Effect of supplemental humic and butyric acid on performance and mortality in broilers raised under various environmental conditions

Evaluating natural compounds as a way of enhancing performance and reducing mortality in broilers is important for the poultry industry. Four experiments, involving 1,668 male Ross 708 broilers, were conducted to determine the effect of humic acid (MFG) and protected butyric acid (PBA) on performance and death loss throughout the starter and grower-finisher periods. Experiments 1 and 2 (conducted in early summer and late summer and fall) had between 4 and 6 treatments with MFG and PBA fed alone or in combination with 10 (0.22 m(2)/bird) to 12 (0.18 m(2)/bird) broilers per pen. The combination of MFG and PBA significantly improved performance and livability in experiment 1, but had no effect in experiment 2. Experiments 3 (early summer) and 4 (middle of summer) had 20 broilers per pen (0.11 m(2)/bird). Treatments for experiments 3 and 4 were (1) control, (2) control + MFG (4 and 2 lb/ton for starter and grower-finisher, respectively), (3) control + MFG (4 and 2 lb/ton) + PBA (0.66 and 0.33 lb/ton) for starter and grower-finisher, respectively, and (4) control + MFG (4 and 2 lb/ton) + PBA (1.1 and 0.55 lb/ton). No significant performance differences were observed in experiment 3. In contrast, broilers on treatment 4 in experiment 4 had significant responses in ADG and FCR, along with lower mortalities in extremely hot weather, compared with treatment 1, for the overall (d 0-45) period. Based on these data, especially during heat stress, broilers fed a mixture of MFG and PBA have improved growth and feed efficiency along with lower mortalities.