Effects of a synbiotic feed additive on milk quality and calving interval in Brazilian dairy herds
Data on milk quality and reproduction were collected from 22 dairy herds in the Brazilian states of Paraná, Rio Grande do Sul, Minas Gerais and Goiás. These herds were selected because each one had used the synbiotic Biofórmula Leite ® (Biofórmula, Goiânia-GO, Brazil) at the minimum dose of 2 g∙animal-1∙day-1for a minimum of one year and had records of milk yield and quality and herd reproduction for at least one year before and one year after the start of treatment. The synbiotic contained a mixture or probiotic microorganisms, prebiotics and fibrolytic enzymes. After data tabulation and verification, seven herds (total 189 cows) had sufficient information to study treatment effects on milk quality and three (total 115 cows) had enough for reproductive performance, all primarily Holsteins. The data for the 12 months preceding treatment were considered as the control, and those for 12 months following initiation of treatment as treated. Somatic cell count (SCC) data were log-transformed prior to analysis. These data were subjected to a meta-analysis using a mixed model considering herd as a random variable and treatment as a fixed effect nested within herd. There were no significant differences between treatments in milk yields and the concentrations of fat, protein and total milk solids in milk, but there were reductions in SCC (-41%, 654,963 vs. 386,473 SC/mL, P < 0.001) and in calving interval (-73 days, 446.3 vs. 373.4 days, P < 0.01) following initiation of treatment with the synbiotic. The synbiotic feed additive used in this study proved to be an effective tool in the reduction of somatic cells in milk as well as in improving the fertility of cows in commercial dairy herds, confirming results obtained under research conditions.
dairy, somatic cells, reproduction