Biological and Economic Efficiency of Partial Dietary Substitution of Soybean (Glycine max) Meal with Cowpea (Vigna unguiculata) Meal in Broiler Production

This manuscript explores the biological and economic efficiency of partial dietary substitution of soybean (Glycine max) meal with cowpea (Vigna unguiculata) meal in broiler production. As a result of the shortage of soybean in Zimbabwe due to droughts, inadequate irrigation infrastructure, high input costs, and price controls, the authors identified an alternative to soybean meal in cowpea meal due to its availability and similar amino acid profile to soybean meal. The experiment was carried out at Cold Storage Company in Kadoma. A total of 150 unsexed day-old broiler chicks (Cobb 500) were used. All the birds were brooded in one pen during the first two weeks of age and fed with standard broiler starter mash from National Foods PVT LTD for adaptation. The birds were randomly allocated into five equal groups, each with three replicates and 10 birds per replicate at three weeks of age. Five experimental diets: T1 (100% soybean meal + 0% cowpeas meal), T2 (75% soybean meal + 25% cowpeas meal), T3 (50% soybean meal + 50% cowpeas meal), T4 (25% soybean meal + 75% cowpeas meal) and T5 (0% soybean meal + 100% cowpeas meal) were formulated to be iso-caloric and iso-nitrogenous to meet nutrient requirements of broilers according to NRC (2001). Ration formulation using maize, soybean and cowpea meal as ingredients for broiler starter (21% Crude Protein) and broiler finisher (19% Crude Protein) was done using the Pearson Square Method. Feed intake (g) and weight gain (g) were recorded weekly. Feed Conversion Ratio (FCR) and bioeconomic efficiency were calculated weekly. The experiment lasted for five weeks. The results showed that total Dry Matter Intake for Treatment 1 was the highest (3285 g), and Dry Matter Intakes for Treatments 2, 3 and 4 (3284 g, 3284 g and 3284 g) were not significantly different (P > 0.05) and Dry Matter Intake for Treatment 5 was the lowest (3282 g). Weight gains for Treatments 1 and 2 (2089 g and 2089 g) were not different (P > 0.05), Treatments 3 and 4 (2098 g and 2103 g) were not different (P > 0.05) and Treatment 5 had the lowest gain of 1990 g. Feed Conversion Ratio for Treatments 1 and 2 (1.572 and 1.572) was not significantly different (P > 0.05), Treatments 3 and 4 (1.565 and 1.562) were not different (P > 0.05) and Treatment 5 had the highest FCR (1.64). The bioeconomic efficiency results were significantly different (P < 0.05) for Treatments 1, 2, 3, 4 and 5 (42.16, 41.93, 41.46, 41.13 and 42.66, respectively). Based on the analyses and results, the authors concluded that cowpea meal