影响胚胎移植受体羊同期发情效果的因素

用进口阴道海绵栓、进口孕酮阴道栓、同产前列腺素-氯前列烯醇对受体山羊进行同期发情处理。结果，3种药物的处理效果都比较好，差异不显著。选择不同营养状况的受体羊，用同一种药物处理，结果，营养状况良好的受体羊同期发情效果最好，同期发情率、移植率、妊娠率分别达到100%、86.7%、75.0%。选择西农萨能奶山羊、唐山奶山羊、苏北白羊用同一种经药物处理，结果表明，品种对受体羊同期发情效果影响不大。在不同季节用同一种药物处理受体羊，4、6月份同期发情效果影响明显比11月份差，11月份处理的受体羊同期发情率、移植率、妊娠率分别达93.5%、70.9%、58.0%。     

受体羊同期发情处理技术

以不同的方法在同一季节 ,对当地鲁白山羊进行同期发情处理 ,并对同期发情效果进行比较。结果表明 ,采用氯前列烯醇和CIDR配合PMSG诱导发情在发情率上有明显的差异 (P <0 0 5 ) ;在受体羊移植可用率上差异明显 (P <0 0 5 )。后一种方法效果好于前者。     

受体羊重复使用对同期发情和胚胎移植效果的影响

对106只受体山羊进行同期发情处理，第2年、第3年再重复2次对其中部分受体羊进行同期发情处理，结果表明：第3次同期发情效果显著低于前2次。将102枚波尔山羊胚胎移植给68只受体羊，第2年将70枚胚胎移植给其中的36只，第3年将42枚胚胎移植给第2年手术过的21只受体，结果表明：手术次数及受体羊重复使用对胚胎移植效果影响不显著。     

受体羊同期发情调控的影响因素

通过对影响同期发情调控的受体羊品种、激素、激素处理方法、季节、饲养管理、受体年龄等因素的分析，说明这些因素对提高受体羊的同期发情率和受胎率有一定的作用。     

受体牛重复使用对同期发情效果和胚胎移植受胎率的影响

为了探讨受体牛重复使用对同期发情和胚胎移植受胎率的影响,对部分地区2003～2004年的数据进行分析.结果表明:两次同期率为77.4%和72.7%,黄体合格率为64.6%和62.3%,二者之间差异都不显著(P＞0.05);两次移植受胎率为71.8%和67.7%,差异不显著(P＞0.05).     

同期发情对奶牛不同季节受胎率的影响

同期发情对奶牛不同季节受胎率的影响广东省农业科学院畜牧研究所（广州５１０６５０）余德谦广州地区的高温高湿时间特长，对奶牛繁殖性能的影响很大。据对广州的６８９７头成年母牛进行统计，６—９月份其平均情期受胎率为２０．５％，而在凉爽的１１—４月份为５４．２...     

母牛自然发情与同期发情受胎率的对比分析

通过试验观察受体母牛在自然发情和同期发情后的发情表现，直肠检查卵巢上黄体的生长发育情况，判断最佳移植黄体级别与时间。本试验采取3种方法：I、自然发情法，II、PGF2α单次注射法，III、PGF2α两次注射法，对受体牛做冷冻胚胎移植时发情率和受胎率的对比试验。结果显示，方法II和方法Ⅲ同期发情率明显高于自然发情母牛，差异显著（P＜0.05）；方法II和方法Ⅲ两组之间的移植受胎率差异不显著（P＞0.05）；方法Ⅲ的同期发情率高达82.76%，高于方法II 12.39%；方法Ⅲ黄体A级率70.10%，显著高于方法I和方法II（P＜0.05），方法I、方法II分别为51.60%和57.40%。在小规模散养条件下使用方法I比较经济方便，规模化饲养条件下使用方法Ⅲ，节省人力物力，比较实用。     

供受体羊发情同期化程度对胚胎移植效果的影响

将2008枚鲜胚移植给1146只受体羊,移植单胚和双胚的受体总妊娠率为63.1r3/1146,移植胚胎成羔率为52.861/2008。结果表明供、受体发情同步差在 1～ 0.5d、0d和-0.5～-1d时,移植单胚的受体妊娠率和胚胎成羔率没有明显的差异P>0.05;移植双胚的受体差异显著P<0.05,同步差为0d时的胚胎移植效果最好。移植双胚的受体中,奶山羊受体与供体同步差为-0.5～-1d和0d时,胚胎成羔率显著高于同步差为 1～ 0.5d的受体P<0.05;成都麻羊与供体同步差在 1～ 0.5d、0d和-0.5～-1d时,其胚胎成羔率均有显著差异P<0.05;南江黄羊和大耳羊做受体时,供、受体同步差在 1～ 0.5d、0d和-0.5～-1d时进行胚胎移植,胚胎成羔率无统计学差异。     

青海藏羊同期发情效果分析

为了研究不同同期发情方法对青海藏羊的发情效果,作者通过2种药物处理方法进行试验研究,第1组使用阴道栓+PMSG+PG法,第2组使用PG法。结果表明,本试验同期发情处理110只青海藏羊,其中试验1组处理羊只60只,发情羊只52只,发情率为83.67%,受胎率为84.62%;试验2组处理羊只50只,发情羊只39只,发情率为78%,受胎率为79.49%。实验结果表明,试验1组处理方法优于试验2组,繁殖期内利用第一种方法处理结果较有优势。     

孕马血清促性腺激素诱导受体羊同期发情效果

进行胚胎移植时,不仅要求受体羊的黄体质量好,而且其子宫内环境又要与采胚时的供体羊一致。在实施规模化胚胎移植工作中,由于所选择的受体羊发情周期往往不整齐,如果仅靠选择自然发情羊来确保足够数量可移植受体羊的按时移植是比较困难的,必须要对受体羊采用诱导同期发情处理。     

不同胚胎移植方法对天祝白牦牛受胎率的影响

为提高胚胎移植技术在牦牛上的运用效果,选用51头甘肃省天祝县健康黑牦牛作为受体,以纯种天祝白牦牛作为供体生产胚胎,分别对同期发情处理和自然发情的受体牛进行鲜胚和冻胚移植试验。结果,同期发情处理的受体牛鲜胚移植的受胎率显著高于冻胚移植的受胎率(P0.05),分别为52%和38.5%;在自然发情受体牛的胚胎移植中也得到了相似结果,鲜胚和冻胚的移植受胎率分别为60%和50%,同期发情处理牛的平均妊娠率则低于自然发情受体牛的平均妊娠率(P0.05),二者分别为47.5%和54.5%。结论,牦牛鲜胚移植的受胎率明显高于冻胚移植的受胎率,而且自然发情受体牛的受胎率高于同期发情处理牛。     

PMSG对甘肃高山细毛羊同期发情和繁殖率的影响

在甘肃省肃南县康乐乡对甘肃高山细毛羊应用阴道栓与孕马血清促性腺激素(PMSG) 结合处理,结果表明,不同注射剂量和处理方式对母羊的同期发情和繁殖率均有影响,在埋栓后12.5 d注射550 IU PMSG并在放栓后14 d撤除阴道栓后的0-48 h发情率显著高于其他试验组(P<0.05);在埋栓后13 d注射600 IU PMSG同时撤除阴道栓的试验组繁殖率最高(P<0.05)。但综合繁殖率和经济效益考虑,在埋栓后间隔12.5 d注射550 IU PMSG并在放栓后14 d撤除阴道栓0-48 h的试验组效果最好,平均每只母羊净收入可达773.7元。     

Effects of pre- and postpubertal feeding on production traits at first and second estrus in gilts

The effects of feeding level on body weight (BW), lifetime growth rate, backfat thickness (BF), fatness (BF/BW) and ovulation rate at first (puberty) and second estrus were examined in 145 gilts. From 47.2 kg until puberty, gilts were fed 2.0 kg/d (L) or had ad libitum access to feed (H). From puberty to second estrus, the feed allowance of one-half of the L gilts was increased to 2.8 kg/d. Flush-feeding only normalized ovulation rate (OR) to that observed in gilts with ad libitum access to feed. At puberty, a quadratic negative relationship between lifetime growth rate and age indicated that age at puberty was minimum at a growth rate of less than or equal to .60 kg/d. Thereafter, age at puberty became independent of, or possibly positively related to, lifetime growth rate. Gilts with higher lifetime growth rate also were heavier and fatter at puberty. It was concluded that puberty may have been attained when a certain BF or fatness was achieved, because growth rate of restricted-fed gilts and quickly growing gilts with ad libitum access to feed may have been associated with reduced fat deposition. Hence, maximizing growth rate in replacement gilts does not hasten the attainment of puberty. Growth rate may be manipulated by feed restriction, in order to attain a target BW at boar stimulation (approximately 90 kg), which would coincide with a minimum age (approximately 155 d) and BW at puberty (approximately 97 kg). Nutritional flushing during the first estrous cycle then could be used to normalize OR at mating at second estrus of gilts that were restricted-fed when prepubertal.     

Effects of feeding zearalenone to sows on rebreeding and pregnancy

Two trials were conducted with a total of 91 lactating sows fed 0, 5 or 10 ppm dietary zearalenone (Z) and 0 or 15% dietary alfalfa in a factorial arrangement to evaluate their influence on reproductive performance to 40 d postbreeding. Feeding of Z did not alter the proportion of sows returning to estrus; however, the weaning-to-estrus interval increased when increased dietary Z was fed in Trial 2, with a similar trend at the highest level in Trial 1. The average number of fetuses per sow with fetuses tended to decrease (P less than .05) with increasing dietary Z in Trial 2, but not in Trial 1. Embryonic mortality did not appear to increase when the ratio of fetuses to corpora lutea was compared in sows with fetuses in Trial 1, but it did increase in Trial 2. The trend to increased numbers of bred sows that were non-pregnant at slaughter when dietary Z increased in Trial 1 was not observed in Trial 2. Dietary dehydrated alfalfa meal did not appear to modify the effects of Z in these trials.     

不同诱导发情对胚胎移植产羔率的影响

在湖北、山东、陕西等地区，对当地的土种山羊采用不同同期发情方法处理，并进行了胚胎移植。移植受体羊359只，产羔218只，产羔率为60.72%。（1）采用PG、CIDR＋PMSG、孕酮海绵栓＋PMSG等方法进行处理时发情率无显著差异；（2）氯前列烯醇组黄体合格率77.78%，显著低于CIDR＋PMSG组黄体合格率（97.70%）、孕酮海绵栓＋PMSG组黄体合格率（97.08%）；氯前列稀醇组移植利用率70％，显著低于CIDR＋PMSG组移植利用率（91.43%）、孕酮少绵栓＋PMSG组移植利用率（97.86%）；（3）氯前列烯醇组受体羊产羔率48.99%，显著低于CIDR＋PMSG组产羔率（67.97%）、孕酮海绵栓＋PMSG组产羔率（62.41%）。     

胚胎类型对波尔山羊胚胎移植成功率的影响

供体羊超数排卵后,于发情后的第6～7天从子宫角冲胚,将冲出的胚胎随机移植给与供体发情相差±24小时受体黄体侧的子宫角.结果表明桑椹胚、早期囊胚、囊胚、扩张囊胚、孵化胚的移植受胎率分别为52.6%(81/154),59.4%(19/32),66.2%(43/65),57.7%(45/78),52.2%(24/46),相互之间差异不显著(P>0.05),而移胚后妊娠羊产羔率分别为85.6%(101/118),88.5%(23/26),98.3%(58/59),78.3%(65/83),81.8%(27/33),除囊胚与扩张囊胚产羔率差异高度显著外(P<0.01),其余各组之间差异均不显著(P>0.05).     

Comparison of progestin-based estrus synchronization protocols before fixed-time artificial insemination on pregnancy rate in beef heifers

The objective of the experiment was to compare pregnancy rates resulting from fixed-time AI after administration of either 1 of 2 controlled internal drug release (CIDR)-based protocols. Heifers at 3 locations (location 1, n = 78; location 2, n = 61; and location 3, n = 78) were assigned to 1 of 2 treatments within reproductive tract scores (1 = immature to 5 = cycling) by age and BW. Heifers assigned to CIDR Select received a CIDR insert (1.38 g of progesterone) from d 0 to 14 followed by GnRH (100 mug, i.m.) 9 d after CIDR removal (d 23) and PGF2alpha (PG, 25 mg, i.m.) 7 d after GnRH treatment (d 30). Heifers assigned to CO-Synch + CIDR were administered GnRH and received a CIDR insert on d 23 and PG and CIDR removal on d 30. Heifers at location 1 were fitted with a HeatWatch estrus detection system transmitter from the time of PG until 24 d after fixed-time AI to allow for continuous estrus detection. Artificial insemination was performed at predetermined fixed times for heifers in both treatments at 72 or 54 h after PG for the CIDR Select and CO-Synch + CIDR groups, respectively. All heifers were administered GnRH at the time of AI. Blood samples were collected 10 d before and immediately before treatment initiation (d 0) to determine pretreatment estrous cyclicity (progesterone > or = 0.5 ng/mL). At location 1, the estrous response during the synchronized period was greater (P = 0.06; 87 vs. 69%, respectively), and the variance for interval to estrus after PG was reduced among CIDR Select- (P < 0.01) compared with CO-Synch + CIDR-treated heifers. Fixed-time AI pregnancy rates were significantly greater (P = 0.02) after the CIDR Select protocol (62%) compared with the CO-Synch + CIDR protocol (47%). In summary, the CIDR Select protocol resulted in a greater and more synchronous estrous response and significantly greater fixed-time AI pregnancy rates compared with the CO-Synch + CIDR protocol.