Ruminant Nutrition: Dairy--Fats.

The article presents abstracts of various papers related to animal nutrition that were presented during the symposium held on July 27, 2005 in Cincinnati, Ohio, which was organized by the American Dairy Science Association, the American Society of Animal Science, and the Canadian Society of Animal Science. One of the papers discussed is "Fatty Acid Composition in Rumen Bacteria Isolated From Ruminal and Duodenal Digesta," by B. Vlaeminck, R.J. Dewhurst, and V. Fievez. The objective of this study was to compare the fatty acid composition in rumen bacteria isolated from the liquid and solid phase of the rumen and duodenal digesta from dairy cows fed diets varying in forage:concentrate. Another paper discussed is "Development of an In Vitro Method to Estimate Fat Digestibility in the Small Intestine of Ruminants," by T. Glindemann, K.H. Suedekum and E. Wisker. Supplementation of dairy cow diets with rumen-protected fat (RPF) has consistently increased yields of milk and milk fat, and may also improve reproductive performance of ruminants. Although one important feature of the effects of RPF is digestibility in the small intestine, this variable is only very infrequently reported. The objective of the current study was therefore to develop an in vitro method to estimate the digestibility of fats in the small intestine of ruminants by closely mimicking the chemical and physical conditions within the small intestine.