非繁殖季节母驴诱导发情、排卵效果的研究

[目的]研究前列腺素F2α（PGF2α）、孕马血清促性腺激素（PMSG）、人绒毛膜促性腺激素（hCG）3种激素在不同处理方案下对内蒙古通辽地区乏情期母驴卵泡生长情况、排卵率、发情率、受胎率与妊娠率的影响。[方法]将50头2～6岁、体重接近、体况良好、处于乏情期的母驴随机分为A、B、C、D4组,其中D组为未使用任何激素的空白对照组。首先,采用PGF2α、PMSG进行诱导发情试验,对A、B、C3组母驴注射2mL／头PGF2α,连续处理5d,第6天对A、B组母驴分别注射PMSG 1000IU,头和500IU,头;C组不做PMSG处理。诱导发情后将A、B组再细分为A1、A2和B1、B2组,当A1、B1、C3组中母驴卵泡直径大于35mm时注射hCG（总量1500IU）进行诱导排卵;A2、B2不做hCG处理,由卵泡自然发育至排卵。对所有诱导发情后有发情表现的母驴进行自然本交。同时,在试验期间利用直肠检查和B超检查对母驴的卵巢发育进行监测。『结果]c组发情率为30％,经PGF2α处理第5天时卵巢黄体基本全部消退;A组和B组的发情率分别为93．33％和86．66％,二者差异不大,但均明显高于C组。A1、B1最终的排卵率为100％和77．78％,而A2和B2的排卵率为60．00％和50．00％。A,组受胎率和妊娠率最高,分别达到了88．89％和80．00％,其次是B,组分别为66．67％和60．00％,B2、C2组的受胎率和妊娠率都较低,D组虽然有1头母驴发情,但配种后未妊娠。[结论]单独使用PGF2α对非繁殖季节母驴诱导发情效果不明显,但其对消除母驴黄体有明显作用;PGF2α与PMSG联用对诱导乏情母驴发情效果较好。使用PGF2α与PMSG对处于乏情期的母驴诱导发情后,注射hCG对母驴卵巢上优势卵泡具有明显的促进排卵作用,能加快优势卵泡的排卵,且明显提高母驴的排卵率。该试验确定的最佳方案为：注射0．2mgPGF2α连续处理5d,第6天注射PMSG 500lU,当优势卵泡直径达35mm时注射hCG 1500lU,排卵后配种。     

羊同期发情腹腔镜输精最佳时间的研究

[目的]确定羊同期发情腹腔镜输精的最佳时间。[方法]选取繁殖机能正常、营养状况良好的适龄母羊,在试验母羊阴道内放置孕酮海绵栓10~14 d,撤栓时肌肉注射250~330 IU/只孕马血清促性腺激素（PMSG）。撤栓后12~24 h开始试情,早晚各1次。按撤栓后时间及发情时间不同分4组进行腹腔镜输精：1组为撤栓后46~50 h输精（n=138）,2组为撤栓后50~54 h输精（n=156）,3组为撤栓后54~58 h输精（n=275）,4组为羊发情后30~36 h输精（n=226）。输精后第40~45天进行B超检查,计算各组母羊受胎率。[结果]发情后30~36 h输精的母羊（4组）受胎率最高,为97.79%,其次为撤栓后50~54 h输精的母羊（2组）,受胎率为97.44%,撤栓后46~50 h输精的母羊（1组）受胎率为91.30%;撤栓后54~58 h输精的母羊（3组）受胎率最低,为89.82%。[结论]采用同期发情配合腹腔镜输精技术进行母羊人工授精,最佳输精时间为撤栓后50~54 h以及母羊发情后30~36 h。     

青年母牛卵泡大小与妊娠成功的关系

早期研究表明:经产母牛输精期卵泡大小显著影响其受胎率和授精后胚胎/胎儿死亡率,但对自然排卵的母牛受胎率没有影响。本研究目标是分析青年母年受胎率、胚胎/胎儿死亡率同排卵前期卵泡大小、诱导或自发排卵后血液循环中雌二醇浓度之间的关系。青年母牛分为成2组不同的繁殖牛群进行人工授精:①利用同期发情和诱导排卵后授精(TAI,n=98);②在23 d发情周期中,利用电子检测仪检测母牛发情后12 h授精(自然排卵,n=110)。利用直肠超声波检查输精时卵泡大小和输精后27、41、55和68d怀孕状态。测定的青年母牛中仅有6头出现后期胚胎或早期胎儿死亡。繁殖牛群和卵泡大小的相互作用并不影响母牛受胎率。结合繁殖牛群数据分析,卵泡大小对受胎率的对数回归特征表现为曲线(P<0.01),并且预测出卵泡大小为12.8mm时,受胎率最高(为68.0±4.9%)。卵泡直径小于10.7 mm或大于15.7 mm时,受胎率都较直径为12.8 mm卵泡低。直径小于10.7 mm卵泡(有28%的青年母牛妊娠)则比大于15.7 mm的卵泡(仅有4%)更易受孕。授精后24 h内有发情行为的青年母牛所排卵泡直径(12.2±0.2 mm)、雌二醇浓度(9.9±0.6)以及妊娠率(63%)都显著高于无发情行为的母牛(分别为11.1±0.3mm,6.6±0.7,20%)(P<0.01)。然而,对卵泡大小差异进行分析后,发现妊娠率又与发情行为表现和雌二醇浓度无关。因此,血清雌二醇浓度和发情行为对妊娠的影响似乎通过卵泡大小来介导的,并且优化卵泡大小的管理实践可以提高受胎率。     

驴发情期卵泡变化初探

采用实时B型超声显像法,初步观察了4头母驴3个发情期卵泡的发育过程,以确定其排卵和输精时间。结果表明:驴卵泡直径大约每天增加1.5~3 mm,优势卵泡平均每天增长2.1 mm,发情周期在20~24 d之间,发情一般持续5~7 d,约在发情停止前1 d排卵。体格较大的驴发情期间卵泡数比体格较小的驴卵泡数多。     

超排处理对家兔生殖器官形态及激素水平的影响

【目的】 研究超排处理对家兔生殖器官组织形态和激素水平的影响。【方法】 将12只家兔分为试验组和对照组，每组各6只，在试验组家兔大腿内侧肌内注射70 IU孕马血清促性腺激素（pregnant mare serum gonadotropin，PMSG），72 h后同位置注射100 IU人绒毛促性腺激素（human chorionic gonadotropin，hCG），对照组均同时注射等体积生理盐水。试验组与对照组均采取与公兔合笼刺激诱导排卵，合笼24 h处死家兔并采集卵巢、输卵管、子宫，测量卵巢长度、宽度、厚度，子宫长度、宽度、周长、子宫壁厚度和输卵管长度、漏斗部宽度、峡部宽度、壶腹部宽度，并将卵巢制作成组织切片，通过HE染色研究卵巢卵泡变化；分别在注射PMSG前、注射hCG前及处死前采集对照组和试验组家兔耳缘静脉血，用ELISA法检测血清中抑制素（inhibin，INH）、促卵泡素（follicle-stimulating hormone，FSH）、促黄体素（luteinizing hormone，LH）、雌二醇（estradiol，E₂）和孕酮（progesterone，P₄）的含量。【结果】 与对照组相比，试验组卵巢组织重量、长度、宽度、厚度、充血卵泡数、排卵点数和闭锁卵泡数均极显著增加（P<0.01），卵巢内次级卵泡的直径显著变小（P<0.05）；输卵管长度、壶腹部宽度和子宫宽度均显著增加（P<0.05），输卵管漏斗部宽度和子宫长度均极显著增加（P<0.01）。在3个不同采血时间，对照组家兔血清中INH水平呈递增趋势，在注射hCG前和处死前试验组INH含量均显著低于对照组（P<0.05）；注射hCG前，试验组血清中FSH含量显著高于对照组（P<0.05），而在处死前试验组血清中FSH含量显著低于对照组（P<0.05）；注射hCG前和处死前试验组血清中LH含量均显著高于对照组（P<0.05）；试验组与对照组家兔血清中P₄和E₂含量在各时间点差异均不显著（P>0.05）。【结论】 70 IU PMSG+100 IU hCG组合的超排处理使家兔的卵巢体积增大、表面排卵点数增多，并协同内源激素作用于卵巢，获得较好的超排效果。     

提高母驴受胎率体会

<正> 提高母驴的受胎率,必须做到:1 确定排卵时间,做到适时配种主要根据直检如卵巢上的卵泡已经破裂,形状由圆形变为不规则形,卵泡腔形成一个凹陷,这时,应迅速输精。据对30头发情母驴的配种观察,其受胎率为86.6%。如卵巢上的卵泡呈球形,卵泡内充满液体,卵饱壁较薄,有一按即破之感觉,此时可输精一次。以后隔12小时再输精一次,据对15头发情母驴配种观察,受胎率为93.3%。结合阴道流出分泌粘液,且透明度低,粘稠,能     

hCG促进马属动物排卵的研究进展

马属动物属季节性单胎动物,从母马或母驴出现发情表现到排卵,持续3~13 d不等,该生理特征极大地影响其繁殖效率。hCG作为LH类似物不会受性激素反馈调节机制的制约,广泛应用于马属动物卵泡发育和排卵。从性激素在哺乳动物卵泡发育过程中的作用、马属动物主卵泡波与LH诱导的优势卵泡排卵、外源性激素对马属动物卵泡发育的影响、hCG的结构与功能、hCG在延长母马黄体期的应用和hCG在马属动物超数排卵中的应用6个方面内容阐述hCG促进马属动物排卵的研究进展。     

德州驴冷冻精液定时输精技术与情期受孕率初探

为提升驴冻精利用率并探究适用于规模化驴养殖场的冻精输精技术,本实验对253头3~7岁健康适繁德州母驴的354个情期开展促排卵和冻精输精试验。选取卵泡直径≥30 mm的发情母驴51头,随机分为2组,其中31头肌肉注射GnRH药物0.8 mL,当天记为第0天(D010:00);另外20头为对照组,肌肉注射0.8 mL生理盐水,统计排卵率。经促排处理并采用同一输精方法的自然发情母驴归为同一试验组。输精实验中,在驴群集中排卵发生前的4 h(D₁16:00)、2 h(D₁18:00)、0 h(D₁20:00)分别对母驴群开展不同输精剂量的单次输精试验(10、5、2支/头);将在D₁20:00的单次输精改为在D₁20:00和D204:00各进行1次输精,分组记为5+5支组(31头)、2+2支组(32头)、1+1支组(21头)。结果发现:发情母驴肌肉注射GnRH药物后34~48 h集中排卵,排卵率(80.65%)显著高于对照组(55.00%);单次输精试验中母驴的情期受孕率在9.52%~29.41%,且不同时间点、不同输精支数组受孕率差异不显著;母驴集中排卵区间内进行2次定时输精试验发现,5+5支组、2+2支组、1+1支组情期受孕率分别为35.48%、31.25%、19.05%(P>0.05),5+5支组的情期受孕率(35.48%)显著高于D₁20:00单次2支组(14.71%)。使用2次定时输精可以在提高冻精利用率的基础上获得较为理想的情期受孕率。     

腾冲马同期发情和定时输精技术研究

本实验旨在探究孕酮缓释硅胶栓结合氯前列醇钠和促性腺激素释放激素(GnRH)类似物处理对母马同期发情和定时输精效果的影响。在繁殖季节,选取43头不同胎次的健康空怀腾冲母马,分为A、B组。A组(n=23)中第1、2、3胎次母马数量分别为6、10、7头,均肌注1 mL GnRH类似物记作第0天,第2天阴道内埋植阴道孕酮缓释硅胶栓,第8天肌肉注射4 mL氯前列醇钠,第11天取栓的同时再次肌肉注射4 mL氯前列醇钠,第12～16天B超检查卵泡发育状态。当卵泡直径到33 mm时,注射GnRH类似物1 mL,8 h后用低温保存的公马精液进行输精,输精后24 h和48 h检查母马排卵率,配种后15 d检查受胎率。B组(n=20)均为第2胎次,不做任何激素处理,在自然发情条件下进行B超检测和人工授精处理,记录其发情、排卵和受胎率。结果表明:A组在处理的第12～16天,86.95%的母马卵巢出现直径大于33mm的卵泡,一次输精后的情期受胎率为65.00%;B组在12～16 d内,20.00%的母马卵巢出现直径大于33mm的卵泡,情期受胎率为75.00%。本实验方案对前3胎次母马的发情同步率和怀孕率没有显著差异。因此,本实验处理方案可以使母马群在配种季节集中发情和配种,大大减少卵泡发育的检查时间和配种次数,并能获得较理想的受胎率。     

应用B超技术监测青年母牛卵巢动态变化的研究

通过B超监测11头青年母牛的卵巢动态变化。显示在自然发情状态下，排卵当天卵巢直径的平均值为18．24mm，排卵前一天平均值为21．94mm，排卵后一天平均值为21．63mm。卵泡发育以卵泡波的形式出现，本实验观察到3—4个卵泡波，以3个卵泡波为主，占81．82％，4个卵泡波的占18．18％；青年母牛左侧卵巢优势卵泡的平均直径为11．71±0．71mm，成熟卵泡的平均直径为14．76±0．94mm；右侧卵巢优势卵泡的平均直径为13．02±1．97mm，成熟卵泡的平均直径为14．34±1．30mm.     

Comparative Efficacy of Histrelin Acetate and hCG for Inducing Ovulation in Brazilian Northeastern Jennies (Equus africanus asinus)

The goal of this study was to compare the efficiency of histrelin acetate (GnRH analog) and human chorionic gonadotropin (hCG) to hasten ovulation in Brazilian Northeastern jennies (Equus africanus asinus). Thirty cycles of ten jennies were randomly assigned in one of the three groups: G0 (control group), saline; G1, 250 μg of histrelin acetate; G2, 2500 IU of hCG. Jennies were evaluated by transrectal palpation and ultrasonography, and had the administration of an ovulation-inducing agent when a follicle measuring between 29 and 32 mm of diameter was diagnosed. Jennies were monitored every 6 hours by transrectal ultrasonography until ovulation. The interval between prostaglandin administration and ovulation was lower (P < .05) in jennies from the G1 (145.2 ± 34.6 hours) and G2 (147.4 ± 27.3 hours) groups compared with the control cycle (220.0 ± 41.8 hours). Both treatments (G1, 41.15 ± 3.5 hours; G2, 37.8 ± 2.5 hours) also reduced (P < .05) the interval that jennies took to ovulate after the administration of the ovulation-inducing agent compared with the control (81.8 ± 28.8 hours). All jennies from G1 and G2 ovulated up to 48 hours after ovulation induction, whereas 100% of jennies in the control cycle ovulated later (>48 hours from the administration of saline). In conclusion, both histrelin acetate and hCG at the used dose are efficient ovulation-inducing agents in jennies promoting ovulation up to 48 hours after administration.     

Attempt to control the day of ovulation in cycling pony mares by associating a GnRH antagonist with hCG

With the objective of controlling the day of ovulation, 40 mares were assigned to a control or three treated groups: A3d, A4d, and A5d. The treated groups received antarelix (Teverelix 0.01 mg/kg, i.v., twice a day) for 3, 4, or 5 days from the day the dominant follicle (F1) reached 28 mm (=D0), and one injection of hCG (1600 IU, i.v.) on D1, D2, or D3, respectively. Control mares received one injection of hCG when F1 reached 35 mm. Plasma LH, FSH, progesterone, and total estrogens were assayed. In the A3d, A4d, and A5d groups, 9 (90%), 6 (60%), and 5 (50%) out of 10 mares, respectively, ovulated on the expected day (i.e. between 24 and 48 h after hCG injection). In the control group, 7/10 (70%) presented the typical response to hCG. For 3 mares in both the A4d and A5d groups, the dominant follicle at the time the treatment was started did not ovulate and ovulation was postponed for between 11 and 15 days after the end of treatment. In the treated mares, the LH surge was abolished, and total estrogens were depressed during the preovulatory peak but the concentrations of FSH were not modified. Endocrine parameters were not altered in postponed cycles. Fertility did not differ in treated and control cycles. These results demonstrate that in mares: (1) ovulation can be programmed on a specific day of a 3-day period, with a success rate of 67%, by a treatment associating antarelix and one injection of hCG; (2) nevertheless in 20% of cases the dominant follicle regresses and does not ovulate; (3) for these mares ovulation is postponed by approximately 2 weeks; (4) terminal growth of the preovulatory follicle only requires low circulating concentrations of LH but atresia induced by a GnRH antagonist is significant when this treatment is administrated for more than 18 h.     

连续重复超数排卵、冲胚对引进品种肉羊快速扩繁的效果研究

[目的] 评价引进品种肉羊的连续重复超数排卵（超排）、冲胚、胚胎移植等繁育技术集成模式的应用效果。[方法] 于2016—2018年,对选取的1 575只澳洲白（n=230）、白头杜泊（n=228）、黑头杜泊（n=541）、白头萨福克（n=200）、黑头萨福克（n=376）5个品种母羊,进行间隔30 d以上的连续同期发情（孕酮海绵栓）与超排（330~450 IU FSH+200~300 IU PMSG+0.1 mg PG）处理;经过腹腔内窥镜输精后进行子宫角冲胚,回收胚胎后计数并评估质量,挑取部分胚胎进行移植;对比分析品种、季节、重复超排次数等对胚胎生产指标的影响。[结果] 共获得18 496枚胚胎,有14 971枚可用胚;胚胎移植后的受胎率为69.8%,产羔率为93.2%;只均总胚数和只均可用胚数2项指标显示,胚胎生产特性以白头萨福克、黑头萨福克、黑头杜泊较好,澳洲白次之,白头杜泊最差;不同品种母羊连续重复超排冲胚后回收的只均总胚数和只均可用胚数持续增长,直到第4或第5次;澳洲白的超排冲胚效果在春季较好,而其他品种在冬季较好。[结论] 连续重复超数排卵、冲胚技术对于扩繁引进肉羊品种群体是可行的,应根据不同品种及其表现出的季节特性科学、适时应用。     

奶牛临床型乳腺炎致病菌分离鉴定及2种常见用药方案的疗效研究

为了研究奶牛乳腺炎致病菌种类,同时比较青霉素、链霉素合并使用与沃瑞特单独使用在奶牛临床型乳腺炎的治疗中的疗效差异,以100头患有临床型乳腺炎的奶牛为研究对象,对从乳样中分离到的细菌进行鉴定;在同一饲养管理条件下将上述患牛分为对照组（4头）、沃瑞特组（50头）、青链霉素组（46头）进行疗效对比研究。结果表明,致病菌葡萄球菌的分离率为37.0%、大肠杆菌为30.1%、克雷伯菌为 18.3%、链球菌为2.4%,其他菌为12.2%,占比例最高的是葡萄球菌;2种用药方案均收到良好的治疗效果,青链霉素组治愈率为78.26%,沃瑞特治愈率为66.00%,青链霉素组治愈率显著高于沃瑞特组。     

Use of a GnRH antagonist,antarelix, associated or not with hCG,to control ovulation in cyclic pony mares

The GnRH antagonist antarelix (Teverelix™) was administered to mares (0.01 mg/kg, i.v., twice a day) during the periovulatory period. In Experiment 1, 20 mares were divided into a treated (A3d−) and a control (Control−) group. A3d− mares received antarelix for 3 days from the day when the dominant follicle (F1) reached 32 mm (D0). In Experiment 2, 10 mares were divided into a treated (A6d+) and a control (Control+) group. A6d+ mares received antarelix for 6 days from D0 and hCG was injected in all animals (1600 IU, i.v.) on D1. Pregnancies were determined 13 days after ovulation. In both experiments, antarelix interrupted or totally abolished the LH surge. In Experiment 1, 5/10 of the A3d− mares (with maximum LH concentrations of 11.6 ng/ml at the beginning of treatment) ovulated at the same time as the Control− mares; the other five mares (with LH concentrations under 5.4 ng/ml) ovulated 13.4±0.6 days later. In Experiment 2, all the A6d+ mares ovulated at the same time as the Control+ mares. In treated mares which ovulated during the treatment, progesterone concentrations and fertility did not differ from control mares. These results demonstrate that in mares: (1) a small elevation of endogenous LH can induce ovulation, (2) ovulation can be postponed approximately 13 days after a 3-day antarelix treatment if initiated just before the preovulatory LH surge, (3) ovulation can be induced by hCG on depressed levels of endogenous LH, (4) the inhibition of the post ovulatory LH surge has no effect either on the corpus luteum or on fertility.     

Comparison of HCG, buserelin and luprostiol for induction of ovulation in cycling mares

Sixty nonlactating light-horse mares were used to compare the efficacy of hCG, buserelin (a GnRH analog) and luprostiol (a PGF₂α analog) for induction of ovulation in cycling mares. Mares were assigned to 1 of 4 treatments: 1) controls; 2) 40 μg buserelin IM at 12 hr intervals during estrus until ovulation; 3) 7.5 mg IM luprostiol; and 4) 3,300 IU hCG. Treatments were given once a mare obtained a ≥35mm follicle and had been in estrus ≥2 days. Both buserelin and hCG shortened (p<0.05) the interval from treatment to ovulation compared to controls; whereas, luprostiol failed to hasten ovulation. Number of follicles ovulated was similar among all 4 groups. Although buserelin and hCG were equal in their ability to induce ovulation, an average of 3.8 injections of buserelin was required for hastening of ovulation.     

Characteristics of follicular dynamics and reproductive hormone profiles during oestrous cycles of jennies over an entire year

Although donkeys have been domesticated for over 6,000 years, limited information is available concerning their reproductive physiology, especially under intensive rearing conditions. The aims of this experiment were to study follicular dynamics and reproductive hormone variation in jennies during the inter-ovulatory interval in different seasons. A total of 12 continuous cycles of six Dezhou Black (DB) donkey jennies were examined in four different seasons. The diameters of the six largest follicles of each jenny were measured daily by ultrasonography, and blood samples were collected at fixed times for reproductive hormone assays. The results demonstrated that most jennies displayed regular oestrous cycles in all seasons. The follicular dynamics were similar in Spring, Summer and Winter, while the jennies had longer oestrous cycles with delayed follicular deviation and dominant selection in Autumn. At least two follicular waves were observed in each oestrous cycle, throughout the study, but two jennies presented oestrous cycles with three follicular waves in the Autumn. The numbers of follicular waves were consistent with the numbers of FSH surges. Oestrous characteristics of the jennies in a large herd were also analysed. The results showed that the rates of regular oestrous cycles were 83.1% (265/319), 89.6% (215/240), 80.2% (235/293) and 77.1% (178/231), with 26.4% (70/265), 19.5% (42/215), 22.1% (52/235) and 23.0% (41/178) double ovulation rates in Spring, Summer, Autumn and Winter, respectively. The results presented may be useful for donkey farms in the design of breeding strategies.