Effect of contact with male on the physical and chemical qualities of eggs of black harco layers

Abstract

A group of 30 Black HARCO laying hers were reared together with 3 mature cocks, while another group were reared in an adjacent pen without cocks. Thus, while the first group of hens had full physical contact (including mating) with the males, the second group was restricted only to auditory and visual contacts with the males. Twelve eggs were selected at 2 - weekly interval within a 12 - week period from each group and chemically analyzed for total protein, cholesterol in the yolk were determined by colourimetric methods while the shell calcium concentration was determined by a litrumetric method. Egg yolk cholesterol was higher (P<0.05) in hens exposed to full physical contact with the males (16.78 vs 14.20 mg/ml) whereas egg yolk protein, albumen protein and egg shell calcium concentrations were not significantly different (P>0.05) between the 2 groups. Egg weight, egg components weights and hen day egg production were also lower in those hens exposed to full contact with the males. Physical contacts (including mating) between the cock and hen resulted in higher yolk cholesterol and lower physical qualities of eggs produced under such management system.