Efeito da suplementação de uma associação de levedura viva e hidrolisada sobre a qualidade do leite e desempenho produtivo de vacas leiteiras

Abstract

Supplementation with yeast is associated with changes in the rumen to the auxiliary fiber digestibility and thus generating impacts on health and animal performance. In addition to improving ruminal microflora, components of the yeast cell wall having immunomodulating potential. The aim of this study was to evaluate the effect on performance, health of the mammary gland and metabolic profile of dairy cows supplemented with yeast culture plus enzymatically hydrolyzed yeast (YC-EHY) during the transition period and lactation. Thirty multiparous Holstein dairy cows were divided into two groups: control group receiving the diet necessary to meet the needs according to the NRC 2001 and YC-EHY group who received the same diet than the control group plus 28 g of yeast plus hydrolyzed enzymatically yeast of Saccharomyces cerevisiae (YC-EHY; Celmanax ® , Vi-COR, Mason City, IA). The animals began supplementation at 35 days for the expected calving date. Cows remained on their respective treatment through 150 days postpartum . Body condition score (BCS), body weight, composition, somatic cell count (SCC) and milk production were evaluated weekly. Plasma samples collected on −21, −7,0, 3, 7, 14, 21, 35 and 42 d relative to calving were analyzed for albumin, β-hydroxybutyrate (BHB), urea and nonesterified fatty acids (NEFA). Data were analyzed using mixed models with repeated measures over time. Milk production was higher (27.88±0.98, 24.58±0.99 kg/day for the YC-EHY group and control respectively; P=0,03) during the first 50 days in milk with no differences in milk composition except a decrease in protein content (P=0,03) in the YC-EHY group. There was no effect on SCC values (P=0,55), but in a frequency distribution of a range of CCS, there was a trend of higher frequency values below 250,000 cells / mL when cows were supplemented with yeast (P = 0,08). Supplementing YC-EHY but did not affect albumin, BHB, urea and NEFA concentrations. Feeding yeast culture did not show additional effects on BSC. The supplementation of yeast culture associated with hydrolyzed yeast during the transition period was effective in improving milk production wit hout altering the metabolic profile of the animals during the transition period and may have benefits for animal immunity reflected in a lower frequency of SCC.