The ncd2-overexpressing Sphingomonas sp. Z392 strain was verified to reduce ammonia levels in our previous study. To ensure its safe utilization, this study investigated the effects of strains on the gut health and meat quality of broiler chickens. Four groups were designed for the experiment: control group (CK), wild-type strain group (WT), ncd2 gene knockout strain group (KO), and ncd2-overexpressing strain group (OV). The last three groups were supplemented with the corresponding strains at a concentration of 4.0 × 105 CFU/mL in drinking water for 42 d. Microscopic and ultrastructural observations revealed that the ncd2-overexpressing Sphingomonas sp. Z392 strain increased the number of goblet cells in the villi of small intestine, lysosomes in the ileal epithelial cells and mitochondria in the colonic epithelial cells, and improved the swelling degree of mitochondria in the jejunal epithelial cells. In the OV group, the number of broiler chickens with digestive tract diseases was approximately one-fourth that in the CK group and the disease duration was significantly shortened. The OV broiler chickens showed the different weight gain with an increase of 8.83%, 3.56%, 7.18% compared to CK, WT, KO groups, respectively. In terms of meat quality, the drip loss of chest and leg muscles had the lowest value, decreased by 51.26% and 49.15% compared to CK group respectively. At the same time, the meat yellowing value (b* value) was higher than other groups. In summary, the ncd2-overexpressing Sphingomonas sp. Z392 strain could effectively improve the intestinal healthy of broiler chickens and enhance their growth performance and meat quality.
Wang et al. (Fri,) studied this question.