Effects of replacing maized meal with a low tannin white sorghum meal, macia on productivity of ross 308 broiler chickens

Thesis (M. Sc. Agriculture (Animal Production)) -- University of Limpopo, 2018

Two experiments were conducted to determine the effect of replacing maize meal with a low tannin sorghum meal (Macia) on productivity, gut morphology, carcass characteristics and bone morphometrics of Ross 308 broiler chickens aged one to 42 days. In each experiment, a total of 160 Ross 308 broiler chickens were assigned to a complete randomized design with 5 treatments, replicated 4 times with 8 chickens per replicate. Five diets were formulated to contain sorghum replacement levels at 0, 25, 50, 75 and 100% to meet the nutrient requirements of Ross 308 broiler chickens. Data was analysed using statistical analysis of variance. The first experiment determined the effect of replacing maize meal with a low tannin white sorghum meal on productivity and gut morphology of unsexed Ross 308 broiler chickens aged 1 to 21 days. Feed intake, growth rate, feed conversion ratio, live weight, N-retention, caecum and large intestine digesta pH, large intestine lengths, crop, gizzard, caecum and large intestine weights, gut intestinal villi height, crypt depth and villi height to crypt depth ratio of unsexed Ross 308 broiler chickens were not affected (P>0.05) by the treatment effects. However, replacement of maize meal with sorghum meal improved (P<0.05) metabolisable energy intake and small intestine digesta pH values. It was concluded that maize meal can be replaced by a low tannin white sorghum meal in the diet without adverse effects on unsexed Ross 308 broiler chickens aged one to 21 days. The second experiment determined the effect of replacing maize meal with sorghum meal on productivity, gut morphology, carcass characteristics and bone morphometrics of Ross 308 male broiler chickens aged 22 to 42 days. Replacing maize meal with sorghum meal had no effect (P>0.05) on feed intake, feed conversion ratio (FCR), live weight and nitrogen retention (N-retention) of male Ross 308 broiler chickens aged 22 to 42 days. Replacing maize meal with sorghum meal improved (P<0.05) ME intake and growth rate of the chickens. Caecum and large intestine digesta pH, GIT, caecum and large intestine lengths, small intestine, caecum and large intestine weights, gut intestinal villi height, crypt depth and villi height to crypt depth ratio, drumstick, thigh and wing weights, drumstick, thigh and wing colour, meat sensory evaluation, meat pH and bone morphometrics of male Ross 308 broiler chickens were not affected (P>0.05) by replacement of maize meal with sorghum vii meal. It was concluded that maize meal can be replaced by a low tannin white sorghum meal at 25, 50, 75 and 100% levels without causing adverse effects on productivity and carcass characteristics of male broiler chickens aged 22 to 42 days. Key words: Low tannin sorghum meal, Maize meal, Broiler chickens, Growth rate, Carcass characteristics.

National Research Foundation (NRF)