Title of the manuscript: Laying hen responses to multi-strain Bacillus-based probiotic supplementation from 25 to 37 weeks of age Multi-strain Bacillus-based probiotics improved the egg quality, tibia traits, and beneficial cecal bacteria counts, without affecting the productive performance of Hy-Line Brown layers ABSTRACT Objective: Investigate the the efficacy of Bacillus-based probiotics supplemented at two different levels to modulate the productive performance, egg quality, tibia traits, and specific cecal bacteria counts of Hy-Line Brown layers efficacy of supplementing different levels of a multi-strain Bacillus-based probiotic on the productive performance, egg quality, specific cecal bacteria counts, and tibia characteristics of Hy-Line Brown layers over 12-weeks period from 25 to 37 weeks of age..
Methods:A total of 216 twenty-five-week-old hens were randomly distributed into 3 experimental experimental diets with 12 replicates of 6 birds per cage. Diets included basal diet supplemented with 0 (CON), 3 × 10 8 (PRO1), or 3 × 10 9 (PRO2) CFU of the test probiotic containing Bacillus subtilis PB6, Bacillus subtilis FXA, and Bacillus licheniformis G3 per kilogram of feed.Results: Improved egg weights and mass at 29 weeks; and feed intake at 31 weeks (p < 0.10) were noticed with the probiotic-supplemented PRO1 and PRO2 dietsProductive performance was unaffected (p > 0.05) with probiotics. Considering egg quality, the shell thickness, Haugh units, and yolk color were improved; but yolk cholesterol was lowered (p < 0.05) with probioticsupplemented PRO1 and PRO2 diets at the end of 29 weeks. At the end of both 33 and 37 weeks, the egg-breaking strength, shell color and thickness, albumen height, Haugh units, and yolk color were improved; but yolk cholesterol was similarly lowered (p < 0.05) with the PRO1 and PRO2 diets. Over the entire 12 weeks, the egg-breaking strength, shell color and thickness, and yolk color
A c c e p t e d A r t i c l e4 wer e i mproved; but yol k chol est er ol was r educed ( p < 0. 05) wi t h t he PRO1 and PRO2 di et s. Pr obi ot i cs i n t he PRO1 and PRO2 di et s I i mproved ( p < 0. 05) t he t i bi a Ca, ash, wei ght s, and densi t y; and r ai sed cecal count s of Bi f i dobact eri a and Lactobacilli (p < 0.05) were noticed with PRO1 and PRO2 diets. Improved tibia P but reduced Clostridia counts (p < 0.10) were also observed with the PRO1 and PRO2 diets.
Conclusion:Increasing probiotic Bacillus subtilis PB6, Bacillus subtilis FXA, and Bacillus licheniformis supplementation at 3 ×10 9 CFU/kg of feed did not result in further improvements of the measured parameters. Probiotic supplementation of Bacillus subtilis PB6, Bacillus subtilis FXA, and Bacillus licheniformis G3 at 3 ×10 8 CFU/kg of feed is adequate to significantly improve egg quality, lower yolk cholesterol, enhance several tibia traits; , and raise the populations of beneficial cecal bacteria that are considered beneficial. Modest improvements in several productive parameters and tibia P but reduced Clostridia were also obser...