PubMed Health⌕ Search

Biomedical subjects

F R Murdock

Publications and source records attributed to F R Murdock.

4 recordsLinked to original sources
PubMed1984

Influence of prepartum dietary crude protein on growth hormone, insulin, reproduction, and lactation of dairy cows.

Effects of prepartum dietary crude protein on growth hormone, insulin in blood plasma, and subsequent reproduction and lactation were investigated in 30 Holsteins. Cows were fed either 80 or 100% of the crude protein recommended by National Research Council starting about 60 days precalving. Postcalving all animals were fed according to recommendations. Blood was sampled on days 220 (start of experiment), 250, 270, and 280 of gestation and on days 10 and 30 postpartum. Cows fed 80% crude protein prepartum showed decreased intake of dry matter and urea nitrogen in blood plasma prepartum, and yields of milk and total solids decreased by about 15%. Body weight changes through 30 days postpartum were not significantly different between treatments. There were no significant differences for growth hormone and insulin except growth hormone tended to be higher on day 270 of gestation for cows fed 80% crude protein. Insulin was negatively correlated with lactation number -5.1 to -5.6. Reproductive efficiency was similar between treatment groups. Lower crude protein intake during the dry period decreased dry matter intake and yields of milk and total solids.

Animals↗
PubMed1980

Fiber sources for complete calf starter rations.

Complete calf starter rations containing either 1) alfalfa hay, 2) cottonseed hulls, or 3) alfalfa-beet pulp as sources of fiber were fed to Holstein heifer calves at two locations on a limited milk program from 3 days to 12 wk of age. Rations were isonitrogenous and similar in content of crude fiber and acid detergent fiber. Although growth and development were normal on all rations, calves fed the cottonseed hull ration consumed more starter and gained more body weight than calves fed the other sources of fiber. The similarity of feed efficiencies, rumen pH, and molar ratios of volatile fatty acids between rations indicated no appreciable differences in rumen development or function. The growth response of calves fed the cottonseed hull ration appeared to be a result of better ration acceptability for which no reason was evident. Calves raised at Puyallup gained more body weight than calves at Pullman, and these gains were made more efficiently. These location effects may be related to seasonal differences and greater demands for production of body heat. Although the incidence of scours was less for calves fed alfalfa hay starter, the incidence and severity of bloat were higher for that ration.

Animal Feed↗
PubMed1977

Protein for calves on a limited milk-early weaning system.

Complete pelleted calf starter rations were fed to Holstein heifer calves on a limited milk-early weaning program from 3 days to 12 wk of age. Five rations fed to each of 10 calves were to contain crude protein percentages of 10, 12.5, 12.5 with 97% urea, 15, and 15 with 1.1% urea (as fed). The digestible protein:digestible energy ratios (g digestible protein/Mcal digestible energy) of the rations (in same order) were 23.4, 30.7, 28.8, 36.4, and 41.5. Average birth weight was 42.9 kg and weaning weight at 4 wk, 52.8 kg. Treatment effects on feed intake, average daily gain, and feed efficiency were analyzed after adjustment of birth weight and removal of effects of block and location. Feed intake for 12 wk was greater for 15% crude protein with 1.1% urea than for either 12.5% ration but not different from 10% protein. Average daily gain was increased for 15% protein rations compared to 10 or 12.5% protein. Gain by claves fed 10% protein was equal to that by those fed 12.5% protein. Feed efficiency during wk 5 to 12 was improved for 15% with vegetable protein compared to 10% crude protein or the 12.5% crude protein ration with vegetable protein. There were no differences in intake, gain, or efficiency between urea and vegetable protein.

Animal Feed↗