Evaluation of egg production and egg quality of Sasso and Kuroiler chickens fed three diets at varying levels of supplementation under a semi-intensive system of production in Tanzania

Abstract

Context Genetically improved chickens raised under a semi-intensive system have been shown to maintain performance in terms of egg production and egg quality by feeding low-cost diets at different levels of supplementation, but reports on the supplementation regimes by using low-cost diets are limited. Aim This study aimed to evaluate the effect of dietary supplementation regimes on egg production and egg quality of genetically improved dual-purpose chickens under a semi-intensive system. Methods A total of 480 female chickens aged 20 weeks were randomly assigned to 24 treatment combinations in a 2 × 3 × 4 factorial experiment with two replicates each. The treatments were breeds (Sasso and Kuroiler), diets (D1 – commercial, D2 – medium-cost and D3 – low-cost) and levels of supplementation (100%, 75%, 50% and 25%). Key results The results show that breed, diet and level of dietary supplementation had a significant effect (P < 0.05) on age at first lay and egg production parameters. Sasso chickens showed higher hen-day egg production and hen housed egg production values across all diets and levels of supplementation. Diet and levels of feed supplementation significantly affected egg weight (P < 0.05), with 100% supplementation level resulting in the heaviest eggs and 25% supplementation level resulting in the lightest eggs. All internal egg qualities except Haugh units were significantly (P < 0.05) influenced by the level of supplementation, whereas the effect of diets was only significant (P < 0.05) for a few internal egg quality variables, such as yolk weight and yolk diameter. The cost of production was higher for commercial diet-fed and highly supplemented birds. Conclusion Egg productivity and egg quality traits were significantly improved by breed, diet and higher levels of supplementation. However, less-supplemented (25% and 50%) birds gave numerically higher income over feed compared with those on higher levels of supplementations for the first 20 weeks of production. Implication These findings have the potential to reduce the cost of egg production for dual-purpose improved chicken breeds while maintaining good egg quality under a semi-intensive system of production.