Chemical composition and nutrient degradability in elephant grass silage inoculated with Streptococcus bovisisolated from the rumen

Abstract

The objective of the present study was to assess the chemical and bromatological composition and in situ degradability of elephant grass silages inoculated with Streptococcus bovisisolated from cattle rumen. A complete randomized design was used with four treatments and six replications: elephant grass silage, elephant grass silage inoculated with 106 CFU/g Streptococcus bovisJB1 strains; elephant grass silage inoculated with 106 CFU/gStreptococcus bovis HC5 strains; elephant grass silage inoculated with 106 CFU/g Enterococcus faeciumwith six replications each. The pH and ammoniacal nitrogen values were lower (P<0.05) for the silages inoculated with Streptococcus bovis JB1 and HC5, respectively. The silage inoculated withStreptococcus bovis had a higher crude protein content (P<0.05) and there were no differences for the fiber contents in the silage. The (a)soluble fraction degradability, especially in the silages inoculated with Streptococcus bovis JB1 and HC5, had higher values, 30.77 and 29.97%, for dry matter and 31.01 and 36.66% for crude protein, respectively. Inoculation with Streptococcus bovis improved the fermentation profile, protein value and rumen degradability of the nutrients.

Objetivou-se avaliar a composição químico-bromatológica e a degradabilidade in situ de silagens de capim-elefante inoculadas com Streptococcus bovisisolado do rúmen bovino. O delineamento experimental foi o inteiramente casualizado, com quatro tratamentos e seis repetições: Silagem de capim-elefante; Silagem de capim-elefante inoculada com 106CFU/g de estirpes de Streptococcus bovis JB1; Silagem de capim-elefante inoculada com 106 CFU/g de estirpes deStreptococcus bovis HC5; Silagem de capim-elefante inoculada com 106 CFU/g de estirpes de Enterococcus faecium com seis repetições. Os valores de pH e N-amoniacal foram menores (P<0,05) para as silagens inoculadas com Streptococcus bovis JB1 e HC5, respectivamente. A silagem inoculada com Streptococcus bovis apresentou maior teor (P<0,05) de proteína bruta e não houve diferenças para os teores de fibras nas silagens. A degradabilidade da fração solúvel (a), principalmente nas silagens inoculadas com oStreptococcus bovis JB1 e HC5, apresentou maiores valores, 30,77 e 29,97%, respectivamente, para a matéria seca e 37,01 e 36,66% para a proteína bruta, respectivamente. Conclui-se que a inoculação com o Streptococcus bovis melhora o perfil fermentativo, o valor proteico e a degradabilidade ruminal dos nutrientes.