Rumen Development, Intestinal Growth and Hepatic Metabolism In The Pre- and Postweaning Ruminant

Both the role of intestinal development and the process of transitioning calves from their neonatal reliance on nutrients supplied from milk to nutrients supplied from grain are of substantial economic importance to the producer. Improvements to the calf nutritional regime can decrease mortality and disease susceptibility, increase postweaning rate of gain, ultimately enhancing the rate of herd genetic improvement (due to increased capacity for voluntary culling). Current feeding practices including daily encouragement to eat grain diets result in weaning from milk by 3 to 4 wk of age. Although the mechanisms are not yet completely understood, development of a viable fermentation within the rumen is required…