Suplementação de leveduras e Aspergillus oryzae para vacas leiteiras: uma meta-análise

Abstract

Advances in the ruminant nutrition demand new nutritional strategies, so that the beneficial effects are improved and the deleterious ones are minimized or excluded. As a strategy, the use of fed additives has been adopted. In this way, additives for intestinal flora regulators, such as probiotics and prebiotics, become an alternative to the use of antibiotics in ruminants’ nutrition. There are many studies evaluating the effects of the use of probiotics and prebiotics in dairy cattle feeding, mainly using live yeasts of the genus Saccharomyces cerevisiae, as well as cell wall, and Aspergillus oryzae fermentation extract. Despite this, the results observed are still controversial. Therefore, a meta-analytical study in relation to the subject addressed can assist in the constitution of some concepts and better establish them. Thus, the objective was to evaluate through meta-analysis the benefits of using live yeasts of the genus Saccharomyces cerevisiae (LY), yeast fermentation products (SCFP) and fermentation extract of Aspergillus oryzae (AO) in the diet of dairy cows, as well as, which is the best additive to improve ruminal parameters, performance and animal health. For that, 116 studies were compiled that evaluated the intake, ruminal parameters and digestibility of nutrients and milk production and composition of dairy cows supplemented or not with these additives. It was observed that the milk production of cows supplemented with LY increased 7.08% compared to non-supplemented cows (P <0.0001), as well as reduced losses during lactation by 44.54% (P <0.05). In addition, fat, total solids, solids not fat and milk lactose were also increased with LY supplementation, while somatic cell counts were reduced by 39.8% (P <0.05). The apparent digestibility of the neutral detergent fiber and crude protein in the diet was increased by the addition of LY, however, increases in the concentration of volatile fatty acids in the rumen were not observed by any of the treatments. In addition, dry matter intake was increased by 1.07% with AO supplementation compared to other treatments. Thus, it can be inferred that supplementation with LY is the best option among the additives evaluated to improve ruminal and digestibility parameters, and the productive efficiency of dairy cows.