Modeling the Effect of Lameness on Culling of Dairy Cows in Tehran Province

Objective-To assess the effect of lameness on culling of dairy cows in Tehran province. Design- Historical cohort study. Study population and procedures- 7067 first- and second-parity Holstein dairy cows that calved from March, 21 2007 to March, 20 2008 were until next calving or culling. Logistic regression was conducted data. Results-The overall lactational culling rate for eligible cows in the study was 22.09% (95% CI: 19.26-24.9%). Lameness was an important factor in the model and increased odds of culling (OR= 1.32; 95% Confidence interval = 1.15-1.51). Moreover, parity, 60-day cumulative milk yield, and herd size increased culling odds. We did not find evidence for a significant effect of calving season on culling. Conclusion- Lameness is an important factor in culling decision in dairy herds in this area.