Detrimental Effect of Tannin on Growth Performance, Visceras Weight and Blood Biochemistry in Broiler Chickens Reared Under Tropical Area

Restriction of antibiotic growth promoters (AGP) in Indonesia reduces broiler production due to bacterial diseases. Some poultry farmers have attempted to replace AGP with phytogenic compounds, such as tannin as an in-feed additive. Therefore, this study was carried out to investigate the effects of tannin administration on the production performance, viscera weight, and lipoprotein levels of tropically-raised broiler chickens. Cobb Strain broiler chicks aged one day were used in an experiment with a completely random design, three treatments, and four replicate pens, each containing nine birds. Three dietary treatments were assigned to the birds: basal diet (negative control), basal diet+0.03% Zn Bacitracyn (positive control), and basal diet+0.05% tannin for the starter phase of 1-21 days and the grower phase of 22-42 days, respectively. Tannin supplementation significantly increased the feed conversion ratio in all phases relative to the control group. Tannin supplementation in the diet significantly reduced daily feed intake during the grower phase, final body weight, carcass weight, intestine weight, liver weight, and total visceral weight, compared to the control group. Tannin had lower levels of aspartate aminotransferase but higher levels of low-density lipoprotein and alanine aminotransferase. Tannin addition in broiler diets might not improve growth performance and health. Therefore, it is not suggested as a substitute for AGPs in broiler diets.