One thousand and eighty-five newly received, stressed calves were used in studies to determine the effectiveness of certain mass medication procedures for reducing morbidity from shipping fever-bovine respiratory disease complex. In two experiments, im injections of oxytetracycline at 11 mg/kg body wt for 3 successive days reduced treatment days/calf purchased 21 (P<.05) and 31% (P<.05). Oral administration of 150 mg of sulfadimethoxine/kg body wt reduced treatment days/calf purchased 20 (P<.05) and 54% (P<.05) in the same two experiments. When sulfadimethoxine followed oxytetracycline on the third injection day an 81% reduction in treatment days/calf purchased was obtained, indicating an additive effect of the two drugs. The use of long acting oxytetracycline and sustained release sulfadimethoxine at the time of processing resulted in a 90% reduction in treatment days/calf purchased (P<.01) and required only one handling of the calves for mass medication purposes.
ABSTRACT BEEF cattle with an initial weight of about 600 lb (270 kg) fed a high energy ration were maintained at constant air temperatures of 20.3, 24.1 or 29.3 C for 84 days. There was a significant depression in feed intake and rate of gain at 29.3 C compared to 20.3 C. A similar test at air temperatures of 21.1, 16.4 and 12.4 C showed significant differences in rate of gain at the three temperatures with a decline with lowering temperature. This change and the accompanying change in feed efficiency does not seem to be explained by changes in thermal environment and the reason remains unclear.
Foram realizados experimentos para determinar a resposta de crescimento do gado Zebu e Holandes aos olhos de cana frescos ou ensilados suplementados e nao suplementados. Os suplementos estudados foram o melaco, mandioca e farelo de algodao. Os ganhos de peso do gado alimentado com silagem sem suplemento foram significativamente mais baixos do que os que se alimentaram com olhos de cana frescos sem suplemento. Os dados sobre a utilizacao da energia, contudo, indicaram que o problema ligava-se a palatalidade e nao a utilizacao do nutriente. Os olhos de cana frescos apenas, mantiveram o peso corporal, enquanto que o gado recebendo silagem perdeu peso. Nem o melaco, nem as raizes de mandioca fornecidos na dose de 0,5 kg por 100 kg de peso corporal tiveram qualquer efeito estimulante como suplemento dos olhos de cana. O farelo de algodao, por sua vez, causou um estimulo de 0,78 kg por cabeca e por dia, quando fornecido na mesma dose. Os valores de energia liquida para manutencao e producao foram determinados para os olhos de cana e para o farelo de algodao por uma tecnica comparativa de abate, usando a gravidade especifica das carcacas de um grupo inicial servido como amostra, sendo todos os animais abatidos no fim do estudo. A energia liquida para a manutencao dos olhos de cana, tanto frescos como ensilados foi 1,04 megcal por kg de materia seca, enquanto que a energia liquida para a producao foi 0,46 megcal por kg de materia seca. Os valores correspondentes para o farelo de algodao foram 1,62 e 1,27 megcal por kg de materia seca. Dessa forma, para manutencao os olhos de cana valeram 64% de farelo de algodao como uma fonte de energia, mas para a producao, os olhos de cana valeram apenas 36% do valor do farelo de algodao.
Feed consumption and weight gains of yearling cattle transported from Florida to New Mexico were determined on three receiving diets. Rates of gain achieved during a 28-d receiving period and 14-d transition period were related to gains made during the following 190-d finishing period. Cattle received on 50% or 75% concentrate diets for 4 wk plus grass hay for the first wk then 75% concentrates for 14 d, gained 34 kg more weight than cattle fed grass hay alone for 4 wk then 75% concentrates for 14 d (P◄.01). When all cattle were fed an 85% concentrate diet for 190 d, those previously fed hay alone made 14 kg of compensatory gain, but still lacked 20 kg of making equal gains to those received on 75% concentrates, and lacked 17 kg of making equal gains to those received on 50% concentrates. This indicates that receiving diets for stressed yearling cattle should contain from 50% to 75% concentrates because much of the weight gain advantage achieved during receiving will be maintained during finishing.
1. A total of sixty-three wether lambs, 4–6 months old, were fed on diets low in phosphorus and adequate in calcium (0.072–0.073% P, 0.38–0.40% Ca) or adequate in both (0.38–0.40% P, 0.40% Ca) for 134 or 142 days. 2. Concentrations of serum inorganic P and Ca and alkaline phosphatase activity were studied during the depletion period. Bones were taken for histological analysis at the end of the 142 days. 3. After the preliminary depletion period, a metabolism study was conducted in which the effects of previous P depletion and dietary Ca:P ratio upon Ca and P absorption, as measured by isotope techniques, were studied. 4. Histological analysis of bones showed the presence of lesions characteristic of late rickets in some sheep and of severe osteoporosis in others. 5. A wide dietary Ca:P ratio had no apparent effect on P absorption when P intake was adequate. The availability of P was lowered by a diet deficient in P with a wide Ca:P ratio. 6. Previous P depletion resulted in enhanced P absorption during the first 11.5 days after an increased intake of P, but this effect was not shown during days 14–21 after the increase. 7. Ca absorption was reduced by giving a diet low in P and was increased when the intake of P was raised. 8. The response to wide dietary Ca:P ratios by ruminants and non-ruminants is reviewed, and a hypothesis, based upon a knowledge of the intestinal reaction of these species, is offered for the finding that ruminants tolerate wider dietary Ca:P ratios than non-ruminant species.
A study on the time of concentrate supplementation to rations made up of maximum amounts of alfalfa hay or alfalfa soilage indicated that a continuous supplement of barley and beet pulp was superior to a supplement fed only the second half of the feeding period. Although daily gains were not stimulated, the dressing percent and carcass grades were improved. Evidence is presented showing the gains made by the steers being continuously supplemented contained more energy than the gains of the other groups. A second study indicated that the level of continuous barley and beet pulp supplementation to alfalfa soilage should amount to approximately 0.7 lb. per 100 lb. body weight. This level did not significantly stimulate daily gains above 0.5 lb. per 100 lb. body weight but increased the dressing percent and carcass grade. Evidence is presented showing that this level increased the energy content of the gain, although not significantly increasing the gain. The data presented emphasize the danger of misinterpretation of the results of feeding trials based solely on weight gain and feed consumption. The estimated NE in megacal. per pound of TDN varied from an average of 0.79 for roughage alone to 0.93 for rations averaging 68% roughage and 32% barley and beet pulp.
Three-hundred-ninety-five calves subjected to the stresses of marketing and shipping were used to test various energy levels in receiving rations. Rations containing 38, 46, 50 and 54 megcal of NEg per 100 lb (.84, 1.01, 1.10 and 1.19 megcal per kilogram) were compared. The rations contained 20, 55, 72 and 90% concentrates. Performance improved with increasing concentrate or energy level until the 72% level was reached. Calves fed the 90% concentrate level were slower starting than those fed the 72% ration although after the first week the performance was good. Because of the disease stress the first week, the 90% ration is not recommended. The majority of the first treatments of sick calves occurred during the first 7 days following arrival. When receiving calves on the 72% concentrate ration, no advantage was found in providing free access to long stem alfalfa hay.
