晋南黄牛冷配后裔的考察报告

运城地区黄牛冷配工作是从1978年开始在面上推广的。四年多来,黄牛冷配头数逐年增加,1982年全区冷配母牛3.4万头,占母牛受配总数的5O％。今年年底予计可以达     

“星火计划”为黄牛改良和发展商品养牛业开创了新途径

甘肃省的养牛业,自1979年开始黄牛冷配改良以来,发展较快。冷配技术大面积普及,黄牛改良取得了可喜成效。全省已在63个县(市)建立冷配点749个,10年累计冷配母牛82.67万头,产活西黄、利黄、黑黄等改良牛40.63万头。黄牛冷配改良工作,1986年后进入大面积丰产丰收阶段,从冻精生产到冷配服务,布局合理、三站配套(冻精站、液氮站、基层冻配点),以当年授配母牛13万头、翌年产活改良牛8.5万头以上的速度向前推进。冷配     

前郭县:黄牛改良无死角

几年来,吉林省前郭县以改良为突破口,大力发展养牛业取得了显著成效。1996年,这个县投放液氮罐128个,建冷配点195个,冷配母牛达17860头,受胎14823头,受胎率达83％,共产活改良犊牛14000头,据测算,黄牛人工改良可为社会增加效益1000余万元。     

灵璧县黄牛改良冷配工作初见成效

<正> 灵璧县共有17万农户,大家畜存栏15.8万头,其中黄牛12.7万头,占大家畜总数80.4％,能繁殖母牛5.6万头,占黄牛总数44.1％.该县黄牛属华北牛类型中的一个类群,体型小、役力弱、生长发育慢。为了改变这些缺点,从1981年开始引进西门塔尔冻精,对当地黄牛进行杂交改良,截止目前共冷配母牛40520头,近3年冷配头数连续突破万头,受胎率由1981年的42.3％提高到72.5％,已繁殖西门塔尔杂交牛2.1万头,西门塔尔杂交牛生长发育快,役用性能强,经济效益高,表现了明显的杂交优势,我县黄牛改良冷配工作初见成效。     

公主岭加强黄牛冷配站点管理实行标准化生产

１９９９年，吉林省公主岭市在黄牛改良工作中，加大了对基层黄牛冷配站（点）的管理力度，实行标准化生产，取得了显著的成果。公主岭市共有３１个乡镇，３９８个村，３１４０屯，在此范围内，共设１７６个冷配站（点），有输精员１７６人。１９９９年，他们冷配改良黄牛８１３００头，受配率达６２．５％，受胎率达８６％，产仔成活率９５％，累计改良多创社会效益５５００万元。他们的具体做法是： １．强化队伍建设．提高人员素质。黄改工作“三率”能否提高，强化队伍建设，提高人员素质是关键一环。为此，他们把紧紧抓住队伍建设，提…     

"母犊素"对黄牛性别影响的研究

“母犊素”是一种生殖生理调控的激素类药品。喀什地区2004～2005年在6个县的68个冷配站实施“母犊素”的推广使用,目的在于改善冷配母牛母犊出生率偏低的现象,提高农牧民参与黄牛改良的积极性。项目实施参试牛只达3 500头,随机调查产犊头数1 618头,母犊率平均达到58．90％,比未使用“母犊素”处理的母牛产母犊率42．66％净提高16．24％,相对提高38．07％。试验证明,用“母犊素”处理配种母牛,不仅能大幅度提高母犊出生率,还能提高母牛的部分繁殖性能,值得在黄牛改良中推广应用。     

永济市黄牛杂交改良现状及发展方向

1 黄牛改良冷配体系建设基本状况 永济市黄牛改良从1983年开始起步,发展到现在有38个黄牛冷配站点,50名冷配技术员,年冷配母牛在1万头左右,受胎率达到88%以上,冷配站点人员素质高、技术力量雄厚、冷配设施比较齐全,在全区来说独树一帜.     

提高黄牛冷配受胎率的体会

<正>黄牛受胎率的高低,直接影响改良速度和效益的同步增长。提高黄牛冷配受胎率,以获得最高经济效益,是推动黄牛冷配改良的关键。笔者在基层长期从事黄牛繁殖改良推广工作,认识到要提高黄牛冷配受胎率,生产中必须抓好以下几点。1配前补饲,加强营养调控,确保母牛正常繁殖机能牛发情周期受多种因素影响,其中营养起着重要调节作用。繁殖母牛日粮中蛋白质含量不易过高,也不能过低。蛋白质不足可使犊牛生长发育受阻,育成牛初情期延迟,     

民和县满坪地区黄牛不孕的主要原因及防治

民和县满坪地区2007—2008年共实施黄牛冷配改良541头，共接诊黄牛不孕牛145头，占人工改良数的26.8％。满坪地区黄牛不孕的主要原因为子宫内膜炎、卵巢静止两种，分别占不孕的58．62％、25％；该区黄牛改良中大部分为本交，而人工授精的黄牛只占20％左右。加强人工授精工作和早期诊治母牛产科疾病，是防治黄牛不孕症的主要措施。     

四川黄牛改良综合技术应用示范效果

为探索适合我省农区养牛生产的黄牛改良综合技术，在宣汉、汉源两县选点应用杂交改良、繁殖配种、难孕母牛防治、犊牛适时断奶、杂交母牛培育和肉牛肥育等技术，在农村户养条件下，其试验结果为：参配母牛１０１８头次，年均受胎率达９２．２４％，建卡母牛２６０头，年度繁殖率９５．０５％；杂种母牛头平年产奶提高５０．７６％，达１７４９．９ｋｇ；强度肥育的杂交公牛日增重为ｌ１７３ｇ，屠宰率５４．７％；农户养牛经济效益显著提高。     

Duration of estrus in relation to reproduction results in pigs on commercial farms.

This research was conducted to determine factors that influence duration of estrus, AI strategy, and reproduction results between and within commercial swine farms that use AI. Data from 15,186 sows and gilts on 55 farms for a period of 6.1+/-4.2 mo per farm were used in this study. The average duration of estrus was 48.4+/-1.0 h, ranging from 31 to 64 h, and was consistent from month to month within a farm (repeatability of 86%). Differences in duration of estrus between farms accounted for 23% of the total variation in duration of estrus. On most farms (n = 45), gilts showed a shorter (P < .05) duration of estrus than sows (40.8+/-1.1 h vs 48.5+/-1.0 h). The duration of first estrus after weaning was longer (P < .0001) compared with that of repeat-breeder sows (50.2+/-1.0 h vs 46.8+/-1.0 h). Duration of estrus decreased (P < .05) when interval from weaning to estrus increased from 4 to 6 d (56.0 +/- 1.2 h vs 45.8 +/-1.2 h). The regression of interval from onset to estrus to first AI and interval from weaning to estrus varied between farms and ranged from -7.4 to +1.3 h/d; four farms had a positive relationship. Farrowing rate decreased (P < .05) from 89.7+/-2.7% to 78.2+/-5.74 when the interval from weaning to estrus increased from 4 to 10 d. The litter size decreased (P < .05) from 11.7 to 10.6 pigs when the interval from weaning to estrus increased from 4 to 7 d. Compared with a single AI, double AI in sows and gilts resulted in a 4.3 and 7.0% higher (P < .05) farrowing rate, respectively. When the first AI was performed after expected ovulation, reproduction results were lower than when AI was performed before or at expected ovulation in sows. Duration of estrus was not related to farrowing rate or litter size in individual pigs. Number of inseminations per estrus, time of AI, and duration of estrus were correlated, which made it difficult to assess which of these factors was primarily related to the farrowing rate or litter size. Knowledge of average duration of estrus on farms and of factors that influence the duration of estrus on commercial farms can help to improve the efficiency of the AI strategy specific for each farm.     

Effects of AI protocol and time interval from onset of estrus to AI on conception rate in Japanese Black cows

Two different artificial insemination (AI) protocols were investigated to determine the effect of the time interval from the onset of estrus (as detected by a pedometer) to the AI on the conception rate in Japanese Black cows. Seventy‐three cows were divided into two groups that received AI either after the induction of synchronized ovulation (synchronized AI group; n = 26) or at the time of observed estrus (control AI group; n = 47). Each group was further divided into two subgroups, which were artificially inseminated either 0–12 h (early AI group; n = 21) or 12–24 h (late AI group; n = 52) after the onset of estrus. There was no significant difference in the conception rate between the synchronized AI and control AI groups. The AI protocol and the detection of estrus using a threshold of counted steps (as measured by a pedometer) in this study could be effective for planned reproduction management without the observation of standing estrus in Japanese Black cows.     

奶牛性控冻精应用效果研究

[目的]X/Y精子分离技术是目前最先进、最经济的性别控制手段,该技术在现代奶牛生产中的广泛应用,不仅能有效提高奶牛的产母率,加快优质奶牛群扩繁速度,而且可显著提升奶牛种群的整体质量和繁殖效益.[方法]本试验用X/Y种畜(天津)有限公司生产的奶牛性控冻精在定西兴牧奶牛养殖场进行试验,共授配奶牛67头,怀孕45头,情期受胎率平均为67.16%;共产犊牛39头,其中母犊36头,公犊3头,死亡6头,母犊率达到92.31%;对其中20头犊牛出生时的体重、体尺进行了阶段性测定,并与本场使用常规冻精所产母犊的生长发育指标进行比较,两者差异不显著(P＞0.05).[结果]表明,奶牛性控冻精在受胎率和提高母犊率方面具有良好的综合试验效果.[结论]对规模化奶牛场的快速扩群和品质提升具有较高的实用价值.     

受体绵羊人工授精后移植胚胎的试验

试验通过使用人工授精后绵羊作为受体进行胚胎移植,以寻找一种更加有效的方法提高绵羊胚胎移植的经济效益。试验中使用FSH对10只无角道赛特绵羊进行超数排卵处理,同时对60只受体小尾寒羊进行同期发情。供体羊在发情配种后4.5～5.0d从子宫角收集胚胎。同时,将胚胎移植到同期发情并进行人工授精的受体羊子宫内。总共有57枚可用胚移植给44只受体小尾寒羊,32只怀孕到分娩,共产下羔羊51只(无角道赛特羔28只,道赛特与小尾寒羊杂种羔23只)。此外,经人工授精但未进行手术移植的7只小尾寒羊产下15只杂种羔羊。移胚植受体妊娠率72.7%(32/44),移胚受体繁殖率118%(51/44),受体利用率88.3%(53/60)。移胚受体总妊娠率和受体利用率均显著高于常规ET组(P<0.01)。与常规胚胎移植相比,受体羊人工授精后移植胚胎不仅提高了无角道赛特母羊的繁殖率,而且提高了受体羊的利用率。     

Effect of ovsynch versus prostaglandin F2α protocol on estrus response,ovulation rate,timing of ovulation and pregnancy per artificial insemination in Sahiwal cows

Sahiwal cow is Bos indicus which is an important dairy breed of tropical and sub‐tropical region. Research on reproduction is rare in this breed. The objectives of the present study were to determine the effect of Ovsynch (OVS) versus prostaglandin F_2α (PG) protocol on estrus response and its intensity, ovulation rate, timing of ovulation and pregnancy per artificial insemination (AI) in Sahiwal cows. Experimental cows (n = 80) were of mixed parity, lactating, suckled, ≥120 days postpartum with body condition score 3.08 ± 0.34 and 375‐475 kg of body weight which were randomly assigned to receive either OVS (n = 46) or PG (n =34) protocol. Cows were inseminated twice at 12 and 24 h after second gonadotropin releasing hormone in the OVS group, and 72 and 84 h after administration of prostaglandin F_2α in PG group, respectively. The results revealed that estrus response did not differ (P > 0.05) and was 87% in OVS and 78% in PG cows. Ovulation rate did not differ (P > 0.05) and was 50% in both, OVS and PG cows. The pregnancy per AI did not differ (P > 0.05) and was 43% in OVS compared to 31% in PG cows. It is concluded that estrus response, ovulation rate and pregnancy per AI of OVS protocol is the same as PG in Sahiwal cows.     

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。     

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。     

牛胚胎移植研究进展

人工授精技术可极大地提高公畜的利用效率，而胚胎移植技术则是充分挖掘优良母畜的繁殖潜力的有效途径。该技术的应用可从很大程度上提高母畜的繁殖率，从而在短时间内迅速扩大优良种群，加速畜群改良和纯种繁育进程，也是迅速提高我国牛群整体水平的重要而有效的手段，本文就牛胚胎移植的研究现状、关键技术以及影响胚胎移植的因素作以探讨。