Herd and environmental determinants of reproductive performance in Swedish dairy herds, 2001-2009

Abstract

This was a retrospective cohort study of Swedish dairy herds. Summary measures of production and reproductive performance, details of soil, moss mineral concentrations, and temperature and rainfall measurements at each herd location were available for the period September 2001 to August 2009. A Bayesian mixed-effects regression model including spatial and non-spatial heterogeneity terms was developed to quantify associations between hypothesised explanatory variables and mean herd breeding interval, defined as the difference between mean calving to last service interval and mean calving to first service interval for each fiscal year. Mean herd breeding intervals were shorter in herds with gr..