湖羊精液冷冻对受胎率的影响

本试验利用前期筛选的湖羊精液冷冻稀释液及冷冻保护剂制作湖羊冻精,对比冻精和鲜精的精子活力和顶体完整率。同时,对40头初产母羊和40头经产母羊进行同期发情处理,然后分组进行鲜精和冻精输精试验,跟踪受胎率。结果表明,冻精的活力和顶体完整率分别为0.396和49.2%,显著低于鲜精;初产母羊和经产母羊的冻精受胎率分别为41.7%和33.3%,也显著低于鲜精。说明湖羊精液冷冻对湖羊精子质量和母羊受胎率都存在显著影响。     

提高马冷冻精液受胎率的研究

<正> 五十年代随着牛精液冷冻成功,六十年代以来马精液冷冻,国内外进展迅速,成就很大,目前受胎率已接近鲜精水平。在冷冻技术方面改进很快,由非浓缩精液改为浓缩精液;在分装冷冻方面,有采用大安培(10毫升)、小颗粒(0.1毫升)、铝薄片、塑料薄膜袋、细管、片状等多种方法;在解冻上,有干解和湿解之分;在受胎率方面由30％多,已提高到50％左右。马的精液冷冻,现在已由试验阶段逐步向应用阶段过渡。我国马的精液冷冻研究工作起步并不晚,但中途停顿了,大量工作是随着牛的冻     

试管水牛技术研究

水牛卵巢卵母细胞经体外成熟培养、体外受精和受精卵在体外培育的胚胎移植给受体母水牛,结果表明：①卵母细胞体外培养成熟率71．6％、受精分裂率52．8％、囊胚率(占授精卵母细胞)27．2％。②双鲜胚移植受胎率36．2％(30．0％～44．8％),双胎率24％;双冻胚移植受胎率20．0％;生产试管水牛24头,全部成活,其中冻胚试管水牛3头;双胞胎3对。③胚胎冷冻方面：采用玻璃化胚胎冷冻技术,冷冻胚胎解冻后存活率64．4%。     

羊冷冻精液的制作与应用技术研究

研究筛选出了进行羊冷冻精液制作的绵羊、山羊稀释液配方,冻制羊冷冻精液解冻后活力和顶体完整率都达到了进行羊冷冻精液输精质量标准要求。应用绵羊冷冻精液给母羊输精,情期配种受胎率达到了65%;应用山羊冷冻精液给母羊输精,情期配种受胎率达到了66%,并取得了显著的改良效果。     

关于提高“冷配”受胎率的几个技术问题

<正> 洛阳地区自1974年开始引进肉用和乳肉兼用牛,采用冷冻精液人工授精技术,受胎率逐年有新提高由74年的6.0％提高到83年的73％。 在提高受胎率的同时,各地还减少了精液消耗量,每头牛消耗冻精颗粒由1974年的6.2个减至1982年的2.24个,每个颗粒剂量为0.1毫升,含有效精子数1000万;现将几年来提高牛“冷配”受胎率归纳如下。     

大熊猫细管冻精制备程序的建立与应用

筛选了不同的冷冻稀释液(TEST,蔗糖-卵黄-甘油液)、不同的冷冻剂型(颗粒法,细管法)、不同甘油终浓度、不同的解冻液(M199,Ham′sF10)等条件,在此基础上,建立了大熊猫细管冻精制备程序。与传统颗粒冻精制备技术相比,本试验极显著地提高了大熊猫冷冻精液质量,冷冻精液活力从35.45%提高到57.88%(P<0.01);顶体完整率从42.25%提高到78.24%(P<0.01)。从1999年至2002年共有14只雌性大熊猫在共计36只次发情配种中采用了细管冻精,较1992～1998年采用传统颗粒冻精的总受胎率提高了11.2个百分点(达到55.6%),其中经产健康适龄雌性大熊猫的受胎率提高了27.3个百分点(达到83.3%),处女大熊猫的受胎率提高了8.8个百分点(达到58.8%)。     

羊冷冻精液的制作与应用技术研究

课题研究筛选出了进行羊冷冻精液制作的绵羊、山羊稀释液配方,冻制羊冷冻精液解冻后的活力和顶体完整率都达到了进行羊冷冻精液输精质量标准要求,应用绵羊冷冻精液给母羊输精,情期配种受胎率达到了65%,应用山羊冷冻精液给母羊输精,情期配种受胎率达到了66%的较好水平,并取得了显著的改良效果。     

公牛塑料细管冻精制作方法与应用效果的研究

本试验就细管冻精和颗粒冻精的冷冻效果和受胎情况进行了对比分析。结果表明，采用设定的工艺流程制作的细管冻精与颗粒冻精，其精子的解冻活率和复苏率没有显著差异（ｐ〉０．０５），采用水平冻结方式和垂直冻结方式生产的细管冻精，其精子的解冻活率和复苏率也无显著差异（ｐ〉０．０５）。但细管冻精的情期受胎率和一次输精受胎率却显著高于颗粒冻精。表明细管冻精的应用效果优于颗粒冻精。     

猪精液冷冻技术试验

从稀释液和解冻液的筛选，平衡时间、平衡温度、冷冻剂型的选择等方面进行试验。试验结果：猪精液冷冻后活率为３０％－６０％；解冻后的复苏率为５１．４２％－５８．７２％；保存３０天的冻精与保存３６０天的冻精受胎率无明显差异（Ｐ＞０．０１）；冻精保存期一年以上；输精受胎率达６３．６４％（６０％－６６．６６％），平均窝产仔６．１头。     

奶牛胚胎体外保存时间和温度对移植受胎率的影响

试验对胚胎在体外保存时间的长短及温度与移植妊娠率的关系进行统计分析，胚胎收集后分别在0-3h,3-6h和6h后冷冻，解冻后移植受胎率分别为46.07%,43.33%,30.56%,0-3h和3-6h冷冻的胚胎，移植受胎率没有明显差异（P〉0。05），6h后的冻胚与6h以前的冻胚移植受胎率差异显著（P〈0．05）。胚胎分别在室温和37℃保存5h后冷冻，解冻后移植受胎率分别为39．74％、42．24％（P〉0．05）。     

不同季节不同生产因素对荷斯坦奶牛性控冻精人工输精受胎率的影响

为研究不同季节、不同胎次、不同发情方式及不同泌乳天数等因素对奶牛单个情期受胎率的影响,选取2169头奶牛进行统计分析。结果显示,奶牛秋冬季配种受胎率较春夏季高,冬季情期受胎率显著高于春、夏两季（P＜0.05）,初产奶牛情期受胎率高于经产奶牛（P＜0.01）,自然发情情期受胎率极显著高于同期发情药物处理奶牛（P＜0.01）,不同泌乳阶段对受胎率影响不大（P＞0.05）。     

JSAR Innovative Technology Award. Development of ovulation synchronization and fixed time artificial insemination in dairy cows

Recently, reproductive management has become more difficult as a result of increased herd size. Problems with missing estrous signs and decrease in conception rate by artificial insemination (AI) performed at wrong timing have caused low AI conception rates. In 1995, ovulation synchronization and fixed-time AI (Ovsynch/TAI) was developed in the USA as a new reproductive technology, which was accepted as an useful reproductive management tool in many countries. However, no information on the use of Ovsynch/TAI was available in Japan. It was, therefore, warranted to show the ovulation rate and conception rate after Ovsynch/TAI using gonadotropin releasing hormone analogue (GnRH-A, fertirelin acetate) and prostaglandin F2alpha (PGF2alpha)-THAM, both were commercially available in this country. The conception rate after Ovsynch/TAI has been known to vary among different herds and individuals. Investigation and analysis of factors affecting the conception rate was also warranted to improve the conception rate. A series of experiments were carried out to establish Ovsynch/TAI using domestically produced GnRH-A and PGF2alpha and to study factors affecting conception rate after Ovsynch protocol. Ovsynch using 100 microg GnRH-A and 25 mg PGF2alpha were observed using ultrasonography. As a result, a high synchronization rate of ovulation at 16 to 20 h after the second GnRH injection was confirmed. The conception rate after Ovsynch/TAI was compared in 87 cows with the conception rate after AI at estrus induced by PGF2alpha (139 cows). Conception rate after Ovsynch/TAI was higher than the figure after AI at induced estrus (59.1% vs 20.9%, P<0.05). The dose of GnRH-A was also studied and a practical dose of GnRH-A was found to be 50 microg per cow. To clarify some factors affecting the conception rate after Ovsynch/TAI, 1,558 cows were investigated for the state of their ovaries, days after calving, parity, season, ovarian cyclicity postpartum and nutritional state at the day of Ovsynch. The overall conception rate after Ovsynch/TAI was 51.5%. Fifty-six cows (3.6%) showed estrus at 6 to 7 d after the first injection of GnRH-A. The conception rate after Ovsynch/TAI was low in cows that were 40 to 60 d postpartum, those in their 5th lactation or more, those bred in July to August, and those recovering ovarian cyclicity later than 56 d postpartum. The conception rate after Ovsynch/TAI was high in cows in which body condition score (BCS) was 3.75 at dry period and 3.0 at the day of Ovsynch. In conclusion, Ovsynch/TAI is an effective tool for the reproductive management of dairy cows. A steady and sufficient conception rate after Ovsynch/TAI could be expected by taking the factors affecting the conception rate into the consideration.     

温湿度与母猪受胎率关系的研究

通过对中山市某大型猪场 449头母猪第一情期受胎率的统计及其与温湿度等主要气候生态因子的相关分析表明 ,气温对母猪第一情期受胎率的影响较大 ,它们之间呈极显著的负相关关系。其中月均气温、平均最高气温、平均最低气温及高于 30℃天数与母猪第一情期受胎率的相关系数分别为 - 0 8875 ,- 0 850 7、 - 0 90 84和 - 0 90 5 9,而气湿与情期受胎率的相关系数只有 - 0 2 65 7,经检验相关关系不显著 (P >0 0 5)。高温高湿的气候 ,最易使母猪第一情期受胎率下降。改善养猪的环境 ,夏季要注意防暑或调整日粮或配种时间 ,以提高受胎率     

Effect of breed and other animal-related factors on conception rate to artificial insemination with frozen semen in mares in Ethiopia

Equine reproduction is unique by having long behavioral estrus and differences in time of breeding between breeds and individuals of mares. An experimental study was conducted at the Balderas Sport Horses and Recreational Center, Addis Ababa, Ethiopia, from January to June, 2018, to evaluate conception rate to frozen semen in local and exotic crossbreed mares. Mares were teased to characterize estrus behavior and examined by ultrasound in determining imminent ovulation. Inseminations were done post ovulation within an average of 6–9 h using frozen-thawed semen. The overall conception rate to frozen semen was 15/21 (71.43%) with 8/11 (72.73%) in crossbreed and 7/10 (70%) in local breed mares. Age and body condition score (BCS) of animals had no significant effect on conception rate to AI with frozen semen. A slightly higher conception rate was obtained when ovulation was from the right ovary than when ovulated from the left ovary. A higher conception rate was obtained when the diameter of the preovulatory follicle was ≤ 45 mm than above diameter. The conception rate increased significantly with increased number of services/conception with an overall mean ± (SEM) of 2.2 ± 0.2 services/conception. A more number of services/conception were required for local breed (2.7 ± 0.2) than crossbreed mares (1.8 ± 0.3) and again for lower body condition scores than higher condition scores of mares. In conclusion, the increased number of services improved the conception rate with significant difference between breed of mares, whereas good management of mares for improved body conditions could be required to decrease the number of services per conception.

     

使用PMSG等激素提高四川黄牛繁殖效率研究初报

母牛发情一定阶段应用ＰＭＳＧ，氯前列烯醇和抗ＰＭＳＧ血清处理，８头交牛发情率８７．５％，第一情期受胎率７１．４％总受胎率８５．７％，得一胎孪生母牛，比对照组有明显提高。该处理方法在缩短空怀期，治疗屡配不孕等方面也表现了良好作用，是提高母牛繁殖效率的有效方法，值得扩大试验推广。     

Relationships between the conception rate of estrus synchronization using estradiol benzoate and CIDR (progesterone) and other parameters in holstein lactating dairy cows

The purpose of this study was to determine the relationships between conception rate and other parameters before estrus synchronization with a Controlled Internal Drug Release Device (CIDR) and estradiol benzoate (EB). In the estrus synchronization program, animals were injected with 2 mg EB and then received a CIDR. Seven days later, the CIDR was removed and the animals were given an injection of Prostaglandin F(2alpha). Twenty-four hours later, they received an injection of 1 mg EB, and they were artificially inseminated 24 h after that. This program was applied to 258 Holstein cows in Tohoku-machi (Aomori, Japan). Blood was collected at the beginning of the program, and the conception rate was determined about 40 days after insemination. The relationships among conception rate, blood biochemical values, age, body condition score and days in milk were statistically analyzed to determine better conditions for cow conception. The conception rate of the cows in the high progesterone group (more than 1 ng/ml, P(4)+) was significantly higher than that of the low progesterone group (less than 1 ng/ml, P(4)-; 47.9% vs. 28.6% P<0.01). In the P(4)- groups, the serum phospholipid level was significantly higher in the conception group than in the non-conception group, and the same tendency was seen in the P(4)+ groups. Blood urea nitrogen (BUN), albumin (Alb), and total cholesterol (TChol) were significantly higher in the conception group compared with the non-conception group, but no with P(4) was observed. We concluded that 1) the conception rate of the P(4)- group was remarkably low, that 2) the low conception rate and low P(4) level was related to a low PL level and that 3) BUN, Alb and TChol were higher in the conception group, although no relation with P(4) was found.     

维生素B12解冻液在绵羊人工授精中的应用

应用维生素B12注射液做绵羊冻精的解冻液,实施人工授精配种来提高绵羊受胎率和羔羊成活率。结果表明,试验组绵羊受胎率达96.0%,羔羊成活率达94.2%,而对照组绵羊受胎率为78.0%,羔羊成活率为85.4%,试验组与对照组绵羊受胎率和羔羊成活率均有显著性差异(P<0.05)。     

配后净宫技术提高子宫内膜炎奶牛受胎率的试验

对患子宫内膜炎的试验占在发情时延适时输精,输精后１２子宫灌注５ｇ／Ｌ盐酸环丙沙星溶液,情期受胎率为６１．２％（１０４／１７０）。试验对照组奶牛应用同样药物治疗,痊愈后下一个发情期,健康对照组奶牛不作处理,平均情期受胎率分别为４７．２％和４６．４４％。     

Improved knowledge about conception rates influences the decision to stop insemination in dairy cows

The conception rate in dairy cows is dependent on a number of cow factors such as days in milk and insemination number. Unfortunately, some of these factors were not accounted for in optimal insemination and replacement decision models. By using wrong estimates of the conception rate, the calculated optimal insemination and replacement policy might differ from the real optimal insemination and replacement policy. The objective of this study was to evaluate different sets of conception rates with an increasing level of accuracy to determine the insemination policy. An existing dynamic program for optimal insemination and replacement was used to compare three different scenarios in the estimation of conception rates, based on the reproductive performance of Dutch dairy cattle: (i) constant conception rate throughout lactation, (ii) conception rate dependent on parity and months in milk, and (iii) conception rate dependent on parity, months in milk and insemination number. The time step of the model was 30.4 days (1 month). The discounted future cash flow of culling a cow at each time step (replace a heifer immediately) was compared with keeping that cow under optimal future decisions. The difference between immediate culling and optimal decisions is defined as the retention pay-off. The insemination value was calculated as the difference between the future cash flow between immediate insemination of a cow and waiting one time-step. The results show that the difference in the insemination values and the optimal time to stop insemination depend on parity, lactation stage and the relative milk yield. In older cows with equal milk yields and at the same months in milk, the insemination value was lower than in younger cows. Within a parity, the insemination value was higher for cows with a higher milk yield. On individual cow level, using more accurate conception rate as input in the optimal insemination and replacement model might reduce miscalculation of the economic consequences for at least of €20-€38 per cow per year. Basing insemination decisions on less accurate input of the probabilities of conception, however, did not have an economic consequence at the herd level. In conclusion, using the appropriate conception rate as input in the optimal insemination and replacement model would increase the precise decision for the optimal time to stop insemination and hence improve the reproductive management efficacy.     

影响西门塔尔母牛情期受胎率因素的分析

为探讨影响新疆地区西门塔尔母牛情期受胎率的因素,本试验采用SAS 8.1对影响情期受胎率的配种季节、与配公牛和母牛年龄3个因素进行最小二乘方差分析,各水平间进行Duncan多重比较并分析不同水平对情期受胎率的影响。结果表明,不同配种季节对西门塔尔母牛情期受胎率影响极显著(P<0.01),春季西门塔尔母牛情期受胎率极显著低于夏季、秋季、冬季(P<0.01),冬季情期受胎率最高(64.7%),而春季情期受胎率最低(40.0%);与配公牛对西门塔尔母牛情期受胎率无显著影响(P>0.05);母牛年龄对西门塔尔母牛情期受胎率的影响极显著(P<0.01),随着母牛年龄的逐渐增加情期受胎率有降低的趋势。依据本研究结果,可针对各影响因素合理有效的调控,从而提高母牛的情期受胎率,最终提高牛场经济效益。