Response to abomasal infusion of XXXX of weaned dairy @entity291 fed a complete pelleted starter ration based on by-product feeds.

@entity1522 @entity1568 @entity2227 @entity2228 @entity535 @entity2734 @entity1853 @entity493 @entity563 @entity3505 @entity599 @entity291 @entity413
Three abomasal infusion trials were to determine the first-limiting @entity535 for @entity1568 retention of postweaned Holstein bull @entity291 fed a starter ration based on cereal by-product feeds. Ration ingredients contributed the following percentages of total @entity1522 : @entity3505 middlings 38, brewer's grains 24, hominy feed 21, oat hulls 10, distiller's grains 6, and molasses 1. Dry matter of the pelleted ration contained 13 to 14% crude protein and .23 to .26% @entity599 . Each trial was a replicated 4 x 4 Latin square with 9-day periods. @entity291 were weaned at 4 wk and infusions initiated at 5 to 6 wk of age. Abomasal infusion of the 10 essential @entity1522 , an isonitrogenous quantity of an equimolar mixture of @entity493 , @entity2734 , @entity2227 , @entity2228 , and @entity563 , or an isocaloric quantity of @entity413 indicated that essential @entity535 (s) rather than nonspecific @entity1568 or energy was limiting protein synthesis. Quadratic responses in urine @entity1568 excretion and retained @entity1568 occurred when 0, .3, .6, and 1.2 g @entity1853 /kg starter ration were infused. Greatest responses occurred with .6 g @entity1853 , which increased retained @entity1568 11 and 19% and decreased urine @entity1568 7 and 10%. The relationship between infused @entity1853 and plasma @entity1853 was linear. Infusions in all trials had no effect on digestibility of energy and @entity1568 .
