Effect of different vegetable oils fed to lactating ewes on milk and cheese fatty acid profile

Abstract

The aim of this study was to evaluate the effects of different vegetables oils fed to lactating ewes on milk and cheese fatty acid (FA) profile. After lambing, 48 Churra ewes were fed 2.1 kg of 40:60 (as-fed basis) lucerne:concentrate total mixed ration (TMR) daily and were milked twice a day. Ewes were assigned to 1 of 4 groups, which received 3% (as-fed basis) of the corresponding oil added daily to the TMR: hydrogenated palm oil (Con), olive oil (Oli), soybean oil (Soy) or linseed oil (Lin). On d 55 of lactation, 3 cheeses per treatment were made from the milk and samples of milk and cheeses were collected for FA analyses. The data were subjected to ANOVA according to a 2 (milk and cheese) by 4 (oils) factorial design using the MIXED procedure of SAS. Regardless the type of oil added to the diet, milk and cheese FA profiles were not different (P > 0.10). Cheese and milk samples from Con treatment had the greatest saturated FA (SFA) contents, but the least long chain FA (LCFA, > 18C), vaccenic (VA), and rumenic (RA) acid contents (P < 0.001). Milk and cheese from Soy treatment had the least SFA (P < 0.001), but the greatest VA, RA and linoleic acid contents and n6/n3 ratio (P < 0.001). Lin and Soy ewes produced milk and cheese with the greatest amount of polyunsaturated FA (P < 0.001). Olive oil supplementation increased oleic acid and decreased linoleic acid content (P < 0.001), whereas Lin gave raise to the greatest linolenic acid content and the least n6/n3 ratio (P < 0.001). From the results observed, it can be concluded that supplementing the diet of lactating ewes with oils is a suitable way of modulating naturally the FA profile of their milk and cheese.