Effect of Humic Substance Supplementation on Performance and Gut Health in Broilers

The study was conducted to investigate the effect of dietary supplementation of humic substance (HS) on performance of broilers. 120, day old broiler chicks were randomly distributed into 6 experimental groups with 5 replicates of 4 chicks each. The standard broiler diets (CON) were formulated as per commercial chick feed specification (2011). Dietary treatment AGP was same as CON with addition of AGP whereas, in HS0.1, HS0.2, HS0.3 and HS0.4 replacing antibiotic with HS @ 1, 2, 3 and 4 g/kg feed respectively. Individual body weight and feed intake of broilers were recorded and thus feed to gain ratio and EPEI % was calculated. Birds were sacrificed to estimate carcass traits, intestinal histomorphometry and caecal microbial count. Immunological response in broilers and liver function tests (SGOT and SGPT) were estimated. The performance of broilers (0-6 weeks) indicated that supplementation of HS0.4 in the broiler diet significantly (p<0.05) improved their body weight. Better feed to gain ratio and EPEI % was observed with HS0.2 compared to CON. Crude protein and crude fat utilization improved significantly (p<0.05) in broilers fed with HS0.2 and HS0.4. Supplementation of HS significantly (p<0.05) improved intestine villus height, crypt depth and VH:CD ratio. Caecal E. coli count was lowered, humoral immune response, weight of bursa of fabricius, spleen, serum IgG and IL-10 levels were increased in HS supplemented groups compared to CON. HS inclusion had no effect on the carcass traits, nutrient composition of meat and liver function tests. Lower feed cost per kg weight gain and improved economic efficiency was observed in broilers fed on diets supplemented with HS0.2. It can be concluded that supplementation of HS0.2 in feed can be used as an economically efficient alternative to antibiotic growth promoters in broilers diet.