C, Lo II s c'9J
Presented at Ihe 32nd
Florida nutrition Conference
Sponsored by the
FLORIDA FEED ASSOCIATION
FLORIDA COOPERATIVE EXTENSION SERVICE
Institute of Food and Agricultural Sciences
University of Florida
October 30, 1975
TABLE OF CONTENTS
Dried Poultry Litter for Dairy Cattle.
H. H. Van Horn................................................. 1
Present Status of the Value of Recycling Animal Wastes to the
J. P. Fontenot 3
Relative Feeding Value of Grain Sorghams and Corn For
Finishing Beef Steers
J. E. Bertrand 5
Relative Feeding Value of Grain Sorghum and Corn When Fed to
Growing Finishing Swine
David L. Hammell 7
What is the Vitamin K, Choline and Vitamin E-Selenium Situation
in Swine Feeding
Joe H. Conrad 10
Acid Treatment of Grain for Animal Feeding
R. F. Sewell 13
Feeding for Increased Egg Size
Carroll R. Douglas 14
Recent Up-Date on Aflatoxins in Animal Feeds
Pat B. Hamilton 16
Vitamins A, D and E for Dairy Cattle
Barney Harris, Jr. 17
Forages in Beef Production
W. M. Warren 19
Self-Feeding of Dairy Cattle
S. P. Marshall 21
Making Maximum Use of Non-Protein Nitrogen Compounds in Animal
J. K. Loosli .................................................. 23
DRIED POULTRY WASTE FOR LACTATING DAIRY COWS
H. H. Van Horn and Barney Harris, Jr.
Dairy Science Dept., University of Florida
Poultry waste materials for animal feeding have been fed un-
processed, air-dried, and ensiled. Fermentation of ensiling eliminates
disease hazards to animals. However, because of storage, handling,
mixing, transportation and hygienic needs in order to make the product
available to many livestock producers, high-temperature drying may be
the most practical way of preparing the product in most cases.
Nutritional value of poultry waste is very variable and depends
on the source of waste, type of litter, amount of litter used, feed
consumed by birds, age of waste, amount wasted in manure, ventilation,
processing temperature, etc. Considerable research has shown nutrition-
al value and favorable performance with poultry waste with beef cattle,
sheep, and dairy cattle. Research has been lacking, however, with
commercially dried poultry waste for lactating cows. Therefore, the
objective of this research was to test for effects of various levels
of dried layer waste in complete rations for lactating cows on feed
intake, milk production and composition and digestibility.
Dried poultry waste (DPW) used in these experiments was obtained
from a diversified farming enterprise in Florida with about 50,000
laying hens. High moisture, raw laying hen excreta was converted to
a product with 10% moisture or less with dehydrating equipment consisting
of a Coleman rotary drier imported from England. Composition of the
final product used in the experiment is listed in Table 1. It is
important to note the high ash percent as well as a relatively low
protein percent in this product. Rather high temperatures of processing
and long-time storage of raw material prior to processing (7 to 180 days)
were the most probable causes for the loss of non-protein nitrogen.
Four rations containing 0, 10, 20 and 30% DPW substituted for
citrus pulp were formulated and fed to 24 lactating cows. A fixed
amount of 30% cottonseed hulls was used for all rations as the main
crude fiber and small amounts of urea were used to balance protein
content. DPW was used as the only source of calcium and phosphorus
supplementation in 10, 20 and 30% DPW rations. All concentrate mixtures
were balanced to 13% crude protein (air-dry basis).
The results of the experiment are shown in Table 2. Low accept-
ability by all cows of 30% DPW rations was easily observed from the
beginning of the experiment. Acceptability of 20% DPW was rather low
but less pronounced, with 10% DPW being eaten equally as well as the
control ration. There was an increase in density of rations as the
level of DPW increased since we were substituting DPW for citrus pulp.
Degree of dustiness of the ration also was increased and its color
varied from dark yellow for the 0% DPW (control) to dark gray for 30%
DPW. However, no ration had noticeable extraneous odors.
Milk yield was also equal to the 0% DPW diets when 10% DPW was fed.
However, higher levels of DPW significantly depressed feed intake, milk
yield, milk protein percent, and total yields of milk nutrients as well
as depressing body weight.
Reduction in fat percent for 10% DPW as compared to control appears
to be the result of citrus pulp reduction (10%) since decrease in milk
yield was minimum. Citrus pulp is important in maintaining fat percent
in rations of similar composition, thus suggesting that loss of effective
fiber was the reason for the drop in fat percent. There appeared to be
no major effect on digestibility of various nutrients in going from 0
to 10% DPW but there was a depression in digestibility of energy, protein
and fiber in the 20 and 30% diets as compared to the 0 and 10% DPW diets.
In summary, the product used in these studies was more nearly a
mineral supplement (60% ash) than a high-energy feedstuff like citrus
pulp, the product replaced when DPW was added. Even so, DPW levels up
to 10% can be used in complete rations for lactating cows with little
or no reduction in feed intake and milk production, and DPW can serve
as a source of calcium and phosphorus. Higher levels of DPW should be
restricted to situations where reduced feed intake and performance can
Table 1. Analyzed composition of poultry waste
(as fed in expt.)
Equivalent protein from NPN
Table 2. Average daily means of treatment responses
Sv Dried poultry waste ration
Response variable% 10% 20% 30%
0% 10% 20% 30%
Feed intake (Ibs/day) 53.6 54.1 45.5 36.9
Milk yield (lbs/day) 44.6 43.6 38.6 33.7
Milk-fat (%) 3.64 3.38 3.35 3.02
Milk solids-not-fat (%) 8.46 8.41 8.27 8.26
Milk protein (%) 3.08 2.88 2.75 2.68
Solids-corrected-milk (Ibs/day) 41.4 38.7 33.7 28.1
PRESENT STATUS OF THE VALUE TO THE ANIMAL
INDUSTRY OF RECYCLING ANIMAL WASTES BY FEEDING
J. P. Fontenot
Department of Animal Science
Virginia Polytechnic Institute and State University
About 1.6 billion tons of animal wastes are produced annually in
the U.S. About 50% of the waste is produced in confinement and is collec-
table, so as much as 800 million tons of waste could potentially be used
as animal feed.
Poultry wastes are rich in crude protein (about 30%, dry basis),
calcium and phosphorus, and are fair in energy value. Dried poultry manure
has been found to be low in protein and energy value for layers, but
including it in layer diets at levels of up to 25% did not lower egg pro-
duction. The nitrogen in broiler litter and caged layer manure is
efficiently utilized by ruminants, although about 50% of it is in non-
protein form. The energy value of these for cattle is similar to that of
good quality hay.
Poultry wastes can be heat processed for drying and destruction of
potential pathogens. Ensiling of broiler litter with certain levels of
moisture or with feeds such as corn forage and high moisture grain has
reduced coliforms. Ensiling the high protein waste with low protein corn
forage and grain looks especially promising in producing a silage which will
not need protein supplementation. Limited work indicates that layer waste
ensiled with a dry feed such as grass hay will produce a nutritious feed.
Limited research indicatesthat fresh or dry swine waste is utilized
quite efficiently by swine. Good performance has been obtained in swine
which received oxidation ditch mixed liquor from swine manure, compared to
those which received tap water.
The digestibility of cattle wastes varies inversely with the level of
roughage fed the cattle producing the waste. High heat processing of the
waste appears to lower digestibility, but addition of certain chemicals
such as sodium hydroxide improves digestibility of cattle waste. Ensiling
of cattle waste with grass hay, corn silage and corn grain has produced
desirable feedstuffs. Separation of the components of cattle manure by
water washing, and ensiling the fibrous fraction looks quite promising.
Feeding animal wastes has not adversely affected the taste of meat,
milk and eggs.
Recycling animal wastes by feeding is not sanctioned by FDA due to
potential hazards from pathogens and residues. No indication has been
obtained of harmful effects in humans consuming products from animals fed
waste. Copper toxicity has occurred in sheep fed broiler litter with high
copper levels, but this has not caused any problems with cattle since they
are not as sensitive to high copper levels. Pathogens in animal waste can
be destroyed by heat or chemical treatment or by ensiling the waste.
Molds present no problem if the wastes are handled and stored properly.
Pesticide residues pose no serious problem in feeding animal wastes.
Some wastes such as broiler litter may contain medicinal drug residues,
but no harmful levels of these have been detected in meat or liver of
cattle fed litter, following a modest withdrawal period.
Utilization of animal wastes is a more practical approach than
simply disposal. Information available indicates that a considerable amount of
animal wastes can be safely recycled by feeding. An Environmental Impact
Analysis Report concerning feeding of animal wastes was prepared by an
Industry Ad Hoc Committee and was submitted to FDA within the past year.
The Report indicates that with proper processing of the wastes and a
reasonable withdrawal period, feeding the wastes would not endanger human
and animal health. The Report shows that feeding these wastes would have
a beneficial effect on the environment. The level of waste fed would
depend on the level of production of the animals. For animals in low production
such as pregnant beef cows, the level used could approach 100%, whereas for
fattening cattle the level of waste will likely be 10 to 25% of the total
ration. The high protein and phosphorus content of poultry wastes would make
them valuable as range supplements for cows and stocker cattle. It has
been estimated that waste recycling by feeding could save 40 million tons of
grain annually. It appears that this is a conservative figure.
RELATIVE FEEDING VALUE OF SORGHUM GRAIN AND CORN
FOR FINISHING BEEF STEERS
J. E. BERTRAND
University of Florida
Agricultural Research Center, Jay
The beef cattle feeding industry in Florida would benefit greatly
if another high quality feed grain, in addition to corn, was readily
available. Grain sorghum is not as limited to time of planting, is more
tolerant to short periods of drought, will produce as much or more grain
per acre than corn, and has a good potential for the production of grain
in many areas of Florida.
Results obtained at the Agricultural Research Center, Jay, showed
that the feeding value of sorghum grain for finishing beef steers was
quite variable depending on type (NBR, non-bird-resistant, and BR, bird-
resistant) and method of processing (rolled high-moisture and ground dry
sorghum grain). The feeding value of corn was also improved by feeding
it as rolled high-moisture corn instead of ground dry corn.
Steers receiving ground dry corn in finishing rations containing
silage usually gained faster and were from 15% to 56% more efficient
in converting total ration dry matter to gain than steers receiving difr
ferent types of ground dry sorghum grain (a mixture of varieties, NBR,
and BR). In every instance, the daily dry matter consumption was higher
for steers receiving the sorghum grain rations. This indicated that
steers tried to compensate for the lower available energy in sorghum
grain when compared to corn by increasing their consumption of the sorghum
Steers receiving rolled high-moisture corn in finishing ration con-
taining silage did not always gain faster than steers receiving rolled
high-moisture sorghum grain. However, steers receiving high-moisture
corn were from 14% to 20% more efficient in converting total ration dry
matter to gain than steers receiving different types of high-moisture
sorghum grain (a mixture of varieties and NBR). Daily dry matter con-
sumption was again higher for steers receiving the sorghum grain ration.
There was a difference in the feeding value of NBR and BR sorghum
grain for finishing beef steers. Steers receiving NBR sorghum grain
(high-moisture and dry) gained faster and were more efficient (9% and
29%, respectively) in converting total ration dry matter to gain than
steers receiving BR sorghum grain (high-moisture and dry). The feeding
value of BR sorghum grain was improved considerably by feeding it as
high-moisture instead of dry grain. Steers fed the rolled high-moisture
BR sorghum grain ration were approximately 18% more efficient in conver-
ting total ration dry matter to gain than steers receiving the ground
dry BR sorghum grain ration. Palatability did not appear to be the pro-
blem with BR sorghum grain, because steers receiving this type of grain
consumed more dry matter than steers receiving NBR sorghum grain.
A farmer-feeder growing grain to feed to his cattle should evaluate
corn and the two types (NBR and BR) of sorghum grain from an agronomical,
bird damage, and nutritional standpoint and grow the one which fits advan-
tageously in his total farm program. He may wish to grow both corn and
and sorghum for grain in different cropping systems. The feeder buying
grain to feed to his cattle will need to consider the difference in
price between corn and sorghum and the type of sorghum grain (NBR and
BR) available to him.
RELATIVE FEEDING VALUE OF GRAIN SORGHUM AND CORN WHEN
FED TO GROWING-FINISHING SWINE
DAVID L. HAMMELL
Agricultural Research Center
Live Oak, Florida
Of interest to livestock producers in a grain deficient area is the
possibility of producing enough grain so as to become self-supporting or
not have to import grain. In Florida, other than corn, grain sorghum
would appear to be an alternative grain which consequently could be used
in the livestock feeding industry. However, certain unanswered questions
come to mind and foremost among many is "What is the relative feeding
value of grain sorghum as compared to corn"?
To acquaint one with grain sorghum, one must realize there are two
predominant kinds or species which may be grown. One is the bird-resis-
tant (BR) varieties which have the brown or bronze colored seed coat
and second are the non bird-resistant (NBR) varieties which have the
white or yellow colored seed coat. The seed coat color may be recognized
quite readily just prior to harvesting of the grain. Ass ciated with
the differences in seed coat color is the nutritional value of the grain
Research conducted at experiment stations in Florida since 1969
(table 1) indicate that pigs fed BR and NBR grain sorghum gain in the
same per day as with corn. With respect to feed required per unit of
gain, pigs fed the BR sorghums consistently required more feed than
those fed corn. The results with NBR sorghums are not as consistent
but limited information would indicate that NBR sorghums are similar to
corn in nutritional value. The Florida experiments to date with grain
sorghum would indicate that BR grain sorghum has 83% and NBR sorghum has
99% the nutritional value of corn. Based on the data collected it ap-
pears that NBR sorghums are worth approximately 16% more than BR sorghums.
Compared chemically, the energy, protein, amino acid, vitamin and
mineral content of both sorghums (NBR and BR) are quite similar to that
of No. 2 yellow corn; however, Gree (1974) indicates the tannin content
of BR sorghum varieties (1.14 to 1.8) tannic acid equivalents is con-
siderably higher than that of the NBR sorghum varieties (0.23 to 0.51).
Apparently the high content of tannins is responsible for the poor feed
conversion observed when BR sorghums are fed to growing-finishing swine.
The nutritional properties of sorghums are important; however, other
factors may contribute to the relative feeding value of sorghums as com-
pared to corn. Experience at the Agricultural Research Center, Live Oak,
Florida indicates that grain sorghums are more difficult to store and
that insect damage is more severe than with corn. Problems of this na-
ture tend to lower the nutritional value of grain sorghum.
Table 1. Summary of Performance of Pigs Fed Corn, Bird-Resistant
Grain Sorghum and Non Bird-Resistant Grain Sorghum
Average Daily Gain
Corn BR NBR
Durrance and Hollis, 1969 1.76
Hollis and Palmer, 1969 1.58 1.67
Maxson et al., 1971 1.57 1.82
Houser et al., 1972 1.69 1.59 1.69
Wallace, et al., 1974 1.89 1.74 1.86
Hammell, 1974 1.51 1.49
Hammell, 1975 1.79 1.72
Combs, unpubl. data 1.24 1.14 1.10
Mean 1.61 1.62 1.55
Feed Required Per Unit of Gain
Durrance and Hollis, 1969 4.27
Hollis and Palmer, 1969 3.29 4.04
Maxson, et al., 1971 3.27 3.60
Houser, et al., 1972 3.13 3.53 3.13
Wallace, et al, 1974 3.06 3.71 3.36
Hammell, 1974 2.55 3.05
Hammell, 1975 2.73 3.16
Combs, unpubl. data 2.09 2.16 2.19
Mean 2.87 3.44 2.89
Relative Efficiency 83% 99%
Combs, G. E. Unpublished data.
Durrance, K. L. and G. R. Hollis. 1969. High moisture grain in grow-
ing-finishing swine rations. Fla. Mimeo Ser. SVS 69-2.
Green, V. E. 1974. Yield and digestibility of bird-resistant and non
bird-resistant grain sorghums. Soil and Crop Sci. Soc. Fla. 33:13.
Hammell, D. L. 1974. Effect of feeding acid preserved grains on perfor-
mance of pigs. Fla. Mineo Ser. ARCLO 74-1.
Hollis, G. R. and A. Z. Palmer. 1969. Grain sorghum as a replacement
for corn in the ration of growing-finishing swine. Fla. Mimeo
Ser. SVS 70-1.
Houser, R. H. and H. W. Lundy. 1972. Florida grown corn, bird-resistant
grain sorghum and non bird-resistant grain sorghum for growing-
finishing swine. Fla. Mimeo Rpt. SW 1972-3.
Maxson, W. E., R. H. Houser, R. L. Shirley and A. Z. Palmer. 1971.
Sulfate, selenium or bentonite as feed additives for swine fed
bird-resistant milo diets. Fla. Mimeo Ser. ARCLO 71-2.
Wallace, H. D., G. E. Combs and R. H. Houser. 1974. Florida grown bird-
resistant grain sorghum and non bird-resistant grain sorghum for
growing-finishing swine. Fla. Mimeo Rpt. AL-1974-11.
WHAT IS THE VITAMIN K, CHOLINE AND
VITAMIN E-SELENIUM SITUATION IN SWINE FEEDING
JOE H. CONRAD
Department of Animal Science
University of Florida, Gainesville
A deficiency of vitamin K is characterized by an alteration in the
blood clotting mechanism. Severe deficiencies are associated with a
bleeding tendency, hemorrhage or hemophilia-like condition. The defi-
ciency may result from lack of sufficient vitamin K, lack of bacterial
synthesis of the vitamin within the intestinal tract, inadequate absorp-
tion, or inability of the liver to use available vitamin K because of
either hepatic disease or the presence of a variety of antivitamin K
In recent years, bleeding has been reported in pigs of different
ages under a wide range of conditions; however, this condition is most
frequent in young pigs in confinement. In many situations the pigs have
responded to supplemental vitamin K. The exact causes for these appar-
ent cases of vitamin K deficiency are not known. Among the causes postu-
lated are the following:
1. Feeding of sucrose or other ingredients which increase the rate of
passage and decrease bacterial synthesis.
2. Use of high levels of vitamin A which decrease intestinal
absorption of vitamin K.
3. Increased use of antimicrobial compounds which reduce the
microflora of the intestines.
4. Aflatoxins and other mycotoxins in the feed which interfere
with vitamin K synthesis.
5. Use of pens with slotted floors which prevent coprophagy
(eating of feces).
6. More confinement feeding and reduced use of good sources of
vitamin K such as pasture and alfalfa.
The 1973 NRC publication on Nutrient Requirements of Swine recommends
a level of 2.2 grams of menadione (vitamin K) per ton. This is the mini-
mal supplemental level which is now recommended. Aflatoxins in Florida
are of constant concern and supplemental vitamin K will help to reduce the
A number of studies recently have demonstrated a beneficial effect
from supplemental choline in swine diets. The exact function of choline
is not known, but it is a part of phospholipids and acetylcholine. These
are involved in fatty acid metabolism and the transmission of nerve im-
pulses. Choline also furnishes labile methyl groups, spares methionine
and is involved in preventing fatty livers and hemorrhagic kidneys.
Results from 22 trials conducted at nine midwestern universities
showed that 350 mg of supplemental choline per pound of gestation diet
improved performance. Sows supplemented with choline farrowed more total
pigs (10.54 vs 9.89), more live pigs (9.33 vs 8.64) and weaned more pigs
per litter (7.72 vs 7.29) than sows fed rations without supplemental
A deficiency of choline in young pigs results in unthriftness,
shortlegged and pot-bellied conformation, lack of coordination, lack of
proper rigidity in the joints, fatty livers and renal glomerular occlusion.
Recent research at Illinois has shown that the availability of choline
in soybean meal ranges between 60 and 75% (Molitoris and Baker, 1975).
Soybean meal is a much better source of choline than grains. Therefore,
lowering the protein level, use of synthetic lysine and reduced methion-
ine levels increase the need for supplemental choline.
The following supplemental choline levels in grams per ton of com-
plete ration are suggested under practical conditions: gestating sows
and boars, 400; lactating sows, none; 10 to 25 lb pigs, 400; 25 to 50 lb
pigs, 200; 50 to 125 lb pigs, 100; 125 lb to market, none.
Vitamin E Selenium
Selenium was approved for swine by the Food and Drug Administration
on February 7, 1974. Because it is considerably less expensive than
vitamin E, approved selenium levels of 0.1 ppm either began replacing or
reducing the concentration of supplemental vitamin E in swine rations.
Corn used for feeding swine in Florida can be expected to be selenium
deficient. Florida grown corn used in a recent swine study was found to
contain 0.02 ppm of Se. Corn grown in the central and eastern corn belt
has been reported to contain minimum selenium levels of 0.01 to 0.04 ppm
with average selenium levels of 0.03 to 0.09 ppm. Only corn grown in
Nebraska and North and South Dakota had levels outside these ranges. Fur-
thermore, the average biological availability of selenium is about 33% in
animal protein materials and 65 to 100% in plant materials. Recent studies
on the selenium content of dried whey show that selenium values were low
except in Minnesota.
During an experiment in the summer of 1968 which I was conducting at
Purdue University, six of 128 pigs, or about 5%, died suddenly without
prior clinical signs of illness or evidence of infectious agents. Diag-
nostic reports revealed 1) liver necrosis which appeared as scattered red
spots and mottled areas on the surface of the liver, 2) muscle degenera-
tion characterized by pale and waxy appearance and 3) yellowish pigmenta-
tion and generalized edema of tissues. A subsequent study was conducted
in which average daily gains were increased 11% with vitamin E, 10% with
selenium and 8% with the combination of vitamin E and selenium.
Some of the metabolic functions of selenium and vitamin E are
interrelated. Each has a sparing and complementary effect on the
other, but both are essential dietary nutrients. From a nutritionist
and feed manufacturer's viewpoint, much less supplemental vitamin E
is needed when adequate levels of dietary selenium are present. For
example, if 20,000 I.U. of vitamin E/ton are recommended with low
levels of selenium, one half or less of this level would be satis-
factory with adequate levels of selenium. It appears that the total
selenium level needed in practical swine diets is at least 0.1 mg per
kilogram of feed and that the vitamin E requirement is about 11 I.U.
of vitamin E per kilogram of feed.
Both sodium selenate and sodium selenite are approved, but some
prefer sodium selenate because it is more stable and less reacting
with other nutrients in the pre-mixes. The alpha tocopheral is the
preferred form of vitamin E since it has the higher nutritional value.
It is recommended that selenium be added to all swine diets at
levels of 0.05 to 0.1 ppm and that vitamin E be added at 5 I.U. per
pound of feed.
Conrad, J. H., T. W. Perry, B. D. Virgin and R. B. Harrignton. 1969.
Vitamin E, selenium, normal and Opaque-2, regular and high moisture
corn for G-F swine. J. Animal Sci. 29:131 (Abstr.).
Hitchcock, J. P., T. I. Hedrick, D. E. Ullrey and W. S. Clark. 1975.
Se in dried whey by season and location. J. Animal Sci. 41:270
Kornegar, E. T. 1974. Supplemental choline for swine. Feedstuffs, May
20, 1974. pp. 21, 24.
Molitoris, B. A. and D. H. Baker. 1975. Choline availability in soybean
meal. J. Animal Sci. 41:322 (Abstr.).
Neufville, M. H., H. D. Wallace and G. E. Combs. 1973. Vitamin K supple-
mentation of swine diets. J. Animal Sci. 37:288 (Abstr.).
Neufville, M. H. 1974. Nutrition and management practices for early
weaned pigs with special emphasis on a sugar-induced hemorrhagic
syndrome. Ph.D. Thesis, Major Professor H. D. Wallace, University
NRC-42 Committee on Swine Nutrition. 1973. Effect of supplemental cho-
line on reproductive performance of sows. J. Animal Sci. 37:281
Ullrey, D. E. 1973. Selenium deficiency in swine rations. Hog Farm
ACID TREATMENT OF GRAIN FOR ANIMAL FEEDING
R. F. SEWELL
Ralston Purina Company, St. Louis, Missouri
The calcium and sodium salts of propionic acid have long been used
in the feed, food and pharmaceutical industries as mold inhibitors and
preservatives. Several years ago organic acids, primarily propionic
and formic, were used successfully in Great Britian to preserve high
moisture grain and forage. The practice was later introduced in Canada.
More recently, this method of high moisture grain preservation has be-
come increasingly common in various areas of the United States.
Economic advantages which encourage the production of high mois-
ture grain include earlier harvest and reduction of field losses; elim-
ination of artificial drying that has become more expensive with rising
energy costs and is often a bottleneck at harvest time; and improved
feed efficiency. On the other hand, disadvantageswhich are associated
with the production of high moisture grain are higher storage costs and
less flexibility in marketing strategy, since high moisture grain is
usually fed directly to livestock.
Propionic, acetic, and formic are the acids usually employed in
the preservation of high moisture grains. These organic acids are used
either in various combinations or individually. Propionic acid is the
most effective preservative of the three and the acid form appears to be
more effective than the calcium or sodium salts.
The quantity of acid required for effective preservation is depen-
dent upon the moisture level in the grain, the make-up of the acid pre-
servative and environmental temperature in storage. Application levels
have ranged between 1 and 2% of the grain by weight.
Since organic acids give off a pungent odor, the preservative
should be applied only in well ventilated quarters. It is important
that the acid be applied uniformly so that each kernel of grain receives
Many feeding trials with dairy, beef and swine have been reported
in which acid preserved grain was compared with conventionally dried
grain. High moisture grain preserved with organic acids has generally been
equal to dry grain when fed on an equal dry matter basis to these species.
FEEDING FOR INCREASED EGG SIZE
CARROLL R. DOUGLAS
Department of Poultry Science
University of Florida, Gainesville
(Presented at 1975 Florida Nutrition Conference, Gainesville, October 30, 1975)
For many years, one of the common problems confronting the commercial
egg industry has been a reduction in size ot eggs laid d-uringhot weather.'
In looking at the problem, it seemed to be most obvious in tiocks of layers /
which were approaching peak production during the months of May, June,
July and August. The egg size problem is also reflected in the increased
spread in price between large and medium during summer months indicating ar -
surplus of medium eggs during this period. 7-
Egg size is influenced by several factors including: 1) Genetics 2) 1
Stage of sexual maturity 3) Age 4) Certain drugs 5) Nutrition and 6) Size 4 tn
or weight of the pullet. In any population of pullets of the same strain,
age and treatment, the largest hens usually will lay the largest eggs.
The Poultry Science Department had been doing research for several
years on the influence of nutrition and various environmental treatments
during the growing period upon laying house performance of pullets. We
were able to grow pullets on a diet containing 9% protein, which reduced
body size and delayed sexual maturity. During periods of high priced pro-
tein, a saving of 20 250 per pullet could be realized using this feeding
Since a protein deficiency during the growing period reduced body
weight, would a high level of protein produce heavier pullets? Further,
would heavier pullets produce larger eggs? An experiment was initiated
to study the effect of protein level during the grower period upon egg
size of pullets.
Commercial Leghorn-type pullets, hatched on November 7, were grown to
8 weeks on a starter diet containing 21% protein. At 8 weeks the pullets
were divided into three groups with group 1 receiving 9% protein, group 2
receiving 14% protein and group 3 receiving 21% protein. At 18 weeks
group 1 was placed on 14% protein. At 20 weeks (March 29) all birds were
placed in laying cages and fed a layer diet containing 16% protein. All
diets were fed free choice.
At 20 weeks of age, average body weights for the pullets fed 9%, 14%
and 21% protein grower diets were 2.59, 2.99 and 3.16 pounds, respectively
and at 60 weeks of age body weights were 3.61, 3.63 and 3.77 pounds.
Those birds grown on 21% protein were able to maintain heavier body weights
throughout the laying period.
The heavier body weights were reflected in larger eggs being laid by
the group receiving 21% protein. Throughout the laying period, eggs laid
by the 21% protein group were approximately one gram heavier than eggs
laid by the other two groups. When this difference in egg weight is tran-
slated into egg size expressed as percent large and extra large eggs laid
by each group, it was found that those birds which received 21% protein
during the growing period laid approximately 6% more large and extra
large eggs than those fed 14% protein.
In summary, the following points should be considered: 1- We have
produced heavier pullets at 20 weeks of age by feeding a diet containing
21% protein for 8 to 20 weeks than by feeding a diet containing 14% pro-
tein for the same period.
2- The heavier birds maintained this weight difference throughout
the laying period.
3- The heavier birds laid approximately 6% more large and extra
4- For pullets reaching peak production during May, June, July
and August (hot weather) it may be important to use the higher protein
level during the growing in order to produce heavier pullets for in-
creased egg size.
RECENT UP-DATE ON AFLATOXINS IN ANIMAL FEEDS
PAT B. HAMILTON
Department of Poultry Science
North Carolina State University
Raleigh, North Carolina 27607
Aflatoxins cause many problems in animals and all of them are bad.
They range from catastrophic to subclinical effects that show up only
on the profit and loss statement. They include poor growth rates,
poor feed conversion ratios and increased mortality. Increased sus-
ceptibility to bruising, impaired blood coagulation, impaired kidney
function, altered immune responsiveness resulting in vaccine failures
and increased susceptibility to infectious agents, and decreased
ability to resist stresses occur during aflatoxicosis. Reproductive
systems are impaired resulting in repeat breeding, abortion, decreased
birth weights, decreased milk production, and decreased milk fat in
cattle and swine. Decreased egg production, reduced hatchability and
smaller eggs occur in poultry. Aflatoxicosis interacts with nutrition
causing an increased protein and fat requirement. Interactions with
vitamin D and riboflavin deficiencies occur. The economic losses
caused by alfatoxin cannot be calculated presently but they are very
The control of mycotoxins is imperfect at the present stage of
knowledge but there are several useful things that the animal and feed
industries can do to protect themselves. Try to limit the moisture con-
tent as much as possible. Clean up mills, storage bins and feed bins.
Tighten management and make the control of mycotoxins an organization-
wide commitment. The use of antifungal agents in the feed to prevent
formation of aflatoxin has proved beneficial. Finally, try to stay
abreast of the latest information since this is a fast developing area.
nc~- /^ 0^ Aru-9
VITAMINS A, D AND E FOR DAIRY CATTLE
DR. BARNEY HARRIS, JR.
Department of Dairy Science
University of Florida, Gainesville
Vitamins A, D and E are all fat soluble vitamins. The fat soluble
vitamins are stored in the fat or lipid portion of the feed.
All animals require a dietary source of vitamin A. The vitamin
does not occur as vitamin A in grasses or legumes but rather as its
precursor, carotene. Carotene or provitamin A is transformed into
vitamin A in the animal's body.
One of the more important roles of vitamin A in the body is main-
taining healthy tissues the integrity of epithelial tissues. In the
young calf, deficiency symptoms usually start with watery eyes, mild
symptoms of respiratory problems such as nasal discharges, often
accompanied by a cough and scours or diarrhea. If this condition is
allowed to persist, pneumonia usually follows. Night blindness is a
common symptom of vitamin A deficiency and may be observed when animals
are moved about in a dim light. A lack of vitamin A reduces the ani-
mal's protection against invading organisms, making animals more sus-
ceptible to infections. Increased infections in the reproductive tract
would quickly lead to reduced breeding efficiency.
The 1971 National Research Council (NRC) publication states that
a 1400 pound dairy cow needs about 28,000 USP units of vitamin A.
Florida dairymen are encouraged to add 4 to 6 million units of vitamin
A per ton a feed.
The importance of vitamin D for the efficient utilization of cal-
cium and phosphorus has been recognized for many years. Increasing the
amount of vitamin D a few days prior to freshening has been an effective
means of reducing the incidence of milk fever when a wide ratio of cal-
cium to phosphorus existed. Less vitamin D is needed as the ratio of
calcium to phosphorus approaches 1.3 to 1.0 in the ration.
More work is needed to further show a need for adding vitamin D to
dairy cattle rations under sub-tropical conditions. However, where
silent heat and lowered fertility is a problem, one should consider add-
ing 1 to 3 million units of vitamin D per ton of feed.
Compounds having vitamin E activity are known chemically as tocophe-
rols. The most striking chemical characteristic of the vitamin E is its
antioxidant property. In fact, these compounds are used in foods as a
antioxidants in order to protect other vitamins from oxidative destruction.
Experimental vitamin E deficiencies have been produced in the
laboratory with calves. They showed essentially the same symptoms
as calves with white muscle disease (muscular dystrophy). The first
deficiency symptoms include weakening of the leg muscles, impairment
of tongue that prevents suckling, and eventually the calf is unable
The requirements of dairy cattle for vitamin E supplementation
has not been established. Apparently, normal growth, reproduction
and lactation can be maintained on special diets low in vitamin E.
Milk produced by cows on special diets low in vitamin E will usually
develop an oxidized (cardboard) flavor. The feeding of 50 to 100
units of vitamin E per cow per day is reported to substantially re-
duce the problem.
FORAGES IN BEEF PRODUCTION
W. M. WARREN
Department of Animal & Dairy Sciences
Agricultural Experiment Station
Auburn University, Alabama
Cow-calf operations are the basic unit of the beef industry and rely
on forages almost exclusively for the necessary nutrition. The utiliza-
tion of forages that cannot be consumed directly by man in the production
of a high quality food item represents a characteristic peculiar to the
beef industry and vital to man's food supply. An efficient utilization
of these forage nutrients, as well as concentrates, in the efficient
production of beef is essential.
If cow-calf operators are to stay in business, gross returns per
brood cow must be increased. Cattlemen will bankrupt selling weanling
calves for less than $100. Certain alternative management opportunities
are available to cattlemen in the Southeast that offer promise for in-
creasing gross income and a chance for profit. The aim of these programs
is to increase market weight and value through the efficient use of for-
ages, with or without supplements. Our combination of a mild climate and
adequate moisture makes this possible.
COOL SEASON GRAZING
Gains of 1.6 to nearly 2 pounds per day have been obtained over a
6-7 months grazing season with thriftly, well-bred beef steers on a for-
age combination of cereal grain, rye grass and clover. The market for
this 650-800 pound feeder steer is much stronger than for a 350 pound
stocker calf. Heavier stocker calves perform even better than light cal-
ves on such grazing and a high percent will carry Good and Choice slaugh-
ter finish at the end of grazing.
In a double cropping system, grazing rye following peanuts, stocker
calves gained 1.6 pounds daily for 136 days and weighed 640 pounds as
PERENNIAL FORAGE CROPS
Performance of stocker calves grazing cool-season perennial grasses
such as tall fescue or orchardgrass has averaged 180 to 200 pounds per
steer for the season, and beef gain per acre has averaged 320 to 360
pounds. Orchardgrass supported a higher average daily gain per steer than
fescue (1.80 vs. 1.35), but stocking rate was greater on fescue (2.0 vs.
1.5 steers per acre). Desirable weight feeder steers are produced on
Warm season grasses such as the bermudas, bahia, and dalliagrass
support a daily gain of about 1.2 lb. Stocking rate will vary with a-
mount of nitrate fertilizer applied, with Coastal or bahia supporting 2
to 3 steers per acre with heavy applications. Cattle grow at a reason-
able rate on such forages, but do not gain at a rapid enough rate to ob-
tain Good slaughter finish.
By supplying a high energy supplement to steers on Coastal in the
amount of 1.3 percent of body weight, gains of 1.9 pounds per day were
obtained and 35% of the steers produced Choice carcasses and the balance
Our studies show that beef from cattle finished on high quality graz-
ing is just as acceptable as that from comparable cattle fed out on tradi-
tional fattening rations.
Opportunities to increase body weight, value per steer and possible
net profit do exist. As the world demand for grain becomes more acute,
a greater use of forages in beef production may become essential. These
alternative managements systems have the potential to become a signifi-
cant economic factor in the Southeast and also produce vitally essential
food for humans.
SELF-FEEDING OF DAIRY CATTLE
S. P. MARSHALL AND H. H. VAN HORN
Department of Dairy Science
University of Florida, Gainesville
Self-feeding is defined as an arrangement whereby feed is made
available to cattle at all times allowing them to regulate intake.
Frequency of replenishing the feed supply may vary with conditions.
A modification of this concept frequently encountered is where a com-
plete feed, semi-complete feed or concentrate mixture is offered to
appetite twice daily at or following milking. Other feeds (pasture,
hay, concentrate etc.) may or may not be available additionally.
Self-feeding frequently is practiced with dairy cattle under condi-
tions where they are unable to consume nutrients in excess of the level
desired or acceptable. This condition prevails in high producing cows
and young calves. Self-feeding also has been practiced in wintering
Lactating cows of large breeds generally can consume enough energy
(depending upon ration) to support production of approximately 75 pounds
of milk per day. During the period of high production when cows need
about 3.2 to 3.5 pounds of dry matter daily per 100 pounds body weight
to meet requirements, self-feeding will help to achieve the needed feed
A feeding management problem that has been difficult to resolve
under practical conditions is to increase rapidly energy intake from
the prepartum level at calving to meet the rapidly rising postpartum
requirements as production sharply increases. Lagging energy intake or
inappetence resulting from overeating of concentrates have been frequent
problems during this period. Recent research (now in press) at Florida
and Cornell University indicate that self-feeding complete rations is an
improved method for resolving the problem. At Florida the cows were
self-fed a complete ration beginning about two weeks before calving and
continued for 8 weeks into lactation. Feed intake and production were
high. Both peaked in the 7th week of lactation with a dry matter in-
take of about 4% of body weight and milk production averaging 60 pounds
daily. Inappetence problems were few and about what one might antici-
pate on low roughage type rations fed at high intake levels.
At Cornell, cows were switched abruptly at 4 days in lactation from
self-fed low forage rations (95 or 80% forage ) to rations containing
either 60 or 40 percent forage (equal parts of corn and haycrop silage).
There were no adverse effects on animal health, feed intake or milk
production attributable to changes in rations and feeding programs. Out
of 72 cows two cases of "off feed" occurred 23 days after ration change
and one case of diarrhea occurred soon after the change.
At Florida, four calf starters were self-fed a ration which was
basically corn and soybean meal. Four different diets containing 15
and 30%, 15 and 0%, 0 and 30% and 0 and 0% cottonseed hulls and citrus
pulpjrespectively, were compared through 84 days of age. Calves on the
15% cottonseed hulls and 0% citrus pulp had consumed more feed and had
gained more body weight at 28, 56, and 83 days of age. In a second
experiment, corn-soybean meal rations containing 5, 15, and 25% cotton-
seed hulls were compared. Weight gains were not different for the
treatments but the animals tended to consume more ration as the level
of cottonseed hulls was increased. This suggests that the benefits
derived from the addition of 15 percent cottonseed hulls in the first
experiment could be obtained by a level as low as 5%.
Self-feeding dairy heifers complete rations containing about 80%
cottonseed hulls plus protein supplement, minerals and vitamins produced
about normal growth rate of a wintering program at North Carolina State
University. A self-fed ration of soybean hulls, vitamins and minerals
supported gains of 1.9 pounds daily which were slightly above normal
Thus, self feeding rations has the advantages of convenience,
reducing feeding costs, and improving animal performance in feeding
programs with high-producing cows and young calves where nutrient needs
equal or exceed intake free choice feeding. Nutrient intake in other
cattle can be regulated by adjusting the roughage-to-concentrate ratio
of the ration.
Making Maximum Use of Non-protein Nitrogen
Compounds in Animal Feeding
J. K. Loosli, Visiting Professor
Department of Animal Science
University of Florida, Gainesville
Many different non-protein compounds have been evaluated as replacements
for vegetable protein sources in ruminant diets. Urea is the one extensively
used in the U.S.A. at present because of its availability and lower cost
than other compounds. In spite of its extensive use, urea has some disadvantages
as a protein replacement. Its high solubility and rapid hydrolysis may result
in toxicity under some conditions, but restricting the intake and regulating
feeding management can easily avoid any harmful effects. Urea-containing feeds
may become unpalatible and lowered intakes may limit animal production.
Certain other compounds do not have these disadvantages. For example, biuret
(2 molecules of urea) and DUIB (2 molecules of urea plus one of isobutylaldehyde),
which has recently been developed in Europe, are less soluble than urea, lack
taste and are non-toxic. While both of these materials are useful, it remains
to be seen whether or not they can compete with urea. Combinations of urea
and a carbohydrate feed designed to slow down the rate of ammonia release have
shown promise of increasing urea utilization in some tests, but not always.
Ammoniation of various feeds has produced variable results and improvement
in utilization of NPN has not resulted consistently. Adding anhydrous ammonia to
corn at ensiling time has given favorable results with dairy cattle fed high
silage diets. The nitrogen appears to be less soluble than added urea and
the presence of corn grain and volatile fatty acids may favor ammonia utilization.
Liquid supplements of molasses and urea have increased in acceptance in
recent years because of both favorable price and convenience of use. This mixture
is a good carrier for minerals and vitamins for grazing cattle or when only poor
quality forage is fed. After reviewing the research, an FAO committee (1971)
reported that NPN supplements are useful to reduce weight losses of cattle during
periods of herbage shortage or low availability, but they cannot turn poor
roughage into good feed and thus do not provide substantial growth of young
cattle or milk yields of lactating cows. NPN is better utilized when high
roughage rations contain some starch or cereal grains than when molasses is
the sole source of carbohydrate. Both molasses and urea increase the intake
of poor quality forage. A recent study in Australia (Ernst et al., 1975)
showed that urea increased hay intake 14.6%. Molasses alone increased the
intake 27.8% and the combination resulted in a 65.4% increase. Urea alone or
with molasses also increased the digestibility of the hay. Of special interest
in Florida, is the observation that Brahman-Shorthorn cross steers consumed
20% more hay than straight Shorthorns and had equal digestibility.
There are a number of factors which favor the efficient utilization of NPN.
A lack of several mineral elements limit bacterial growth in the rumen, and
certain B vitamins are needed by some rumen bacteria. Thus insuring adequate
intake of these nutrients is important, and offering minerals free choice to
grazing cattle does not insure that each animal will satisfy its needs. Alfalfa-
urea pellets have given good utilization of NPN, but it remains a question
whether the minerals or some other factors are responsible.
The amount of NPN added to a ration needs to be regulated by the amount of
NPN naturally present in the feeds. In alfalfa hay, 12% of the nitrogen is NPN
compared to 44% in alfalfa silage. NPN accounts for 49% of the nitrogen in corn
silage and up to 71% in urea-treated corn silage. Some true protein must be
included in the ration of ruminants for best performance, and insoluble protein
which bypasses the rumen rather than being broken down by bacteria gives best
The high price and shortage of vegetable protein feeds in recent years has
greatly stimulated research to devise methods of further improving the amount
of NPN which can be efficiently utilized in ruminant rations and we can expect
to see further advances in the next few years.
There are a number of recent reviews of research on NPN (Elam, 1974; Helmer
and Bartly, 1971; Huber, 1975; Loosli and McDonald, 1968; N.A.S., 1975) and
new research is being published regularly (Kertz and Everett, 1975).
Elam, C. J. Sulfur requirement of ruminants. Proc. AFMA Nutrition Council
34th Semi-Annual meeting, Nov. 1974. (AFMA, 1701 Ft. Myer Drive, Arlington,
Va. 22209. FEEDSTUFFS.
Ernst, A. J., J. F. Limpus and P. K. Rourke, 1975. Effect of supplements of
molasses and urea on intake and digestibility of native pasture hay by
steers. Exptl. Agr. & Anim. Husb. 15:451-455.
F.A.O., 1971. The value of non-protein nitrogen for ruminants consuming poor
herbages. Kampala, Uganda.
Helmer, L. G. and E. E. Bartley, 1971. Progress in the utilization of urea as
a protein replacer for ruminants. A Review. J. Dairy Sci. 54:25-51.
Huber, J. T., 1975. Protein and non-protein nitrogen utilization in practical
dairy rations. J. Anim. Sci. 41:954-961.
Kertz, A. F. and J. P. Everett, Jr., 1975. Utilization of urea by lactating
cows-an industry viewpoint. J. Anim. Sci. 41:945-953.
Loosli, J. K. and I. W. McDonald, 1968. Non-protein nitrogen in the nutrition of
ruminants. FAO Agr. Studies No. 75. Rome.
N.A.S., 1975. Urea and other non-protein nitrogen compounds as protein nitrogen
replacements in Animal Nutrition. National Academy of Sciences. (In press).