摘要
We studied the influence of two different extenders, a milk-based versus a TRIS-based extender, using a split-sample technique, on fertility after single and double vaginal inseminations in natural estrous in Norwegian Crossbred ewes. Semen from 21 Norwegian Crossbred rams, all aged approximately 0.5 years, was used for AI of totally 561 Norwegian Crossbred ewes housed at 37 different farms. The farmers performed the inseminations themselves. The ewes were allocated to four parallel groups based on the two extenders and single or double inseminations (2×2). The farmers were recommended to inseminate the ewes between 12 and 24 h after detection of natural standing estrous. Vaginal insemination with cooled liquid semen diluted in the milk-based extender resulted in a statistically significant (P<0.01) better fertility of about 10% units both as 25-day NR (non return rate)—and lambing rates, compared with semen diluted in the TRIS-based extender. Double inseminations gave significantly higher (P=0.03) fertility results for both extenders expressed as 25-day NR results, but was not quite statistically significant when expressed as lambing rates (P=0.06) compared with single insemination. The overall 25-day NR results for the milk-based extender (66.4%) after single inseminations is in accordance with both the national results (67.1%) based on vaginal inseminations of 11.377 ewes, as well as with the results from a previous study in the same region achieving a 25-day NR results of 63.3%. In conclusion, liquid ram semen diluted in a milk-based extender and vaginally inseminated once in natural heat, with a semen dose of 150×106 spermatozoa, gave acceptable fertility results and is to be recommended as the method of choice in Norway.
摘要译文
我们研究了两种不同的补充剂，一种基于牛奶的补充剂和一种基于TRIS的补充剂的影响，使用分裂样品技术，挪威杂种母羊自然发情单双重阴道分娩后的生育能力。来自21只挪威杂种公羊的精液，全部约为0.5岁，被用于在37个不同的农场共有561只挪威杂种母羊的AI。农民自己进行了授精。母羊被分配到四个平行集团的基础上的两个扩展和单或双授精（2×2）。建议农民在发现自然发情后12至24小时内将母羊授精。在乳基稀释液中稀释的经冷却的液体精液的阴道授精产生统计学显着性（P 0.05）。01）与以TRIS为基础的补充剂稀释的精液相比，约10％单位更好的生育率（25天NR（不归还率）和产羔率）。双重授精给出了25天NR结果的补充剂的显着更高的生育率结果（P \x3d 0.03）但与单次授精相比，当表示为产羔率（P \x3d 0.06）时，不具有统计学意义。牛奶补充剂的整体25天NR结果（66。4％）是根据全国结果（67.1％）根据11.377母羊的阴道分娩，以及同一地区先前研究的结果，实现了25天的63.3％的NR结果。结论是，将液体公羊精液稀释于乳基增量剂中，并在自然热的情况下进行一次阴道授精，精液剂量为150×106精子，给出了可接受的生育结果，并被推荐为挪威的首选方法。
HeikoPaulenz[a];LennartSöderquist[b];TormodÅdnøy[c];Ove HaraldFossen[d];Kjell AndersenBerg[e];. Effect of milk- and TRIS-based extenders on the fertility of sheep inseminated vaginally once or twice with liquid semen[J]. Theriogenology, 2003,60(4): 759-766