Influência da saúde de vacas leiteiras sobre o desempenho reprodutivo

Abstract

In the context of dairy farming, diseases impacting cattle reproduction pose significant concerns due to their potential to reduce productivity, profitability, and the quality of derived products such as milk and meat. These conditions include low conception rates, abortions, early embryo loss, and repeated estrus, leading to substantial losses in dairy operations. A comprehensive understanding of the causes, effects on reproductive health, diagnostic methods, and preventive strategies is crucial to ensure the welfare and performance of cattle, as well as the sustainability of dairy farming. Hence, the main goal of this study was to evaluate the impact of disease occurrence, metabolic, and hematological parameters on the conception rate of Holstein dairy cows in the northeastern region of Rio Grande do Sul. The study involved 60 Holstein cows, categorized into pregnant and non-pregnant groups based on their pregnancy status. Among cows that experienced disease events, the conception rate was 41.18%, while cows without health disorders had a conception rate of 72.9%. Regarding hematological parameters, there was no significant difference in hematocrit levels between pregnant and non-pregnant cows (29.89 ±3.70 vs 30.36 ±3.63). However, the analysis of biochemical parameters revealed significant differences in free fatty acid (FFA) levels between pregnant and non-pregnant cows (0.218 ±0.14 vs 0.155 ± 0.04 mmol/l, respectively). The correlation matrix showed positive interactions between hematocrit and haptoglobin levels (r=0.3287, P=0.01), as well as FFA and calcium concentration (r=0.3094, P<0.05). Glucose exhibited a significant negative correlation with β-hydroxybutyrate (BHB) (r=-0.4116, P=0.01), along with calcium concentration and Babesia bigemina parasitemia levels (r=-0.2619, P<0.05). However, no significant correlations were observed between hematocrit and glucose, hematocrit and FFA, hemoglobin and calcium, as well as among other analyzed variables. This study emphasizes the complex relationships between health, metabolism, and fertility in dairy cows, highlighting the adverse effects of postpartum diseases on conception rates. Understanding these interactions is essential to mitigate the impacts of health issues on productive and reproductive performance in dairy cows, thereby contributing to the development of strategies that enhance the health of these animals.