Nutrient utilisation and blood metabolites of scavenging chickens across rainy and dry seasons in semi-arid and sub-humid environments

Before supplementing scavenging chickens with feed, it is crucial to investigate their nutritional status. This study aimed to determine the nutritional status and blood biochemical parameters of scavenging chickens during the rainy and dry seasons in sub-humid and semi-arid areas of KwaZulu-Natal, South Africa. A total of 80 scavenging chickens were used. Chickens were slaughtered in the afternoon, and samples from different compartments of the gastrointestinal tract (GIT) were collected and analysed. Blood samples were also collected at slaughter. Results showed that environment and season significantly influenced the nutrient composition of GIT contents and blood metabolites. Chickens from semi-arid environments had higher dry matter, ash, and true metabolisable energy in their GIT contents compared to those from sub-humid areas (P < 0.05). Dry matter, crude fibre, and ether extract levels were higher during the dry season, whereas true metabolisable energy was greater in the rainy season (P < 0.05). Nutrient composition varied across GIT compartments, with dry matter, ash, fat, and crude fibre generally decreasing from the crop to the ileum (P < 0.05) but increasing in the cecum, reflecting microbial fermentation activity. Blood biochemical analysis indicated that chickens in the sub-humid environment had higher total protein, globulin, albumin, and triglycerides compared to those in the semi-arid environment (P < 0.05). Seasonal effects showed higher total protein, globulin, cholesterol, triglycerides, and uric acid during the rainy season (P < 0.05), while albumin was higher in the dry season (P < 0.05). These findings reveal important variations in the nutritional and physiological status of scavenging chickens across environments and seasons, which should be considered when designing feed supplementation strategies.