Elsevier

Journal of Dairy Science

Volume 81, Issue 8, August 1998, Pages 2215-2220
Journal of Dairy Science

Article
Effect of Ruminally Protected Amino Acids on Milk Yield and Composition of Jersey Cows Fed Whole Cottonseed1

https://doi.org/10.3168/jds.S0022-0302(98)75800-XGet rights and content
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Abstract

The objectives of this experiment were to determine whether ruminally protected amino acids (AA) increased milk protein when this content was depressed by the addition of whole cottonseeds in the diets of early lactation Jersey cows. Treatments were 1) a control diet, 2) a diet containing whole cottonseed, and 3) a diet containing whole cottonseed and ruminally protected lysine and methionine. Cows were assigned to treatments at a mean of 7 d postpartum and remained on the experiment for 18 wk. Dry matter intake and yields of milk, milk fat, fat-corrected milk, and energy-corrected milk were not affected by treatment. Milk fat content tended to decrease for cows fed diets containing whole cottonseed. However, the percentages of milk protein, total N, and casein N were depressed by the addition of whole cottonseed and were increased by the addition of ruminally protected AA. Plasma concentrations of methionine, but not lysine, were increased when ruminally protected AA were fed, suggesting that lysine was the most limiting.

Key words

dairy
whole cottonseed
ruminally protected amino acids
fat

Abbreviation key

RPAA
ruminally protected AA
WCS
whole cottonseed

Cited by (0)

1

Technical Contribution Number 4237 of the South Carolina Agricultural Experiment Station.

2

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