Effects of CLA, Soybean Oil, and Used Soybean Oil from Fish Friers in Sheep Diets on Milk Lipids and Lamb Tissues

The use of omega fatty acids during pregnancy and lactation could be a beneficial strategy to improve health and production in ruminants. In this study, the effect of the dietary addition of c9, t11 and t10, c12 isomers of conjugated linoleic acid (CLA) in pure soybean oil (T1) was compared with pure soybean oil (T2) and soybean oil discarded after frying fish (Centropomus undecimalis, Pagrus pagrus, and Caranx crysos; T3) on the fatty acid profile in ewe milk and the tissues of their lambs. Forty-five multiparous ewes (East Friesian × Katahdin), 32 to 35 months old, 70 days pregnant, were randomly assigned to one of the three experimental diets. The fatty acid profile, total solids, fat, protein, and lactose in milk were determined 14 days postpartum. Fifteen lambs from each treatment were sacrificed at 70 days of age, and the fatty acid profiles in perirenal fat, muscle, and brain were determined. In milk, fat and total solids content were lower with T1. On the other hand, linoleic acid content, the sum of omega-6 and DHA were higher in T1 compared to other groups (p < 0.05). In the brain, stearic acid and linoleic acid concentration increased with T1; eicosapentaenoic acid decreased and omega-3s increased with T3, while DHA was lower in T2 (p < 0.05). The addition of CLA isomers or discarded soybean oil in ewe diet from pregnancy to lactation is advantageous for the ewe since less energy in the form of milk fat is lost. In addition, increasing the concentration of omega fatty acids in ewe diet to improve omega fatty acids in lamb’s brain could be a feed strategy to increase their productivity and health.