Sex-Specific Body Weight Prediction Accuracy in Improved and Exotic Chicken Strains In Nigeria

Abstract

This study evaluated the accuracy of body weight prediction in three chicken strains—Aco Black, Noiler, and ISA Brown—using regression models, with a focus on sex-specific and growth-stage-specific relationships. Methods: A total of 360 day-old chicks (comprising 60 males and 60 females per strain) were raised under uniform management conditions at the University of Abuja Research Farm. Weekly body weights were recorded from day-old to week 8. Regression analysis was employed to assess the predictive power of early and mid-growth body weights for subsequent growth stages. Results: Hatch weight was a poor predictor of subsequent growth across all strains and sexes (R² < 0.20), indicating that initial weight alone does not reliably reflect later performance. In contrast, body weights recorded during the mid-growth phase exhibited stronger predictive relationships. For Aco Black, week 4 body weight was a significant predictor of week 7 (R²= 0.779, p< 0.001) and week 8 (R²=0.518, p< 0.001). In Noilers, week 5 body weight provided the highest prediction accuracy for week 8 (R² = 0.867, p < 0.001). Sex-specific analysis revealed notable differences; for example, in Aco Black males, week 5 significantly predicted week 6 (R² = 0.674, p < 0.01), while in females, week 1 predicted week 4 (R² = 0.463, p < 0.05). ISA Brown showed predictive relationships, although with generally weaker correlations than the dual-purpose strains. Conclusion: These findings demonstrate that growth-stage-specific and sex-specific prediction models are more effective than relying on hatch weight alone. The study underscores the importance of using intermediate growth measurements for accurate forecasting of final body weight, which is critical for selection, breeding decisions, and efficient management practices in poultry production