Effect of different levels of chromium nicotinate on growth performance and antibody titre responses to Newcastle and Avian Influenza disease in heat-stressed broiler chicks

Abstract

High ambient temperature reduces feed intake, live weight gain, and feed efficiency (Siegel, 1995), thus negatively influencing the performance of broilers. Heat stress has also been shown to suppress immune responses of broiler. Chromium is an essential nutrient required to promote the action of insulin in body tissues so that the body can use sugars, proteins and fats. Cr deficiency can disrupt carbohydrate and protein metabolism, reduce insulin sensitivity in peripheral tissues and impair growth rate (Vincent, 2000).Chromium is important in altering the immune response by immunostimulatory or immunosuppressive processes as shown by its effects on T and B lymphocytes, macrophages and cytokine production. Dietary chromium supplementation has been reported to have a positive effect on growth rate and feed efficiency of growing poultry under stress conditions (Sahin et al., 2002). Another reason for supplementing chromium is due to the fact that chromium is excreted excessively during stress (Anderson, 1994). Also the dietary requirement of livestock for chromium has not been defined yet (NRC, 1997). This study was to investigate the effects of different levels of Cr nicotinate on the growth performance and antibody titres against Newcastle and Influenza disease in broilers.