奶牛繁殖障碍的防治

奶牛的繁殖障碍是兽医临床上常遇到的问题 ,是造成母牛空怀的主要原因 ,直接影响着牛群的繁殖力。1　卵巢疾病的防治1 1　卵泡发育障碍卵泡发育障碍包括卵巢发育不全、卵巢静止及卵巢萎缩。除改善营养外 ,还应采取下述办法 :.孕马血清促性腺激素 (ＰＭＳＧ) 10 0 0单位一次肌肉注射 ;ＦＳＨ 2 0 0单位一次肌肉注射 ;维生素Ａ 2 5万单位 ,维生素Ｄ 2 .5万单位 ,维生素Ｅ 4 0 0ｍｇ ,一次肌肉注射 ,7ｄ1次 ,连用 2次。发情前 1ｄ内服《加减八珍汤》 :当归、川芎、白芍、云苓、红花、党参、山药、阳起石 ,菟丝子、巴戟、补骨脂、小香、益母草、…     

奶牛繁殖障碍病的防治

奶牛繁殖障碍性疾病是指奶牛配种后屡配不孕的现象.通过对卵巢疾病的防治、子宫内膜炎的治疗以及防治时应注意的问题进行概述,以便为奶牛养殖业的进一步发展和科学规划布局提供科学参考.     

中药防治奶牛繁殖障碍系列制剂的实验验证

奶牛繁殖障碍常造成繁殖下降,使年产犊减少或产犊间隔时间延长,奶牛的产奶量也因而随之骤减。目前国内外治疗繁殖障碍,一般均借助于外源性激素制剂或抗生素。但长期反复使用,一方面会引起机体生殖内分泌的紊乱,另一方面由于乳、肉、蛋的残留激素、抗生素也会危及人体...     

奶牛繁殖障碍原因及其防治措施

当前,随着奶牛产量的不断提高,奶牛不孕症的发病率也在不断上升,奶牛的繁殖障碍问题已经成为了十分严重的问题。这种情况在高产的奶牛身上尤为突出。在产后泌乳的高峰期因为各种刺激的影响,导致其发情症状表现不明显、受胎率低或者是不发情,致使繁殖率下降。这种情况不但加大了奶牛的管理费用,还降低了产犊数。因此,必须认真分析奶牛繁殖障碍的原因,并找到其防治措施。     

奶牛繁殖障碍的防治

1奶牛繁殖障碍发生的原因虽然造成奶牛繁殖障碍的原因很多,但总的来说,可分为先天性和后天获得性两大类。先天性繁殖障碍包括幼稚病、生殖器官畸形、两性畸形和自身免     

奶牛繁殖障碍疾病防治的研究进展

奶牛繁殖障碍疾病严重影响着奶牛业经济的发展。在此围绕引起奶牛繁殖障碍的三个主要因素（饲养管理不当、生殖器管疾病和繁殖技术失误）,从奶牛繁殖障碍疾病的发病原因、临床症状、诊断方法、治疗原则以及预防对策上进行概述。     

奶牛繁殖障碍综合征的病因及综合防治

奶牛繁殖障碍综合征可分为先天性繁殖障碍和后天获得性繁殖障碍两大类。为了更加全面地认识和有效控制奶牛繁殖障碍综合征的发生,对奶牛繁殖障碍综合征的发病原因、临床症状、诊断方法以及治疗原则进行了较为全面的概述。     

奶牛繁殖障碍的原因与防治对策

奶牛繁殖障碍是指公牛和母牛生殖机能紊乱和生殖器官畸形,以及由此引起生殖活动的异常现象。引起繁殖障碍的原因有个体遗传、营养及饲养、环境与气候、生殖器官功能异常与疾病等因素。需要针对引起繁殖障碍的原因进行有效防治,以提高奶牛的繁殖能力,提升养殖的经济效益。     

奶牛繁殖障碍的防治

奶牛繁殖障碍的防治天津市奶牛研究所（３００３８１）于德涌１　奶牛繁殖障碍的基本防治方针和程序在奶牛出现非传染性繁殖障碍疾患时，应首先考虑的是子宫状况，其次是卵巢状况。在子宫较好的情况时，卵巢疾患可以自身修复加以调整和救护。这是因为奶牛的卵巢附着于子宫...     

浅析奶牛繁殖障碍的主要病因及防治方法

本文对诱发奶牛繁殖障碍的主要病因：胎衣不下、子宫内膜炎、卵巢囊肿等疾病进行了分析,并提出了防治建议,希望对其它奶牛场有一定的参考价值。     

奶牛分子育种的研究进展

奶牛分子育种是将来奶牛品种改良的主要工具。奶牛主效数量性状基因座育种和转基因育种主要包括构建基因图谱 ,并据此定位主效数量性状基因座或与之连锁的DNA标记 ,通过转基因技术改良奶牛重要经济性状或研究开发乳腺生物反应器。     

Prevention and control of lameness in dairy cattle

The prevention and control of lameness are essential if a dairy herd is to return a profit. Breeding, feeding, housing, and management practices are all involved, and errors or omissions in any of these areas can result in catastrophic lameness. An accurate diagnosis and proper treatment are necessary to minimize losses when lameness occurs.     

奶牛流行热的防治

牛流行热是由牛流行热病毒引起的急性、热性传染病,一般发生于夏季或夏秋之交,潜伏期一般为3～5天。流行热传播速度快、流行面广、发病率高,但死亡率低。1流行病学牛流行热是由节肢动物传播的一种病毒性传染病。蚊和库蠓是牛流行热的媒介昆虫。在自然条件下,通过吸血昆虫的叮咬     

奶牛高效养殖生产技术

近几年,随着人们生活水平的不断提高,奶产品需求量逐年增加,我县城郊出现了以发展饲料转化率占第一位的奶牛养殖热.饲养奶牛的过程中,多数农户饲养管理粗放,在产乳技术的诸多环节上存在很多不合理性,影响了奶牛产奶性能的发挥,造成奶牛产乳量减少,效益不高.根据笔者在实际工作中的体会,简单谈一下实现奶牛高产高效的技术要点,供奶牛户参考.     

Characterisation of the repeat breeding syndrome in Swedish dairy cattle

Repeat breeding (RB), defined as cows failure to conceive from 3 or more regularly spaced services in the absence of detectable abnormalities, is a costly problem for the dairy producer. To elucidate the occurrence of RB in Swedish dairy herds and to identify risk factors of the syndrome totally 57,616 dairy cows in 1,541 herds were investigated based on data from the official Swedish production-, AI- and disease-recording schemes. The characteristics of the RB syndrome were studied on both herd and individual cow level. The effects of risk factors on the herd frequency of RB were studied by logistic regression. A generalised linear mixed model with logit link, and accounting for herd-level variation by including a random effect of herd, was used to study the individual animal risk for RB. The total percentage of RB animals was 10.1% and the median proportion of RB animals in the herds studied was 7.5%. The proportion of RB cows in herds increased with decreased herd sizes with decreased average days from calving to first AI, with increased herd incidence of clinical mastitis, with decreased reproductive disorders, and increased other diseases treated by a veterinarian. On animal level, the risk factors were milk yield, lactation number, difficult calving or dystocia, season at first service, days in milk at first service and veterinary treatment for reproductive disorders before the first service. Cows being an RB animal in the previous lactation had a higher risk of becoming an RB animal also in the present lactation. In conclusion our results show that the repeat breeding syndrome is a multifactorial problem involving a number of extrinsic factors as well as intrinsic factors coupled to the individual animal.     

Stochastic simulation of dairy cattle nucleus breeding schemes: Influence of breeding strategy and biased breeding values in the population

SUMMARY: A stochastic simulation model of an open nucleus scheme was used to study the consequences of the breeding strategy and biased lactation records for population cows. Selection was for a single sex-limited trait with a heritability of 0.25 and based on animal model breeding value estimates. Selection of dams was across age classes while sires were required to have a progeny test before they could be selected as proven bull or bull sire. Dams to breed nucleus replacements and young bulls could be selected from the nucleus and the top population which contained 240 and 1600 replacement heifers annually. The first 15 years of the simulated period was used to reach a population with an equilibrium genetic progress for a progeny testing scheme. Comparisons were based on the 25 year period after an alternative breeding scheme was adopted. The annual genetic gain was calculated from the last 10 years of that period. The annual genetic gain in an open nucleus breeding scheme was .247 σ(a) . The annual genetic gain increased 5.4% when MOET was also used on cows selected to breed replacements for the top population. When, in addition the number of sires used on top population cows was reduced from 8 to 4, that being the number used in the nucleus, the annual genetic gain increased by another 2.8%. The reduction in annual genetic gain due to biased lactation records of top population cows ranged from 4.6 to 15.4%. The average bias in estimated breeding values of the top population dams selected to breed nucleus replacements ranged from 0.53 to 2,52 σ(a) . The regression coefficient of the EBV of the bull after progeny testing on the EBV of the dam at the time of selection was 0.55 without biased lactations and ranged from 0.10 to 0.27 with biased lactations. The reduction in genetic gain was especially related to the regression coefficient and to a lesser extent to the average bias. In practice, the expected reduction in annual genetic gain from biased lactation records of population cows is expected to be between 5 and 10 %. ZUSAMMENFASSUNG: Stochastische Simulation von Milchvieh-Nukleussystemen: Einflu? der Zuchtstrategie und verzerrter Zuchtwerte in der Population Eine stochastische Simulation eines offenen Nukleussystems wurde zur Untersuchung der Konsequenzen der Zuchtstrategie und verzerrter Laktationsabschlüsse für Populationskühe untersucht. Selektion bezog sich auf ein einzelnes weibliches Merkmal mit Heritabilit?t von 1/4 und gründete auf Tiermodell Zuchtwertsch?tzungen, Selektion von Muttertieren über Altersklassen, w?hrend Stiere vor der Selektion einen Nachkommenschaftstest haben mu?ten. Muttertiere für Nukleus- und Jungstiere kommen vom Nukleus und Spitzen der Population, die 240 und 1600 nachgestellte Kalbinnen umfa?ten. Die ersten 15 Jahre der simulierten Periode wurden zum Erreichen einer Population mit Gleichgewichtsfortschritt für ein Nachkommenschaftsprüfsystem verwendet. Vergleiche beruhten auf einer 25-Jahre-Periode nach Einrichtung des alternativen Zuchtsystems, und der j?hrliche Zuchtfortschritt wurde für die letzten 10 Jahre berechnet. Der j?hrliche Zuchtfortschritt im offenen Nukleussystem war 0,247 σ(a) und nahm um 5,4% zu, wenn MOETauch für Kühe zum Ersatz der Spitzenpopulation verwendet wurde. Wenn darüber hinaus die Zahl der Vatertiere in der Spitzenpopulation von 8 auf 4 reduziert wurde, die Zahl der im Nukleus verwendeten, konnte der j?hrliche genetische Fortschritt um weitere 2, 8% gesteigert werden. Die Verminderung des Zuchtfortschrittes auf Grund von verzerrten Laktationsabschlüssen der Spitzenkühe der Population variierte von 4,6 bis 15,4%. Die durchschnittliche Verzerrung der gesch?tzten Zuchtwerte der Populationsspitzenkühe für die Nukleusremonte bewegte sich von 0,53 bis 2,52 σ(a) . Der Regressionskoeffizient von EBV der Stiere auf Grund von Nachkommenschaftsprüfung auf EBV der Muttertiere beim Zeitpunkt der Selektion war 0,55 ohne verzerrte Laktationen und schwankte zwischen 0,10 und 0,27 bei verzerrten Laktationen. Die Verminderung des genetischen Fortschritts hing deutlich mit dem Regressionskoeffizient zusammen und weniger mit der durchschnittlichen Verzerrung. In der Praxis ist zu erwarten, da? die Reduktion des Zuchtfortschrittes durch verzerrte Laktationsabschlüsse der Population zwischen 5 und 10% liegt.     

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.