Análise da interação da leucose enzoótica bovina sobre células somáticas e parâmetros lácteos

Abstract

The dairy industry is growing increasingly in Brazil and stands out for its high production, which classifies the country as one of the main milk producers. One point to be noted is the composition of milk, as the industry is increasingly attentive to protein and fat content, as well as somatic cell count (SCC). These parameters affect the yield and quality of dairy products. Among the factors that affect milk quality are chronic diseases, such as Bovine Enzootic Leukosis (BEL). Positive animals can develop immunosuppression, increasing susceptibility to new diseases, such as mastitis. This alteration in the body harms the health of the mammary gland and leads to a reduction in both the quantity and quality of milk composition. In this sense, the objective of the present study was to test animals for BEL through the Agar Gel Immunodiffusion test (AGID), concerning the age (firstcalvers or multiparous) of the cows, somatic cell count (SCC), and milk quality. For this purpose, 52 dairy female bovines from a herd in southwestern Paraná were randomly selected to determine the prevalence of BEL and to analyze milk samples regarding SCC, fat, protein, and total solids. The results of the AGID test showed a prevalence of 76.92% of the disease in the evaluated herd. The highest positivity was found in multiparous cows. No statistically significant differences were observed between positive and negative animals for BEL when total solids, fat, or SCC were evaluated. Significant differences were found in the protein composition of milk between positive and negative animals for BEL. It is concluded that this study demonstrated a high prevalence of BEL on the property, being more common in older cows, which reinforces the relationship between the disease and the duration of exposure. Although no statistically significant results were found associating the disease with SCC or dairy compounds, the importance of early diagnosis and the eradication of the disease in the herd is emphasized.