ASSOCIATIONS OF NUTRITION AND MANAGEMENT STRATEGIES DURING THE DRY AND EARLY LACTATION PERIODS WITH METABOLIC- AND INFLAMMATION-RELATED BIOMARKERS, HEALTH, MILK PRODUCTION, AND REPRODUCTIVE PERFORMANCE OF DAIRY COWS ON COMMERCIAL DAIRY FARMS IN THE NORTHEASTERN US

Abstract

The transition cow period is arguably the most demanding time in a dairy cow’s life due to an increase in nutrient demand, metabolic and endocrine changes, diet changes, and management factors. Minimizing disruptions during this time period can ease the transition into lactation; however, limited controlled- and large epidemiological-research exists exploring the relationships between nutrition and management factors during the transition cow period with postpartum cow health and performance outcomes. Therefore, the objectives were to: 1) provide a description of current management and nutrition practices and cow outcomes in surveyed commercial dairy herds in the Northeastern US, 2) investigate critical thresholds for prepartum nonesterified fatty acids (NEFA) and postpartum NEFA, β-hydroxybutyrate (BHB), and haptoglobin (Hp) and their association with negative health events, milk production, and reproductive performance at the cow- and herd-level, 3) identify relationships between dry period and periparturient period nutritional strategies as characterized by diet contents of starch, forage NDF, or both, with metabolic- (NEFA and BHB) and inflammation-related (Hp) biomarkers, health disorders, milk production, and reproductive performance, and 4) identify relationships between putative transition period management factors with metabolic- and inflammation-related biomarkers, health disorders, milk production, and reproductive performance. In general, elevated biomarkers were associated with negative postpartum outcomes at the cow- and herd-level. Our results support feeding multiparous cows a high fiber close-up and high starch fresh diet and feeding primiparous cows a controlled-energy far-off, high fiber close-up, and high starch fresh diet for optimal postpartum performance and health. During the prepartum period, our results support increasing the proportion of particles on the Penn State Particle Separator 19-mm sieve for the prepartum diets and optimizing bunk space during the close-up period. During the fresh period, our results support maximizing bunk space, avoiding commingling, increasing the feeding frequency, and avoiding high peuNDF240 or uNDF240 diets. At the herd-level, our results support the practice of avoiding vaccination in the calving pen, utilizing a calving pen (moving to a pen when showing signs of labor) compared to a maternity pen (moving to a pen at least 0 to 3 d prior to expected parturition), reducing the number of prepartum and postpartum pen moves for primiparous cows, and avoiding long stays (≥8 h) in the calving pen after parturition.