An Evaluation of the Lipoprotein Composition and Corresponding Apolipoproteins in the Newly Hatched Male and Female Broiler Chick from Two Different Age Flocks

Abstract

The purpose of this experiment was to investigate the effects of breeder flock age (30 vs. 39 weeks) and sex of the newly hatched chicks on lipoprotein composition and apolipoprotein AI (apoAI) and B (apoB) concentrations. Additionally, fast protein liquid chromatography (FPLC) was used to evaluate which lipoprotein fraction (VLDL vs. LDL vs. HDL) carried the bulk of cholesterol in newly hatched chicks. Other lipoproteins were separated by density gradient ultracentrifugation to determine their chemical composition. Serum apoAI and apoB were compared by density scanning of VLDL, IDL, LDL and HDL fractions from sequential ultracentrifugation spins. The lipoprotein profile and apolipoprotein concentrations were similar for all chicks, so samples were pooled across both sexes and age groups to strengthen the data. For the lipoproteins, VLDL had the highest level of triglycerides followed by IDL, whereas the LDL particles had the highest levels of cholesterol esters compared to all other fractions. After separating the lipoprotein particles by size (FPLC) it was determined that both LDL and HDL carried approximately equal levels of cholesterol. These data suggest that lipoproteins in newly hatched chicks are not effected by sex or flock age chosen. In addition, LDL and HDL cholesterol are carried equally in newly hatched chicks.

Liver Lipid Accumulation in Duck Embryos and Hatchlings Change with Parental Age¹

“…Additionally, the transfer of this gross energy to the developing duck embryo during incubation is more efficient. Increased breeder age was associated with increased percentage RYW and RLW, which was consistent with the findings of Latour et al [10] and Applegate et al [8].…”

The Circulating Levels of Lipoproteins in Embryos and Newly Hatched Ducklings Change with Parental Age¹

“…Interestingly, different lipoproteins predominate at different times during incubation and the early posthatch period. At hatch, cholesterol is carried equally between LDL and HDL particles [3], but by 3 days of age, HDL becomes the predominate carrier of circulating cholesterol [16]. Lazier et al [17] observed that the level of mRNA for ApoB, the primary protein of VLDL and LDL, increases in the vascular yolk sac membrane through incubation.…”

“…1.67. The sum of these components (PRO, TG, free cholesterol, CE, and PL) represents nearly 100% of the lipoprotein composition [3]. Hence, relative changes in these components within VLDL and LDL may provide some clues of their altered nature.…”

“…As the ApoB concentrations declined, apolipoprotein AI, the primary protein of highdensity lipoproteins (HDL) particles, increased. We [3] have previously determined that LDL and HDL particles from newly hatched chicks carry the bulk of plasma cholesterol (40% each), while VLDL particles only carry approximately 20% at hatch. The blood concentrations of HDL continue to rise and become the primary cholesterol carrier in broiler chicks by 5 days of age [3].…”