Mekuriaw Zeleke, Assefa Habtemariam, Tegegne Azage, Muluneh Dagne
International Livestock Research Institute (ILRI), LIVES Project, Bahir Dar, Ethiopia.
International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia.
Trop Anim Health Prod. 2016 Jan;48(1):53-7. doi: 10.1007/s11250-015-0919-z. Epub 2015 Oct 6.
Natural lambing in sheep in Ethiopia occurs throughout the year in a scattered manner negatively affecting survival and growth rates of the lambs born during the unfavorable season of the year. Thus, controlling the time of mating artificially using exogenous source of hormones is considered as one of the ways to mitigated problems related to haphazard lambing. To this end, an experiment was conducted to evaluate efficacy of prostaglandin-based estrus synchronization protocol in local and crossbred ewes. A total of 160 ewes (80 local and 80 crossbreds) which lambed at least once and aged 3-5 years were used. Lutalyse® (dinoprost tromethamine sterile solution equivalent to 5 mg dinoprost per ml) and its analog, Synchromate® (cloprostenol sodium equivalent to 0.250 mg cloprostenol per ml), were tested at different doses. The treatments used were intramuscular injection of (1) 2.50 ml of Lutalyse® (12.5 mg dinoprost tromethamine), (2) 2 ml of Lutalyse® (10.0 mg dinoprost tromethamine), (3) 1 ml of Synchromate® (0.25 mg of cloprostenol Sodium), and (4) 0.8 ml of Synchromate® (0.20 mg of cloprostenol Sodium). Forty ewes (20 local and 20 crossbreds) were allocated per treatment. Following injection of the respective hormones, rams of known fertility were introduced into the flock for the duration of 96 h at the ratio of one ram to 10 ewes. All estrus synchronization protocols except treatment 4 (0.8 ml of Synchromate®) induced estrus (heat) in majority (55-65%) of local and crossbred ewes within 96 h post-hormone injection. The time interval from hormone administration to onset of estrus was also more or less similar for all treatment groups except for treatment group 4 which showed heat quicker. The highest lambing rate was recorded in local ewes (84.62% (11/13) treated with 2.5 ml of Lutalyse®, whereas the least was obtained in crossbreds (33.33% (3/9) treated with 0.8 ml Synchromate®. In conclusion, even though 2.5 ml and 2 ml of Lutalyse® or 1 ml of Synchromate® were able to induce heat in majority of local and crossbred ewes, the highest lambing percentage was obtained from ewes treated with 2.5 ml of Lutalyse®. Therefore, the use of 2.5 ml Lutalyse® is recommended to synchronize estrus in local and crossbred ewes under Ethiopian smallholder sheep production system for the benefit of improved lambing rate.
在埃塞俄比亚，绵羊全年都会自然产羔，但分布零散，这对在一年中不利季节出生的羔羊的存活率和生长率产生了负面影响。因此，使用外源激素人工控制配种时间被视为减轻与随意产羔相关问题的方法之一。为此，开展了一项实验，以评估基于前列腺素的发情同步方案对本地和杂交母羊的效果。总共使用了160只母羊（80只本地母羊和80只杂交母羊），这些母羊至少产过一次羔，年龄在3至5岁之间。对Lutalyse®（每毫升含5毫克地诺前列素的地诺前列素 tromethamine无菌溶液）及其类似物Synchromate®（每毫升含0.250毫克氯前列醇钠）进行了不同剂量的测试。所使用的处理方法为肌肉注射：(1) 2.50毫升Lutalyse®（12.5毫克地诺前列素 tromethamine）；(2) 2毫升Lutalyse®（10.0毫克地诺前列素 tromethamine）；(3) 1毫升Synchromate®（0.25毫克氯前列醇钠）；(4) 0.8毫升Synchromate®（0.20毫克氯前列醇钠）。每个处理组分配40只母羊（20只本地母羊和20只杂交母羊）。注射相应激素后，将已知繁殖力的公羊以1只公羊配10只母羊的比例放入羊群中96小时。除处理4（0.8毫升Synchromate®）外，所有发情同步方案在激素注射后96小时内都能使大多数（55 - 65%）的本地和杂交母羊发情。除处理组4发情较快外，所有处理组从激素给药到发情开始的时间间隔大致相似。本地母羊产羔率最高的是用2.5毫升Lutalyse®处理的母羊（84.62%（11/13）），而杂交母羊产羔率最低的是用0.8毫升Synchromate®处理的母羊（33.33%（3/9））。总之，尽管2.5毫升和2毫升Lutalyse®或1毫升Synchromate®能够使大多数本地和杂交母羊发情，但产羔率最高的是用2.5毫升Lutalyse®处理的母羊。因此，建议在埃塞俄比亚小农养羊生产系统中，使用2.5毫升Lutalyse®来同步本地和杂交母羊的发情，以提高产羔率。
