Abstract
Effects of dietary protein level and addition of egg yolk on the growth and plasma lipids in rats were studied. Weanling male rats of Wistar strain were divided into 4 test groups: 10% casein (10C), 10% casein+0.6% dried egg yolk (10CE), 20% casein (20C), 20% casein+0.6% dried egg yolk (20CE). The diets were fed to the rats from 12 through 17 o'clock for 10 weeks.
There were no significant differences between 20C and 20CE in body weight, food intake, plasma cholesterol (Ch), HDL-Ch, plasma triacylglycerol (TG), plasma phospholipid (PL) and carcass compo-sition.
Body weight, food intake and carcass crude fat in 10CE were significantly higher than those in 10C. Carcass moisture in 10CE was significantly lower than that in 10C. Plasma TG in 10C and 10CE was significantly lower than that in 20C and 20CE. Plasma Ch and HDL2-Ch in 10CE were significantly higher than that in 20CE at the end of the 4th week, but at the end of the 8th week there were no differences among them.
Egg yolk and dietary protein levels had little effect on HDL3-Ch, plasma and HDL ester ratio, HDL-Ch/plasma Ch, plasma PL and carcass crude protein.
In conclusion, egg yolk was thought to have little or no effect when rats were fed the 20% casein diet; however, when rats were fed the 10% casein diet, addition of egg yolk caused rise in food intake and nutritional condition was presumed to be improved to some extent.
