Effect of dietary cholesterol and genotype on cholesterol metabolism in roosters

An experiment, involving 32 roosters, was designed to study the interaction of dietary cholesterol and genotype on cholesterol metabolism in roosters. The two lines of birds used in this study had been divergently selected for high and low oxygen consumption and had been shown to differ significantly (P less than .01) in body weight gain and carcass lipid deposition from hatch to 4 weeks of age. The dietary treatments, administered for a 2-week period, were 0 and 1% dietary cholesterol added to a basal mash diet. Two separate trials were run, each with 16 roosters, resulting in four replicates of each treatment per line for each trial (block). After the trial period, the birds were injected with 1-(14)C-acetate and livers were removed; hepatic cholesterol synthesis was measured by the uptake of labeled acetate into liver digitonin precipitable sterols. Plasma and liver cholesterol levels were also measured. The data were analyzed as a randomized complete block design. Added dietary cholesterol significantly (P less than .01) increased both plasma and liver cholesterol levels over the control while significantly (P less than .01) decreasing the uptake of acetate into hepatic cholesterol in both lines by about 7-fold. Plasma cholesterol was significantly (P less than .05) greater in the high than low oxygen-consuming birds, and liver cholesterol was higher (P less than .10) in the low than high oxygen-consuming line.(ABSTRACT TRUNCATED AT 250 WORDS)