The present study was designed to investigate the effects of conjugated lin
oleic acid (CLA) on yolk usage and circulating very low density lipoprotein
s (VLDL) during incubation (Day 15) and through 6 d posthatch. Eggs enriche
d with CLA were obtained from hens subjected to the following treatments. G
roup A hens served as the control group, Group B hens received 1 g CLA ever
y other day, Group C hens received 1 g CLA every 4th d, and Group D hens we
re sham-supplemented with 1 g safflower oil every other day. Enrichment wit
h CLA did not effect fertility, hatch of fertile, BW, or yolk-free BW of em
bryos or chicks. However, there were significant changes in relative yolk s
ac weight (RYW) and composition of circulating VLDL particles. Across all d
ietary treatments (Groups B, C, and D), 15-d embryos had smaller RYW compar
ed with Group A embryos; this difference remained through 2 d posthatch. Du
ring that period (15 d of incubation through 2 d posthatch), however, embry
os and chicks from Group B hens exhibited a unique absorption pattern such
that little to no yolk was utilized between hatch and 2 d posthatch, a peri
od normally characterized by high yolk-lipid utilization. Similar to the RY
W effects, VLDL particles were also altered by hen-induced treatment. Speci
fically, at hatch, chicks from Group A hens had the highest percentage of t
riglycerides (TG) within their VLDL particles compared with chicks from hen
s under all other treatments. This trend in VLDL particles was continued at
4 d posthatch. The present study demonstrates that CLA enrichment of eggs
alters relative yolk sac absorption and the composition of circulating VLDL
particles.