Performance of Steers and Rumen Fermentation as Influenced by Physical form of Ingredients and Alfalfa: Corn Ratio

Yearling steers previously wintered on pelleted alfalfa hay were fed finishing rations consisting of different pelleted alfalfa-to-cracked corn ratios. Comparable steers were fed finishing rations consisting of coarsely ground alfalfa hay fed with either cracked or pelleted corn and pelleted alfalfa hay fed with either cracked or pelleted corn. Gains increased as the level of coarsely cracked corn, fed with pelleted alfalfa hay, was increased from 0 to 75%. Carcass grade, dressing percent and fat thickness over the rib eye increased with increased levels of corn in the ration. Steers fed a ration with a 75:25 ratio of corn to alfalfa did not perform as well or consume as much feed when corn was pelleted as when cracked, regardless of the form in which alfalfa was fed. There was a nonsignificant increase in rumen propionate when the concentrate-to-roughage ratio was changed from 0:100 to 75:25 when all animals in the experiment were sampled only once. This became significant when two animals on each treatment were sampled repeatedly over an 8-hr, period. Increasing corn in the ration increased weight gain and narrowed the acetate to propionate ratio. Pelleting corn in the ration did not alter significantly the concentration of VFA in the rumen. In a second trial ground and long hay were fed with pelleted and cracked corn in all combinations to yearling steers. The feeding of pelleted corn significantly reduced corn consumption and animal performance. The physical form of hay did not influence significantly animal performance when fed with high levels of corn.