Effects of Soybean Oil Or Rumen Protected Conjugated Linoleic Acid Supplementation on Accumulation of Conjugated Linoleic Acid in Dairy Cows' Milk (Report‪)‬

ABSTRACT : The effects of feeding soybean oil (SBO) or rumen protected conjugated linoleic acid (RP-CLA) on CLA accumulation in milk, and performance of lactating dairy cows were studied. Twenty four Holstein Friesian crossbred lactating dairy cows, averaging 126[+ or -]45 days in milk, 15.6[+ or -]2.43 kg of milk and 452[+ or -]51 kg body weight were stratified randomly and assigned in a randomized complete block design (RCBD) to three treatments of 8 cows each. The treatments were control, 150 g of SBO and 150 g of RP-CLA supplementation. Performance parameters showed that DM intake, NELP intake and body weight change were similar across treatments, while CP intake was decreased by SBO and RP-CLA supplementation. Milk yield and milk composition were not significantly different among treatments, except for milk fat percentage and fat yield which were significantly decreased by 27% (p0.05) and by 28% (p0.01), respectively, by RP-CLA supplements compared with control treatment. Feeding RP-CLA reduced 3.5% FCM compared with the other treatments (p0.003). Both SBO and RP-CLA supplementation reduced C16:0 fatty acids but increased [greater than or equal to] C18:0 and CLA concentration in milk fat. (Key Words : Conjugated Linoleic Acid, Rumen-protected Conjugated Linoleic Acid, Soybean Oil, Fatty Acid, Milk Production and Composition) INTRODUCTION