Utilização de cultura de levedura Saccharomyces cerevisiae em vacas durante período pré e pós-parto

Abstract

The objective was to evaluate the efficiency of including yeast culture in the diet of cows pre-partum and during lactation to improve productive performance and milk quality. A randomized block design was used, with 40 Holstein cows divided into two treatments (control and yeast culture) and fed with diets containing a forage:concentrate ratio according to their physiological stage. In the pre-partum and lactation period, dry matter intake (DMI), microbial synthesis, rumen pH and blood parameters were evaluated; during lactation, milk production, milk composition (fat, protein, lactose, total solids and non-fat solids), milk urea nitrogen (NUL) and somatic cell count (SCC) were evaluated. Cows supplemented with yeast showed greater milk production, with significant improvements in lactose and reduction in SCC, and without significant differences in fat, protein and total solids content in milk. The animals with yeast culture supplementation showed 2.03 kg/day in milk production, and the birth order obtained a total of 4.78 and 4.98 kg/day of milk from the multiparous compared to the primiparous, respectively. In the milk composition, animals with yeast culture had an effect (P < 0.05) with a higher level of lactose (0.113 g/100g) and lower SCC. When evaluating the order of delivery x treatment interaction, primiparous women (P < 0.05) obtained higher lactose (0.15 g/100g) and 160,037 less CCS, compared to multiparous women. Animals that consumed yeast culture showed a treatment effect (P < 0.05) for dry matter intake (DMI) with 1.07 kg higher and lower levels of β-hydrobutyrate (βhB) 0.21 mmol/L and pH rumen 0.11 units. Inclusion of yeast culture increased alanine aminotransferase (ALT) to 1.78 mg/dL and decreased gamma glutamyl transpeptidase (GGT) levels to 3.87 mg/dL. Regarding the treatment x phase interaction, there was an effect (P < 0.05) for βhB for lactating cows fed with yeast culture, showing an average of 0.45 mmol/L lower compared to animals in the control treatment. There were no effects of treatment or treatment x phase interaction (P > 0.05) regarding microbial synthesis. Lactation curve analysis demonstrated greater productive persistence and better mammary gland health in cows with the addition of yeast culture. It is concluded that supplementation with yeast culture is an effective strategy to optimize DMI, blood parameters, milk production and the health of lactating cows.