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Introduction | |
Overseeding Bermudagrass pastures... | |
Bermudagrass varieties | |
Hay standards and infrared evaluation... | |
Improving low quality hay with... |
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Historic note
Historic note Title Page Title page Introduction Introduction Overseeding Bermudagrass pastures with winter annuals Page 1 Page 2 Page 3 Page 4 Page 5 Bermudagrass varieties Page 1 Page 2 Page 3 Page 4 Page 5 Page 6 Hay standards and infrared evaluation of Bermudagrass Page 7 Page 8 Page 9 Page 10 Page 11 Improving low quality hay with ammonia Page 12 Page 13 Page 14 Page 15 Page 16 Page 17 |
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HISTORIC NOTE The publications in this collection do not reflect current scientific knowledge or recommendations. These texts represent the historic publishing record of the Institute for Food and Agricultural Sciences and should be used only to trace the historic work of the Institute and its staff. Current IFAS research may be found on the Electronic Data Information Source (EDIS) site maintained by the Florida Cooperative Extension Service. Copyright 2005, Board of Trustees, University of Florida Research Report NF84-5 FALL FORAGE FORUM -- &W as 0 0 111111111111116. jlwl&jw^bB^ i k BERMUDAGRASS PROCEED SIXTH ANNUAL MEETING NOVEMBER 1,1984 G-UME LIBRARY JUL 1 ib:3 I.F.A.S.- Univ. of Florida SPONSORED BY INSTITUTE OF FOOD AND AGRICULTURAL SCIENCES UNIVERSITY OF FLORIDA J.T. Woeste, Dean for Extension F.A. Wood, Dean for Research N FVr~ Proceedings of the Sixth Annual Fall Forage Forum Several topics concerning bermudagrass are dis- cussed in the proceedings. Each speaker on the program has had many years of experience working with bermuda- grass and the program should provide useful information for farmers who use bermudagrass in their farm program. D. L. Wrigh C. G. Chambliss Dr. Bob Stanley, University of Florida - Quincy Mr. Danny Stevens, Gilchrist County Dr. Charlie Ruelke, University of Florida - Gainesville Dr. John Moore, University of Florida - Gainesville Dr. Bill Kunkle, University of Florida - Gainesville Overseeding Bermudagrass Pastures With Winter Annuals1 R. L. Stanley, Jr.2 The bermudagrasses make up one of the main perennial forage species in the southeastern United States, particularly in the Coastal Plains area. It has been estimated that approximately 10 million acres of Coastal Bermudagrass have been planted in the southeastern U.S. (Dr. G. W. Burton, personal communication). Bermudagrass begins to "green up" in March, but little grazing is available until April. Usually, there is a peak production period in mid-summer when rain showers become frequent enough to maintain soil moisture levels necessary for good growth. Often about 2/3 of the total forage produced during the season will be in June, July, and August. After September 30 there is usually very little, if any, forage produced. This means that for 6 months of the year (Oct. 1 Mar. 31) no forage is produced by the bermudagrasses. Overseeding into the grass to make use of the dormant period might deserve some consideration. 1 Manuscript prepared for Fall Forage Forum, Nov. 1, 1984 at NFREC, Quincy, Fla. Associate Professor (Associate Agronomist), North Florida Research and Education Center, Quincy, Fla. 32351. The following may be possible reasons to consider overseeding bermudagrass sods: 1. Better utilization of land resources. 2. Increase forage production by extending grazing season. 3. Increase forage quality. The winter annual grasses and clovers are much higher in quality and are available at a critical time in production cycle of the cow. 4. Use of legumes can add nitrogen to the grass. 5. Grain (such as wheat) harvested can be a source of cash to aid in cash flow. We do not have a very wide choice of adapted cool season annuals for seeding into bermudagrass sods. Some that have been successful, along with management considerations, are discussed below. A. Legumes. In North Florida crimson and arrowleaf clovers are the most adapted legumes for overseeding perennial grass sods. Red clover and subterranean clovers also show promise. Two of the major advantages to be gained by using the clovers are the high quality of the forage and the addition of nitrogen by the legume. To grow legumes successfully requires careful management, as their requirements are more critical than those of the commonly grown grasses. The following consideration will aid in successful legume production: 1. Lime properly pH should be 6.0-7.0 and CaO level of 900 or above. 2. Fertilize properly Legumes require generous amounts of P and K. Minor elements will probably be needed. Soil test results should guide the lime and fertilizer program, but in the absence of soil test results the equivalent of about 600 lbs/A of 0-14-14 should be applied at planting with a supplemental application of 100 lb/A of muriate of potash in the spring. 3. Inoculation a) Use specific inoculant b) Make sure inoculant is fresh c) Store properly cool, dry d) Use sticker and/or coating e) Reinoculate if seed are not planted in 24 hours. 4. Use high quality certified seed (arrowleaf clover seed should be sacrified). 5. Planting Seed must be in contact with soil and preferable covered 1/4 3/4 inches deep. a) Remove excess grass residue graze, mow, burn, etc. b) Light disking or sod seeder may be used to plant. c) Plant only when moisture is adequate for germin- ation between Sept. 15 and Nov. 15. 6. Manage to favor the clover. a) Don't graze too early b) Don't overgraze c) Rotational grazing is preferred. B. Small grains and/or ryegrass for grazing. Small grains overseeded into bermudagrass is usually not ready to graze as early as when planted into a prepared seedbed. Grazing may not be available until late December or January on the sod. The use of ryegrass with the small grain can help maintain high quality and extend the grazing season. 1. Management considerations a) Lime and fertilize by soil test results b) Remove excess grass residue prior to planting c) Plant only when moisture is adequate d) Use a seeder which will cover the seed well. C. Wheat for grain - Recent work at the North Florida Research and Education Center at Quincy indicate that wheat may be success- fully produced by planting into a bermudagrass sod with a "no-till" drill. Table 1. Wheat yield as influenced by tillage treatments from three previous crops (Quincy, 1982). Tillage Previous Crop Avg. across Treatment Soybeans Bahiagrass Bermudagrass crops bottom plow 60.8 a 42.5 a 47.8 a 50.3 a chisel plow 53.4 a 36.8 a 50.1 a 46.8 a harrow 48.5 ab 41.4 a 52.0 a 47.3 a no-till 36.3 b 20.6 b 47.1 a 34.7 b average across tillage treatments 49.8 35.3 49.2 *Means in a column followed by different letters are statisti- cally different at the 5% level of probability. Following are some considerations when growing wheat for grain in bermudagrass. 1) Use an early maturing wheat to reduce competition from the bermuda during grain fill in the spring. 2) Plant as soon after Nov. 15 as possible. This will also result in earlier maturity of the wheat, allowing greater production from the bermudagrass. 3) The bermudagrass can make use of any residual fertili- zer from the wheat, but must be fertilized according to production goals. 4) Nitrogen requirements will be greater than on prepared land. Competition from the grass in early spring during grain fill has resulted in symptoms of N deficiency. In the absence of specific recommendations an additional 40-50 lbs/A of N is suggested. -1- 1. BERMUDAGRASS VARIETIES 2. by 0. Charles Ruelke We have come a long way since common bermudagrass, Cynodon dactylon L., was brought to Savannah Georgia in 1751 by Governor Henry Ellis. As early as 1807 bermudagrass was referred to as one of the most important grasses in the South. When southern farmers were trying to grow cotton or corn, common bermudagrass was a weed pest and some states declared it was a noxious weed. Yet, its ability to persist and produce during drought, and heat on sandy soils made it a valuable forage and cover crop. However, it was not until a hybrid from "Tift" bermudagrass and an introduction from Africa was developed into the variety "Coastal" bermudagrass, that farmers had a tall growing, frost resistant, higher yielding, nematode resistant variety, which could be used for grazing hay, pellets or other forms of forage. Since the development of Coastal bermudagrass, and the management practices which bring about the best production, there have been continued efforts to develop new varieties that are better than Coastal. Suwannee bermudagrass is a tall growing hybrid developed at Tifton that will out yield Coastal on lighter sandier soils, but is less tolerant of close grazing and is less winter hardy. Midland bermudagrass is a hybrid between Coastal and a cold hardy common from Indiana. It is more cold hardy than Coastal, but has not yielded as well as Coastal in Florida. f Coastcross-1, a hybrid between Coastal and a plant from Kenya was found to be 12% more digestable than Coastal and gave greater average daily gains in cattle. Coastcross-1 grows taller and spreads more rapidly and its leaves are softer and broader. Because of its very limited underground rhizome development it is less protected from winter injury and therefore, loss of stands can occur in North Florida. Alicia bermudagrass was a highly advertised bermudagrass of the recent past, which has been extensively tested in Florida. It has been found to be easy to establish and produces early in the spring. However, total annual yields have been consistently less than Coastal and digestibilities were significantly lower than Coastal. 1. Presented at the 6th Annual Fall Forage Forum held November 1, 1984 at the North Florida Research and Education Center, Quincy, Florida 32351. 2. Professor of Agronomy, Department of Agronomy of the Institute of Food and Agricultural Sciences, University of Florida at Gainesville, Florida 32611. -2- In Mississippi, a variety was developed called Callie Giant bermudagrass. This variety has out yielded Coastal in tests in Florida and has slightly higher digestability at the same age. HIowever, Callie has been found to be quite susceptable to a rust disease which has been shown to reduce its digestibility. Callie is also less winter hardy than Coastal in North Florida. Efforts are now in progress to improve yield, digestibility and cold tolerance of the latest bermudagrass hybrids. Tifton 44 is the best of several thousand hybrids screened for winter hardiness. Coastal, and a bermudagrass that survived near Berlin, Germany, for 15 years were used as parents. Compared to Coastal, Tifton 44 has finer stems, cures faster as hay, has more rhizomes and starts growth earlier in the spring. Fed to steers, Tifton 44 gave 19% better average daily gains. In Florida, it is usually not until the second year that full yield potential is realized. Several other unreleased hybrids evaluated in Florida along with Tifton 44 are Tifton hybrids 72-81 and 72-84. Hybrid 72-81 is a taller and more erect growing bermudagrass which has consistently produced higher hay yields in Florida than Tifton 44. Hybrid 72-84 is a short, leafy, dense grass, higher in digestibility, and it adapts itself better to grazing. Tests which are in progress at Jay, Florida, indicate that 72-81, 72-84 and Callie bermudagrass could have potential for North Florida. In April of 1984,a notice of release of Tifton 68 bermudagrass (Cynodon Nlymfuensis Vander) was circulated. This hybrid lead all entries at all clipping frequencies in % IVDMD. However, Temperatures of 12 degrees F killed most of the plants. Although this hybrid may be adapted to the tropics it did not persist at Gainesville, Florida. The most recent released hybrid bermudagrass which looks most promising for North Florida is Tifton Hybrid 78. This is a cross between Tifton 44 and Callie bermudagrass, incorporating cold tolerance, higher yield, and higher digestibility than Coastal. Tests run at Tifton showed a 25.3% greater yield, 7.4% higher IVDMD, 30% more steer days per acre, 36% more live weight gain per acre and 13% greater average daily gain from Tifton 78 than from Coastal. Two releases of planting material to growers who qualify for certification were made in 1984. Sources of planting material can be obtained by writing to the Coastal Plain Experiment Station, P.O. Box 748, Tifton, Georgia, 31793-0748. Forage production and forage quality evaluation of bermudagrasses grown in Gainesville, Florida, are shown in Tables 1, 2 & 3. In Table 1, it can be observed that in the 3rd year after establishment on Arredondo Fine Sand Soils, bermudagrasses generally out yielded bahiagrasses and digitgrasses. Tifton 44 out yielded Coastal and contained a higher percentage of in vitro organic matter digested, (IVOMD) and more digested organic matter (DOM) per acre. Dry matter yields per acre by harvests shown in Table 2, were taken the first year following establishment. Tifton 78 and Hybrid 72-81 appeared to establish very rapidly and produced a higher 1st cutting yields than Tifton 44 or Coastal, while Tifton 44, Hybrid 72-81 and Tifton 78 produced more total yield than Coastal. In Table 3 it can be noted that most of the new hybrids had a higher % IVOMD than Coastal at the same age and that Tifton 44 and Tifton 78 produced more #/A DOM than Coastal. Hybrids 72-81 and 35-3 were also superior in the first year of this test. Conclusions Coastal bermudagrass has been, and remains a standard perennial grass which is well suited for hay, grazing, pellets, and other forms of forage. Several new and more promising cultivars are becoming available which produce higher yields or higher digestibility, or better cold tolerance. For North and Northwest Florida, on upland well drained soils, the new varieties Tifton 44 and Tifton 73 look most promising at the present time. -3'- Table 21 Results of Five Harvests of Forage from Promising New Hybrids and Cultivars of Perennial Forage grasses Harvested at Gainesville, Florida in 1980. Cultivar Evaluated # D.M./A1 % IVOMD2 #/A DOM3 Coastal bermudagrass Tifton Hybrid 21-6 bermudagrass Tifton Hybrid 31-6 bermudagrass Tifton Hybrid 34-8 bermudagrass Tifton Hybrid 35-3 bermudagrass Tifton Hybrid 36-2 bermudagrass Tifton Hybrid 46-8 bermudagrass Tifton Hybrid 49-4 bermudagrass Coastcross-1 bermudagrass Callie Giant bermudagrass Tifton 44 bermudagrass Apomict 54 bahiagrass Apomict 91 bahiagrass 4th Cycle Pensacola bahiagrass Survenola digitgrass Pangola digitgrass Transvala digitgrass Rhizomatous digitgrass Pensacola bahiagrass Argentine bahiagrass 14,335 abc 7,347 kl 15,058 ab 15,809 a 13,525 bcd 7,539 kl 7,530 kl 9,499 hij 9,432 ij 13,354 cd 15,486 a 11,996 defg 12,727 cdef 13,172 cde 11,541 efg 10,577 ghi 8,632 jk 6,110-L 11,173 fgh 8,351 jk Established June 10, 1977 on Arredondo Loamy Fine Gainesville, Florida 32611. Sand on the Agronomy Farm at Totals followed by the same letter are not significantly different at the .05 level of significance by the Waller-Duncan test. All cultivars received 60#/A of nitrogen from a 15-5-10 (N-P20 -K0O) fertilizer containing 20#T of FTE #503, prior to each of 5 harvests in 19 0 which were made at approximately after five weeks of growth). 46.29 54.66 51.69 49.0 52.60 54.52 55.30 55.16 54.60 49.12 48.50 44.85 38.70 39.85 62.61 54.36 59.51 62.23 36.85 42.28 5756 bc 3429 g 6773 a 6730 a 6145 abc 3484 fg 3529 fg 4492 d 4442 d 5665 c 6533 ab 4641 d 4236 def 4519 d 6120 abc 4846 d 4340 de 3208 g 3557 efg 2970 g Table 2. Pounds Dry Matter Per Acre of Newest Hybrids and Cultivars at Gainesville, Florida, in 1983. of Bermudagrass Harvested Harvest Number and Date of Harvest in 1983 Entry Evaluated Coastal bermudagrass Tifton 44 bermudagrass Hybrid 78-22 =Tifton 78 Hybrid 79-6 Hybrid 79-9 Hybrid 79-13 Hybrid 79-16 Hybrid 79-17 Hybrid 80-2 Hybrid 80-5 Hybrid 80-10 Hybrid 80-12 Hybrid 35-3 Hybrid 72-81 1st Cut May 12 1202 841 2069 1512 1531 943 1391 939 978 1246 963 892 1974 2087 2nd Cut June 21 2154 1492 3143 2916 2469 1973 1583 1535 1320 1351 1799 757 3044 3525 3rd Cut July 27 2415 2227 2863 2375 2674 2703 2306 2204 1887 1984 2442 1891 2803 3051 4th Cut Aug 30 1784 1398 1610 1425 1553 1483 1151 1321 1232 1574 1208 950 1731 2045 5th Cdt Oct 11 1472 987 1341 960 1388 1227 977 1291 1102 993 980 938 1681 1743 Established on June 3, 1982, on Arredondo Loamy Fine Sand on the Agromomy Farm at Gainesville, Florida, 32611. All entries received 60 lbs/A of nitrogen prior to each of five harvests In 1983. from a 15-5-10 (N-P205-K20) fertilizer containing 20#/T of FTE #503, 1. 6th cut in November 1983 omitted due to uneven damage from Striped Grass Loopers. 1983 Totals 9,027 13,945 11,026 9,188 9,615 8,329 7,408 7,290 6,519 7,153 7,392 5,429 11,233 12,451 ........ ..-.,,. Table 3 Results of Five Harvests of the Newest Hybrids and Cultivars of Bermuda- grass Harvested at Gainesville, Florida in 1983. Entry Evaluated #D.M./A % IVOMD #/A DOM Coastal bermudagrass 9,027 54.02 4,876 Tifton 44 bermudagrass 13,945 52.22 7,279 Hybrid 78-22=Tifton 78 11,026 55.47 6,116 Hybrid 79-6 9,188 59.95 5,049 Hybrid 79-9 9,615 56.77 5,458 Hybrid 79-13 8.329 56.95 4,743 Hybrid 79-16 7,408 55.22 4,090 Hybrid 79-17 7,290 56.60 4,126 Hybrid 80-2 6,519 56.22 3,664 Hybrid 80-5 7,153 60.55 4,331 Hybrid 80-10 7,392 57.12 4,222 Hybrid 80-12 5,429 55.20 2,996 Hybrid 35-3 11,233 53.72 6,034 Hybrid 72-81 12,451 53.47 6,658 Established on June 3, 1982, on Arredondo Loamy Fine Sand on the Agronomy Farm at Gainesville, Florida 32611. All entries received 60 Ibs/A of nitrogen from a 15-5-10 (N-P205-K20) fertilizer c ing 20#/T of FTE #503, prior to each of 5 harvests in 1983. 6th Harvest in November 1983 was omitted due to uneven damage from Striped Grass Lo- opers. Hay Standards and Infrared Evaluation of Bermudagrass John E. Moore Professor of Animal Science University of Florida, Gainesville, 32611 Since January, 1982, a Forage Testing Program has been under development for Florida. The program centers around Near-Infrared Reflectance (NIR) analysis conducted at the Ona Agricultural Research Center. Samples are submitted through County Extension offices. Results of NIR analysis are being returned in about five days. Reports include Crude Protein (CP), Total Digestible Nutrients (TDN) and Quality Index (QI). Quality Index was developed for this program as an overall measure of forage nutritional value. It is an estimate of the voluntary intake of TDN when the forage is fed alone and free-choice. The objective of this discussion is to describe Hay Standards based on QI and to review estimates of bermudagrass quality obtained by NIR analysis of samples submitted to the Forage Testing Program. Hay Standards Table 1 shows shows the expected relationship between QI and animal performance. The QI is voluntary intake of TDN expressed as a multiple of the maintenance TDN requirement. If QI equals 1.0, animals would be expected to only maintain themselves. However, a lactating cow could not maintain weight on hay having a QI of 1.0 because she would have to mobilize body tissue for energy. Table 1. Relationship Between Forage Quality Index and Expected Performance by Heifers and Cows Quality Indexa Expected Performance <1.0 1.0 1.4 1.8 2.2 Heifer Weight Change, lb/day loss 0 0.6 1.3 1.9 Cow Milk Production, lb/day 0b 0b 10b 20b 30b aVoluntary intake of TDN as a multiple of the maintenance TDN requirement (a QI of 1.0 = maintenance). bLactating cows producing more milk than expected will suffer weight loss unless supplemented. Table 2 shows the results of a series of our studies on the quality of summer perennial grasses. These hays were harvested after various regrowth intervals following an initial harvest in June. At two weeks regrowth, bermudagrass QI was about 1.4 which would support about 0.6 lb/day gain by heifers (Table 1). After eight weeks regrowth, bermudagrass would only maintain weight of cattle unless supplements were fed. Digitgrasses tended to have slightly higher quality than bermudagrasses and bahiagrasses at given stages of maturity. Table 3 shows that the season of harvest may be just as important as stage of maturity in determining quality of bermudagrass. Even when cut at regular regrowth intervals throughout the season, quality tended to decline as the season advanced. Table 2. Effect of Species and Maturity upon Quality Index, Total Digestible Nutrients (TDN) and Crude Protein (CP) of Florida Grassesa Weeks of Quality Species Regrowth Indexb TDNc CPc Bermudagrass 2 1.38(2)d 56.3(2) 16.0(2) 4 1.34(9) 57.1(9) 13.6(9) 6 1.21(7) 52.6(7) 9.0(7) 8 1.00(7) 47.9(7) 7.5(7) 10 0.92(4) 46.1(5) 8.3(5) Bahiagrass 2 1.33(7) 58.6(10) 11.6(10) 4 1.17(10) 55.8(12) 9.8(12) 6 1.20(8) 55.4(9) 8.5(9) 8 1.09(7) 54.4(3) 7.5(7) 10 0.75(3) 46.8(4) 6.9(4) Digitgrass 2 1.51(11) 60.4(11) 13.4(11) 4 1.48(16) 59.4(16) 12.6(16) 6 1.25(13) 57.8(14) 8.9(14) 8 1.10(13) 55.1(13) 6.6(13) 10 0.78(3) 49.7(4) 6.5(4) aData summarized from several exp bVoluntary intake of TDN as a mul cPercent of dry matter. dAverage (number of experiments). eriments, University of Florida. tiple of maintenance. Table 3. Quality of Coastal Bermudagrass Hay Harvested at Different Maturities and Seasonsa Weeks of Harvest Date Item Regrowth 6/14 7/12 8/9 9/6 10/4 TDN, %b 4 54.6 56.9 52.0 52.7 45.8 6 51.6 50.7 46.9 49.4 48.4 8 52.2 51.2 45.9 46.8 43.6 Quality Indexc 4 1.38 1.35 1.28 1.34 1.12 6 1.32 1.37 1.02 1.19 1.21 8 1.32 1.09 0.85 1.06 0.75 ADG, lbd 4 0.57 0.78 0.72 0.63 0.28 6 0.34 0.48 -.04 0.42 0.22 8 0.16 0.07 -.39 0.07 -.39 aAdapted from Nelson, et al., Louisiana Agr. Exp. Sta. Bull. 730, October, 1980. bTDN = Total Digestible Nutrients, % of dry matter. cVoluntary intake of TDN as a multiple of maintenance. dADG = Average Daily Gain, in pounds (feeding trial conducted December through February). It is not intended that Hay Standards be used to set the price of hay, but results of forage testing should be useful in negotiations of price between buyer and seller. High quality forage is more expensive to produce but should be worth more if it gives higher animal production with less need for purchased supplement. A forage test may be used along with other information, experience and good judgement in making management decisions regarding nutritional needs of the beef herd. If the forage is inadequate to meet management objectives, then a supplementation program may be developed. Table 4 shows calculations of the supplemental CP and TDN required for different classes of beef cattle consuming different qualities of hay. For example, if a cow producing 15 lb of milk was fed hay having a QI of 1.2, supplements should provide 0.7 Ib of CP and 2.5 lb of TDN in order to prevent weight loss. Table 4. Estimated Need for Supplemental TDN and Crude Protein (CP) For Cattle Fed Different Quality Foragesa Animal: Pregnant Cow Lactating Cowb Growing Heifer Weight, Ib: 1000 1000 500 Production, lb/day: .9 gain 15 milk 1.0 cain Supplement Needed: CP TDN CP TDN CP TDN Forage Quality QIc TDN,% CP,% .9 43-52 4- 9 .25 2.2 1.4 5.5 .7 4.2 1.2 51-58 5-12 .7 2.5 .4 2.0 1.5 56-64 7-20 - aKunkle, Proc. Florida Beef Cattle Short Course, 1984. pp 77-85. bCows maintaining weight. cPounds per head per day of Crude Protein (CP) or Total Digestible Nutrients (TDN). TDN must be supplied with high energy feeds such as grain or molasses. cI = Quality Index (voluntary intake of TDN as a multiple of maintenance). Infrared Analyses Table 5 shows the results of NIR analyses of grass samples submitted to the Pilot Program. Most of the hays had QI values of 1.0 to 1.2. Many of the hays, even those with the higher QI values, had low protein (less than 7%) suggesting the need for supplemental protein. Values for QI and CP should be considered separately since within a given QI there is a wide range in CP values. Even if QI values are above 1.0, supplemental protein may be needed if the level of CP is below the requirement. Bermudagrass (including some stargrass) samples submitted had a wide range in QI from the lowest (0.8) to the highest (1.5). These data are similar to those obtained on research hays cut at advanced maturity (Table 2) or late in the season (Table 3). Table 5. Ranges in Near Infrared Reflectance Estimates of Quality Index, Crude Protein and Total Digestible Nutrients (TDN) in Hays from the Florida Forage Testing Program Coiposition. % of Dry Matter Quality Indexa No. Crude Protein TDN All Grasses: 0.8 1 6.6 41.8 0.9 13 1.7 8.2 41.2 47.5 1.0 35 2.7 9.5 45.1 50.7 1.1 68 2.3 11.4 47.5 55.1 1.2 40 2.8 12.9 50.6 57.4 1.3 15 3.0 16.0 56.0 58.2 1.4 8 9.4 13.2 57.0 62.2 1.5 3 12.2 23.3 63.8 64.8 Bermudagrass: 0.8 1 6.6 41.8 0.9 6 3.9 8.2 42.7 47.5 1.0 26 3.5 9.5 45.8 50.7 1.1 34 4.6 11.4 49.7 55.1 1.2 24 4.9 12.9 50.6 57.4 1.3 11 9.3 16.0 56.0 58.2 1.4 6 9.4 13.2 57.0 60.8 1.5 3 12.2 23.3 63.8 64.8 Bahiagrass: 0.9 3 1.7 5.0 42.0 44.9 1.0 4 3.5 7.0 46.3 48.8 1.1 17 3.9 8.1 47.5 52.5 1.2 4 8.2 9.6 54.3 55.2 1.3 0 - 1.4 1 12.8 62.2 Digitgrass: 1.0 2 4.6 6.2 46.1 46.1 1.1 15 2.3 7.2 47.6 52.5 1.2 10 2.8 10.6 52.3 55.1 1.3 3 5.5 10.2 56.4 57.6 Hemarthria: 0.9 4 2.0 3.6 41.2 44.2 1.0 3 2.7 8.8 45.1 48.3 1.1 2 2.9 9.1 49.5 51.7 1.2 2 8.6 10.5 52.0 52.6 1.3 1 2.9 58.2 1.4 1 9.5 59.0 voluntary intake of TDN as a multiple of maintenance. Summary and Conclusions: Hay standards have been developed for Florida which are related to animal performance. Quality Index is an estimate of the voluntary intake of Total Digestible Nutrients when the hay is fed alone and free-choice. There is a close relationship between Quality Index and expected animal performance. An Extension Forage Testing Program has been initiated which utilizes Near-Infrared Reflectance analysis to provide results which include Quality Index, Total Digestible Nutrients and Crude Protein. Information from the test may be used to negotiate hay price and to formulate a supplementation program. It is possible to have bermudagrass hay of relatively high quality, but most hays submitted to the Forage Testing Program were of low to medium quality. The reasons for the lower quality of many of these hays are (1) the species are tropical grasses which have low inherent quality and which mature rapidly, (2) the effects of the hot, humid environment are to decrease quality, and (3) harvest is often delayed due to frequent summer rains. The wide range in quality of Florida summer perennial grass hays demonstrates the need for testing of each cutting if quality information is important in the livestock management plan. Irproving Low Quality Hay With Ammonia William E. Kunkle Extension Beef Specialist Department of Animal Science University of Florida Gainesville, FL Many ranchers in Florida feed hay to their cattle during the winter months when pasture is not available. Much of the hay is harvested after the summer rainy months and is low in digestible nutrients (TDN) and pro- tein. Supplemental energy and protein are often required for acceptable performance of beef cattle, especially cows with calves and growing heif- ers. Anhydrous armmnia treatment of low quality hay and crop residues is an effective and economical method of increasing the crude protein, TDN and consumption of these low quality feeds. The treatment of low quality forages with anhydrous ammonia was first investigated by European and Canadian researchers. Since the late 70's considerable research has been conducted in the United States. This report will summarize results from Florida research and give pertinent information from research across the United States. Procedures for Treating Hay Type of Hay. Most of the research has been conducted on mature grass hay or crop residues. These require supplements in most feeding programs and have the most potential for improvement. A few examples are mature grass hays (over 8 weeks between cuttings), bahia grass hay cut after seed pro- duction, corn stalks, wheat and other straws, etc. Level of Amnonia. Research trials have shown good results when 2.5 to 2.7% anhydrous amionia was applied to the hay. A 1000 lb. round bale would require 25 to 27 lb of anhydrous ammonia. Lower levels of aamonia were not as effective in increasing digestibility of the hay. Length of Treatment. The time required to obtain increased feeding value is dependent on temperature. During warm weather (over 70F average) two weeks should be sufficient but during cool weather four to six weeks has shown better results. The hay can be treated for periods longer than needed with no problems. The hay pile can be kept covered until it is fed. Treatment Method. A few bales of hay should be weighed to determine the aiiount of ammonia needed. The bales need to be stacked in a pile and covered with polyethylene prior to releasing anmonia. The bales can be stacked with two on the ground and one placed in the groove to help shed rain off the plastic. (Example: 8 ). A pile of bales with 15 bales end to end in the above configuration will contain 45 bales and can be covered with a 28'x 100' piece of plastic. Many people have used six mil polyethylene (clear or black) that is available at many construction suppliers. The anhydrous ammonia is a liquid until vol- atilization; therefore, a container such as a clean steel drum is needed to hold the liquid. This will require a 55-gallon drum with open top or equivalent for each ten bales. The drums are placed around the stack of rolls and 6' to 10' of 3/4' black plastic pipe is secured into each drum. The pile is covered with polyethylene and dirt is used along the edges to pull the polyethylene tight and make a seal with the ground to prevent escape of ammonia. Polyethylene is not needed on the ground under the stack. The plastic pipe from each drum is left exposed under the plastic for connecting the ammonia tank. The hose from the anhydrous tank can have the hand tightened adapter removed and with pipe fittings reduced to a 1/2" pipe that can be attached to the 3/4" plastic pipe and secured with a clamp. The anhydrous ammonia is allowed to flow slowly into each drum and the amount is determined accurately with a metering device or estimat- ed with the percentage full gauge. The anhydrous ammonia will volatilize in two to seven days depending on the temperature. It is imperative that the polyethylene is well sealed prior to adding awmonia. Punctures or tears in the polyethylene can be repaired with duct or plastic tape. The hay should be treated with anhydrous ammonia soon after covering with polyethylene to prevent molding caused by condensation. Safety. Anhydrous ammonia is a caustic and potent chemical. It readily seeks water and will volatilize and spread very rapidly. The 3/4" plastic pipe system to convey anhydrous armonia into the drums should have open ends to prevent a build-up of pressure. An operator should make absolute- ly sure all connections are tight prior to releasing the arimonia. The tank, valves, regulators and hoses should be properly maintained. The applicator should wear goggles, rubber gloves and protective clothing when handling ammonia. Fresh water should be kept nearby for cleansing the skin or eyes in case of an accident. Always be aware of prevailing winds and position the equipment accordingly. Benefits of Aimonia Treatment Crude Protein. The crude protein content of low quality grass hays is often below 6% and anhydrous animonia treatment will increase the crude protein above 12% in rost situations. Three trials with bermuda grass hay resulted in crude protein levels from 12.7% to 14.1% after anhydrous anrmonia treatment (Table 1). Table 1. EFFECT OF AI1MONIA TREAfTENT ON THE CRUDE PROTEIN COICENT AiD DIGESTIBILITY OF HAY Bermuda Grass Bermuda Trial 1a Trial 2,4 and Bahiaa Level of Ammonia, % dry matter 3.0 2.8 2.6 Crude Protein, %c Untreated 5.5 7.5 4.2 Armmonia 12.9 14.1 12.7 In Vitro Organic Matter Digestibility, %c Untreated 40.0 40.5 42.2 Ammonia 50.9 57.2 53.3 aReference: 1983 Florida Beef Cattle Research Report, p. 107. bReference: 1984 Florida Beef Cattle Research Report, p. 64. cAverage level in dry matter. A summary of 24 trials from 8 states showed the crude protein of wheat straw increased from 3.6 to 8.9%, corn residue increased from 5.9 to 12.0%, milo residue increased from 7.0 to 15.8% and soybean straw from 6.0 to 12.5%. Forages with higher moisture levels tend to retain more of the ammonia and have larger increases in their crude protein. However, crude protein levels above 10% may be higher than can be efficiently utilized in many feeding situations because the level of digestible energy limits the amount on non-protein nitrogen that is utilized. Digestibility. The digestibility of low quality forages is increased 6 to 15 percentage units after treatment with anhydrous ammonia. Three trials with bernudagrass hay showed the digestibility increased 10.9 to 16.7 percentage units after treatment with anhydrous anmonia (Table 1). A summary of trials from 10 states showed the digestibility of wheat straw increased 10.4 percentage units, corn residue increased 8.3 percentage units, milo residue increased 15 percentage units and soybean straw increased 6 percentage units after ammonia treatment. Consumption and Wasteage. The rate of digestion is increased which allows the cattle to consume more of the low quality forage. A summary of 14 trials from several states showed a 22% increase in forage consumed with a range from 9 to 39% increase in consumption. A reduction in wasted hay has also been noted after ammonia treatment. Cattle will consume weath- ered hay on the outside of the bales much more readily than prior to treat- ment. In some feeding trials estimated losses due to wasted hay have been reduced to 10% or below. The increased consumption can be offset in part by a reduction in wasted hay. Two trials (Tables 2 and 3) with Bermuda- grass hay in Florida have resulted in a 10.1 and 5.7% increase in hay offered to the cattle but the actual consumption was probably increased even more because wasted hay was not accurately quantitated. Cattle Performance. The increases in consumption and digestibility result in rore TDN intake and better performance of the cattle. Beef cows receiv- ing ammonia treated hay and supplement consumed less supplement and lost 66 lb less weight during the calving period (Table 2). In fact beef cows fed only ariionia treated hay lost less weight (35 lb) and had similar pregnancy rates, calving intervals and calf weaning weights compared to cows fed untreated hay and 4.4 lb/day of a 16% liquid supplement. In another trial (Table 3) lactating beef cows fed amronia treated nay had similar weight losses during the trial but shorter calving intervals and heavier calf weaning weights than beef cows fed untreated hay and a similar supplement. The protein supplied in the anmionia treated hay appeared to be utilized nearly as good as cottonseed meal in this trial where corn and molasses supplements were also provided. A summary of eight trials with gestating beef cows from other states showed a .67 lb/day better per-formance for anmonia treated crop residues compared to untreated residues. A summary of seven trials with growing calves showed a .26 lb/day increase in gain for calves fed anmonia treated hays and crop residues compared to untreated crop residues. Costs and Returns Costs. The costs of treating a stack of 45 large round bales and a ton of hay are outlined as follows: Cost of Treatment Cost/Unit 45 Rolls Ton Anhydrous anmonia (25 lb/roll) $300/ton $170 $ 7.60 Polyethylene (6 mil x 28' x 100') $ 70 each $ 70 $ 3.10 Labor (12 hrs/stack) $ 4/hr $ 48 $ 2.10 $288 $12.80 Returns. An estimation of the level of supplemental corn and urea needed to provide a nutrition level equal to ammonia treated hay was calculated. Amrmonia treatment of low quality hay was assumed to increase consumption 20%, increase hay offered by 10% (part of increased consumption from reduced wasteage), and increase digestibility by 8 percentage units (42% to 50%). The calculations are as follows: Untreated Hay Ammonia Treated Hay Hay offered, lb/day 20 22 Fraction consumed .8 .9 Hay consumed, lb/day 16 19.8 Digestibility .42 .50 TDN consumed, lb/day 6.7 9.9 Difference, lb/day -- 3.2 The extra 3.2 lb of TDN and .8 lb crude protein consumed by beef cows consuming ammonia treated hay can be supplied by 4 lb of corn and .2 lb of urea. The daily costs are as follows: Untreated Hay Ammonia Treated Hay Hay ($50/ton) 20 lb x $.025/1b=.50 22 lb x$.025/lb =.55 NH3Treatment ($12.80/ton) 22 lb x$.0064/lb =.14 Corn ($140/ton) 4 lb x $.07/lb =.28 - Urea ($300/ton) .2 lb x $.15/lb =.03 - Total Cost, $/day .81 $.69 In this example, an investment of $.19/day in ammonia and extra hay provided nutrition equal to $.31/day from corn and urea. Ammonia treatment cost only 61% as much as a comparable level of supplement from corn and urea. Other Factors The ammonia added to the hay is non-protein nitrogen and requires several minerals to be present for efficient utilization. Sulfur is required by bacteria before the ammonia can be synthesized into protein and is routinely added to commercial supplements containing non-protein nitrogen. Sulfur is present in mineral supplements but only at trace amounts. A good source of sulfur is potassium and magnesium sulfate (Dynamate) and 1.25 ounces/hd/day mixed in the mineral or a grain should provide adequate sulfur. Low quality hays are often very deficient in phosphorus especially for lactating beef cows. In many cases 4-6 ounces/day of a mineral supplement containing 8% phosphorus may be required to correct the deficiency in the lactating beef cow. Precautions Amronia treatment of some types of forages has resulted in the death of cattle in a few cases. Most of these cases have involved grain sorghum residue or wheat cut for hay. The cattle have exhibited very aggressive behavior and have been reported to run through fences, corrals, side of barns, etc. The cattle become unpredictable in behavior and are dangerous. Several cattle deaths have resulted from self inflicted in- juries. The compound suspected of causing the problem is 4-methyl- imidazole. This compound is formed when ammonia reacts with sugars. The situations where problems have developed involved higher quality forages that contain sugars. Levels of aunonia above the recommended level of 3% may have been used in some cases. I am not aware of any problems in Florida and problems are not expected if low quality forages are treated at recoriended levels. TABLE 2. EFFECTSS OF AtlOMNI;, TF.EArT:E:;T OF 5EF:UD..GFASS HAY AND SUPPLEMENTAL FEED ON THE PERFORMANCE OF BEEF COWSa Untreated Hay Hay 3% ;flnonia 16% Liquid 16% Liquid No Supplement Supplement Supplement No. Of Cows 20 20 19 Hay Offeredb lb/cow/day 19.1 22.0 22.0 Supplement Consumed Ib/cow/day 4.4 3.1 -- Cow Weight Change, lb (113 days) Open Cows +7 ( 6) +11 ( 6) +25 ( 6) Cows with Calvesc -248 (14) -182 (14) -213 (13) Cows Pregnant, %d 90 90 100 Calving Internal, days (Cows with Calves) 372 (12) 366 (11) 376 (11) Calf, 205 Day Wean Wt., lb. 433 (12) 420 (13) 425 (12) alpine Acres Research Farm, University of Florida, 1983 Florida Beef Cattle Research Report, p. 107. Hay offered to cows, 5-10% of hay not consumed. CAngus cows calved in October and November, includes weight loss of calving (No. of cows), Initial Weight was 1104 lb. dExperiment ended at beginning of breeding season and cows gained weight during 70 day breeding season. TABLE 3. EFFECTS OF ANHYDROUS AMMONIA TREATMENT OF BERMUDAGRASS HAY AND A COTTONSEED MEAL SUPPLEMENT ON THE PERFORMANCE OF LACTATING BEEF COWSa Untreated Hayb Ammonia Hay Ammonia Hay Item Cottonseed Cottonseed Corn No. of Cows Hay Offered, lb/cow/day Initial Cow Weight, lb (11-29-82) 13 24.7 1029 27 Cow Daily Gain, lb 11/29 to 3/22 (113 days) 3/22 to 6/6 (78 days) Cow Condition Change 11/29 to 3/22 3/22 to 6/6 -.46 .11c +.13 + .19 -.39 1 .17 -.31 + .15 13 27.2 1038 27 -.35 + .11 +.69 19 -.34 .17 +.36 .15 13 26.1 1015 27 -.53 .11c + c,d +.51 .20c' -.45 .17c +.46 .15d Pregnancy, % Calving Interval, days 205 Wean Weight, lbe 377 + 4c 403 + 23C 444 18 'd 366 5c 463 23d alpine Acres Research Farm, University of Florida, 1984 Florida Beef Cattle Research Report, p. 64. Anhydrous ammonia applied at 2.8% of hay dry matter, cottonseed meal based supplement (23% crude protein) fed at 3.8 lb/cow/day, corn based supplement (8 % crude protein) fed at rate of 3.6 lb/cow/day. c,dMeans with different superscripts all significantly different (P(.05) eP. 07. 359 3d |