Effects of feeding a Bacillus-based probiotic to grazing Nellore bulls finished on tropical pasture.
- 1School of Agricultural and Veterinarian Sciences, São Paulo State University (UNESP), Jaboticabal, São Paulo, 01049-010, Brazil.
- 2School of Agricultural and Veterinarian Sciences, São Paulo State University (UNESP), Jaboticabal, São Paulo, 01049-010, Brazil. [email protected].
Abstract
Interest in probiotics as an alternative to ionophores has increased, particularly in pasture-based systems using energy supplementation. While these additives aim to improve feed efficiency and mitigate acidosis risk, probiotics may also modulate rumen function by enhancing fiber digestion. This study evaluated the effects of including a Bacillus-based probiotic in an energy supplement on intake, performance, total tract digestibility, and rumen and cecum morphometrics of finishing Nellore cattle. Twenty-eight bulls (502.6 ± 7.0 kg) were blocked by initial body weight and assigned to four paddocks of Urochloa brizantha cv. Marandu. A ground corn-based supplement was offered daily at 0.3% of body weight for 112 d with either no probiotic (CON; n = 14) or 2 g/animal of Bacillus licheniformis and Bacillus subtilis (6.4 × 10⁹ CFU/g; n = 14) using a Calan gate system. Forage intake and fecal output were estimated using indigestible neutral detergent fiber and titanium dioxide. Probiotic supplementation reduced pasture intake (6.32 vs. 7.18 kg/d; P = 0.04), total dry matter intake (8.23 vs. 9.25 kg/d; P = 0.02), and total crude protein intake (0.83 vs. 0.92 kg/d; P = 0.02), as well as NDF intake (4.40 vs. 5.04 kg/d; P = 0.02), without affecting nutrient digestibility (P > 0.10). Average daily gain was reduced (0.75 vs. 0.91 kg/d; P = 0.02), as was final P8 fat thickness (6.47 vs. 7.49 mm; P = 0.05), whereas feed efficiency (0.098 vs. 0.101; P = 0.76), hot carcass weight (318.61 vs. 320.32 kg; P = 0.70), and dressing percentage (53.88 vs. 52.65%; P = 0.30) were unchanged. Rumen and cecum morphometrics were not affected. Supplementation with this Bacillus-based probiotic did not improve performance of pasture-finished Nellore bulls, indicating limited benefits under these conditions and highlighting the need to clarify interactions among probiotic strains, supplementation level, and rumen kinetics.
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BibTeX
@article{oliveira2026effects,
title = {{Effects of feeding a Bacillus-based probiotic to grazing Nellore bulls finished on tropical pasture.}},
author = {Rodrigo J Oliveira and Barbara C Afonso and Bernardo C Petean and Giovanna L O Araujo and Pedro H C Ribeiro and Ariany F Toledo and Danilo Domingues Millen},
journal = {Tropical animal health and production},
year = {2026},
month = oct,
doi = {10.1007/s11250-026-05430-x},
url = {https://europepmc.org/article/MED/42894074},
note = {CC BY},
}
RIS
TY - JOUR
TI - Effects of feeding a Bacillus-based probiotic to grazing Nellore bulls finished on tropical pasture.
AU - Rodrigo J Oliveira
AU - Barbara C Afonso
AU - Bernardo C Petean
AU - Giovanna L O Araujo
AU - Pedro H C Ribeiro
AU - Ariany F Toledo
AU - Danilo Domingues Millen
PY - 2026
DA - 2026/10/18
JO - Tropical animal health and production
DO - 10.1007/s11250-026-05430-x
UR - https://europepmc.org/article/MED/42894074
AB - Interest in probiotics as an alternative to ionophores has increased, particularly in pasture-based systems using energy supplementation. While these additives aim to improve feed efficiency and mitigate acidosis risk, probiotics may also modulate rumen function by enhancing fiber digestion. This study evaluated the effects of including a Bacillus-based probiotic in an energy supplement on intake, performance, total tract digestibility, and rumen and cecum morphometrics of finishing Nellore cattle. Twenty-eight bulls (502.6 ± 7.0 kg) were blocked by initial body weight and assigned to four paddocks of Urochloa brizantha cv. Marandu. A ground corn-based supplement was offered daily at 0.3% of body weight for 112 d with either no probiotic (CON; n = 14) or 2 g/animal of Bacillus licheniformis and Bacillus subtilis (6.4 × 10⁹ CFU/g; n = 14) using a Calan gate system. Forage intake and fecal output were estimated using indigestible neutral detergent fiber and titanium dioxide. Probiotic supplementation reduced pasture intake (6.32 vs. 7.18 kg/d; P = 0.04), total dry matter intake (8.23 vs. 9.25 kg/d; P = 0.02), and total crude protein intake (0.83 vs. 0.92 kg/d; P = 0.02), as well as NDF intake (4.40 vs. 5.04 kg/d; P = 0.02), without affecting nutrient digestibility (P > 0.10). Average daily gain was reduced (0.75 vs. 0.91 kg/d; P = 0.02), as was final P8 fat thickness (6.47 vs. 7.49 mm; P = 0.05), whereas feed efficiency (0.098 vs. 0.101; P = 0.76), hot carcass weight (318.61 vs. 320.32 kg; P = 0.70), and dressing percentage (53.88 vs. 52.65%; P = 0.30) were unchanged. Rumen and cecum morphometrics were not affected. Supplementation with this Bacillus-based probiotic did not improve performance of pasture-finished Nellore bulls, indicating limited benefits under these conditions and highlighting the need to clarify interactions among probiotic strains, supplementation level, and rumen kinetics.
SN - 0049-4747
SN - 1573-7438
ER -