Oestrus synchronization in Nelore cattle under different handling. Effects of timing PGF2? injection following CIDR removal on oestrus response, follicular dynamics and pregnancy rate

      Аннотация: Beef cattle still possess important position in tropical countries. However, it has generally been accepted that heat detection in zebu cattle under tropical environment is not as obvious as that in temperate environment. Thus, heat detection is still a problem that may have effect on the reproductive performance in beef cattle. In order to improve the reproductive performance, advances in assisted reproductive biotechnology, genetic improvement, and improve in management should be incorporated to attain good calf crops. It is known that, stress due to handling may influence on the reproductive performance. On the other hand, less handling and gentle interaction with animal could improve the reproductive performance, which in return could increase the income of the farm. Therefore, the improved oestrus synchrony is related to greater pregnancy rates and hence improves the reproductive performance, which in return could increase the income of the farm. In addition, the welfare and kindness should be done for the improvement in the animal productivity.

Ключевые слова: Stress, pregnancy rate, handling, Oestrus Synchronization, oestrus response, Nelore cattle