Metabolism of living organisms can be disrupted by the changes in the environment and nutrient intake causing serious diseases such as sudden deaths in broilers. High environmental temperature and ad libitum feeding were suspected as predisposing factors inducing sudden deaths. Our objective was to determine the changes in serum enzyme levels and liver lesions in broiler birds subjected to high temperature and ad libitum feeding. COBB 500 broiler strain was (n=90) divided into three groups including control group (n=30) treatment 1 (n=30, 35°C for 12 h per day) and treatment 2 (n=30, fed ad libitum) and studied from 26 days to 40 days of age. Blood samples (1.5 ml) with 6 replications were withdrawn from wing vein of the birds. The serum Alkaline Phosphatase (ALP), Alanine Transaminase (ALT), Aspartate Aminotransferase (AST), Total Protein and Albumin levels were assessed using commercial kits. Liver tissues of 14, 20, 33 and 38 days old birds from treatment 3 (33°C, ad libitum feeding) were fixed, processed and stained with Haemotoxylin and Eosin for histopathological assessment. Data were analyzed using General Linear Model in Minitab 14. The ALP levels were increased with age in control group and treatment 1 group but decreased in the treatment 2 group. The ALT levels were decreased with age in control group and treatment 1, whereas, increased in the treatment 2 group. AST levels were increased in all three groups. The total Protein levels were increased in treatment 2 but Albumin levels were remained similar throughout the lifespan of birds. Histopathological studies revealed that hepatic necrosis was common in older birds.
Tropical Agricultural Research Vol. 26 (4): 584 – 595 (2015)