Risk factors affecting the culling of Iranian Holstein dairy cows

This experiment was conducted to evaluate the association between risk factors and the risk of culling in Iranian Holstein cows. The data consisted of 329,772 lactation records obtained from the Animal Breeding Center of Iran (2003 - 2012) and logistic regression was applied to investigate the associations between the predictor and response variables. The response variable in this experiment was the risk of culling and predictor variables were included calving season, parity, birth type, calving ease, standardized 305-d milk yield, age at the first calving, region and the number of calving cows in the herd. Risk factors analysis showed that the risk of culling significantly (P