Comparison of sexual synchronization protocols in the cold season in dairy cows

This study was conducted to determine the pregnancy rate in response two sexual synchronization protocols 70 healthy multiparous Fleckvieh dairy cows during cold and warm seasons. After pairing by actual parturition date [cold seasons (-38 0 ºC) (Nov - Feb) vs. (0 32 (Mar-Oct)], were randomly subjected either Co-Synch (CoS) or double PGF2α injection (dPG) on d 35 postpartum. Data Chi-Square (2) analysis at first service. Overall rates (%) service 57.1 40.0 for Groups CoS dPG, respectively (2 = 2.03, P 0.15) 35.0 66.7% seasons, 6.78, 0.009). The protocol effect insignificant 1.17, 0.28) 1.62, 0.20) season. In summary, conditions negatively affected methods did not differ improve when exposed conditions.