Conjugated linoleic acid (CLA) during last week of gestation and lactation alters colostrum and milk fat composition and performance of reproductive sows

The objectives of this experiment were to study the effect of dietary supplement of a commercial source of CLA, supplied either in the gestation/lactation period or during the post-weaning period, on sow and piglet performance and on the transfer of CLA into colostrum and milk. The experiment was designed to assess both the effect of dietary CLA supplementation to the sow in lactation and on the piglets in the nursery. There were four treatments for nursery piglets arranged factorially, two dietary treatments for origin sows (0 g/kg vs 10 g/kg CLA) and two treatments for weaned piglets (0 g/kg vs 10 g/kg CLA). Immediately after parturition, 10 mL of colostrum was collected from the functional glands of each sow. On day 23 after farrowing, milk samples were also collected. Lower backfat thickness was observed after 28 days of lactation in all groups, and the loss was higher for the control than CLA group (P<0.004). No effect of dietary treatment was observed for colostrum crude fat content, but a lower concentration of crude fat was observed in milk from sows fed the diet containing CLA (P<0.01). Feeding sows a CLA (10 g/kg) enriched diet during gestation and lactation increased the concentration of CLA and altered the concentration of fatty acids in colostrum and milk. Dietary CLA produced higher saturated fatty acids (SFA) and lower monounsaturated fatty acids (MUFA) concentration in all cases, but no alteration in total polyunsaturated fatty acids (PUFA) concentration. Dietary CLA had a positive influence on the C17:0 (P=0.007), C18:0, SFA, c9, t11 and t10, c12 proportions (P<0.001) and a negative effect on C16:1n-7 (P<0.001), MUFA (P<0.05), MUFA/SFA (P<0.01), C16:1n-7/C16:0 and C18:1n-9/C18:0 (P<0.001) ratios in the colostrum. Dietary CLA had a positive influence on the C14:0, C15:1, C16:0, C18:0, c9, t11, t10, c12, C20:0, C20:1, C20:5n-3 and SFA proportions (P<0.001) and a negative effect on C16:1n-9, C16:1n-7, C17:1, C18:1n-9, C20:4n-6, MUFA, MUFA/SFA, C16:1n-7/C16:0 and C18:1n-9/C18:0 (P<0.001) in milk. CLA administration to sows reduced backfat thickness loss during the lactation period and led to higher piglet weight at weaning. No effect of sow or piglet diet was observed on the main productive characteristics.