No abstract

To determine whether it could also improve the production performance of Eimeria-infected broilers, Weizmannia coagulans strain SANK70258 (WC) supplementation was compared with coccidiostat lasalocid-A sodium (AM) administration. First, to determine the optimum WC dose, newly hatched broiler chick groups (n = 10) were untreated or consecutively given WC (0.005%, 0.01%, 0.03%, and 0.1%) and AM until slaughter (31 days of age). At day 21, all chicks were infected with coccidia. From the economical and practical viewpoints, 0.03% WC supplementation was the best dose. Second, newly hatched broiler chick groups (n = 10) were untreated or given 0.03% WC and AM. Each group was run in triplicate. At day 21, two chicks/pen with the farthest body weights as per the group’s mean body weight were spared, and the remaining inoculated with coccidia. At days 42 and 49, the WC and AM groups had significantly greater body weights and daily weight gains. Intestinal lesion scores were lower in 29-day-old AM and WC. Oocyst numbers were lower in 29- and 49-day-old AM and WC, but only 29- and 49-day-old AM had higher Escherichia coli levels. To conclude, although WC and AM induced similar growth performance in coccidium-infected chicks, unlike AM, the E. coli levels did not increase with WC.

To determine the mechanisms by which Weizmannia coagulans SANK70258 (WC) supplementation improved growth performance and coccidial symptoms, we assessed the gene expressions and the microbiota compositions in the small intestinal tissues and digestas of coccidium-infected broilers previously given WC or lasalocid-A sodium (AM). WC supplementation significantly upregulated the gene expressions related to intestinal immunity and barrier functions, such as IL17A, IL17F, IL10, cathelicidin-2 and pIgR. Body weights, and Claudin-1 and IL10 expressions were positively correlated (r = 0.41, p < 0.05 and r = 0.37, p = 0.06, respectively), whereas lesion scores of the small intestine and IL17A expression were negatively correlated (r = −0.33, p = 0.09). The microbiota analysis detected that genus Alistipes was more abundant in WC-supplemented broilers than in control, and positively correlated with body weights and Claudin-1 expression (r = 0.61, p < 0.05 and r = 0.51, p < 0.05, respectively). Intriguingly, genus Enterococcus was most abundant in WC-supplemented broilers and positively correlated with IL17A expression (r = 0.49, p < 0.05). Interestingly, Escherichia-Shigella was significantly more abundant in the small intestinal digestas of AM-administered broilers than in those of control. To summarize, WC supplementation modulated and immunostimulated the microbiotas of broilers, specifically genera Alistipes and Enterococcus, which led to the improvement of weight gain and coccidial symptoms, without disrupting the intestinal microbiota compositions, as AM did.