诱导母猪同期分娩的技术

在集约化猪场中,要求严格按工艺流程有节奏地进行养猪生产。为了避免夜间产仔和有效地提高商品猪的整体质量,常采用同期分娩解决这一难题。作为调控繁殖节律的技术之一,药物诱导母猪同期分娩已成为集约化养猪业的一个重要研究课题。本文对前列腺素F2α和氦前列烯醇在母猪同期分娩中的应用作一简单介绍。     

不同激素处理富源本地黄牛与短本杂一代黄牛同期发情试验

为了比较不同品种的黄牛用不同激素处理后的同期发情效果,以筛选出适合本地不同牛群及环境的较优杂交方案.将137头健康空怀黄母牛(其中本地黄母牛72头,短本杂一代黄母牛65头)分为4个组,第1、2组为本地黄母牛,第3、4组为短本杂一代黄母牛,分别用2种不同的方法进行同期发情处理.第1、3组注射三合激素;第2、4组注射促排3号-氯前列烯醇-促排3号.结果表明,第1组、第2组、第3组、第4组经不同的激素处理后,发情率分别为59.38%、87.5%、58.62%、86.11%,第2组的发情率显著高于第1组(P＜0.05),第4组的发情率显著高于第3组(P＜0.05),而第1组和第3组、第2组和第4组的发情率差异不显著(P＞0.05).结果提示发情率的高低与品种的相关性不大,促排3号-氯前列烯醇-促排3号可能是较适合富源黄母牛的同期发情方案.     

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。     

Untersuchungen zur Brunstsynchronisation und Samenübertragung bei Schafen verschiedener Rassen

Inhalt Bei insgesamt 500 Schafen (260 Merino, 120 Dagliç, 120 Ramliç) in drei Schafzuchtbetrieben in der Türkei wurde durch Verabreichung von Gestagen-Vaginal-schwämmchen + PMSG oder PGF_2α (ein- bzw. zweimal) die Brunst induziert. 4 bis 6 Stunden nach der Brunstbeobachtung mittels Suchbock erfolgte die zervikale Besamung mit tiefgefrorenem (TG) oder frisch gewonnenem Sperma von Böcken der jeweils selben Rassen. Mit Hilfe von Gestagen+PMSG wurde bei allen Rassen die höchste Östrusinduktionsrate (96, 7 bis 98,3%) erzielt. Einmalige PGF_2α Verabreichung rief bei 60%, zweimalige PGF_2α Injektion im Abstand von 9 Tagen bei 88,3% der Schafe Brunst hervor. PGF_2α hatte den besten Synchronisationseffekt (80,6 bis 88,2%) 48 Stunden nach der Applikation. Die Non Return Raten 35 bis 40 Tage nach Besamung betrugen unabhängig vom Synchronisationsverfahren und von der Rasse 21,4 bis 41,9% bzw. 55,6 bis 84,2% nach Verwendung von TG- bzw. Frischsamen. Die besten Non Return Ergebnisse wurden bei den drei Rassen nach Brunstinduktion mit Gestagen+PMSG beobachtet. Rasseabhängige Unterschiede bezüglich der Brunstinduktion-und -synchronisation ließen sich statistisch nicht absichern. Contents: Investigations upon oestrus synchronization and artificial insemination in ewes of different breeds In a total of 500 ewes (260 Merino, 120 Dagliç, 120 Ramliç) of three sheep breeding farms in Turkey oestrus induction was performed by application of progestagen imprepated vaginal sponges+PMSG or of PGF_2α (given once or twice). 4 to 6 hours after oestrus detection by a teaser ram the ewes were inseminated cervically with frozen-thawed or fresh semen of rams of the same breeds. In all breeds the highest rate of oestrus induction (96.7 to 98.3%) was obtained by means of progestagen+PMSG. A single injection of PGF_2α provoced heat in 60%, while two injections with an interval of 9 days induced oestrus in 88.3% of the treated ewes. PGF_2α had the best synchronizing effect (80.6 to 88.2%) at 48 hours after application. Regardless of the breed and the synchronization method, the non return rates 35 to 40 days after insemination were 21.4 to 41.9% and 55.6 to 84.2% for frozen-thawed and fresh semen resp. In all breeds the best non return results were observed after oestrus induction with progestagen+PMSG. With regard to induction and synchronization of oestrus breed dependent differences could not be statistically confirmed.     

猪定时输精技术研究进展

猪定时输精技术主要分为简式定时输精和精准定时输精。采用定时输精技术可达到生猪生产批次化的目标,该技术是现代规模化养殖企业实现"全进全出"制的重要技术手段。本文综述了猪定时输精技术的发展历程,阐释了定时输精的技术原理,简要比较了几种生殖激素的使用和输精方案的实施,为猪定时输精技术的生产应用提供参考。     

Effect of oestrous synchrony between embryo donors and recipients,embryo quality and state on the pregnancy rate in beef cattle

This study aimed to evaluate the effect of oestrous synchrony between donors and recipients and the embryo quality on the pregnancy rate in beef cow recipients. The experiment was performed over two years at an embryo transfer (ET ) centre in Southern Brazil. Ninety Aberdeen Angus cows were subjected to superovulation (SOV ) protocols, resulting in the recovery of 1,048 transferable embryos. Eleven groups were formed with intervals of 6 hr, from ?30 to +30 hr, with respect to recipient versus donor oestrous detection. Evaluation of embryo quality was according to the IETS guidelines. The overall pregnancy rate was 52%. Effects related to donor and recipient oestrous synchronization on pregnancy rate were observed (p  =  .01), ranging from 36% to 50%. The embryo quality rate affected the pregnancy rate, where Grade I resulted in 57% and Grade III in 43% of pregnancy (p  <  .001). The embryonic state (frozen or fresh) showed no (p  >  .05) effect on pregnancy rate: 53% for fresh embryos and 44% for frozen embryos. The odds ratio for explanatory variables causing pregnancy indicated that Grade III embryos had 31% less chance of conception compared to Grade I. Thus, oestrous synchrony between donor and recipient, considering ±30 hr apart, can affect the pregnancy rate along with embryo quality.     

Efficacy of using previously used controlled internal drug release (CIDR) insert on the reproductive performance,hormone profiles and economic measures of sheep

This study was conducted using 120 multiparous Awassi ewes during the breeding season to compare the effects of using previously used controlled internal drug release (CIDR) on the hormone profiles, reproductive performance and economic measures of ewes. Ewes were randomized to receive one of five previously used CIDR (previously used for 6, 12, 18, 24 or 30 days) or the new CIDR as a control for 6 days (CIDR6, CIDR12, CIDR18, CIDR24, CIDR30, and CIDR0 [control], respectively). Blood samples were collected on four occasions, at the time of CIDR insertion, after 3 days of insertion, and at the time of withdrawal and insemination. Serum estradiol (E2) and progesterone (P4) concentrations were measured. Timed insemination was performed 48 hr post‐CIDR withdrawal. Pregnancy was diagnosed by ultrasonography 23 days after insemination and confirmed on day 35. The heat detection rate was significantly (p < 0.05) higher in the CIDR0 and CIDR6 groups than in the CIDR18 and CIDR30 groups. The total pregnancy rate and fecundity were significantly (p < 0.05) higher in the CIDR6 group than in other groups. P4 level was significantly (p < 0.05) higher in the CIDR0 group than in the CIDR30 group at the time of removal. At each time point, the E2 level was significantly (p < 0.05) higher in the CIDR6 group than at the other groups. The total variable cost, total cost, return and net profit were higher in the CIDR6 and CIDR0 groups than in the other groups. In conclusion, although previously used CIDRs are efficient at synchronizing oestrus in ewes, the duration of previously usage significantly affected the reproductive parameters and economic profit. CIDRs previously used for 6 days and new CIDRs provided the highest fertility and fecundity rates, besides return and net profit. Economically, it is not advisable to use CIDRs that previously used for 12 days or more.     

Effect of body condition score and reuse of progesterone‐releasing intravaginal devices on conception rate following timed artificial insemination in Nelore cows

This study had the aim of investigating the efficiency of timed artificial insemination (TAI) through the progesterone‐releasing intravaginal device (PRID), used in new condition and for the second and third times in Nelore cows. The effects of device reuse and body condition score (BCS) on the conception rate (CR) were evaluated in 1,122 multiparous Nelore cows (mean BCS of 2.7 ± 0.4), which were randomly distributed into three groups that received new (n = 330), once (n = 439) and twice used (n = 353) PRID. Among the 1,122 females that underwent TAI, 573 became pregnant, thus representing an overall CR of 51.06%. Cows with BCS between 2.75 and 4.0 had greater (p < .0001) CR (69.75%) than cows with BSC of 2.0–2.5 (32.98%). It was observed that the CR through using PRID was 60.00%, 51.71% and 41.93% for new, once and twice used PRID, respectively, with difference between all groups (p < .0001). Under tropical conditions, animals with BCS greater than 2.5 had a higher CR, and the CR decreased proportionally with the number of times that the PRID had been used.     

性控冻精对同期发情奶牛输精效果观察

为观察奶牛养殖场应用同期发情后,实施性控冻精人工授精的效果进行试验。本试验设立性控组和常规组,分别进行人工授精,在相同饲养管理条件下观察两组试验奶牛配种、妊娠、产母犊情况。结果表明:同期发情率为81.43%,而且84.38集中在36h内;试验组奶牛产母犊率达94.12%,明显高于常规组55.56%的产母犊率,说明该性控冻精在奶牛性别控制中的效果明显,值得推广。     

椭球膨胀法建立独立坐标系在公路工程中的应用

由于高斯-克吕格投影在海拔较高的地区投影变形问题,造成GPS测量的成果转换到国家统一的坐标系中不能直接应用于工程测量中,根据椭球膨胀法的原理,采用移动中央子午线和抬高投影面的方法,以减少投影变形的影响,并在内蒙古某黄河大桥中成功应用.应用这种方法不但能满足工程测量的要求,而且节省了人力财力,还提高了测量效率.