Effect of Castration on Growth and Carcass Characteristics of Egyptian Local Baladi Goats and their Crosses with Alpine and Anglo-Nubian

Abstract

Fifty-three male Baladi kids (B) and Baladi crosses with Alpine (1/2 AL 1/2 B) and  Anglo-Nubian (1/2 AN 1/2 B and 3/4 AN 1/4 B) born at the farm of Animal production, Minia, Egypt, over a period of 2 years (1989 to 1990) were used. At four weeks of age male kids which represent the four mentioned genotypes were randomely distributed into three groups: the first was completely castrated, the second was partially castrated and the third group was left intact. Kids were weaned at 4 months and slaughtered at 12 months of age. Breed types of kids significantly (P < 0.05 and P < 0.01) affected body weights at 1  and 6 months of age, infavouring crossbred kids. But body weights at 12 months of age were not significantly different by breed type of kids. Baladi kids had insignificantly high value of body weight gain than those of crossbred kids during the period  from castration till slaughter. Castration had a significant effect (P < 0.01) on live body weight at 12 months of age and on body weight gain during the period from castration till slaughter, infavour of partially castrated animals. Breed type of kids showed non-significant effect on most carcass traits, while castration had a significant effect (P < 0.05 and P < 0.01) on most carcass traits. Partially  castrated animals had higher values of slaughter weight (S.W), carcass weight, percentages of non-visceral components and edible offals related to slaughter weights and  had lower values for both meat/bone ratio in carcass and percentage of visceral fat related to slaughter weight than those of other groups.  Baladi and 1/2 AN 1/2 B groups showed the highest percentage of prime cuts related to slaughter weight, but 1/2 AL 1/2 B and 3/4 AN 1/4 B had the lowest values. Castration had a significant effect on percentages of both neck and leg cuts related to carcass weight, where castrated animals showed highest percentage of prime cuts related to slaughter weight. Breed type of kids showed non-significant effect on both physical components and  chemical analysis of the 9-11th rib cut but castration showed a significant effect on  percentages of fat and moisture in 9-11th rib cut where complete castrated animals had higher value of fat and lower value of moisture in lean. Using partial castration procedure enhanced both growth performance and meat production and modified the amount of carcass fat. The carcass weight of male goat kids could be predicted from pre-slaughter live body measurements.