Nutrient digestibility in the digestive tract of Nelore cattle supplemented with Bacillus-based probiotic

• Grant number: 24/16317-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2024
• End date: October 31, 2025
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Nutrition and Feeding
• Principal Investigator: Danilo Domingues Millen
• Grantee: Eduardo Bergamasco Pereira
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil

Abstract

The use of Bacillus as probiotics for ruminants has tended to increase the digestibility of fiber in foods. Strains such as B. Subtilis and B. Licheniformis alter the structure of fibrous components and modulate rumen fermentation, increasing production efficiency in several species. The objective of this study is to evaluate the effect of probiotics based on Bacillus subtilis and Bacillus licheniformis on pasture consumption and nutrient digestibility in Nelore cattle finished on pasture. 28 Nelore cattle, entire males, with an initial body weight of 405 kg, will be blocked by body weight and distributed in four paddocks of Urochloa brizantha cv. Marandu, being randomly assigned to two treatments: control (without additive) or supplemented with Bovacillus® (Bacillus subtilis and Bacillus licheniformis, [2 g/head/day]). The experimental period will be 127 days, with the initial 15 days for adapting the animals to the Calan Gate® system and 112 days for data collection, divided into 4 periods of 28 days. The supplement will be provided at 0.3% of the animals' body weight, once a day. The animals will undergo feces collection directly from the rectal ampoule between d11 and d15 of each experimental period. Samples of supplement food, pasture and feces will be subjected to chemical composition analyses to determine the digestibility of nutrients by the relationship between consumption and excretion of each nutritional component of the diet. The data will be analyzed by PROC MIXED of SAS (2003), considering significance of the F test at P ¿ 0.05, for the fixed effect of the inclusion of Bovacillus® in the supplement.