A estreita relação entre a microbiota ruminal e os aditivos microbianos

Abstract

The objective of this review is to discuss aspects related to ruminal microbiota, especially of animals raised in extensive systems, and to relate modulatory mechanisms of microbial additives with the microorganism population and ruminal parameters. Different modulators of the ruminal microbiota have been studied in order to improve the microbial activity in the rumen. Feeding with prebiotics, probiotics or both; and supplementation with competitive exclusion cultures have been used to limit the proliferation of E. coli O157 in production animals that act as potential reservoirs of this bacterial strain. It is also known that live microbial cultures of the exogenous fungi Aspergillus oryzae and Saccharomyces cerevisiae and their extracts have been used as dietary supplements in the animal diet, and that these can improve the productivity of ruminants by approximately seven to eight percent. It was found that the additive constituted of Saccharomyces cerevisiae tends to stimulate the growth of cellulolytic bacteria in the rumen of newborn lambs. However, despite several positive reports, different barriers still occur in the field for the use of additives in animal production. Several results are found, often justified by the animal condition, selection and viability of product strains. Future studies are needed to elucidate the best form of administration and applicability, especially for animals adapted to the tropical climate, with lack rainfall and feeds of low nutritional value.