Influence of protein degradability and evaporative cooling on performance of lactating cows during hot environmental temperatures
AuthorTaylor, Ronald Brian, 1962-
Cattle -- Feeding and feeds -- Climatic factors.
AdvisorHuber, J. Tal
MetadataShow full item record
PublisherThe University of Arizona.
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AbstractTwo trials were conducted to determine the effect of protein degradability (low (LD) vs high (HD)) and evaporative cooling (shade cooling vs shade) on performance of 60 lactating Holstein cows in mid-lactation. Cooling and the LD diet increased milk production, 3.5% FCM and feed efficiency in trial 1 (24 cows) while in trial 2 (36 cows) LD diet increased milk production and feed efficiency and cooling did not exert a significant effect. Differences between trials were probably due to higher environmental temperature humidity indexes (77.0 vs 72.0), and a higher quality of the rumen bypass protein in the LD diet in trial 2 than trial 1. Cooling reduced respiration rates in trial 1 and respiration rates, rectal and inner ear temperatures in trial 2. Eating patterns were unaffected by protein degradability or cooling.
Degree ProgramGraduate College