Analyse quantitative de l'effet des bactéries probiotiques sur les fermentations dans le rumen et les performances des bovins en production

Abstract

Subacute ruminal acidosis is a major concern in nutrition of high-producing ruminants. Its prevention by supplementing diets with probiotic bacteria (PB) is a potentially effective strategy that should be considered in light of the ability of probiotics to positively modulate the ruminal flora and fermentations. A meta-analysis of 33 experiments (82 treatments) was made to highlight the effect of PB, used alone or associated with the yeast Saccharomyces cerevisiae (PB + SC), on ruminal parameters and animal performance of dairy and beef cattle. Although in beef cattle supplementation with PB or with PB + SC did not affect the average animal performance, in dairy cows, supplementation with PB + SC increased intake (+ 1.7 kg/day) and milk production (+ 2.36 kg/day) without affecting milk composition. The effect of probiotics on ruminal fermentations was inconsistent and relatively weak. However, for low initial mean pH values (pH < 5.75), supplementation with PB alone or PB + SC significantly increased the pH. Finally, although not included in the statistical model because of limited data, animal responses also appear to depend on the type of PB used.