THE ASSOCIATION OF SERUM NONESTERIFIED FATTY-ACIDS AND CHOLESTEROL, MANAGEMENT AND FEEDING PRACTICES WITH PERIPARTUM DISEASE IN DAIRY-COWS

A prospective study was conducted to determine the relationship of ser um nonesterified fatty acids (NEFA) and cholesterol concentrations and herd management practices to the occurrence of metritis, mastitis and retained placenta in Holstein cows in Michigan. Serum samples were co llected once prepartum and once postpartum from 257 cows, Animals were under observation for disease occurrence from the date of calving unt il 3 months postpartum. Metabolic variables used were. (1) prepartum o nly; (2) postpartum only; (3) the NEFA/cholesterol ratio for both pre and postpartum samples. Management variables included maternity manage ment, feed management, and factors such as season and parity. Multivar iable logistic models with random-effect terms to account for the herd effect were used for data analysis. Results showed that: (1) metaboli c events associated with energy insufficiency-increased fat mobilizati on and serum lipoprotein metabolism-were related to increased risk of metritis and retained placenta; (2) higher energy consumption during t he last weeks of the dry period might reduce disease risk at parturiti on; (3) serum NEFA and cholesterol concentrations have potential as in dicators of disease risk in dairy cows.