ABSTRACT A study was conducted to investigate the influence of breed and sex in the gross anatomy, digesta and histology of Ross 308 broiler and Venda chickens. Chickens were slaughtered at 90 days of age and the pH of the digestive organs was measured immediately after slaughter. The digestive organ weights and lengths of Ross 308 broiler and Venda chickens were measured. Tissue samples of the duodenum, ileum and jejunal from each treatment group were collected and histologically examined. Higher (p<0.05) gizzard pH values were observed in male and female of Ross 308 broiler and Venda chickens. The jejunal and ileal pH values were lower (p<0.05) for Venda chickens than in Ross 308 broiler chickens. The absolute weights of the gastrointestinal tract, crop, proventriculus and gizzard were lighter (p<0.05) in Venda chickens than in Ross 308 broiler chickens. The relative organ weights of the GIT, proventriculus, gizzard and caeca were higher (p<0.05) in Venda chickens than in Ross 308 broiler chickens aged 90 days. Male chickens had higher (p<0.05) relative organ weights than female chickens. Interactions between breed and sex influenced (p<0.05) the absolute weights of the crop, proventriculus, caeca and large intestine. Ileum villus heights of female Venda chickens were higher (p<0.05) than those of female and male Ross 308 broiler and Venda chickens. The male and female Ross 308 broiler chickens had higher (p<0.05) ileum and duodenum crypt depths than male and female Venda chickens. The duodenum and ileum villus height/crypt depth ratios were higher (p<0.05) in male and female Venda chickens than Ross 308 broiler chickens. In overall, male broiler chicken performed better.

A study was conducted to determine the effect of egg weight on hatchability, chick hatch-weight, mortality and subsequent productivity of indigenous Venda chickens. Three hundred and sixty indigenous Venda chicken eggs were collected for a period of a week and selection was done based on the weight of the eggs. A complete randomized design was used, with four treatment weights, each with 90 eggs. The four treatment weights were as follows: below 49 g, between 50 and 59 g, between 60 and 69 g, and above 70 g. Egg weight was positively and strongly correlated with egg hatchability (r² = 0.727) and chick hatch-weight (r² = 0.953). Heavier-sized eggs hatched chicks had higher mortality rates. Growth rate and live weight of the chickens were optimized at different egg weig hts of 56 (r² = 0.657) and 60 (r² = 0.870) g, respectively, for chickens aged 1 to 7 weeks, and egg weig hts of 61 g (r² = 0.514) and 60 g (r² = 0.948), respectively, for chickens aged 8 to 13 weeks. It is concluded that indigenous Venda chicken egg weight affects hatchability, hatch-weight, mortality and subsequent productivity of the chickens. It is concluded that production variables were optimized at different egg weights. This means that the selection of eggs for incubation will depend on the parameter in question.