Breed and sex differences in body composition of sheep in relation to maturity and growth rate

Abstract

SUMMARYTwenty-four lambs (equally representing males and females), born in December 1986, were obtained from each of the Najdi, Awassi and Hejazi sheep breeds kept at the Experimental Station of King Faisal University in Saudi Arabia. The lambs were reared on their dams and fed after weaning on the same diet up to slaughter at 9 months of age. Slaughter and carcass data were analysed for breed and sex differences using the degree of body maturity and growth rate as covariates. After the effects of differences in body maturity and growth rate were removed, significant breed but not sex effects were recorded in skin, feet, carcass and carcass to bone proportions. In Najdi lambs the feet and bone nproportions (g/kg empty body weight) were higher than in Awassi or Hejazi lambs, whereas Awassi lambs possessed lower carcass but higher skin proportions than the other two native breeds.Breed but not sex affected fat distribution. Awassi lambs had higher tail but lower intermuscular fat content (g/kg total body fat) than Najdi or Hejazi lambs. Most body components were significantly related to the degree of body maturity but not to growth rate.