Performance Of Broiler Chickens Fed Pearl Millet As An Energy Source And Acacia Karroo Leaf Meal As An Additive

ABSTRACT 

This study was undertaken to determine the performance and meat sensory attributes of broiler chickens fed with Pearl Millet (Pennisetumg laucum) as a replacement for maize, as well as the potential of tanniferous Acacia karroo (A. karroo) leaf meal as an additive on broiler leanness. The optimum level at which maize can be replaced by pearl millet was also determined. Nutritional compositions of pearl millet and A. karroo leaf meal were determined using the standard Association of Official Analytical Chemists protocols. One hundred and one day old chicks of the breed Cobb 500 were obtained from Namib Poultry Industries and raised on a two phase feeding regime (i.e. starter for 3 weeks and finisher for 4 weeks). During the finisher phase they were fed different treatment diets. In the first trial the treatment diets were formulated such that maize was replaced with pearl millet at levels of 25% (T2), 50% (T3), 75% (T4) and 100% (T5). A standard commercial finisher diet was used as the control (T1). Parameters studied were; voluntary feed intake, weight gain, feed conversion ratio (FCR), fat pad, breast weight, thigh weight, gizzard weight, meat sensory attributes and preference. In the second trial the standard commercial finisher diet was seeded with A. karroo leaf meal as an additive at levels of 0 g/kg (T1), 5 g/kg (T2), and 20 g/kg (T3), to study the effects on the feed intake, weight gain, feed conversion ratio (FCR), fat pad, breast weight, thigh weight, gizzard weight, meat sensory attributes. Feed intake was recorded daily while weight gain was recorded weekly. At the end of the feeding trials, 28 broilers were slaughtered at 42 and 49 days old and evaluated for organs weight (thigh, breast, fat pad and gizzard) and average consumer acceptance. The results of this study have shown that the best replacement level of maize with pearl millet was at 50 %. It was however, found that the replacement of maize by pearl millet can be done up to 100% without producing significantly lower performance (P>0.05) compared to the optimum replacement i.e. at 50%. The study showed that feed manufacturers can use pearl millet as an energy source in place of the imported maize. Addition of 20 g/kg A. karroo leaf meal had a tendency to reduce fat deposition. More than 5 g/kg of A. karroo leaf meal may be added in order to improve fat expression. From the sensory evaluation trial, all the treatments did not affect the preferences significantly meaning the optimum levels of using pearl millet (as a substitute for maize) and A. karroo (as an additive) can safely be recommended without affecting the acceptability and preference of the broiler meat produced.