Fertility of lactating dairy cows inseminated with sex‐sorted or conventional semen after Ovsynch,Presynch–Ovsynch and Double‐Ovsynch protocols |
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| Authors: | Ebru Karakaya‐Bilen Gulnaz Yilmazbas‐Mecitoglu Abdulkadir Keskin Bar&#x;s Guner Enes Serim Jos E P Santos Ahmet Gümen |
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| Institution: | Ebru Karakaya‐Bilen,Gulnaz Yilmazbas‐Mecitoglu,Abdulkadir Keskin,Bar?s Guner,Enes Serim,José E. P. Santos,Ahmet Gümen |
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| Abstract: | The objective was to compare pregnancy per artificial insemination (P/AI) with conventional (CS) or sex‐sorted semen (SS) in dairy cows subjected to one of the three timed AI protocols. Cows (n = 356) were randomly assigned to synchronization with Ovsynch (OVS), Presynch–Ovsynch (PO) or Double‐Ovsynch (DO) and inseminated on Day 77 ± 3 postpartum with either frozen‐thawed SS (n = 182) or CS (n = 184) of the same bull. More cows were cyclic at the beginning of breeding Ovsynch increased (p < 0.01) with presynchronization and it was greater for DO than PO (OVS = 78.5%, PO = 85.1%, DO = 95.6%). Overall, P/AI for SS and CS increased with presynchronization (p < 0.05) on Days 31 (OVS = 35.5%, PO = 47.1%, DO = 48.3%) and 62 (OVS = 30.1%, PO = 43.8%, DO = 43.9%). Regardless of synchronization treatments, insemination with SS reduced P/AI (p < 0.02) on Days 31 (38.1% vs. 50.6%) and 62 (34.5% vs. 45.6%) compared with CS. No interaction was observed between synchronization treatment and type of semen for P/AI, although in cows receiving CS, P/AI was numerically greatest for PO (OVS = 42.0%, PO = 59.3%, DO = 49.0%), and in cows receiving SS, it was numerically greatest for those inseminated following DO (OVS = 27.9%, PO = 35.5%, DO = 47.6%). Thus, presynchronization improved P/AI in cows inseminated with sex‐sorted or conventional semen. |
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| Keywords: | dairy cow ovsynch presynchronization sex‐sorted semen |
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