摘要
Artificial insemination (AI) in sheep is currently limited by the poor fertility obtained following non-surgical intracervical insemination of frozen–thawed semen. An exception to this general finding is the non-return rate of around 58% reported for large scale on-farm AI in Norway. The objective of the present study was to determine if similar results could be obtained under Irish conditions. Comparisons were made between semen collected, and frozen, from rams in Norway (NOR) and Ireland (IRL). The effects of synchronisation and inseminator were also examined. Parous ewes (n=297) of various breed types were inseminated to a natural (N) or synchronised (S) oestrus with either fresh (from Irish rams) or frozen–thawed (IRL and NOR) semen. Ewes were randomly assigned, within breed, to the following treatment groups: (i) Fresh-N: n=28, (ii) Fresh-S: n=30, (iii) IRL-N: n=62, (iv) IRL-S: n=50, (v) NOR-N: n=68, (vi) NOR-S: n=59. Within each group, ewes were inseminated by an experienced Norwegian or by an Irish inseminator. Pregnancy rate did not differ significantly between ewes inseminated to a natural or synchronised oestrus nor between Norwegian and Irish frozen semen. The proportion of ewes pregnant after insemination with fresh semen was 0.82 and 0.70 (treatments i and ii) compared with 0.40, 0.52, 0.34 and 0.37 (treatments (iii)–(vi)) for frozen semen (PPPPP
摘要译文
羊的人工授精（AI）目前受限于冷冻 - 解冻精液的非手术宫颈内授精后获得的不良的生育力。这个普遍发现的例外情况是挪威大规模农场人工智能报告中报告的不报答率约为58％。本研究的目的是确定在爱尔兰条件下是否可以获得类似的结果。收集精液和冷冻精液进行比较，来自挪威（NOR）和爱尔兰（IRL）的公羊。还检查了同步和授精者的影响。将各种品种的帕洛斯母羊（n \x3d 297）与新鲜（来自爱尔兰的公羊）或冷冻 - 解冻（IRL和NOR）精液的自然（N）或同步（S）发情授精。（i）Fresh-N：n \x3d 28，（ii）Fresh-S：n \x3d 30，（iii）IRL-N：n \x3d 62，（iv） IRL-S：n \x3d 50，（v）NOR-N：n \x3d 68，（vi）NOR-S：n \x3d 59。在每一组中，母羊都由有经验的挪威人或爱尔兰的授精者授精。妊娠率在自然或同步发情的母羊以及挪威和爱尔兰冷冻精液之间没有显着差异。与新鲜精液授精后怀孕的母羊比例分别为0.82,0.70（处理Ⅰ和ii），而冷冻精液（PPPPP）的处理（iii） - （vi）分别为0.40,0.52,0.34和0.37
ADonovan[a];J.PHanrahan[a][1];EKummen[b];PDuffy[c];M.PBoland[c];. Fertility in the ewe following cervical insemination with fresh or frozen–thawed semen at a natural or synchronised oestrus[J]. Animal Reproduction Science, 2004,84(3-4): 359-368