Microbial populations and chemical compositionof Panicum maximum-grass silage inoculated with Streptococcus bovis isolated from rumen

Abstract

The objective of this work was to
evaluate the effects of the inoculation of two
strains of Streptococcus bovis (HC5 e JB1) and of
the fermentation period of silos on pH, ammonia
production and development of lactic bacteria (LAB)
and enterobacter (ENT) in Panicum maximum cv.
Mombaça silage. The experimental design was
completely randomized, assigned in factorial
outline 3 x 5 (control and two inoculants and five
opening periods), with tree replicates. There was
effect of inoculants, fermentation period and two
effects interaction, for all analyzed parameters. The
ammonia values increased during fermentation
period, while pH decreased, both control and
inoculated silage, and in the last opening period the
ammonia concentration were 10,69, 9,54 and 8,93
mg/dl and pH values were 4,46, 4,27 and 4,28, to
the control, inoculated with HC5 and inoculated with
JB1 treatment, respectively. The maximum value of
BAL to control treatment was observed at seventh
fermentation day (8,85 log UFC/g). The inoculated
treatments displayed maximum values at fourteenth
day with values 9,11 and 9,41 log UFC/g, to HC5
and JB1, respectively. The inoculation increased
dry matter and crude protein content of silages. The
inoculation with Streptococcus bovis HC5 and JB1
reduces the pH values and decreased the ammonia
concentration, beyond favoring development of lactic
bacteria, in detriment of enterobacter, improving
nutritional value of mombaça-grass silage.