a plastic bag after collection. The samples of the forages were and then ground passing through a 4mm screen for digestibility, CP, ADF and NDF and I mm screen for mineral analysis. Eight soil samples were randomly taken from the different pastures using a soil augur once on the onset of the rains and also once in the rainy season to asses soil minerals and pH. Herbage Mass and Accumulation Representative samples were clipped to a constant height of 15 cm on monthly basis from October 2011 to March 2012.The cage technique was used in quantifying forage accumulation (gr owth senescence). Eight cages 1m x 1m were placed at selected representative sites 4 in the U pland and 4 in the L owland. Cages were placed at sites that represented the average forage mass of the unclipped grassland on the day of cage placement. Since the forage mass of the grass land was already known from other measurements of forage mass during the experiment. The approximate forage mass to start with was known; therefore forage accumulation was determined every month (Forage mass in the cage after 30 da ys average forage mass of the grassland 30 days earlier).

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28 Analysis of Nutrients Forages were analyzed for CP, NDF, ADF, Digestibility and minerals. Forage DM samples for nutritive value were ground in an Udy mill (Udy Corporation, Fort Collins, CO.) to pass a 1 mm screen. Nitrogen concentration was determined using a micro Kjeldahl method, a modification of the aluminum block digestion technique described by Gallaher et al. (1975). Crude protein was determined by multiplying N concentration by 6.25. Forage N DF and ADF concentrations were determined using the Ankom 200 Fiber Analyzer (Ankom Technology,Macedon, NY) according to Van Soet et al.(1991), and IVTD was determined using the ANKOM (2005) adaptation of Van Soet et al. (1996) in an ANKOM Daisy Incubator and an ANKOM 200 Fiber Analyzer (ANKOM Technology, Macedon, NY). Statistical Analysis The data obtained from the study were analyzed using the Glimmix procedure of (SAS institute Inc., Cary, NC, USA, Version 9.2) with Kenward Rogers approxi mation to determine the denominator degrees of freedom for the test of fixed effects. Herbage mass, herbage accumulation rate and nutritional composition of pastures was analyzed as a repeated measures and tested for the effects of location (i.e. U pland an d lowland), month and location *month, with replication and replication *location as the random effects and replication *month *location as the subject. Repeated measures data were separated using the LSD multiple comparison test if a significant prelimina ry F test was 0.10. Results are reported according to main effects when interactions were not significant.

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29 Table 3 1 Chemical Composition of Soils from Experimental Site Onset of the rains Deep into the rainy season Upland Lowland Upland Lowland Soil Ph 4.6 4.6 4.8 5.1 % OM 1.31 3.02 1.19 2.28 % N 0.063 0.1525 0.112 0.06 P (ug/g) 13.56 29.0 12.66 41.60 Ca (ug/g) 5.025 1.805 0.705 2.25 Mg (ug/g) 0.101 0.34 0.118 0.608

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30 Table 3 2 Rainfall Data (mm) During the Experimental Period October November December January February March 8 105 41 229 112 297

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31 Table 3 3. Temperature Date C, During the Experimental Period October November December January February March Morning 18 20 18 18 19 19 Afternoon 31 28 27 24 28 26

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32 CHAPTER 4 RESULTS AN D DISCUSSION Herbage Mass and Accummulation Herbage Mass Herbage mass did not differ at P > 0.05 in the months of October, November and December in both locations but in January, February and March, herbage mass differed P < 0.05 (Table 4 1 ) with L owland s howing greater herbage mass than the U plands and herbage mass in both locations in the months of January February and March kept on increasing as the season progressed. The h erbage mass of the Lowland areas ranged from 1975 kg/ha to 6350 kg/ha while Upla nd ranged from 1738 kg /ha to 5650 kg /ha over the same period (Table 4 1 ) For the period monitored, L owlands were greater in herbage mass in the months of January, February and March. The difference in herbage mass between L owlands and U plands concurs wi th the findings of Willms 1988 and Borke et al (2001) for the Boreal mixed wood, which indicate that U pland grasslands produce less herbage mass than L owlands. The high level Hyparrhenia rufa production from L owlands highlights their importance for suppor ting livestock production These results provide further evidence on the importance of L owlands for providing more herbage mass in January, February and March as Sollenberger and Burns, 2000 observed that increasing forage mass starting from low levels of m ass, is associated with greater bite weight and intake that lead to greater animal performance. Likewise it has been shown that at a similar level of forage mass, increasing forage nutritive value is associated with greater animal performance (Burns et al 1989). However this finding must be tempered by the fact

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33 that L owlands represent a relatively small fraction of the land scape within Diamphwe cattle ranch. L owlands represented an average of 5% of the total landscape within Diamphwe cattle ranch indicat ing U plands continue to provide the majority of the total available forage. Despite their limited area, L owlands demand special attention because of their importance as a concentrated source of abundant forage for livestock. Both L owland and U pland exhibi ted progressive seasonal growth which is important for the ranch but both exhibited greatest growth from the month of January, February and March, which was due to heavy rainfall during this period (Table 3 2). Greater yields in L owlands are likely caused by more available water. Although both landscape positions experienced the same rainfall (Table 3 2), L owlands may receive additional water from adjacent uplands either as overland runoff or through ground water movement (Asamoah et al 2004). Herbage Accum ulation Herbage mass accumulation differed in December to January at P < 0.05 with Lowland showing greater herbage mass accumulation than the Uplands (Table 4 2 ) The rest of the months did not differ between locations P > 0.05 The lack of significant temporal change in accumulated hyparrhenia rufa yield in either U pland or L owland, suggests hyparrhenia rufa regrowth appears to compensate for earlier clipping irrespective of the timing of initial defoliation. According to Mott et al (1992), the rapid re foliation is contributed by the presence of active short meristematic regions remaining on the plant after defoliation. The presence of active meristems on the plant after defoliation allows leaf expansion to result solely from expansion of already formed cells rather than requiring new cell production (Culvenor et al, 1989).

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34 However the high regrowth in December to January for the lowlands may have been enhanced by December drought which affected the whole country (Table 3 2) and this drought favored the L owlands according to (Bork et al 2001) who found that L owlands were more likely to respond to precipitation occurring during the previous dormant season because are less dry while uplands rely heavily on seasonal rainfall. ADF, NDF, IVDMD, CP, A cid D eterg ent F iber (ADF) Irrespective of location, ADF % increased as the rainy season progressed P > 0.05 (Table 4 3 ) This shows that ADF increases with forage maturity. In both U plands and L owlands, the ADF is within the range as recommended in most feedstuff of 5 70% (Van Soest, 1991). ADF is often used to predict digestibility since it is the poorly digested fiber fraction but such predictions are not always accurate as (Van soest, 1991) claims no valid theoretical basis to link ADF to digestion. As ADF increas es, digestibility of forage decreases. N eutral Detergent F iber (NDF) In both Uplands and Lowlands, there was a gradual increase in NDF P > 0.05 as the season progressed i n dicating that NDF increases with maturity of forage ( Table 4 4 ). In both Uplands an d Lowlands, NDF is within the recommended range in most feed stuff of 10 80% (Van Soest 1991). NDF is inversely related to digestibility and intake potential of feed as it predicts the extent of biological degradation which is the process whereby three ma in groups of rumen microbes namely bacteria, protozoa and fungi carry out most digestion of fiber. Most rumen bacteria attach themselves to feed particles, and fiber digestion will only

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35 occur by attached microbes. Fiber causes physical stimulation to the r umen and more protozoa and cellulolytic bacteria are produced which help in breaking down the fiber. In both L owlands and U plands, the range of its NDF is good because it is above the minimum requirement for ruminants according to N.R.C requirement for cattle S ince ruminants need adequate course insoluble fiber for normal rumen function fiber helps in adequate rumination and cellulose digestion which helps in increasing intake. Fiber also helps to maintain rumen pH and cellulolytic microorganisms that produce high acetate to propionate ratio needed for normal lipid metabolism. Daily rumination time is directly proportional to coarse NDF intake and related to body size (Robertson et al 1991) and also NDF is better related to intake and gastro intesti nal fill than any other measure of fiber (Robertson et al 1991). NDF values are important in ration formulation because they reflect the amount of forage the animal can consume. As NDF % increases, dry matter intake will generally decrease. I nvitro D ry M atter D igestibility (IVDMD) Uplands had greater IVDMD P <0.05 in October and November as compared to Lowlands while the rest of the months did not differ P > 0.05 but the least digestible months was December in both locations which could be attributed t o drought experienced in this month which caused more lignification as forage matures fast to cope with the drought (Table 4 5 ) Differences in fiber composition within the months of the study period in both U plands and L owlands were largely not reflect ed in differences in IVDMD. This might be as a result of some contamination with soil during sampling.

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36 In the L owlands, the IVDMD ranged from 53.88% 65.28% while in the U plands IVDMD ranged from 53.90% 70.98% all these fall within the recommended range of most feed stuff of 20 80% (Van Soest, 1991). According to Hanley ( 1989), due to the nutrients requirement of beef cattle, digestible dry matter must be at least 43 70% to meet maintenance, growth, and lactation requirements during the growing season (Rit tenhouse et al 1989). C rude P rotein (CP) Upland showed greater CP % P < 0.05 than the Lowland in the months of October and November but the rest of the months did not differ at P > 0.05 (Table 4 6 ) As Herbage Mass accumulation and maturity increase digest ibility and CP decrease. CP decreased as NDF, ADF and Herbage Mass increased so, CP decreases as plant matures (Sollenberger et al 2011) The simultaneous decline in CP, in L owlands and U plands grasslands better describes the varying season long CP dynami cs in the Ranch. From October to March, L owland CP concentration declined from 11.55% to 6.95% while U pland declined from 15.90% to 6.33% representing a total decrease of 40% on L owlands and 60% on U plands. A small decline in CP among the L owland as compar ed to U pland grassland as the season progressed may be linked to favorable growth due to abundant soil moisture and plants remaining in a younger more vegetative stage of growth (Irving et al 2003).

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37 Macro m inerals C alcium (Ca) In both the L owland and U pland there was a general simultaneous decline in calcium concentration from October to March P > 0.05 (Table 4 7 ) This better describes the decline in calcium concentration as forage mature (Sollenberger et al 2010). Mean calcium levels ranged from 0.295% in March to 0.388% in October in the lowland and 0.298 to 0.359 in the uplands (Table 4 7 ) These mean calcium levels were sufficiently higher than the recommended levels established by N.R.C 1996 for growing, finishing and early lactation of beef cattle P hosphorus (P) There was no difference in P concentration at P > 0.05 between the locations in November but the rest of the months differed P < 0.05 with Upland showing greater P concentration than the Lowlands mainly in early rainy season and the P concent ration decreased as the rainy season progressed (Table 4 8 ) Mean P levels ranged from 0.213% to 0.315% in the L owl ands while in the U plands mean P levels ranged fro m 0.256% to 0.326%. These mean P levels were sufficiently higher than the recommended lev els established by N.R.C 1996 for growing, finishing which is 0.12% to 0.34% and early lactation 0.16% to 0.24%. It is generally recommended that diets for ruminants should have Ca:P ration of about 1:1 to 2:1 (Khan et al 2006) of which in this study the r atio was in accordance to this requirement. Ruminants can tolerate dietary Ca:P ratio of more than 10:1 without any serious effect provided the P in take are adequate (Ternouth,1990)

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38 Potassium ( K ) There were differences in K concentration at P < 0.05 in bo th locations in the month of October, December and February (Table 4 9 ) During these months, U plands showed greater concentration of K than the Lowlands but in both locations there was a general decline in K concentration as the season progressed which w as as a result of maturity of plants (Maryland et al 1987) The range for K levels in the L owland was 1.25% to 1.72% while in the uplands it was 1.25% to 2.64%. In both instances, the concentration of K was above the recommended levels of 0.6 for growing, f inishing and 0.7% for early lactation of beef cattle (N.R.C 1996). An increase in forage K beyond the requirement but with the tolerable levels is attributed to the fact that young forages generally contain considerably more K than required by grazing live stock (Arthington and Mc Dowell 2005). M a g nesium (Mg) Regardless of location, Mg concentration in both Uplands and Lowlands decreased as the season progressed P > 0.05 (Table 4 10 ). The range of Mg concentration in lowlands was 0.98% to 0.215% while in th e uplands the range was 0.175% to 0.215%. In both upland and lowland grassland, the Mg levels were within the recommended range of growing, finishing and early lactation of beef cattle of 0.10.and 0.20 respectively (N.R.C 1996). Sodium ( Na ) In February, Na concentration differed, with Lowlands showing greater Na concentration than the Uplands P < 0.05 (Table 4 11 )

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39 In the L owland, Na levels ranged from 0.003% to 0.01% while in the uplands, Na levels ranged from 0.004% to 0.009. In both instances, Na concen tration was below the recommended for ruminants. The Na requirement for growing and finishing beef cattle is 0.06 % 0.08% and lactating cattle is 0.10% ( NRC 1996 ). Due to secretion of salt in milk, even after prolonged severe deficiency Nacl levels secreted in milk remain high (Loosli 1976). The common salt needs of grazing cattle for example can easily be met with mineral mixtures containing 20 to 35% salt and consumed at a rate of 45 grams per head daily. These findings are in line with the findings of Ar thington and Mc Dowell 2005 that tropical forages normally do not contain sufficient quantities of Na to meet the requirements of grazing livestock throughout the year where large losses of wate r and Na occur in the sweat. S ulphur (S) October showed a greater S concentrati on in the U plands than Lowlands P < 0.05 In the L owland, mean S levels ranged from 0.069% to 0.115% while in the U pland, S levels ranged from 0.063 to 0.140 (Table 4 12 ). In both instances, sulfur levels fell below the recommended req uirement for beef cattle of 0.15% (N.R.C 1996). Supplementation is needed. This means the forage is deficient in Sulfur during this period. The highest need for sulfur for ruminants is for optimum microbial action. (Arthington and Mc Dowell 2005). C h l orine (Cl) The month of October differed in Cl concentration P < 0.05 with U pland showing greater Cl concentration than the L owlands (Table 4 13 ) As the season progressed, Cl concentration declined an indication that Cl becomes diluted as Herbage mass

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40 in creases. In the L owland, Cl levels ranged from 0.308 to 0.760 while in the U pland, Cl levels ranged from 0.305 to 1.040. The Cl requirement for ruminants is generally unknown, but from limited data, the Cl requirement for lactating dairy cows is estimated to be between 0.1% and 0.2% (Fettman et al 1984). From this study, it seems the Cl levels in both L owland and U pland are beyond the recommended but most animals can tolerate large quantities of dietary salt when adequate supply of water is available Mc Dow ell 1992. M icrominerals Iron ( Fe ) Upland differed with L owland in Fe concentration in the months of January and March P < 0.05 Upland showed greater Fe concentration than L owland and the rest of the months did not differ (Table 4 14 ) In the L owland, Iro n levels ranged from 187.3 ppm to 289.3 ppm while in the uplands Iron levels ranged from 191.3 ppm to 447.3ppm.In both U pland and L owland, the Iron levels exceed ed the recommended levels required for ruminants and there is no danger for toxicity, because t he maximum tolerable level is 1000 ppm ( Arthington and Mc Dowell 2005). Iron deficiency is considered rare for grazing livestock due to generally adequate pasture concentration together with contamination of plants by Iron rich soil. The majority of tropi cal soils are acidic, resulting in forage levels of Iron generally in excess requirements. In addition, soil consumption will provide substantial quantities of Iron to grazing livestock. Iron supplementation is most wanted when forages contain less than 10 0 ppm (Arthington and Mc Dowell 2005).

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41 C opper (C u ) Upland differed with Lowlands in Cu concentration in the months of October, November, December and March P < 0.05 Cu concentration was greater in the Upland than in the Lowland (Table 4 15 ) In both l ocations, Cu concentration dec lined as the season progressed. I n the L owland, the mean Cu ranged from 5.25ppm to 7.25 ppm while in the U pland, it ranged from 6.00 to 9.42ppm. Both in the L owland and U pland, there was a gradual decline in Cu levels in the f orages as the season progressed this is in line with Mc Dowell 1996 that forage Cu content decline with forage maturity. In both U pland and L owland, the pasture forages had lower levels of Cu than the minimum recommended requirement for ruminants for diffe rent production purposes (Spears 2003). Deficiency of Cu in grazing cattle could be further intensified by its reported low bioavailability (Khan 2003). Low forage Cu in this study may have been due to its interaction with other elements in soil. Mc Dowel l et al 1993 reported that Cu interacts strongly with trace minerals and macro minerals for absorption by the plants. Fe and Ca are some of the elements that could have had an effect on the absorption of Cu because the concentration of these elements was v ery high as observed in this study (Tables 4 7 and 4 14 ) Ca in the form of carbonate precipitates Cu making it unavailable to plants (Khan 2003) Mo lybdenum (Mo) In the months of December, February and March, Mo concentration differed P < 0.05 between Lowlands and Uplands. In these months, Lowlands showed greater, Mo concentration than the Uplands (Table 4 16 ) This could be attributed to increased soil

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42 pH and poorly drained soil in the lowland since for plant uptake of Mo to occur soils should be poor ly drained. In the L owland grassland, the mean Mo concentration ranged from 1.60 ppm to 3.95 ppm while in the U pland grassland, Mo ppm ranged from 0.95 ppm to 2.05 ppm. In both the L owland and U pland, the Mo concentration exceed ed the recommended req uirements for beef cattle of less than 2 ppm but still falls short of being toxic since in both U plands and L owland, the Mo concentration is below the toxic levels of 5 ppm however actual requirements of Mo are not established (Arthington and Mc Dowell 200 5). No characteristic syndrome of Mo deficiency unrelated to Cu has been recognized and animals perform normally on extremely low dietary levels of Mo. No Mo deficiencies have been reported or identified in grazing ruminants (Arthington and Mc Dowell 2005) An exact estimate of the Mo requirement is impossible since Cu and S alter Mo metabolism. In both the L owland and U pland, a conditioned Cu deficiency is not likely because in the L owland the Cu: M o ratio are 2:1 in line with Miltimore and Mason ( 1971 ) to avoid a conditioned Cu deficiency while in the U pland, the Cu: M o ratio are above 4:1 as proposed by Allway, ( 1973 ) to ensure that the Cu requirement is met. Since S is low in this study, Cu deficiency not a problem. Z i n c (Zn) In the months of October and March, Zn concentration differed in both locations P < 0.05 In October, U pland showed greater Zn concentration which met the recommended requirements for beef cattle while in March, Lowland showed greater Zn concentration than Uplands (Table 4 17 )

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43 In th e L owland, the mean concentration of Zn ranged from 18.9 ppm to 23.5 ppm and in the U pland, Zn concentration ranged from 18.0 ppm to 35.0 ppm. In both the L owland and U pland, the forage is below the recommended requirement for grazing and finishing and for early lactation of beef cattle of 30.0 ppm (NRC 1996). Plant maturity has also been reported to affect Zn concentration of forage (Kabata 1992). Low levels of Zn in soils, plants and animal tissues have now been reported throughout many tropical regions of the world ( Mc Dowell 2002). Zn must be present in the diet of all animals and must be supplied almost continuously because animals have only small amounts of readily available Zn stored in the body. M a n ganese (Mn) Concentration of Mn did not differ in both Uplands and Lowlands P > 0.05, but Mn concentration declined regardless of location as the season progressed (Table 4 18 ) In the L owland, forage mean Mn levels ranged from 94.3 ppm to 261.8 ppm while in the U pland, forage Mn ranged from 69.5 ppm to 219.5 ppm. In both the U pland and L owland, forage Mn exceed ed the recommended requirement for growing and finishing of beef cattle of 20 ppm and early lactation of 40 ppm (N.R.C 1996) Most feeds are adequate in Mn which precludes a need for supplementatio n (Arthington and Mc Dowell 2005). In the study conducted, the concentration exceed ed the requirement for ruminants but animals appear to be highly tolerant of excess dietary Mn. According to N.R.C 1980, maximum dietary tolerable level of Mn for sheep and cattle is 1000 ppm. Co balt (Co) Concentration of Co did not differ in Upland and Lowland P > 0.05 regardless of location, Co concentration declined as the rainy season progressed (Table 4 19 ) In the

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44 L owland, the mean Co levels ranged from 0.043 ppm to 0.5 28 ppm while in the U pland forage Co levels ranged from 0.183 ppm to 0.870 ppm. In both the L owland and U pland, forage met the recommended requirement of 0.1 to 0.25 for beef animals NRC 1996. Conclusion A deeper understanding of the Forage Nutritive Value is needed to reduce the risk of failure when raising cattle at Diamphwe Cattle Ranch. Good forage nutrition may help to overcome some of the problems at the ranch. The development of nutrient supplementation strategies suitable to provide the animals with the required nutrients at critical times of the year is necessary. The results also showed the importance of lowlands for livestock production in the ranch although lowlands constituted only a small fraction of this landscape, they provided greater le vels of herbage mas s throughout the study period. In order to identify grazing strategies, necessary to maintain long term herbage productivity, and quality, an understanding is required of the dynamics of herbage yield and quality within these complex lan dscapes so a recommendation of conducting the study throughout the year is necessary so that soundly based nutrient supplementation strategies can be devised.

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45 Table 4 1 Herbage Mass, kg/ha Month Lowland Upland P value October 2575 a 1738 a 0.182 November 2675 a 1850 a 0.188 December 1975 a 1850 a 0.840 January 6075 b 2750 ab <0.0001 February 6100 b 3200 b <0.0001 March 6350 c 5650 c 0.009 Pooled SEM = 615.1 Trt: P < 0.0001; Period: P < 0.0001; Trt x Period: P = 0.004 abc Means within a column differ; P < 0.05

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46 Table 4 2 Herbage Accumulation, kg/ha daily Month Lowland Upland P value Oct to Nov 3.8 a 4.0 a 0.881 Nov to Dec 0.0 a 7.0 a 0.212 Dec to Jan 146.5 b 14.3 a <0.0001 Jan to Feb 34.0 a 37.5 a 0.938 Feb to March 48.0 a 87.8 b 0.290 Largest SEM = 30.46 Trt: P =0.186; Period: P = 0.004; Trt x Period: P = 0.002 abc Means within a column differ; P < 0.05

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47 Table 4 3 ADF, % of DM Month Lowland Upland P value October 34.17 a 32.67 a 0.100 November 33.66 a 34.01 a 0 .691 December 35.21 a 36.49 b 0.155 January 35.31 a 37.09 bc 0.052 February 38.87 b 38.41 cd 0.610 March 39.63 b 38.90 d 0.418 Pooled SEM = 0.8828 Trt: P =0.749; Period: P < 0.0001; Trt x Period: P = 0.106 abc Means within a column differ; P < 0.05

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48 Table 4 4 NDF, % of DM Month Lowland Upland P value October 64.60 a 62.80 a 0.062 November 61.85 b 62.20 a 0.710 December 64.15 a 64.75 b 0.525 January 64.90 a 65.53 bc 0.508 February 67.88 c 66.55 c 0.165 March 70.13 d 68.73 d 0.143 Pooled SEM = 0.935 Trt: P =0.206; Pe riod: P < 0.0001; Trt x Period: P = 0.227 abc Means within a column differ; P < 0.05

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49 Table 4 5 I n Vitro D ry M atter D igestibility % Month Lowland Upland P value October 62.20 ac 70.98 a 0.003 November 57.88 ab 62.63 b 0.094 Dec ember 53.88 b 53.90 c 0.993 January 64.05 c 63.25 b 0.773 February 65.28 c 61.15 b 0.143 March 59.45 a 62.35 b 0.299 Pooled SEM = 2.744 Trt: P =0.190; Period: P < 0.0001; Trt x Period: P = 0.036 abc Means within a column differ; P < 0.05

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50 Table 4 6 Crude Protein, % of DM Month Lowland Upland P value October 11.55 a 15.90 a <0.0001 November 11.45 a 13.03 b 0.002 December 8.40 b 8.48 c 0.876 January 8.68 b 8.25 c 0.379 February 7.68 c 7.23 d 0.351 March 6.95 c 6.33 d 0.198 Pooled SEM = 0. 476 Trt: P =0.0007; Period: P < 0.0001; Trt x Period: P < 0.0001 abc Means within a column differ; P < 0.05

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51 Table 4 7 Calcium, % of DM Month Lowland Upland P value October 0.388 a 0.359 a 0.173 November 0.375 a 0.365 a 0.542 De cember 0.375 b 0.373 a 0.878 January 0.323 b 0.355 a 0.054 February 0.290 c 0.303 b 0.446 March 0.295 bc 0.298 b 0.878 Pooled SEM = 0.0162 Trt: P =0.871; Period: P < 0.0001; Trt x Period: P = 0.266 abc Means within a column differ; P < 0.05

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52 Table 4 8 Phosphorous, % of DM Month Lowland Upland P value October 0.255 a 0.326 a 0.007 November 0.315 b 0.300 ab 0.471 December 0.255 a 0.295 ab 0.062 January 0.255 a 0.298 ab 0.048 February 0.238 ac 0.280 bc 0.048 March 0.213 c 0.258 c 0.037 Poo led SEM = 0.0205 Trt: P =0.024; Period: P = 0.0001; Trt x Period: P = 0.082 abc Means within a column differ; P < 0.05

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53 Table 4 9 Potassium (K) % of DM Month Lowland Upland P value October 1.69 a 2.64 a <0.0001 November 1.72 a 1.86 b 0.221 December 1.57 ab 1.83 bc 0.035 January 1.62 a 1.62 cd 0.983 February 1.37 b 1.59 d 0.060 March 1.25 b 1.25 e 1.000 Pooled SEM = 0.1425 Trt: P < 0.0001; Period: P < 0.0001; Trt x Period: P = 0.0002 abc Means within a column differ; P < 0.05

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54 Table 4 1 0 Magnesium (Mg) % of DM Month Lowland Upland P value October 0.215 a 0.215 a 1.000 November 0.208 a 0.195 ab 0.334 December 0.200 a 0.210 ab 0.439 January 0.195 a 0.193 ab 0.846 February 0.195 a 0.175 b 0.126 March 0.195 a 0.193 a b 0.846 Pooled SEM = 0.0156 Trt: P = 0.404; Period: P = 0.072; Trt x Period: P = 0.658 abc Means within a column differ; P < 0.05

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55 Table 4 11 Sodium (Na), % of DM Month Lowland Upland P value October 0.009 a 0.009 a 0.731 November 0.006 b 0.005 bc 0.392 D ecember 0.003 c 0.004 b 0.667 January 0.005 b 0.006 c 0.519 February 0.010 a 0.006 bc 0.001 March 0.009 a 0.009 a 0.830 Pooled SEM = 0.0014 Trt: P = 0.315; Period: P < 0.0001; Trt x Period: P = 0.038 abc Means within a column differ; P < 0.05

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56 Table 4 1 2 Sulfur (S), % of DM Month Lowland Upland P value October 0.093 a 0.140 a <0.0001 November 0.115 b 0.113 b 0.716 December 0.085 a 0.090 c 0.468 January 0.087 a 0.088 c 0.716 February 0.068 c 0.078 c 0.151 March 0.060 c 0.063 d 0.716 Pooled SEM = 0.0068 Trt: P = 0.001; Period: P < 0.0001; Trt x Period: P = 0.001 abc Means within a column differ; P < 0.05

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57 Table 4 1 3 Chlorine, (Cl) % of DM Month Lowland Upland P value October 0.463 a 1.040 a <0.0001 November 0.760 b 0.753 b 0. 906 December 0.653 b 0.693 b 0.532 January 0.428 a 0.460 c 0.611 February 0.345 ac 0.330 d 0.814 March 0.308 c 0.305 d 0.969 Pooled SEM = 0.0775 Trt: P = 0.0005; Period: P < 0.0001; Trt x Period: P < 0.0001 abc Means within a column differ; P < 0.05

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58 Table 4 1 4 Fe, ppm Month Lowland Upland P value October 216.8 a 213.2 a 0.922 November 216.3 a 238.8 ac 0.434 December 187.3 a 191.3 a 0.889 January 289.3 b 447.3 b <0.0001 February 270.8 b 293.8 c 0.424 March 201.5 a 288.3 c 0.005 Pooled SEM = 35.96 Trt: P = 0.024; Period: P < 0.0001; Trt x Period: P = 0.003 abc Means within a column differ; P < 0.05

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59 Table 4 1 5 Copper (Cu), ppm Month Lowland Upland P value October 7.25 a 9.42 a 0.001 November 7.00 a 8.00 b 0.027 December 5.25 b 6.00 c 0.092 January 6.50 a 6.50 c 1.000 February 6.67 a 6.00 c 0.165 March 5.75 b 7.75 b <0.0001 Pooled SEM = 0.469 Trt: P < 0.0001; Period: P < 0.0001; Trt x Period: P = 0.001 abc Means within a column differ; P < 0.05

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60 Table 4 1 6 Molybdenum (Mo), ppm Month Lowland Upland P value October 1.60 a 1.46 ab 0.801 November 2.25 a 2.05 a 0.675 December 2.25 a 0.95 b 0.011 January 2.10 a 1.50 ab 0.215 February 3.63 b 1.05 b <0.0001 March 3.95 b 2.03 a 0.001 Pooled SEM = 0.561 Trt: P = 0.010; Period: P = 0. 0002; Trt x Period: P = 0.001 abc Means within a column differ; P < 0.05

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61 Table 4 17 Zinc (Zn), ppm Month Lowland Upland P value October 23.3 a 35.0 a <0.0001 November 23.5 a 22.0 b 0.287 December 18.8 b 19.8 b 0.476 January 22.3 a 21.5 b 0. 592 February 19.0 b 18.5 c 0.721 March 22.3 a 18.0 c 0.004 Pooled SEM = 1.70 Trt: P = 0.113; Period: P < 0.0001; Trt x Period: P < 0.0001 abc Means within a column differ; P < 0.05

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62 Table 4 18 Manganese (Mn), % of DM Month Lowland Upland P value October 243.8 a 219.5 a 0.603 November 261.8 a 159.0 ab 0.011 December 246.3 a 135.3 b 0.007 January 162.8 b 150.0 ab 0.734 February 110.5 bc 109.3 bc 0.973 March 94.3 c 69.5 c 0.510 Pooled SEM = 45.99 Trt: P = 0.101; Period: P < 0.0001; Trt x Period: P = 0.131 abc Means within a column differ; P < 0.05

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63 Table 4 19 Co balt ppm Month Lowland Upland P value October 0.528 a 0.500 ab 0.907 November 0.490 a 0.870 a 0.053 December 0.363 ab 0.365 b 0.990 January 0.263 ab 0.295 b 0.865 February 0 .045 b 0.253 b 0.281 March 0.043 b 0.183 b 0.465 Pooled SEM = 0.2362 Trt: P = 0.194; Period: P = 0.002; Trt x Period: P = 0.681 abc Means within a column differ; P < 0.05

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64 LIST OF REFERENCES Arthington J. D. 09. Essential t race m inerals fo r g razing c attle in Florida. University of Florida IFAS A N 086. Arthington, J. D. 2002. Improving the p roductivity of b eef h eifers in Florida. University of Florida, IFAS, Florida Coop. Ext. Serv., Animal Science Dept., EDIS Publication AN132. Asamoah S A E. W. Bork, B. D. Irving, M. A. Price and R. J. Hudson 2004. S easonal herbage dyanmics on aspen parkland landscapes in central albe rta. Can J. A nim Sci 84 : 149 153. Coleman, S. W., and B. C. Evans. 1986. Effect of nutrition, age, and size on compen satory growth of two breeds of steers. J. Anim. Sci. 63:1968. Holloway, J. W. and W. T. Butts, Jr. 1983. Phenotype and nutritional environment interactions in forage intake and efficiency of Angus cows grazing fescue legume or fescue pastures. J. Anim. Sc i. 56:960. Kadzere C.T. 1995. F eed resources for sustainable ruminant livestock production in southern Africa, African Study Monographs, 16(4):165 180,December 1995. Khalili M E. Lindgren, and T. Vavikko 1993. A survey of mineral status of soil, feed s, and cattle in the selale highlands II trace elements Tropical Animal Health Production 1993. 25,193 20.1 Khan Z. I M. Ashraf, and E. E. Valeem 2006. Forage m ineral s tatus e valuation: The influence of p astures Pak J. Bot,38(4): 1043 1054. Khan Z. I M. Ashraf, and E. E. Valeem 2008 Evaluation of m acro m ineral c oncentrations of f orages in r elation to r uminants r equirements. A case study in Soone Valley, Punjab, Pakistan. Pak J. Bot, 40(1):295 299. Khan Z. I M. Ashraf, and E. E. Valeem 2009. Ev aluation of m ineral c om p osition of f orages for g razing r uminants in Pakistan. Pak J B ot 41(5):2465 2476. Lippke H. 2002. Estimation of f orage i ntake by r uminants on p asture. Crop Sci. 42 : 869 872. Marston, T. T., and K. S. Lusby. 1995. Effects of energy or protein supplements and stage of production on intake and digestibility of hay by beef cows. J. Anim. Sci. 73:651. Mc Dowell L. R M. Kiatoko, J. E. Bertland, H. L. Chapman, F. M. Pate, F. G. Martin and J. H. Conrad 1982. Evaluating the n utritional s tatus of b eef c attle h erds from f our s oil o rder r egions of Florida II Trace Minerals. J Anim Sci 55:38 47.

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65 McDowell, R. E., and A. Hernandez Urdaneta. 1975. Intensive systems for beef production in the tropics. J. Anim. Sci. 41:1228. Mtimuni J. P M. W. Mfitilodze, and L. R. McDowell 1990. Interrelationships of Minerals in soil plant animal system Kuti Ranch. Commn in soil sci plant anal 21(5):415 427 NRC. 1996. Nutrient requirements of beef cattle. 7th Rev. Ed National Academy Press, Washington. Poppi, P. D., and R. S. Mc. Lennan. 1995. Protein and energy utilization by ruminants at pasture. J. Anim. Sci. 73:278. Sollenberger L. E, and J. C. Burns. 2002. Grazing b ehavior of r uminants and d aily p erformance from w arm s eason g rasses. Crop Sci. 42:873 881. Sollenberger L. E, J. E Moore, V. G Allen and C. G. S Pedreira 200 5 Reporting f orage allowance in grazing experiments. Crop Sci 45:896 900 Thomas A and J. McKendrick. 1983. Seasonal c hanges in c hemical c omposition and n utritive v alue of n ative f orages in a s pruce h emlock f orest, Southeastern Alaska. Research Paper PNW 312. Van Soest, P. J., J. B. Robertson, and B. A. Lewis 1991. Methods for dietary fiber, neutral detergent fiber and non starch polysaccharides in relation to animal nutriti on. J. Dairy Sci. 74:3568 3597. Vendramini, J., B. Sellers, L. E. Sollenberger, and M. Silveira. 2011. Mulato II (Brachiaria sp.). University of Florida, Gainesville, FL. IFAS Extension SS AGR 303. Wheeler J. L J. C. Burns R. D. Mochrie and H. D. Gros s. 1973 The c hoice of f ixed, or v ariable s tocking r ate in g razing experiments. Expel. Agric. 9 :289 302. Wolfgang B and W. Bayer 19 89 Adapting tropical pasture research to the production sytem: from Australian ranching to African pastoralis m; Experim ental Agriculture 25: 277 89.

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66 BIOGRAPHICAL SKETCH Felix Goodson Makondi was born in Thyolo M alawi to a p olice o fficer ; Felix attended several primary schools in Thyolo, Blantyre, Zomba, Mangoch i and Lilongwe Districts and secondary education at Saint Pat ricks in Blantyre d istrict Thereafter, he graduated from The University of Malawi, Bunda College of Agriculture with a Bachelor of Science degree in the field of a nimal s cience s in 200 2 Upon graduation, he got a job in the Ministry o f Agriculture as a L ivestock Development Officer with the first posting at Blantyre Agricultural Development Division and later in 2005 was posted to Diamphwe Cattle Ranch In 2010, Felix moved to Florida United States of America to pursue his m aster s degree in a nimal s cie nces at University of Florida with financial support from United States Agency for International Development (USAID ) under t he supervision of Dr. John Arthington His major focus has been on forage nutrition evaluation at a Beef Cattle Ranch