مطالعه ميداني تاثير طول دوره خشكي بر شاخص هاي توليد مثلي پس از زايمان در گاو هلشتاين

Study on the Effect of Dry Period Length on the Reproductive Indexes of Holstein Cows after Parturition

With regards to the importance of dry period and its negative and positive effects on livestock safety, the contingency of dry period on reproduction indices were studied. One hundred Holstein dairy cows from an industrial large dairy farm in Hamadan were selected. The length of dry period was Independent variable and reproductive indices (1. Parturition to first service interval, 2. Open days, and 3. Numbers of service to pregnancy) depended variables. Control variables were 1- Pick of milk production, 2- BCS at the breeding and 3-Numbers of lactation. It is concluded that there was no significant correlation between dry period length and reproductive indices (p>0.05), but inclination to recovery was observed in groups with shorter dry periods. Vet.J.of Islamic.Azjad.Univ., Garmsar Branch. 5,1:35-40,2009.