Conjugated linoleic acid (CLA) during gestation and lactation does not alter sow performance or body weight gain and adiposity in progeny

The objective of this study was to determine the long-term effects of conjugated linoleic acid (CLA) in pigs exposed to CLA during fetal and neonatal growth. Sows were fed a diet with 0.83% soy oil or 0.83% CLA-60 containing 60% active CLA isomers from either d 40 ( group 1; CON n = 8, CLA n = 6) or d 75 ( group 2; CON n = 8, CLA n = 8) of gestation through weaning on d 28. Within group 1, one male and one female piglet per litter ( CON n = 6, CLA n = 5) were sacrificed within 24 hours of birth ( d 0) and body weights recorded. Semitendinosus muscle, subcutaneous adipose tissue and organs, including heart, liver, lung, kidney, brain were weighed and tissue samples were frozen. Two average weight barrows and two gilts per litter were weaned and fed standard diets without added CLA until market weight. CLA did not alter sow's feed intake during gestation or lactation, body weight or backfat thickness, and litter size and weight at birth (P > 0.05). CLA decreased newborn pig heart, but not backfat or semitendinosus muscle weights relative to their body weights ( d 0). CLA decreased pre-weaning weight in selected piglets but this was not maintained post-weaning. CLA decreased total milk fat by 17% (P < 0.01) and resulted in an increase in the relative amount of saturated fatty acids and a decrease in the relative amount of unsaturated fatty acids in milk on d 21 of lactation ( P < 0.05). Decreases in growth rates until d 14 may be due to decreased fat in sow's milk since growth rate and body weight of selected progeny did not differ post-weaning. Serum from newborn CLA pigs suppressed relative preadipocyte number and did not change lipid filling in stromal-vascular cell cultures. The response to this serum was greater in females than in males (P-Diet = 0.04; P-Diet x Gender = 0.04). Thus, there do not seem to be any long-term effects on growth and body composition of market weight pigs given 0.5% CLA through weaning that would be beneficial in a production scheme.