摘要
This report shows the results of a large-scale laparoscopic intrauterine insemination program on a flock of Australian Merino sheep in Argentine Patagonia. The study was carried out on a total of 1824 ewes (3-to-7-yr-old) and 480 ewe hoggets (19–20 months old) on 2 farms in the southeastern region of Santa Cruz Province, in April and May 1996. The animals, divided into 15 groups, were synchronized with vaginal sponges containing 60 mg medroxyprogesterone acetate for 14 d and injected with 200 IU PMSG upon sponge removal. Estrus was screened every 12 h by means of vasectomized marker rams. The animals were inseminated laparoscopically by the intrauterine route using 2 schemes: 1) at a fixed time (12 h) after estrus detection, or 2) at a fixed time (60 h) after sponge removal irrespective of estrus. Pregnancy was determined at 30 d by transrectal ultrasound imaging. The results showed that 1) the onset of estrus occurs most often between 24 and 48 h after sponge removal, 2) ewe hoggets undergo estrus significantly earlier than sexually mature ewes, 3) in those animals showing estrus, there appears to be no relationship between fertility (as assessed by pregnancy outcome) and time of estrus, 4) there is a significant association between the percentage of estrus occurrence and pregnancy rate, 5) fertility is significantly higher in ewes than in hoggets, 6) for practical purposes insemination at a fixed time after the onset of estrus has no advantage over that of to insemination at a fixed time after sponge removal. It is concluded that large-scale laparoscopic intrauterine insemination can be successfully applied in Australian Merino ewes and ewe hoggets in low-productivity areas such as that of Argentine Patagonia and that estrus detection is unnecessary when insemination is performed at 60 h after sponge removal.
摘要译文
这份报告显示了在阿根廷巴塔哥尼亚的一群澳大利亚美利奴羊上进行大规模腹腔镜宫内授精计划的结果。1996年4月和5月在圣克鲁斯省东南部的2个农场共进行了1824只母羊（3-7岁）和480只母羊（19-20个月）的研究。分成15组的动物与含有60mg醋酸甲羟孕酮的阴道海绵同步14天，并在去除海绵时注射200IU PMSG。每12小时通过输精管切除标记公羊筛选发情。通过宫内途径采用2种方案腹腔注射动物：1）在发情检测后的固定时间（12 h）或者2）在去除海绵后的固定时间（60小时），无论发情如何。通过经直肠超声成像在30天测定妊娠。结果表明：1）发情后24〜48 h发情最多，2）母猪发情时间明显早于性成熟母羊，3）在显示发情的那些动物中，生育力（通过妊娠结果评估）与发情时间之间似乎没有关系，4）发情率与妊娠率之间存在显着的相关性; 5）母羊的繁殖力显着高于小猪，6）出于实际的目的，在发情后发情的固定时间进行授精没有优于去除海绵后的固定时间的授精。在阿根廷巴塔哥尼亚这样的低生产力地区，母牛和母羊的母猪被淘汰，并且在去除海绵后60小时进行授精时，不需要发情。
D.Moses[1];A.G.Martínez[1];G.Iorio[1];A.Valcárcel[1];A.Ham[1];H.Pessi[1];R.Castañón[2];A.Maciá[1];M.Ade las Heras[1];. A large-scale program in laparoscopic intrauterine insemination with frozen-thawed semen in Australian Merino sheep in Argentine Patagonia[J]. Theriogenology, 1997,48(4): 651-657