不同处理方法对绵羊冬季同期发情效果及受胎率的影响OA

To improve the estrus synchronization effect and conception rate of pen-fed sheep in winter in the Linxia area and to support large-scale and standardized sheep breeding locally,the production experiment was conducted at local sheep breeding farms by using the estrus synchronization technology.The effects of hormone injection timing,artificial insemination environmental temperature,and vitamin ADE on estrus synchronization and conception were compared and analyzed.Results indicated that the es-trus synchronization rates of pregnant mare serum gonadotropin(PMSG)and cloprostenol sodium(PG)injection one day prior to sup-pository withdrawal increased by 5.82 to 11.52 percentage points compared with that of the treatment involving simultaneous injection with bolus withdrawal.The estrus rate of sheep treated with intramuscular injection of vitamin ADE was 98.88%,which was 4.44 to 11.52 percentage points higher than that of sheep without vitamin ADE injection,whereas the conception rate was 84.09%,which was 6.44 to 14.35 percentage points higher than that of sheep without vitamin ADE injection.The conception rate of sheep treated with in-tramuscular injection of PMSG and PG 1 d before suppository withdrawal and with the ambient temperature around the insemination gun,semen,and operating table maintained at about 25℃during insemination was 5.70 percentage points higher than that of sheep without warming treatment.Combined intramuscular injection of veterinary vitamin ADE further improved the conception rate of sheep and reduced ineffective breeding input.Therefore,it is recommended that,when conducting estrus synchronization in winter at sheep breeding farms in northern China,veterinary vitamin ADE should be injected intramuscularly at 3 mL per sheep on Day 0 at Silicone plugs insertion.PMSG 330 IU and PG 0.1 mg should be injected intramuscularly on Day 11.The Silicone plugs should be removed on the morning of Day 12.On Day 14,heating measures should be adopted to maintain the ambient temperature around the insemination gun,semen,and operating tableat about 25 ℃,the first insemination at 10:00,gonadotropin-releasing hormone A3 at 25 μg and veteri-nary vitamin ADE at 3 mL should be injected intramuscularly,followed by the second insemination at 20:00.This protocol yields opti-mal conception results in sheep.