TY - JOUR T1 - The Comparison of Two Different Seasons Oestrus Synchronization Results with Fixed-Time AI Protocols AU - , Serap Goncu Karakok AU - , Cahit Gungor AU - , Mucella Saler AU - , Metin Ulubilir JO - Journal of Animal and Veterinary Advances VL - 8 IS - 2 SP - 373 EP - 378 PY - 2009 DA - 2001/08/19 SN - 1680-5593 DO - javaa.2009.373.378 UR - https://makhillpublications.co/view-article.php?doi=javaa.2009.373.378 KW - Oestrus synchronization KW -fixed time KW -artificial insemination KW -season KW -protocols KW -Holstein cow AB - The aim of this study, was to compare two different oestrus synchronization methods with fixed-time Artificial Insemination (AI) protocols for Holstein Friesian cow during winter and summer seasons in the Mediterranean region. For this purpose, oestrus was induced using prostaglandins in 110 Holstein Friesian cows kept on an intensive dairy farm. Oestrus was prolonged using progesterone and fixed-time AI applied. Cows were randomly allocated to two groups: The prostaglandin F2α (Lutealyse) group (n = 60), in which cows received 2 injections of prostaglandin 11 days apart; the progesterone group (n = 50), in which cows received an implant at the base of the ear. When the treatments were applied to animals during the summer months the conception rate decreased from 64.81-54.16%. The efficiency of oestrus synchronization with treatments was satisfactory in the winter season, but in the summer months both treatments will require improvements to achieve better results. ER -