如何选购和使用优质奶牛冻精

<正>1奶牛冷冻精液的选购1.1了解供精单位种公牛信息如种公牛系谱、体型结构、育种值报告、公牛的后裔测定成绩、公牛的父母亲表现。从而选择适合本场牛群某些性状改良的公牛冻精。     

不同季节对种公牛精液品质的影响

种公牛优良的精液对牛群的遗传改良起着极其重要的作用,为了提高种公牛精液品质与冷冻精液的质量,通过对不同季节种公牛精液的原精活力、鲜精密度、射精量及冻后活力的变化进行总结分析,研究不同季节对种公牛精液的品质的影响。结果表明:春季种公牛鲜精活力、密度、冻后活力最佳;夏季鲜精活力与冻后活力最差;秋季射精量最高但密度最低,鲜精活力与冻后活力仅高于夏季;冬季射精量最低,但鲜精活力、密度及冻后活力仅次于春季。因此,充分利用适宜生产的季节,合理安排采精,可提高种公牛的鲜精品质,进而提高冻精产量,使优秀种公牛的遗传潜力得到最大的发挥。     

摩拉、尼里/拉菲种公牛促性腺激素释放激素受体(GnRHR)基因序列多态性与精液质量性状的相关分析

为了研究促性腺激素释放激素受体(GnRHR)基因与摩拉、尼里/拉菲种公牛精子质量性状的相关性,试验对28头摩拉、40头尼里/拉菲种公牛的GnRHR基因多态性位点与其2011—2016年精液质量性状的关系进行统计分析。结果表明:GnRHR基因分别与摩拉、尼里/拉菲种公牛精液质量性状具有相关性。摩拉种公牛A13 342G位点,AA型的射精量显著高于AG型(P0.05),AG型的精子密度显著高于AA型(P0.05);T17 221C位点,TT型的冻精活力显著高于TC型(P0.05)。尼里/拉菲种公牛T13 355G位点,TG型的冻精活力显著高于TT、GG型(P0.05);A13 406T位点,AA、AT型的鲜精活力显著高于TT型(P0.05),AA、AT型的鲜精活力无显著差异(P0.05);AT型的冻后活力显著高于AA、TT型(P0.05)。说明GnRHR基因可作为摩拉、尼里/拉菲种公牛精液质量性状的重要分子标记。     

补肾生精散对种公牛精液品质和血浆生殖激素浓度的影响

选用10头么拉水牛种公牛,探讨添加补肾生精散对种公牛血浆促黄体素LH、促卵泡素FSH、睾酮T浓度和精液品质的影响.用药后血浆LH浓度上升,FSH和T浓度下降,种公牛鲜精量、鲜精活力、冻精活力有所改善,说明补肾生精散可改善水牛种公牛精液品质.     

不同品种种公牛繁殖性能分析

[目的]在相同的饲养环境条件下,分析不同品种种公牛之间繁殖性能及适应性的差异。[方法]通过对云南省家畜冷冻精液站四个品种的种公牛相关精液品质测量数据及终生冻精产量数据进行对比分析。[结果]经过对16头种公牛繁殖性能及适应性分析,荷斯坦种公牛原精活力及冻后活力都较其它种公牛表现出较明显的优势;荷斯坦种公牛在有效采精率及冻精产量上也明显高于其它品种公牛。     

电刺激采精器在荷斯坦种公牛上的应用

本文介绍了德国米尼图电刺激采精器(Electro-Ejakulator mit sonde 2,5’’)的基本原理、工作方式,以及利用电刺激采精器采集荷斯坦种公牛精液的情况,并与假阴道法采集该牛精液的结果进行比较。与假阴道法相比较,利用电刺激采精器法获得的精液量显著提高,但精子密度却显著降低;而在原精活力、冻精活力、冻精产量方面无显著差异。利用电刺激采精器对无法以假阴道法采集精液的公牛进行精液采集,取得了良好效果。     

关于公牛冷冻精液冻后存活精子数的探讨

当前评定公牛精液品质的主要依据是采精量、原精活力、精子密度、精子的冻后复活率(冻精活力/原精活力)等项指标。由于不同公牛精液活力、密度、及冻后复活率不同,总的精液品质优劣就无法衡量。在实际工作中,我们常常发现生产性能和外貌优秀的公牛,由于精液品质低     

牛细管冷冻精液对提高解冻后精子活力及增强优秀公牛利用率的探讨

当前评定公牛精液品质的主要依据是采精量、原精活力、精子密度、精子的冻后复活率(冻后活力/原精活力)等项指标。而公牛由于个体间的差异使以上各项评定指标,尤其使冻后解冻活力出现较大差异。精液冷冻主要目的是为充分利用优良种公牛的精液,以先进的手段--深冷技术,制成冻精剂型加以保存,然后解冻(40℃水浴)复     

口蹄疫三价苗对荷斯坦种公牛冷冻精液生产的影响

为研究口蹄疫O型、亚洲Ⅰ型、A型三价灭活疫苗注射对荷斯坦种公牛冷冻精液生产的影响,本研究对2~11岁荷斯坦种公牛肌肉注射口蹄疫O型、亚洲Ⅰ型、A型三价灭活疫苗后,统计分析注射前半个月及注射后第1、2、3、4周的荷斯坦种公牛射精量、鲜精活力、鲜精密度、冻精活力、冻精精子畸形率和冻精产量的差异性。结果显示:(1)2~11岁种公牛各时间段的射精量、鲜精活力、鲜精密度、冻精活力、冻精产量无显著差异(P0.05);而注射后第1周的冻精产量、注射后第2周的畸形率显著高于注射前半个月(P0.05),其他各时间段之间无显著差异(P0.05)。(2)2岁种公牛,注射后第2周的畸形率显著高于注射前半个月(P0.05),其他各时间段之间无显著差异(P0.05);(3)3~5岁种公牛注射后第2周的畸形率显著高于注射后第1周(P0.05),其他各时间段差异不显著(P0.05)。(4)7~11岁种公牛,注射后第1周的畸形率和冻精产量显著高于注射前半个月(P0.05),其他各时间段差异不显著(P0.05)。可以得出,口蹄疫O型、亚洲Ⅰ型、A型三价灭活疫苗注射对荷斯坦种公牛射精量、鲜精活力、鲜精密度、冻精活力无显著影响,对冻精产量无不利影响,并导致畸形率升高,但对不同年龄段种公牛影响不完全相同。     

口蹄疫二价苗对荷斯坦种公牛冷冻精液生产的影响

[目的]研究口蹄疫O型、亚洲Ⅰ型二价灭活疫苗注射对荷斯坦种公牛冷冻精液生产的影响。[方法]2~9岁荷斯坦种公牛肌肉注射口蹄疫O型、亚洲Ⅰ型二价灭活疫苗后,统计分析注射前半个月、注射后第一周、注射后第二周、注射后第三周和注射后第四周的射精量、鲜精活力、鲜精密度、冻精活力、冻精精子畸形率和冻精产量的差异性。[结果](1)2~9岁种公牛各时间段的射精量、鲜精密度、冻精活力、冻精产量无显著差异(P0.05);注射后第一周的鲜精活力显著低于注射前半个月和注射后第二周(P0.05),注射后第二周的畸形率显著高于其他时间段(P0.05),其他各时间段之间无显著差异(P0.05)。(2)2岁种公牛,在各时间段之间无显著差异(P0.05);(3)5~6岁种公牛,注射后第一周的鲜精活力显著低于注射前半个月(P0.05),注射后第二周的畸形率显著高于其他各时间段(P0.05),其他各时间段差异不显著(P0.05)。(4)7~9岁种公牛,注射后第二周的鲜精密度显著低于注射后第三周(P0.05),其他各时间段差异不显著(P0.05)。[结论]口蹄疫O型、亚洲Ⅰ型二价灭活疫苗注射对荷斯坦种公牛射精量、冻精活力和冻精产量无显著影响,对鲜精活力、鲜精密度和冻精精子畸形率有一定影响,并对不同年龄段种公牛的影响有差异性。     

Biochemical studies into variation and repeatability of glutathione concentrations in bovine and bubaline semens

Repeatability (r) value of glutathione (GSH) content was estimated in semen of Tharparkar, Red Dane, their crosses, and Murrah buffalo bulls. Mean GSH values were higher in bovine bull semen as compared to mean GSH values in bubaline bull semen. The r of GSH concentration for the pooled data was 0.1278. This trait is 12.78% repeatable. GSH value in semen of bovine and bubaline bull differed insignificantly. R estimates are expressed for selection of bulls of higher fertility and semen quality.     

Genetic Parameters for Semen Production Traits in Austrian Dual-Purpose Simmental Bulls

Genetic parameters were estimated for semen production traits collected in an Austrian AI centre in the years 2000-2004. In total, 12,746 ejaculates from 301 Austrian dual-purpose Simmental (Fleckvieh) AI bulls were examined considering different effects on ejaculate volume, sperm concentration, percentage of viable spermatozoa in the ejaculate, total spermatozoa per ejaculate and motility. The model for genetic parameter estimation included the fixed effects age of bull, collection interval, number of collections on collection day, bull handler, semen collector, year and month of collection, a random additive genetic component and a permanent environmental effect. Correlations between estimated breeding values for semen traits and male fertility from the routine evaluation were calculated. The fertility trait considered in the routine evaluation is non-return rate 90 for the first insemination. All semen production traits were moderately heritable. Heritabilities for volume, concentration, percentage of viable spermatozoa, total number of spermatozoa and motility were 0.18, 0.14, 0.10, 0.22 and 0.04, respectively. Correlations between breeding values for semen quality traits and routinely estimated breeding values for male fertility were low and ranged from 0.08 to 0.17 indicating that semen production traits are rather poor predictors of male fertility.     

Economic evaluation of breeding strategies for improvement of dairy cattle in Kenya

Cost-benefit analysis using net present value (NPV) as the economic evaluation criterion was used to investigate the economic merits of four breeding strategies used for genetic improvement of dairy cattle in Kenya. The breeding strategies were evaluated over a 25-year period. The costs involved in setting up and running each strategy were obtained from large-scale dairy cattle farms, and government and private institutions involved in genetic improvement of dairy cattle. Only benefits from genetic improvement were considered. The impact on NPV due to changes in genetic and economic parameters was investigated. The ranking of the breeding strategies greatly differed with genetic ranking. Among the local selection programs, a strategy utilizing young bulls, sons of local bulls, was more profitable than one utilizing old progeny tested bulls. Continuous semen importation was not an economically viable alternative. The strategy utilizing young bulls progeny of imported bulls (PIB) was only viable if imports were from countries which are >2.00 SD in genetic merit above the local dairy cattle population. The ranking of strategies was not sensitive to changes in genetic parameters but to economic parameters. The use of local semen from young bulls progeny of local proven bulls is recommended. Alternatively, PIB can be utilized but the semen will have to be imported from countries which are >2.00 SD above the local dairy cattle population or the cost of imported semen should be?≤?US$40 per straw.     

Genetic evaluation of breeding strategies for improvement of dairy cattle in Kenya

Cost-benefit analysis using net present value (NPV) as the economic evaluation criterion was used to investigate the economic merits of four breeding strategies used for genetic improvement of dairy cattle in Kenya. The breeding strategies were evaluated over a 25-year period. The costs involved in setting up and running each strategy were obtained from large-scale dairy cattle farms, and government and private institutions involved in genetic improvement of dairy cattle. Only benefits from genetic improvement were considered. The impact on NPV due to changes in genetic and economic parameters was investigated. The ranking of the breeding strategies greatly differed with genetic ranking. Among the local selection programs, a strategy utilizing young bulls, sons of local bulls, was more profitable than one utilizing old progeny tested bulls. Continuous semen importation was not an economically viable alternative. The strategy utilizing young bulls progeny of imported bulls (PIB) was only viable if imports were from countries which are >2.00 SD in genetic merit above the local dairy cattle population. The ranking of strategies was not sensitive to changes in genetic parameters but to economic parameters. The use of local semen from young bulls progeny of local proven bulls is recommended. Alternatively, PIB can be utilized but the semen will have to be imported from countries which are >2.00 SD above the local dairy cattle population or the cost of imported semen should be ≤ US$40 per straw.     

Effect of chemotherapy on elevated ejaculation time and deteriorated semen characteristics consequent to bovine trypanosomiasis

The effect of the trypanocidal drug Novidium on elevated ejaculation time and deteriorated semen characteristics was studied in Zebu cattle infected with T. vivax and T. congolense. Two groups, comprising six bulls per group, were infected with Trypanosoma vivax or Trypanosoma congolense while three bulls served as controls. Chemotherapy was carried out 12 weeks post-infection on three bulls from each group, leaving three bulls untreated while three bulls served as uninfected controls. Blood samples from treated bulls were all negative for trypanosomes 3 days post-chemotherapy. The animals also had normal body temperature. As the study progressed, clinical signs associated with trypanosomiasis, such as anaemia and cachexia, disappeared gradually in treated bulls. There was some improvement in semen characteristics of some of the bulls at 10 weeks post-chemotherapy with Novidium. However, all bulls infected with T. vivax or T. congolense irrespective of Novidium chemotherapy still had poor semen characteristics manifested by all or some of the following: decreased volume of semen, oligospermia, azoospermia and elevated incidence of spermatozoa morphological abnormalities. They were thus unsuitable for breeding.     

Seminal Leucocytary Profile in Beef Bulls

Despite evidences that seminal leucocytes could affect semen quality, references for the frequency and concentration of these cells in bulls are not available. The aim of this study was to determine the normal concentration of leucocytes in beef bulls and to correlate this characteristic with semen quality. First, 57 bulls from artificial insemination centres were evaluated to obtain the normal leucocytary profile values. Next, 382 bulls were subjected to breeding soundness evaluation. The average concentration of leucocytes in bovine semen was 4.73 × 10⁶/ml. Unsatisfactory bulls showed a higher number of leucocytes/field than that in the satisfactory ones. Logistic regression analysis revealed that the unsatisfactory bulls showed 6.5‐fold more chances of having higher leucocyte counts than satisfactory ones. Values of up to 1 leucocyte/field in the bull ejaculate are considered physiologically normal, whereas >5 leucocytes/field is associated with poor semen quality.     

散养湘西黄牛精液的采集与异地冷冻保存技术研究

通过散养湘西黄牛的精液采集与冷冻保存,有利于收集多个优良血缘,降低种公牛站内种公牛的饲养成本。2010年5月,在张家界市永定区湘西黄牛保种区,挑选年龄为2~4岁,特级种公牛10头,进行精液采集与冷冻保存。结果表明：10头未调教的公牛中,除2头（3号、7号）没有采精调教成功外,其它8头都可采精。每次采精3回,平均每次的射精量在2.33~7.66 mL、平均每次原精密度在7.18×108~1.51×109之间变化。不同个体的射精量与密度没有显著相关性。冻后细管精液在37~39℃温水中进行解冻,冻后活力在0.35~0.45之间,均能达到国家牛冷精液生产标准要求,10头公牛中有8头共生产冷冻精液3537支。因此,在保种区域现场采精,稀释处理后送至种公牛站实施湘西黄牛冻精生产的方法是可行的。     

Effects of testicular biopsy in clinically normal bulls

OBJECTIVE: To determine whether testicular needle biopsy is detrimental to testicular function in clinically normal bulls. DESIGN: Prospective study. ANIMALS: 6 mixed-breed mature bulls. PROCEDURE: A randomly selected testicle from each bull was biopsied with a 14-gauge needle biopsy instrument. Bulls were then evaluated over a 90-day period for changes in scrotal temperature and thermal patterns, ultrasonographic appearance, and quality of spermatozoa. At the end of the 90-day study, bulls were castrated, and testicles were examined grossly and histologically. RESULTS: Changes were detected in scrotal temperatures and thermal patterns and in the breeding soundness examination results during the first 2 weeks of the study. However, there were no long-term changes in semen quality over the course of the experiment. Hyperechoic areas were detected on ultrasonographic examination and corresponded to the areas of penetration by the biopsy instrument. Microscopic lesions that were indicative of testicular dysfunction were not found. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicate that testicular biopsy is a safe procedure in bulls. Testicular biopsy could possibly be used to further examine bulls that have less than satisfactory results for breeding soundness examinations.     

种公牛的饲养管理

随着人工授精技术和精液冷冻技术的发展,极大地提高了种公牛的利用率,减少了种公牛的饲养数量,但对种公牛的质量提出了更高要求。优秀的种公牛要具备充沛的精力、健壮的体格、优良性状的稳定遗传,并能够产生大量高品质精液。种公牛的生育能力是由遗传因素和环境因素共同决定的,环境因素主要包括营养、健康状况以及饲养管理。饲养管理的科学性和规范性在优秀种公牛培育中发挥着重要作用。本文综述了种公牛的选择方法、国家有关种畜禽饲养的相关条例以及国内种公牛培育现状,从种公牛营养需求、科学管理等方面,分析种公牛饲养管理的重要影响因素,探讨提高种公牛饲养管理水平的具体措施。     

Breeding soundness evaluation of bulls by semen analysis,testicular fine needle aspiration cytology and trans-scrotal ultrasonography

The aim of this study was to evaluate the usefulness of trans-scrotal ultrasonography and testicular fine needle aspiration cytology in assessing bulls for breeding suitability. These two techniques were also compared with semen analysis. Bulls presented for breeding soundness evaluation were assessed using all three techniques. The findings of each technique were compared. There was agreement in classification of fertile bulls using all three techniques, suggesting that the combined use of these techniques enhances routine breeding soundness examination. Use of the three techniques also enhances detailed investigation of suspected sub-fertile bulls while accurately identifying testicular cause(s) of sire sub-fertility.