The Substitution Effect of Noug Seed (Guizotia Abyssinica) Cake with Cassava Leaf (Manihot Escutulata C.) Meal on Feed Intake, Growth Performance, and Carcass Traits in Broiler Chickens

Insufficient supply, high prices and competition with the human food means there is a continuous demand for alternative protein sources for poultry. As a result, leaves of multipurpose trees have been reported to be alternative feed ingredients. Among them, cassava leaves is becoming an increasingly important ingredient in poultry diets, largely due to its high availability. This study was thus designed to assess the effect of dietary inclusion of cassava leaf meal (CLM) on feed intake, growth performance, and carcass characteristics of Ross 308 broiler chickens. Five treatment diets were formulated to contain 0% (Treatment 1, T1), 2% (Treatment 2, T2), 4% (Treatment 3, T3), 6% (Treatment 4, T4) and 8% (Treatment 5, T5) of CLM by substituting the Noug seed (Guizotia abyssinica) cake. After two weeks of brooding, 240 unsexed Ross 308 broiler chicks were weighed and randomly allocated to the five treatment diets with four replicates of 12 chickens each. The experiment lasted for 6 weeks, during which feed intake and body weight were assessed on daily and weekly basis, respectively. At the end of the experiment, two chickens (male and female) per replicate of each treatment were randomly selected, fastened overnight, weighed and slaughtered for the determination of carcass parameters. The results indicated that the feed intake (g/chicken/day) was 80.9, 80.4, 80.9, 77.0 and 74.0 for chickens fed with T1, T2, T3, T4 and T5 diets, respectively being higher (p<0.05) for those of T1, T2 and T3 than T4 and T5. Chickens reared in T1, T2 and T3 diets had higher (p<0.05) body weight and total weight gain values than those of T4 and T5. No significance difference was observed in body weight between chickens reared in T1, T2 and T3 diets. The body weight and weight gain parameters were higher (p<0.05) for those chickens reared in T4 than those of T5. The feed conversion ratio did not vary between treatment diets. Chickens reared in T1 had higher (p< 0.001) pre-slaughter weight and dressed carcass than those of other treatments. The values for dressing percentage, and drumsticks were higher (p< 0.001) in chickens reared in T1 and T2 diets than those of T4 and T5. Chickens fed with T1, T2 and T3 diets had higher (p<0.05) values for thighs and wings as compared with those reared in other treatments. The interaction effect of sex by treatment was significant for breast, drumstick, back, gizzard and skin. Male chickens had higher (p<0.05) carcass values than females. It can be concluded that sun-dried cassava leaf can be included up to 4% of the broiler diets by replacing Noug seed cake without any adverse effects on feed intake, growth traits, feed conversion ratio and carcass components.

Keywords: broiler chicken; carcass components; cassava leaf; growth performance; noug seed cake.