Effect of methionine and lysine supplementation on performance and intestinal morphometrics of finisher broiler chickens fed diets containing processed cassava peel meal

Abstract

Context The current high prices of conventional feedstuffs in developing countries seems to warrant intensified efforts to find sustainable alternatives to the major feed ingredients that would support performance without compromising gut health, reduce cost of production and promote a sustainable environment. Aims The aim of the study is to evaluate the performance and health-related responses of finisher broiler chickens to the dietary replacement of corn with processed cassava peel meal (high- quality cassava peel meal) at 50% inclusion level, supplemented with methionine and lysine. Methods Three hundred and twenty Cobb500 broiler chickens were allocated to four dietary treatments on a weight equalization basis. Each treatment was replicated eight times. A control diet based on corn and soybean meal was formulated to meet the recommended digestible methionine and lysine specification of 4.0 and 0.96 g kg−1 respectively (VenCobb 500 Broiler Management Guide, Cobb-Vantress Inc., Siloam Spring, AR) for the finisher phase. The corn in the control diet was replaced with cassava peel meal at 50% replacement level in three other treatments (Diet 2–4). Diets 2–4 were then formulated to contain 100%, 112.5% and 125% of the recommended digestible methionine and 100%, 106.25% and 112.5% of the recommended digestible lysine, yielding 4.0, 4.4, and 4.8 g kg−1 digestible methionine respectively, and 0.96, 1.02, and 1.08 g kg−1 digestible lysine respectively, for the finisher phase. Key results The highest bodyweight gain, improved feed conversion ratio and increased duodenal and jejunal villus height:crypt depth ratio was found in birds fed Diet 4. The lactobacillus count was highest in birds fed Diet 4 and total bacteria counts was highest in birds fed Diet 2. The feed cost per kilogram weight gain was least for the birds fed diets containing the processed cassava peel meal. However, morphological changes were observed in the liver and intestinal tissues of the birds. Conclusion The study showed that the adequate supplementation of methionine and lysine to processed cassava peel meal can improve production performance of finisher broiler chickens but may not prevent morphological changes in the liver and intestine of the birds. Implication The result implied that processed and fortified cassava peel meal can reduce high dependence on maize in the production of finisher broiler chickens, while mitigating the enviromental challenges associated with the disposal of the agrowaste. The morphological changes in the liver and intestine of the birds require further investigation.