The Management of Prostaglandin-controlled Breeding Programs in Beef Cattle — A Five Year Study

A herd of 180 beef cows was synchronized with prostaglandin and bred by artifical insemination for five successive years. Factors influencing the success or failure of estrus synchronizing programs were identified, including the management of nutrition, postpartum interval, cow age and artificial insemination technology. Specific recommendations on the management of prostaglandin-controlled breeding programs resulted in improving the pregnancy rates from 33% in year 1 to 67% in year 5. Improved management and close veterinary supervision were shown to improve the success of an estrus synchronization program.     

Greater participation by veterinarians in the reproductive management of dairy cattle

A program involving greater veterinary participation in detection of estrus and artificial insemination of cattle was evaluated in a 700-cow dairy herd from January 1987 through August 1988. Previous reproductive performance was below normal. First-service pregnancy rate from artificial insemination was 42%, and mean number of nonpregnant days for the cows was 120. Between postpartum days 55 and 62, all cows with functional corpus luteum assessed by rectal palpation were administered prostaglandin each Monday morning. Return visits were made to the herd each Thursday and Friday to observe cows and to inseminate those in estrus. On the other 5 days of the week, the owner or his employees inseminated all cows in estrus. The first-service pregnancy rate for 842 cows observed in estrus and inseminated by the veterinarian was 59%. The pregnancy rate for cows inseminated by the owner and his employees increased from 42% to 50%. The mean number of nonpregnant days for all 700 cows decreased from 120 to 98 days, resulting in approximately $46,000 of increased income for the dairyman or approximately a 4 to 1 return on investment in veterinary service. Results indicate that veterinarians could improve herd reproductive performance and solve chronic herd breeding problems by more actively participating with their clients in estrus detection and artificial insemination programs in cattle. The program allows practicing veterinarians an opportunity to observe cows for estrous behavior, establish their own pregnancy rate data, demonstrate to owners the importance of observing primary signs of estrus, and teach expert artificial insemination techniques.     

羊同期发情及人工授精技术的生产应用

羊同期发情和人工授精技术是在生产中同时应用的配套技术。针对生产中应用羊同期发情技术同期发情率和受胎率参差不齐的实际情况,介绍孕激素栓＋孕马血清促性腺素（PMSG）＋氯前列烯醇（PG）羊同期发情方法,并按照技术应用操作顺序,详细介绍了同期发情及人工授精的具体技术细节,并对影响羊同期发情和人工授精技术应用效果的因素进行了分析,同时针对生产中容易出现的问题,提出了根据羊体况及场管理条件应用同期发情技术的建议。     

冷冻精液输精深度和时间对蒙古羊受胎率的影响

[目的] 研究冷冻精液输精深度和时间对蒙古羊受胎率的影响。[方法] 选取体况健康、繁殖机能正常的蒙古羊母羊作为试验动物,采用孕酮海绵栓对受体母羊进行同期发情处理。应用常规人工输精法（n=135）、过子宫颈输精法[过子宫颈第一皱褶（1~2 cm）输精（n=120）,过子宫颈第二到第三皱褶（3~4 cm）输精（n=120）]、腹腔镜辅助子宫内输精法（n=128）对发情后的母羊进行冷冻精液人工授精。接受常规人工输精法和过子宫颈输精法处理的受体母羊在发情后约14 h和22 h各输精1次,接受腹腔镜辅助子宫内输精法处理的受体母羊在发情后30~36 h输精1次。输精后40 d用B超仪检测母羊妊娠情况,计算并比较接受不同输精方法处理母羊的受胎率。[结果] 腹腔镜辅助子宫内输精法的受体母羊受胎率平均值最高,为60.2%;其次为过子宫颈第二到第三皱褶（3~4 cm）输精,受胎率平均值为58.3%;过子宫颈第一皱褶（1~2 cm）输精和常规输精法的受体母羊受胎率平均值分别为37.5%和36.3%。统计学分析表明,腹腔镜辅助子宫内输精法和过子宫颈第二到第三皱褶（3~4 cm）输精的受体母羊受胎率平均值显著（P<0.05）高于常规输精法和过子宫颈第一皱褶（1~2 cm）输精。[结论] 蒙古羊母羊发情后30~36 h采用腹腔镜辅助子宫内输精法完全穿刺子宫颈输精1次,可获得比常规输精法更高的受胎率;采用过子宫颈输精法在母羊发情后约14 h和22 h各输精1次,当授精深度接近4 cm时可达到与腹腔镜辅助子宫内输精法接近的受胎率。     

不同饲养管理条件下黄牛的同期发情试验

[目的]为了便于集中配种或胚胎移植。[方法]采取了三种方法：一次PG改进法、CI-DR＋PMSG＋PG＋LHRH-A3法、PMSG＋PG＋LHRH-A3法处理三种不同饲养管理条件下的黄牛,诱导同期发情。[结果]表明四次处理的同期发情率分别为100%、100%、98.8%、82.4%,人工授精或胚胎移植受胎率分别为27.3%、80%、76.5%、59.2%。[结论]从经济角度表明一次PG改进法、PMSG＋PG＋LHRH-A3法是比较切合实际,也比较理想的同期发情方法,效果也比较理想。     

A review of current timed-AI (TAI) programs for beef and dairy cattle

This is a review of the physiology and endocrinology of the estrous cycle and how ovarian physiology can be manipulated and controlled for timed artificial insemination (TAI) in beef and dairy cattle. Estrus detection is required for artificial insemination (AI), but it is done poorly in dairy cattle and it is difficult in beef cattle. Protocols that synchronize follicle growth, corpus luteum regression and ovulation, allowing for TAI, result in improved reproductive performance, because all animals are inseminated whether they show estrus or not. As result, TAI programs have become an integral part of reproductive management in many dairy herds and offer beef producers the opportunity to incorporate AI into their herds. Gonadotropin-releasing hormone-based protocols are commonly used in North America for estrus synchronization as part of a TAI program. Protocols that increase pregnancy rates in lactating dairy cows and suckling beef cows have been developed. Protocols that improve pregnancy rates in heifers, acyclic beef cows, and resynchronized lactating dairy cows are also discussed.     

配种前药物处理对母猪繁殖性能的影响

为了减少人工授精过程中人为操作引入的病原微生物,改善母猪断奶后不发情、延迟发情或发情后配种不受孕所导致的母猪繁殖性能降低的现象,在饲养管理良好、免疫程序健全的条件下,试验采用在母猪配种前对其进行药物处理。将试验母猪随机分为2组,A组为断奶经产母猪(n=65),B组为第2情期后的后备母猪(n=58)。将A组进一步分为A-Ⅰ组(n=36,投药组)和A-Ⅱ组(n=29,空白对照组),B组进一步分为B-Ⅰ组(n=34,投药组)和B-Ⅱ组(n=24,空白对照组)。统计发情率、受胎率、分娩率及产仔数等繁殖指标。结果表明:A-Ⅰ组每头母猪断奶10 d内发情率为100%,与A-Ⅱ组发情率(96.55%)相比差异不显著(P>0.05);A-Ⅰ组情期受胎率为91.67%,分娩率为86.11%,产仔数为11.32头,而A-Ⅱ组情期受胎率为85.71%,分娩率为78.57%,产仔数为9.95头,差异均显著(P<0.05);B组内,除健仔数外其余各指标差异均不显著(P>0.05)。说明在配种前给经产母猪投药,可以改善母猪繁殖力。     

Effect of environmental factors on estrus synchronization and artificial insemination success in farmers flock in sheep under semi-arid tropical region

Environmental cues in the different seasons might influence the estrus and lambing percentages. The present study was conducted to assess the effect of environmental factors on estrus synchronization (ES) and artificial insemination success in sheep . During the period from 2012 to 2017, a total of 1,197 ewes of Kheri and Malpura breeds of 34 farms originating from 10 villages were synchronized for estrus and then fixed-time artificial insemination (FTAI) was done. Oestrous synchronization was done by intravaginal progesterone sponges and eCG protocol. Fixed-time cervical insemination was performed 48 and 56 hr after sponge removal in ewes exhibiting estrus, using liquid chilled semen containing 100 million sperm per dose of Patanwadi/Malpura rams. Mean sunshine hours, maximum and minimum ambient temperatures, temperature amplitude, mean relative humidity (RH), temperature-humidity index (THI), mean temperature during sponge-in to sponge-out—12-day period, sponge-out and next day, AI day and AI to next 15 days have been calculated. The estrus response and lambing percentage were higher (p < .05) when ES and FTAI were done during hot-humid with rainfall season. Successful (p < .05) ES occur when the minimum temperature was higher in cold-humid season, and the sunshine hour was higher in hot-humid with scanty rainfall season during sponge-in to sponge-out period. The success of the lambing percentage was higher (p < .05) when maximum temperature, minimum temperature, mean temperature and THI was higher on the day of AI and the next 15-day period, irrespective of the season. The success of FTAI indicates the adaptability of the local breed to tolerate the harsh climate of the hot semi-arid region without much hindrance in lambing percentages.     

二组同期发情方案及定时输精技术 提高牦牛受胎率效果观察

摘 要：为进一步研究牦牛发情不集中、受胎率低的问题,利用二组同期发情方案使牦牛在繁殖季节集中表现发情后定时输精,准确把握输精时机,提高牦牛受胎率。本试验选择在同一草场常年放牧、健康、膘情均达中等以上,年龄3-10岁母牦牛进行同期处理并严格控制处理和配种的时间,观察发情、受胎效果。结果显示,通过二组同期发情方案对牦牛同期发情处理,发情率、受胎率分别为 67%、76%、56%、64%,差异显著（P＜0.05）,同期组2不论同期发情率还是受胎率明显高于同期组1,应加以示范推广。     

Synchronized estrus and fertility of beef cows after weaning calves for short intervals

In Exp. 1, the objective was to determine if interval of separating calves from cows (24 or 48 h) immediately before insemination affects detection and precision of estrus and pregnancy rates of lactating beef cows implanted with norgestomet. Separation of calves from cows for 24 h (n = 418) lengthened intervals to estrus, did not affect precision of estrus, reduced success of detecting estrus and lowered pregnancy rates relative to positive controls (48 h separation, n = 508). Cows with poor body condition, and not suckled for 24 h, conceived at lower rates than cows with similar condition that were not suckled for 48 h. Adverse effects of separation for only 24 h on fertility are apparently due to inadequate intervals between estrus and insemination at 48 h after removing implants. In Exp. 2, the objective was to determine effects of separating calves from cows for 48 h immediately before insemination on detection and precision of estrus and on pregnancy rate of ovulatory lactating beef cows injected twice with prostaglandin F2 alpha (PGF2 alpha). Weaning increased detection of estrus but overall pregnancy rates did not differ between suckled (n = 256) and nonsuckled (n = 221) cows. But, weaning calves improved pregnancy rates of young (2 to 3 yr) cows and reduced fertility among middle (4 to 6 yr)-aged cows. Increased pregnancy rates after weaning calves for 48 h are due largely to greater detection of estrus and inseminating more cows.(ABSTRACT TRUNCATED AT 250 WORDS)     

文山州同期发情—定时输精技术在肉牛生产中的应用

[目的]为探讨同期发情—定时输精技术对云南省文山州母牛繁殖性能的影响,建立适宜于南方肉牛品种改良的轻简推广实用技术程序。[方法]通过肉牛同期发情—定时输精技术程序在文山州广南、砚山、富宁三县的应用效果作比较。[结果]结果表明,使用该技术程序后三县肉牛平均同期发情率为93.24%,平均受胎率达80.94%,应用效果良好;母牛体况对发情效果影响较大,有待提高母牛饲养管理水平。[结论]同期发情—定时输精技术对提高母牛受胎率的效果明显,值得在我国南方肉牛养殖业中大力推广。     

宝鸡地区荷斯坦奶牛发情、排卵及授精效果的比较观测

对宝鸡地区荷斯坦奶牛发情周期排卵时间、授精效果进行了调查，并对其影响因素作了分析研究。研究结果：不同产犊季节对产后第一次发情时间有显著影响，青年牛与成年牛发情后排卵时间有显著差异。产后第一、二次与三次以上发情输精受胎率有显著差异；产后母牛用药物处理和不处理，授精效果差异显著。表明，在奶牛产后子宫正常情况下，在第一、二情期授精效果最好；发情周期在19－23d受胎率提高；排卵8h内输精、受胎率最高。     

寒区马鹿发情鉴定与最佳输精时间的确定

为使寒区马鹿人工授精有标准可循,并提高其受胎率,对2007年大兴安岭地区马鹿人工输精记录进行了分析。结果表明：生产中,寒区马鹿发情鉴定采取＂公鹿试情为主,人为观察为辅＂综合判定的方式比较准确。人工输精最佳时机是发情末期母鹿拒绝试情公鹿爬跨前的1h到拒绝爬跨后的3h。这一个时段母鹿外观特征主要变化是由兴奋转为安静,从接受公鹿爬跨转为拒爬,外阴肿胀基本消退、颜色呈淡红或暗紫色。     

平凉红牛母牛一年一胎繁育技术

为了研究母牛高效繁育技术对平凉红牛母牛繁殖效率和养殖效益的影响,从母牛产后第8天开始,试验组母子分离、定时哺乳、早期断奶,对照组随母哺乳、自然断奶.结果表明,试验组母牛主要在60 d内第一次发情,发情率76.7％,对照组母牛主要在90 d后第一次发情,发情率60％;试验组母牛90 d内受胎率86.7％、第一次授精情期受...     

使用PMSG、HCG调节繁殖末期母蓝狐发情和产仔效果的试验研究

为了提高乏情母狐的利用率,第1年对50只没有发情表现的青年母蓝狐同时一次注射PMSG200IU/只,5d后再注射HCG100IU/只,有42只出现明显发情症状并接受公狐爬跨,发情率84%。对发情母狐实施子宫内输精,结果无一产仔;第2年对50只非典型发情的青年母蓝狐同时一次注射PMSG200IU/只,5d后再注射HCG100IU/只,全部出现明显的发情症状并接受交配。对其实施子宫内输精3次,结果有24只产仔,产仔率48%。试验结果表明,在母狐繁殖末期,联合使用PMSG和HCG对没有发情表现的青年母蓝狐有促使其发情的作用,但不能使其产仔;对有发情表现但不明显的青年母蓝狐有促进其发情并能使其部分怀孕和产仔的作用。     

用ELISA测乳汁孕酮进行奶牛的发情检查和早孕诊断的研究

本试验用ELISA测定了101头奶牛配种期0～2天和配种后18～24天的乳汁孕酮含量,提供了牧场分两阶段测试乳样进行奶牛的发情检查和早孕诊断的可行方案。测定的结果经临床检验核实:发情检查的确诊率为100％;配种后20～22天,妊娠牛和空怀牛的确诊率分别为92.1％和96.9％,可疑率为4.0％,总确诊率为89.9％。     

提高奶水牛人工授精受胎率的技术关键

为了提高奶水牛人工授精的受胎率,准确把握发情症状和适时的输精是技术的关键。本文就奶水牛发情表现、发情观察、适时输精技术要点及应注意的关键性技术措施等作了分析,为奶水牛产业化发展、提高人工授精受胎率提供参考及指导。     

郏县红牛与夏南牛同期发情定时输精效果分析

[目的]探讨“同期发情定时输精”技术在不同群体中的实施效果,提升郏县红牛和夏南牛的繁殖效率,发挥地方良种的繁殖力。[方法]试验以100头郏县红牛和198头夏南牛为研究对象,采用戈那瑞林和PG 079同期发情方案对其进行处理,分析同期发情定时输精效果。[结果]100头郏县红牛的平均受胎率为76.4%,198头夏南牛后备母牛的受胎率为100%。[结论]同期发情定时输精处理的后备牛受胎率高于经产牛。     

Effects of progestagen exposure duration on estrus synchronization and conception rates of crossbreed ewes undergoing fixed time artificial insemination

Synchronization of estrus and ovulation are of paramount importance in modern livestock improvement programs. These methods are critical for assisted reproduction technologies, including artificial insemination and embryo transfer, that can increase productivity. In the current study, subcutaneous implants containing norgestomet were placed for long (14 days), medium (9 days), and short (5 days) periods of time in 70 crossbred ewes undergoing fixed-time artificial insemination. The resulting effects on estrus synchronization and conception rates were subsequently evaluated. Among the synchronized ewes, 85.7% (60/70) underwent estrus over a period of 72 h after progestagen treatment ceased. The shortest mean interval between withdrawal of the device and onset of estrus (34.2 ± 8.9 h) was observed in the G14 days of P4 group (p < 0.05). The conception rate of the G14 days of P4 group was statistically higher than that of the other groups (83.3% vs. 60.9% vs. 47.8%; p < 0.05). In conclusion, 14 days of norgestomet treatment produced higher conception rates and a greater number of pregnancies at the beginning of the breeding season.     

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。