Effects of humic acids on broiler performance and digestive tract traits

This study was carried out to investigate the effect of humic acids (HA) supplementation provided through drinking water on performance, carcass and some gut traits of broilers. In a randomized design, 480 mixed-sexes Ross 308 broilers were allocated into four experimental groups consisted of four replicate (30 birds per replication). All birds were housed in pens over 42 day. All chickens were offered a commercial diet ad libitum in mash form. Treatments were: 1) 0 (H0), 2) 1.7 (H1), 3) 5.1 (H2) and 4) 8.1 ppm (H3) HA per kg live weight supplemented in drinking water. Feed intake and body weight were recorded at 21st and 42nd days of trial. Data were analyzed by one way ANOVA. Live weight gain was higher in H1 group than control group both on 21-42 and 0-42 day periods (P<0.05). Feed consumption in the H1 group was higher than that in H3 group at 0–42 day period. Feed conversion ratio, carcass yield, heart, gizzard, edible viscera, abdominal fat pad and gut weight were not affected by HA supplementation (P>0.05). The H2 treatment caused an increase in liver weight compared to control group. Gut length was higher in H1 group than control group (P<0.05). These results show that 1.7 ppm HA supplementation increased live weight gain and feed consumption without affecting feed efficiency.