Document Type: Review Article

Authors

1 Lecturer of Payam Noor university, Faculty of Agriculture,Qom, Iran

2 Associate Professor of Azad University, Saveh Branch, Saveh, Iran

3 Lecturer of Payam Noor university, Tehran, Iran

Abstract

The reproductive performance of a dairy herd has a significant effect on the profitability of that herd. Common measures of reproductive performance are days to first service, days to conception, calving interval, services per conception, conception rate, estrus detection rate, and pregnancy rate. Most cow operations would benefit economically by reducing the number of operational days, decreasing culling rates due to non-pregnant females, and shortening their calving interval. Several factors influence reproductive performance, but none require more visual attention than heat or estrus detection

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