Effect of the use of probiotic Bacillus subtilis (QST 713) as a growth promoter in broilers: an alternative to bacitracin methylene disalicylate

Abstract

The global poultry trend toward the more responsible use of antibiotics is becoming recurrent and has demanded the need to generate new natural alternatives. Probiotics have gained importance as an option to use as growth promoters. This study aimed to evaluate Bacillus subtillis QST713 as a substitute for an antibiotic growth promoter ( BMD ). A total of 150 male broilers were assigned to three dietary treatments: 1) control diet ( CO ), 2) control diet + 500 g/t of BMD ( AGP ), and 3) control diet + 100 g/t of B. subtilis QST713 ( PB ), respectively. Each treatment was monitored for 5 wk for the productive variables: body weight, accumulated feed consumption, food conversion, and European efficiency factor. At the end of each week, fresh fecal samples were cultured and quantified for E. coli, Enterococcus spp., and Lactobacillus spp. At the end of the trial, blood samples were analyzed for hemogram and intestinal samples (anterior portion) for histomorphometry. The data were statistically analyzed with an analysis of variance and subjected to a least significant difference test (Tukey). The zootechnical yields were similar in the AGP and PB groups ( P ˃ 0.05); both superior to the control group. In the hematological profiles, no difference was observed between the experimental groups. E. coli and Enterococcus counts were significantly lower ( P ˂ 0.05), and Lactobacillus counts were significantly ( P ˂ 0.05) higher in the PB group, relative to CO and AGP groups. No differences ( P ˃ 0.05) were found in bacterial counts between the CO and AGP groups. The intestinal mucosa and villi in the PB group were significantly ( P ˂ 0.05) longer and with less deeper crypts than CO and AGP groups. We conclude that B. subtillis QST713, used at the suggested commercial dose (100 g/ton), is an effective growth-promoting alternative to BMD that modulates the microbiota and intestinal architecture, thus producing zootechnical yields consistent with BMD.

Beneficial Effects of Spore-Forming Bacillus Probiotic Bacteria Isolated From Poultry Microbiota on Broilers' Health, Growth Performance, and Immune System

“…By day 42, a significant increase in the broilers' BW was observed in groups T3 and T4. Our findings corresponded to the other studies on the beneficial effect of Bacillus -based probiotics on growth performance in broilers ( 37 – 40 ). However, in some studies, Bacillus -based probiotics did not significantly affect BW, ADWG, and FCR in the tested groups ( 19 , 20 ).…”

Bacillus subtilis QST 713 Supplementation during Late Gestation in Gilts Reduces Stillbirth and Increases Piglet Birth Weight

“…In chicken, Bacillus subtilis QST 713 stimulated the development of intestinal mucosa and villi, and the growth of Lactobacillus spp., and inhibited Escherichia coli and Enterococcus spp. [ 12 ]. In the pig, Bacillus subtilis QST 713 prevented the growth of Escherichia coli , and promoted the development of beneficial bacteria such as Bulleidia [ 13 ].…”

“…Supplementation of Bacillus subtilis QST 713 was suggested to be an effective approach to control necrotic enteritis in broilers [ 11 ]. Furthermore, Bacillus subtilis QST 713 increased the length of intestinal villi and decreased the number of deep crypts [ 12 ]. Bacillus subtilis QST 713 supplementation also suppressed the harmful effect of antimicrobial on beneficial bacteria in the intestine of the weaned pigs thereby working as “a preventative and/or attenuating compound against dysbiosis in piglets” [ 13 ].…”

Effect of novel Lactobacillus paracaesi microcapsule on growth performance, gut health and microbiome community of broiler chickens

“…Similarly, it is also outlined that probiotics couldn't show a significant improvement in growth performance on poultry ( Lee et al., 2010 ; Waititu et al., 2014 ). Contrarily, the supplementation of different probiotics species has improved overall growth performance over a whole period in broilers ( Rivera-Pérez et al., 2021 ; Wang et al., 2021 ). Variation in the effects on growth performance may be attributed to the use of different strains, doses, breeds of broilers, and methods of administration.…”