PSVI-15 - Effects of Different Dietary Sources of Lipids for Lactating Ewes

Abstract: The aim of this study was to evaluate the effects of diets with fatty acid profiles on lactation performance and milk composition of ewes.Dorper vs. Santa Inês ewes (n=40; 54.9 ± 8.3 kg BW and 14 days in milk) were penned individually and used in a randomized complete block design. Ewes were fed a basal diet (19.87 ± 0.62% CP) containing 70% concentrate and 30% coastcross hay, and no added oil (CON). The remaining diets were added with 4.0% of soybean oil (SO), calcium salts of palm fatty acids (CSPF), or calcium salts of soybean fatty acids (CSSF) (DM basis). Ewes were fed the diets from the week 2 to 10 of lactation. Milk production was determined every 7 days during the experiment. Ewes were separated from their lambs and mechanically milked for emptying of the mammary gland. After 3 hours, using the same procedure, milk production was recorded and samples collected for milk composition analysis. The addition of SO decreased (P< 0.001) DM intake, with no difference between the other treatments. Milk production, as well as the production of fat, protein, lactose and total solids (g/3 hours) were not affected by the treatments. Regarding milk composition, the percentage of milk fat and total solids increased (P< 0.0001) with CSSF. The percentage of protein was less (P< 0.001) in the milk from ewes that received the diet containing CSPF, with no difference between the other diets. Finally, the percentage of lactose was less (P< 0.001) for ewes fed the diet containing calcium salts of palm fatty acids. In conclusion, soybean oil had the greatest negative effect on dry matter intake. All the oil sources modulated the milk composition, with better results in this regard for the calcium salts of palm fatty acids, considering that it increased the fat and total solids content of the milk.