Effects of Bacillus licheniformis HDTN on growth performance and intestinal flora of ‘817’ broilers

Abstract:

The proposal of ban on antibiotics in feed is a turning point for the animal husbandry, marking that the feed industry and animal husbandry have entered a new stage of transformation and upgrading. [Objective] To investigate the effects of adding Bacillus licheniformis HDTN to feed on the growth performance and intestinal flora of ‘817’ broilers. [Methods] B. licheniformis HDTN powder (7.0×10¹⁰ CFU/g) was added to the feed for ‘817’ broilers. The effects of high-, medium-, and low-dose (1 000, 500, and 250 g/t) bacterial addition on the growth performance, serum biochemical indexes, intestinal morphology, and intestinal flora structure of the ‘817’ broilers during 1-56 days were studied, with the group without bacterial addition as the control. [Results] Compared with the control group, the addition of low-dose B. licheniformis HDTN increased the average body weight by 105.47 g (P<0.01) and reduced the feed-to-weight ratio by 0.25 (P<0.05) during days 1-35. The antioxidant indexes in the broiler serum were positively correlated with the dose of HDTN, which reduced oxidative stress in broilers. The content of malondialdehyde was negatively correlated with the dose of HDTN, which suggested that HDTN reduced cellular damage in broilers. The ratio of villus height to crypt depth in the duodenum of the low-dose group was higher than that of the control group (P<0.01). In addition, compared with the control group, medium-dose (P<0.01) and low-dose (P<0.05) groups showed increased relative abundance of Firmicutes, and the medium-dose group showed increased relative abundance of Bacteroides (P<0.05). [Conclusion] Addition of low-dose B. licheniformis HDTN for ‘817’ broilers can improve the growth performance, reduce the feed-to-weight ratio, improve the intestinal morphology, and accelerate the assembly of intestinal flora during days 1-35.