Effect of temperature and dietary energy on live performance blood chemistry and organ proportions in broiler chickens

Abstract

AbstractTwo thousand commercial broiler chickens of both sexes were used to study the effect of temperature (21°C constant (LT) vs 21 to 30 to 21°C cycling (HT)), and dietary energy (13.0 MJ ME kg−1 (LE) vs 13.8 MJ ME kg−1 (HE)) on the live performance, blood pH, Pco2, Po2 and HCO3 and on heart, liver, gizzard and abdominal fat weights as proportions of body weight. Weights and analytical samples were taken at 34 and 54 days. Daily gain was depressed by HT (P < 0.05) but HE overcame this depression in female broilers. The HT treatment reduced (P < 0.05) blood pH and Po2, but increased (P < 0.01) Pco2 and HCO3 levels especially when LE diets were fed. Heart, liver and abdominal fat proportions were all reduced (P < 0.05) by HT in male broilers. Female broilers on HT had reduced heart proportions whereas liver and abdominal fat proportions were increased (P<0.001) especially in those fed HE diets. Gizzard proportions were increased (P<0.05) by HT, and reduced (P<0.05) in birds fed HE diets. Up to 34 days, for both sexes, a combination of LT × LE was superior to all the other combinations. By 54 days, LT × HE and HT × HE were advantageous for males and females, respectively.