Effects of conjugated linoleic acid. 1. Fatty acid modification of yolks and neonatal fatty acid metabolism

The purpose of this study was to evaluate the effects of conjugated linolei c acids (CLA) on neonatal fatty acid metabolism. In this study, layer hens (n = 40) were divided into four equal groups and subjected to the following treatments. Group A served as the control group, Group B received 1 g CLA every other day, Group C received 1 g CLA every 4th d, and Group D was sham -supplemented with 1 g safflower oil every other day. After 4 mo of feeding , Group B hens exhibited an increase in BW and egg size; however, there wer e no differences noted in feed consumption among the various treatment grou ps. At the same time, hens were inseminated with a constant dose of pooled rooster semen to evaluate changes in chick liver and yolk fatty acid metabo lism during neonatal growth. At hatch and through 6 d of age, there were no significant differences in breakout data (fertility and numbers of early-, mid-, or late-dead chicks) or chick BW, respectively. However, Group B chi cks exhibited an increase in liver 18:3n3 and 22:1n9 and a decrease in 20:3 n6 and 22:5n3 fatty acids when compared with chicks from Groups A and D. Al so noted for Group B chicks, yolk 18:0 fatty acid was higher than that for Group A and D chicks. These results suggest that CLA alters lipid metabolis m in growing chicks.