Enrichment of Ewe’s Milk with Dietary n-3 Fatty Acids from Palm, Linseed and Algae Oils in Isoenergetic Rations

SIMPLE SUMMARY: The aim of this research was to evaluate the effects of three lipid supplements in ovine diets on milk healthy fatty acid composition. Rations provided a source of α-linolenic acid, either protected or unprotected from ruminal biohydrogenation (linseed oil and Ca-salts of linseed oil) or long-chain n-3 fatty acids (algae oil). Algae oil supplementation generated the highest levels of n-3 fatty acids in ewe’s milk. However, dry matter intake, milk yield and fat content declined with the inclusion of algae oil in the diet. The fatty acid profiles of milk from both linseed oil supplemented rations did not significantly differ, and both were effective to diminish saturated fatty acids. ABSTRACT: Increasing the levels of n-3 fatty acids (FA) in dairy products is an important goal in terms of enhancing the nutritional value of these foods for the consumer. The purpose of this research was to evaluate the effects of linseed and algae oil supplements in ovine isoenergetic diets on healthy milk fatty acid composition, mainly n-3. Seventy-two Churra dairy ewes were divided and randomly assigned to four experimental treatments for 6 weeks. The treatments consisted of a TMR (40:60 forage:concentrate ratio) that varied according to the inclusion of different types of fat (23 g/100 g TMR): hydrogenated palm oil (control), linseed oil (LO), calcium soap of linseed oil (CaS-LO) and marine algae oil (AO). The most effective lipid supplement to increase n-3 FA in milk was AO. 22:6 n-3 and total n-3 PUFA content increased from 0.02 and 0.60% (control) to 2.63 and 3.53% (AO), respectively. All diets supplemented with n-3 FA diminished the content of saturated FA in milk and its atherogenic index, while the levels of trans-11 18:1 and cis-9 trans-11 18:2 significantly increased. Overall, the enhancement of n-3 FA in ewe’s milk would be advantageous for the manufacture of nutritionally improved cheeses.