Assessment of an in-situ technique to estimate the degradation of lipids in the rumen

✍ Scribed by Rosine Perrier; Brigitte Michalet-Doreau; Dominique Bauchart; Michel Doreau

• Book ID: 102924086
• Publisher: John Wiley and Sons
• Year: 1992
• Tongue: English
• Weight: 541 KB
• Volume: 59
• Category: Article
• ISSN: 0022-5142
• DOI: 10.1002/jsfa.2740590404

✦ Synopsis

Abstract

In‐situ disappearance of alfalfa hay, soybean, soybean meal and maize grain lipids and fatty acids were measured using two dairy cows. Bags were removed after 1, 2, 4 and 8 h incubation. Bacterial colonisation was estimated by labelling bacteria by a ^15^N infusion into the rumen. Results were then subtracted from calculations. Bacterial dry matter, lipids and fatty acids were highest for alfalfa hay and lowest for soybean. Disappearance of lipids and fatty acids was significantly higher for maize than for the other feeds. Stearic and octadecenoic acids appeared in hay and soybean as products of hydrogenation but no distinction could be made between fatty acids leaving the bags and fatty acids appearing or disappearing due to hydrogenation. Complete linolenic acid hydrogenation seems to be limited by the rate of hydrogenation of stearic acid into octadecenoic acids. Nylon bags seem to be a valuable tool to estimate hydrogenation or protection against hydrogenation in high linolenic content feeds.