Correlations between breeder age, egg cholesterol content, blood cholesterol level and hatchability of broiler breeders

1. The research was carried out to investigate correlations between breeder age, egg cholesterol content, blood cholesterol level and hatchability of broiler breeders. 2. Egg cholesterol content increased with increased breeder age. The mean yolk cholesterol contents (mg per g yolk) were 10.47+/-0.28, 15.34+/-0.65 and 15.64+/-0.71 mg/g at 28, 45 and 65 weeks of age, respectively. 3. There were positive correlations between yolk weight and yolk cholesterol content (mg/g yolk) (r=01.941; P<0.01) and egg cholesterol content (mg/egg) (r=0.980; P<0.01). 4. Negative correlations were found between egg yolk cholesterol content and hatchability of fertile eggs (r=-0.345; P<0.05), fertility ratio (r=-0.609; P<0.01) and hatchability of total eggs (r=-0.574; P<0.01). 5. The mean blood cholesterol levels were 165.1+/-11.04, 166.5+/-11.97 and 179.5+/-11.33 mg/dl at 28, 45 and 65 weeks of age, respectively.

The relationship between yolk cholesterol and total lipid concentration throughout the first year of egg production in the domestic fowl

1. Variation of egg yolk cholesterol and total lipid concentration (mg/g wet yolk) throughout the first year of egg production for the domestic fowl is described. 2. Yolk cholesterol concentration decreases between 20 and 30 weeks of age, and then remains constant until 70 weeks of age. Yolk total lipid concentration increases to a maximum at 40 weeks of age before decreasing to its original value at 60 and 70 weeks of age. 3. Bird means for yolk cholesterol and total lipid concentration are negatively related at 20 weeks of age, and essentially independent for the remainder of the first year of egg production. 4. Variation for yolk cholesterol concentration between 30 and 70 weeks of age appears to be a consequence of differences in the proportion of cholesterol to other lipid components. 5. Uptake of plasma lipoproteins characteristic of the immature bird is likely to be responsible for the high yolk cholesterol concentration at 20 weeks of age.

Cholesterol content in market hen eggs

The yolk cholesterol content in eggs of White Hisex laying hybrid from 3 specialized commercial farms averaged 1230, 1330 and 1230 mg/100 g of yolk over an 11-months laying period, i.e. 303, 304 and 309 mg cholesterol/100 g of consumable egg portions. In testing Babcock B-380, Moravia SSL, Shaver Starcross 288, and Hisex HX-1, the av. cholesterol content varied from 1200 to 1360 mg/100 g of yolk or from 372 to 444 mg/100 g of consumable egg portions. Throughout the egg-laying period, the yolk cholesterol content fluctuated rather irregularly and showed great variability (variation coefficient 9.7-18.2%). The values recorded failed to follow any of the common functions of the trend. Intensive market egg production was found to be associated with decreases in yolk cholesterol content.