Effects of lipid encapsulated conjugated linoleic acid (CLA) supplements on lipid metabolism in lactating ewes | Ucinki lipidno enkapsuliranih konjugiranih linolno-kislinskih (cla) dodatkov na presnovo lipidov pri dojecih ovcah

Several studies have proved that trans-10, cis-12 CLA isomer can induce milk fat depression. In lactating ruminants the administration of a supplement containing this isomer can be used as a tool to manipulate milk fat synthesis for reducing negative energy balance in the critical peripartal period. More studies have been performed with dairy cows, however, only few data are published with dairy sheep. The objective of this study was to investigate the effect of a rumen protected form of conjugated linoleic acid (pCLA) supplement on milk and liver lipid content as well as the fatty acid composition of milk and liver lipid in lactating sheep. The animals were divided into two groups. Diet of sheep in the pCLA group was supplemented with CLA product (equal proportions of cis-9, trans-11 and trans-10, cis-12 isomers) on the other hand the animals in control group were fed an isocaloric diet supplemented: hydrogenated triglyceride of palm oil (HTG). In pCLA group we could measure lower total lipid (72.6+/-5.6 vs. 82.0+/-6.0) and triglyceride (49.1+/-5.9 vs. 60.9+/-5.7) concentrations in the liver samples than in the HTG group in the peripartal period (d 21 postpartum). Further more we detected higher milk production (1.89+/-0.13 vs. 1.73+/-0.25 kg/d) and milk protein yield (96.2+/-8.7 vs. 84.9+/-10.2 g/d) lower milk fat content (56.8+/-6.2 vs. 62.7+/-7.1 g/kg) in the pCLA group. Also the CLA supplementation influenced significantly the fatty acid profile in milk and liver lipid. The CLA isomers (cis-9, trans-11 and trans-10, cis-12 C18:2) were increased by CLA supplementation in the milk lipid. In addition, the pCLA resulted in higher proportions of C18:0, cis-9, trans-11 C18:2 and trans-10, cis-12 C18:2 fatty acids and lower cis-9 C18:1 in the liver lipid comparing to HTG. We concluded that pCLA supplementation could decrease the risk of lipid accumulation in the liver of high-lactating dairy ewes in the postpartum period as well as increased the cis-9, trans-11 CLA content of milk lipids; which might have several healthy effects on human consuming sheep milk or milk products.