Effect of immune stress on growth performance and energy metabolism in broiler chickens

This study was conducted to investigate the effects of different types of immune stress on the growth performance and energy metabolism in broiler chickens (Cobb 500). Three hundred and twenty one-day-old broilers were randomly assigned (n = 80 birds/group) to receive one of four treatments: (1) no vaccination, (2) conventional vaccination, (3) cyclophosphamide (CPM) stress and (4) lipopolysaccharide (LPS) stress. The results demonstrated that immune stress reduced the daily feed intake, average daily weight gain, plasma renin activity, serum angiotensin II and amylase activity of jejunal digesta (P < 0.05). The body temperature of broilers increased rapidly after LPS administration on days 16, 18 and 20, but attenuated on days 37, 39 and 41. The data suggested that immune stress can negatively affect the utilisation of energy in broilers, resulting in the decreased growth performance.