奶牛定时输精技术研究

本试验选择产后25~35 d的健康荷斯坦牛,使用促黄体素释放激素A3(LHRH-A3)和前列腺素(PGF2α)2种生殖激素,利用不同方案对参试牛进行定时输精处理,研究奶牛定时输精的技术效果及其影响因素。方案一为Ovsync程序处理(LHRH-A_3+PGF_(2α)+LHRH-A_3),方案二为Ovsync程序改进方案(2次PGF_(2α)处理)。结果表明:方案一与方案二的受胎率分别为21.21%和46.67%,方案二显著高于方案一(P0.05)。方案二于最后一次注射药物之后的18.1~19.0 h和19.1~20.0 h进行定时输精,其受胎率分别为44.44%和50.00%,二者之间差异不显著(P0.05);输精时采用B超检测卵泡直径,发现卵泡直径为≤14.7 mm、14.8~20.0 mm和20.1~25.2 mm时的受胎率分别为0.00%、75.00%和38.46%,卵泡直径为14.8~20.0 mm组的受胎率显著高于卵泡直径≤14.7 mm组(P0.05);不同季节开展定时输精技术的受胎率,春季、夏季、秋季与冬季分别为30.21%、15.56%、40.00%和40.74%,秋季与冬季显著高于夏季(P0.05);高产奶牛与低产奶牛开展定时输精技术,其受胎率分别为55.56%和33.33%,高产与低产组间无显著差异(P0.05)。综上可知,改进后的Ovsync程序比Ovsync程序效果好。     

定时输精对奶牛第一情期受胎率的效果分析

[目的]探讨不同月份和精液类型对利用定时输精程序处理奶牛后第一情期受胎率的影响.[方法]选择93头产后60 d以上不发情和产后配1～3次仍未受胎的奶牛,不检查卵巢直接利用激素生源2+1进行同期发情处理.1～3月份处理41头奶牛,6～8月份处理52头;其中,利用性控精液配种58头,常规精液配种35头.[结果]表明:经定时...     

奶牛定时输精技术的临床应用效果观察

<正>随着奶牛养殖业的不断发展,一些繁殖障碍问题,如奶牛不发情、屡配不孕和情期受胎率低等情况屡见不鲜,严重制约着奶牛饲养的经济效益和奶业发展。为了进一步提高奶牛的繁殖率,笔者于2009     

定时输精技术在规模奶牛场的应用

随着奶牛生产水平的提高,奶牛产后发情不断推迟,严重影响奶牛场繁殖率。为促进产后母牛发情、输精、受胎,不少奶牛场推广应用了奶牛定时排卵、输精技术。为探讨奶牛定时输精的应用效果,合理应用生殖激素,本文对该技术在杭江奶牛场的应用情况进行了总结。     

同期排卵—定时输精技术在奶牛繁殖中的应用

<正>同期排卵-定时输精技术(简称同期排卵)是在短时间内集中处理多头母畜,不需要观察发情就能定时进行有效人工授精的技术。它是改进的同期发情技术。与老的处理方法比,具有效果可靠,使用面广,效率更高,更有     

应用同期排卵定时输精法提高奶牛受胎率

<正>随着牛群规模的增大和劳动力成本的提高,要做到每天对所有空怀母牛都进行发情检测的可能性越来越小。而且如果只根据发情检查进行人工授精那么怀孕的母牛头数是不可能达到生产所需要的标准的。无论是单纯的表型观察,还是依赖于各种辅助措施的发情检查都不可能达到理想的效果。即使在     

预同步定时输精程序对提高奶牛产后繁殖效率的效果观察

在产后35～40d应用预同步定时输精程序对奶牛进行同步排卵处理,结果显示,奶牛产后80d的参配率和情期受胎率分别达到92.6%和46.7%,产后80d和180d的总受胎率分别达到43.3%和93.5%,均显著高于应用其他处理方法或未做处理的对照组。应用预同步定时输精程序,可以节约观察发情时间,提高工作效率,缩短奶牛产后首次配种时间,减少奶牛空怀天数,为奶牛场创造可观的经济效益。     

布舍瑞林在奶牛同期发情-定时输精中的应用效果分析

本研究旨在分析布舍瑞林在荷斯坦奶牛同期发情-定时输精程序中的应用效果.选用61头产后(53±3)d子宫复旧良好的荷斯坦泌乳牛,分2个实验完成.实验I:将21头牛分为阴性对照组、药物对照组、试验组,均采用同期发情-定时输精(Ovsynch)处理方案,阴性对照组用10 mL生理盐水处理,药物对照组用100μg促性腺激素释放...     

定时输精技术在关中奶山羊繁殖上的应用

[目的]探究定时输精技术在关中奶山羊繁殖方面的应用效果。[方法]选定陕西地区奶山羊规模养殖场的经产母羊先进行疾病检测,合格后开展定时输精试验。2020年7—9月,根据羊场存栏实际情况以及生产安排,将407只1胎羊分为4个批次开展试验,2021年7—9月,对同一批羊（2胎羊）以及新加入的1胎羊按照胎次分为4个批次开展试验,统计各个批次的受孕率。[结果] 2020年,奶山羊应用定时输精技术平均受孕率为79.1%,剔除第一批羊的影响（部分可能存在生理缺陷）,平均受孕率为83.4%;2021年,奶山羊应用定时输精技术平均受孕率为84.6%,且2胎羊的受孕率略高于1胎羊。[结论]在繁殖季节,奶山羊应用定时输精技术可获得理想的受孕率;提高优质种公羊的利用率,有利于良种群体的扩繁;可避免生殖器官疾病和寄生虫病的传播。     

同期排卵定时输精技术在水牛养殖中的应用

同期排卵定时输精技术自1995年以来已被广泛应用于奶牛养殖生产中。水牛与奶牛相比繁殖力低,体现在原始卵泡数少且发情征兆不明显。将同期排卵定时输精技术应用于水牛,可明显提高水牛的受配率与受胎率。本文综合比较了国内外水牛同期排卵定时输精技术程序,分析了各种程序的应用效果及优缺点,对加快该技术在水牛繁殖领域的应用具有重要意义。     

肉牛同期排卵-定时输精技术的应用进展

近年来,中国肉牛产业不断调整优化,母牛存栏量持续增长,但国内可繁殖肉用母牛数量持续减少,母牛受胎率普遍不高,犊牛成活率低,已成为制约肉牛产业发展的瓶颈环节。同期排卵-定时输精技术通过应用生殖激素处理调控母牛发情周期,促进母牛发情,从而提高母牛参配率,在提高母牛繁殖力中得到广泛应用,是当今家畜繁殖技术的一个重大突破。由于中国肉牛养殖集约化程度低,同期排卵-定时输精技术在肉牛上的应用尚未得到广泛重视。不同同期排卵-定时输精处理程序各有特点,在实际应用中影响同期排卵-定时输精程序处理母牛发情配种妊娠率的因素很多,如何对该技术实现进一步优化是当前面临的重大难题。国内外针对于同一生殖激素的不同浓度、不同激素组合及激素注射的间隔时间、激素的替换等做了大量的研究。文章综述了定时输精技术原理、主要程序及国内外肉牛同期排卵-定时输精技术研究进展,以期为建立高效的肉牛同期排卵-定时输精技术体系实现该技术在肉牛产业上的应用提供参考。     

Research Advances and Application Status of Timed Artificial Insemination (TAI) in Farm Animals

With the wide application of the artificial insemination (AI) in animal husbandry,the utilization rate of excellent sire got greatly improved.The key point of AI is predicting the time of ovulation and insemination accurately.It is also the point which the animal husbandry technologists highly concerned to improve the application effect of AI.Estrus and ovulation are regulated minutely by reproductive hormones in vivo in farm animals.Timed artificial insemination (TAI) is based on the synchronization of estrus and ovulation,both of which are triggered by reproductive hormones.So the optimal time for AI could be determined from the reproductive hormone treatment.The purpose of TAI is to improve the reproduction performance of farm animals,reduce the workload of identification of estrus,and promote batch management.This review mainly summerized the principles of TAI and its applications status,and the prospects was also discussed.It would provide a reference for the research and application of new reproductive technology in farm animals.     

家畜定时输精技术研究进展与应用现状

随着人工授精技术在畜牧业中的广泛应用,优秀种公畜的利用率得到了极大提高。而人工授精成功的关键是输精的准确性和及时性,因此如何准确预测排卵时间及输精时间是提高人工授精效果的重要途径,也是当前畜牧工作者高度关注的问题。家畜的发情排卵受到体内生殖激素的精密调控,定时输精技术就是在利用生殖激素进行同期发情、同期排卵的基础上,通过调控母畜的发情和排卵来确定人工输精的最佳时间,以期达到提高家畜繁殖性能、减少发情鉴定工作量和促进养殖场批次化管理的目的。作者综述了家畜定时输精的原理及当前的应用现状,同时对其发展前景进行了展望,以期为畜牧业繁殖新技术的研究和应用提供参考依据。     

Effects of Artificial Insemination vs Natural Service Breeding on Production and Reproduction Parameters in Dairy Herds

The effects of four combinations of AI and natural service (NS) breeding on production and reproduction parameters were analyzed using Holstein Dairy Herd Improvement herd summary records for years 1999 through 2002. Herds were assigned to breeding systems (BS) by percentage of NS usage as follows: 1) 0%, 2) 1 to 20%, 3) 21 to 89%, and 4) 90 to 100%. Regions were North, Midsouth, and South. Herd sizes were small (<100 cows), medium (100 to 249 cows), and large (>250 cows). The mean percentages of AI and NS usage over 4 yr by BS were 1) 100%, 0%; 2) 92.9%, 7.1%; 3) 54.2%, 45.8%; and 4) 1.0%, 99.0%. Actual calving interval was shorter (P<0.05) for BS4 compared with the other systems. Herds using a combination of AI and NS (BS2 and BS3) had longer actual calving intervals than did herds in BS1 (P<0.05). Days dry and the percentage of dry periods between 40 to70 d were less for BS1 (P<0.05). The percentage of cows leaving the herd was significantly less for BS4. The percentage of cows leaving the herd for reproductive reasons was greater for BS1 (P<0.05). Overall reproductive efficiency as measured by the percentage of cows in milk and herd milk yield was greater (P<0.05) for BS1 and declined as the percentage of NS increased. Actual calving interval, days dry, and percentage of dry periods between 40 to 70 d were less in the North (P<0.05). Percentage of cows in milk and herd milk yield were greater in the North (P<0.05). Herd milk yield was greater (P<0.05) for large-size herds and decreased with declining herd size.     

青年奶牛同期发情和同期排卵－定时输精试验

试验旨在研究同期发情和同期排卵－定时输精技术在青年奶牛中的应用。选择1046头澳大利亚进口荷斯坦青年奶牛,随机分为两组:一组自然发情人工授精配种(对照组);另一组采用前列腺素F_2α(PGF_2α)诱导母牛发情或按照同期排卵－定时输精程序(Ovsynch或Ovsynch+CIDR法)处理母牛后人工授精配种(试验组),统计同期发情率、不返情率、第一次人工授精妊娠率和21d妊娠率等繁殖指标。结果表明,试验组青年奶牛人工授精后不返情率和第一次人工授精妊娠率与对照组间无显著差异(P>0.05),但21d妊娠率显著高于对照组(53.1%和35.3%,P<0.05)。试验组中,1次PG法、间隔7d2次PG法和间隔11d2次PG法的同期发情率分别为76.1%、81.7%和84.6%,差异均不显著(P>0.05);同期排卵－定时输精组中,Ovsynch法(GPG)和Ovsynch+CIDR法(GPG+CIDR)的不返情率、第一次人工授精妊娠率和21d妊娠率间无显著差异(P>0.05)。不同输精人员可显著影响青年奶牛的第一次人工授精妊娠率(P<0.05),而不同公牛常规冷冻精液对青年奶牛第一次人工授精妊娠率无显著影响(P>0.05)。同期发情及同期排卵－定时输精技术可使青年奶牛集中发情,提高参配率,从而提高21d妊娠率,有效加快青年奶牛人工授精效率,降低饲养成本。     

Improved Prediction of Ovulation Time may Increase Pregnancy Rates to Artificial Insemination in Lactating Dairy Cattle

A prospective observational study was conducted in two Australian dairy herds to assess the potential for improving pregnancy rates (proportions of inseminations that result in pregnancy) to artificial insemination (AI) if the time of ovulation could be predicted with more certainty. Herd 1 calved year‐round and inseminations were performed during two periods each day. Herd 2 calved during autumn–winter and inseminations were performed only after the morning milking each day. In both herds, the AI to ovulation interval of enrolled cows was determined by trans‐rectal ovarian ultrasonography approximately 0, 12, 24 and 36 h after AI, and pregnancy was assessed by palpation per rectum 35–56 days after AI. Also, in Herd 1 vaginal electrical resistance (VER) measurements were taken at approximately 0, 12, 24 and 36 h after AI, and in Herd 2 cows were fitted with neck mounted activity meters that monitored cow activity count in 2‐h periods. There was substantial variation in the intervals from AI to ovulation within and between herds (mean ± SD 21.2 ± 10.7, n = 102; 14.7 ± 10.4, n = 100 in herds 1 and 2, respectively). Pregnancy rates were higher for inseminations close to, but preceding, ovulation. Using combined herd data (n = 202), the highest pregnancy rate (50.8%) was observed for inseminations between 0 and 16 h before ovulation, a period in which only a modest proportion of inseminations (31.2%) occurred. In contrast, pregnancy rate was significantly lower (28.7%; risk ratio 0.6; 95% CI 0.4–1.0; p = 0.039) for inseminations between 16 and 32 h before ovulation, a period where the highest proportion of inseminations (53.2%) occurred. Thus pregnancy rates could potentially be improved if a greater proportion of inseminations were conducted shortly before ovulation. In Herd 1, mean VER during the peri‐ovulatory period varied with time from ovulation. Lowest values (mean ± SEM, VER = 64.8 ± 1.2, n = 55) occurred approximately 18 h before ovulation and were significantly lower than measurements approximately 6 h before ovulation (67.4 ± 1.0; n = 73; p = 0.003). Further work is required to determine if VER can be used to identify ovulation time and hence the optimal time to inseminate in individual animals. In Herd 2 a modest proportion of inseminations (26.9%) occurred between 24 and 40 h after the onset of increased cow activity where the highest pregnancy rate (67.9%) was observed, whereas a significantly lower pregnancy rate (42.4%; risk ratio 0.6; 95% CI 0.4–0.9; p = 0.036) was observed for inseminations between 8 and 24 h after the onset of increased cow activity where the highest proportion of inseminations (56.7%) occurred. Thus cow activity monitoring may be useful to identify the optimal time to inseminate cows. Results from this study indicate that improved methods of ovulation prediction may allow better insemination timing relative to ovulation and consequently increased pregnancy rates.     

临沂市奶山羊鲜精人工授精技术应用

临沂市具有较好的农业资源,适合发展奶山羊养殖业。但是,目前奶山羊传统的自然交配繁育速率较慢,且受胎率低,不利于奶山羊养殖业的快速发展。近年来,由于人工授精技术具有增强繁殖速率、提升受胎率、提高种公羊利用率和降低成本等优点,在畜牧养殖业中的运用和推广十分广泛。但是人工授精的成功率受到母羊发情期、精液采集和保存、输精方式等多种因素的影响,因此增强对该技术的了解,对促进当地奶山羊的良种繁育具有重要意义。     

奶牛人工授精的优缺点和技术要点

奶牛人工授精技术加速了奶牛品种改良进程,实现了将优秀种公牛精液跨区域、超时限的利用共享,极大地促进了养牛业的发展.以奶牛人工授精应用现状为出发点,介绍了人工授精技术的优点和不足,最后结合自身工作经验,从发情鉴定、适时配种、精液解冻、精液检测、输精、精液保存和妊娠检测等技术要点进行概述,以期更好地促进奶牛人工授精技术的应...     

Effect of Acute Bull Exposure Around the Time of Artificial Insemination on Serum Oxytocin and Progesterone Concentrations and Pregnancy Rates in Dairy Cows

This study examined the effect of acute bull exposure around the time of artificial insemination (AI) on oxytocin and progesterone concentrations, and pregnancy rates in dairy cows. Ninety six dairy cows, stratified according to parity into primiparous and pluriparous, were divided into three groups; short bull exposure (SBE; 10 min, n = 32), long bull exposure (LBE; 4 h, n = 32) or no bull exposure (NBE; n = 32). On day 45 post‐partum, all cows were treated with PGF2α on three occasions 11–14 days apart to synchronize oestrus. They were submitted to fixed time AI 80 h after the third PGF2α injection. Cows in the SBE and LBE groups were artificially inseminated 5 min after the introduction of the bull. From a subset of cows (n = 6 per group; three primiparous and three pluriparous), blood samples were collected once every 5 min starting 15 min before AI until 15 min after AI and analysed for oxytocin concentrations. Additional blood samples were collected for measurements of progesterone (P4) concentrations once daily for 4 days starting on the day of AI and once every 3 days thereafter until day 22. The effects of bull exposure, time, parity, difficulty of AI, and pregnancy on oxytocin and P4 concentrations were analysed using the mixed linear model procedure. Mean oxytocin concentrations or change in oxytocin concentrations after bull exposure or AI were not different among groups. Pregnancy rates for the NBE, SBE and LBE groups were 55.5%, 33.3% and 44.4%, respectively, and were not different among groups. In conclusion, acute bull exposure around the time of AI did not affect oxytocin and progesterone concentrations and did not improve pregnancy rates in dairy cattle under these farms conditions.