Physiological and Behavioral Indicators of Welfare in Broiler and Noiler Chicken Strains Raised in a Semi-Arid Environment

Abstract

This study evaluated two broiler strains (Marshall and Cobb 500) and an indigenous improved dual-purpose (Noiler) strain for thermotolerance, hematological indices, serum metabolites, and behavioral traits. The collected data were analyzed using appropriate models, including a linear mixed model, one-way ANOVA and an ordinal regression model. Results of the study indicated a significant (p < 0.05) effect of age on physiological variables but not strain. Similarly, WBC was higher in Cobb 500 birds than Noiler chickens (p < 0.05). Conversely, ALP and urea were higher in Noiler than in the exotic strains, whereas enzyme activity had a nuanced pattern among the study strains. In the same vein, Marshall and Noiler chickens spent more time moving around the pen and sawdust bathing compared to Cobb 500 (p < 0.05). There was a higher number of Noiler birds touchable (χ² = 17.51, p = 0.002), but Cobb 500 birds were less frightened by the grab test (χ² = 8.76, p = 0.0126). These results indicated a trade-off between productivity and welfare across the three genetic groups, highlighting the importance of balancing genetic selection for production with the preservation of natural behaviors and physiological resilience to foster sustainable poultry welfare in a changing climate and escalating environmental stressors.