Determination of the true metabolizable energy of some non-conventional agro-industrial by-products

Thesis Abstract

An experiment was conducted to determine the metabolizable energy of maize pap waste (MPW) and rice milling waste (RMW) using adult male broiler birds. Eighteen male adult broiler birds were used in the experiment. Eight birds were assigned to each of the feedstuff with two birds left unfed which served as the negative control. Each of the samples was ground, made into slurry and force-fed to sixteen 10-week old finisher broiler birds that had been starved for 30 hours. The droppings were collected quantitatively, dried and the gross energy was determined in a bomb calorimeter. The results show that the gross energy, apparent and true metabolizable energy of MPW (4.01, 2.60 and 3.03kcal/g) were significantly (P<0.05) higher than those of RMW (2.94, 0.8 and 1.09kcal/g), respectively. Prior to the determination of the true metabolizable energy, two experiments were conducted concurrently to evaluate the effects of feeding graded levels of MPW and RMW on the performance of broiler birds. A total of one hundred and forty-four 2-week old broiler birds with average weight of 330g were randomly allocated to four dietary treatmentsfreeresearchproject.com.ng containing 0, 10, 20 and 30% MPW and RMW, respectively. The effect of treatments on the final body weight (FBW), average daily weight gain (DWG), average daily feed intake (DFI), feed conversion ratio (FCR), feed cost per weight gain FC/WG, carcass quality and organ characteristics were determined. Differences in DFI and ADG were not significant (P>0.05). Similarly, the FBW of broilers fed the 0, 10, 20 and 30% MPW (3520g, 3470g and 3500g, respectively) and RMW (3345g, 3329g, 3337g and 3330g, respectively) diets were found to be comparable (P>0.05) within the different groups. However, feed cost per unit weight gain decreased significantly with increasing levels of MPW and RMW in the diets. The lower feed cost per kilogram meat produced on 30% MPW and RMW diets suggest that the wastes are economically viable alternative energy sources. It was concluded that at up to the 30% inclusion level of MPW and RMW in the diets, FBW and FCR were not significantly affected (P>0.05). However, the financial return was positively affected (P<0.05) at this level.