The effects of different levels of arginine on cecum microbial population and serum antioxidant properties of healthy and Eimeria-challenged broiler chicks

Coccidiosis is known as one of the most common diseases of poultry in all over the world which characterized by enteritis. It annually causes economic losses in broiler chicks production industry. Genus Eimeria causes coccidiosis in broiler chickens. Insufficient ventilation and humidity, inappropriate stocking density, deficient immune responses, bacterial enteritis, and lack of efficient anticoccidial drugs facilitate development the coccidiosis. Coccidiosis also influence microflora and disturbs their population. Arginine participates in structure of some important biological and physiological molecules in birds. It increases pH and can influence population of bacteria. The present study was conducted to evaluate the effects of different levels of arginine on cecum microbial population and serum antioxidant properties of healthy and Eimeria-challenged broiler chicks.

A total number of 384 one-d-old broiler chick (Ross 308) of mixed sex with initial weight of 42±2 g was purchased from local hatchery. Broiler chicks fed diets supplemented with 85, 100, 125 and 150% of recommended digestible arginine. In 21 days, the half of broiler chicks was challenged with Eimeria spp and broiler chicks were divided into 8 groups with 6 replications and 8 birds/replicate. Experimental treatments included: Broiler chicks challenged with Eimeria and treated with 85% of recommended arginine (85-challenge group), broiler chicks challenged with Eimeria and treated with 100% of recommended arginine (100-challenge group, positive control), broiler chicks challenged with Eimeria and treated with 125% of recommended arginine (125-challenge group), broiler chicks challenged with Eimeria and treated with 150% of recommended arginine (150-challenge group). Healthy groups included: broiler chicks unchallenged with Eimeria and treated with 85% of recommended arginine (85-Healthy group), broiler chicks unchallenged with Eimeria and treated with 100% of recommended arginine (100-Healthy group, negative control), broiler chicks unchallenged with Eimeria and treated with 125% of recommended arginine (125-Healthy group) and broiler chicks unchallenged with Eimeria and treated with 150% of recommended arginine (150-Healthy group). In 21 and 42 days, 2 birds per replicate were killed by decollation. At 42 days of trial, blood samples were collected from 2 birds/replicate and gathered in tubes. The population of E. coli, Lactobasillus, total bacteria, bifidiobacteria and pH were assessed. Part of blood was used as whole blood for measurement of glutathione peroxidase (GPx), superoxide dismutase (SOD), nitric oxide (NO) malondialdehyde (MDA) and total antioxidant status (TAS). malondialdehyde (MDA) were measured by ZELLbio commercial kit (Germany). The levels of GPx (No:430430), SOD (439108), total antioxidant capacity (TAC: NX 2332) and (Randox Laboratories, Ardmore, Crumlin, UK) as recommended by producer Company. The study was conducted based on a completely randomized design in a 4×2 factorial arrangement with infection (challenged and unchallenged) and dietary supplemental of arginine (85, 100, 125 and 150% of the recommended levels).

The results showed that challenge with Eimeria significantly decreased the levels of SOD, GPx and TAS but increased NO and MDA (P0.05). Dietary inclusion of 125 and 150% arginine could significantly increase GPx (p < /p>