生殖激素诱导乏情母猪发情的效果

母猪乏情是集约化猪场的常见问题,尤其是饲养瘦肉型品种猪和采用超早期断奶的猪场,从而给养猪生产带来了严重影响。目前,解决这一问题的常见方式是采用生殖激素人工诱导母猪再次发情。基于此,笔者采用氯前列醇钠等3种生殖激素对乏情大约克母猪进行了对比试验,结果如下。     

注射氯前列烯醇控制母猪分娩时间的试验效果

母猪分娩是规模化猪场生产中的关键环节。在生产中如果母猪夜问分娩往往由于饲养员白天较累，晚上容易疲劳，对接产、保温、防压、辅助仔猪吃初乳、超前免疫等均易造成影响，另外，在冬季由于受外界气温的影响，晚上温度较低，致使仔猪死亡率偏高，严重影响着养猪企业的经济效益。鉴于此，许多生产场家采取用药物控制的办法，改变母猪的分娩时间，使母猪尽量白天分娩，以期达到良好的效果。     

前列腺素诱导母猪分娩时的内分泌状态

选用５头妊娠后期母猪,于妊娠１１１ｄ上午９∶００肌肉注射氯前列烯醇（ＰＧ）０．２０ｍｇ。５头母猪皆于次日白天分娩。从注射前至分娩结束,在整个诱导过程中多次采血,监测了血清中孕酮（Ｐ４）、硫酸雌酮（Ｅ１Ｓ）、催乳素（ＰＲＬ）和皮质醇（ｃｏｒｔｉｓｏｌ）４种激素浓度的变化。结果表明,诱导分娩过程中各种激素的变化和自然分娩基本一样。这就解释了用国产前列腺素诱导母猪分娩,只要处理时间合适（妊娠１１１ｄ或１１２ｄ）,就会有良好效果,不会产生不良副作用。     

氯前列烯醇诱导母猪同期分娩的试验

临产英系大白母猪66头。随机分为两组,试验组36头,用氯前列烯醇诱导分娩;对照组30头,自然分娩。结果:试验组在用药后(24.08±9.18)小时开始分娩,两天内有94.44％(34/36)母猪分娩。试验组白天分娩比例,平均妊娠期、胎衣排出期分别为80.56％、(114.47±0.70)d、(24.92±31.99)min;对照组分别为53.33％、(115.27±1.70)d、(41.97±42.68)min,差异均达到显著水平;而在产程、产仔间隔、头均初生重、窝均死胎数及窝均活仔数等方面,两组间差异不显著。试验结果表明。应用氯前列烯醇诱导可使母猪分娩高度同期化,对新生仔猪无不良影响,经济效益显著。     

母猪分娩三观察

一、观察乳房。母猪分娩前15～20d,乳房开始由前向后逐渐膨大下垂,乳房基部与腹部之间呈现出明显的界限。到产前1周左右,乳房膨胀更加明显,若两排乳头胀得向外开张呈“八”字形并挺直,皮肤紧绷,发红发亮,这就预示着母猪快要分娩。     

氯前列烯醇诱导母猪限期分娩

对６５头妊娠第１１２天母猪肌注ＰＧＦ２α类似物－氯前列烯醇进行诱导分娩,使其妊娠期为１１３天,结果与对照组相比,其死胎率降低４２．８９％,差异显著。而仔猪育成率并未因妊娠期为１１３天而受影响。     

氯前列烯醇诱导母猪同期分娩的试验

临产英系大白母猪66头,随机分为两组,试验组36头,用氯前列烯醇诱导母猪分娩;对照组30头,自然分娩。结果试验组在用药后24.08±9.18h(小时)开始分娩,白天分娩比例,平均妊娠期、胎衣排出时间间隔分别为80.56%、114.47±0.70d、24.92±31.99min。对照组分别为53.33%、115.27±1.70d、41.97±42.68min,差异均达到显著水平;而在产程、产仔间隔、初生窝重、活仔均重、产仔数、死胎数、弱仔数、木乃伊数及活仔数等方面,两组间差异不显著。试验结果表明,应用氯前列烯醇诱导可使母猪分娩高度同期化,对新生仔猪无不良影响,经济效益显著。     

用三合激素诱导母猪发情受胎的试验

在生产实践中，由于饲料不足、营养不全等原因造成的母猪不发情比较普遍，在加强饲养管理的基础上可用三合激素诱情，经生产实践效果较好，受胎率高。     

氯前列烯醇诱导大约克夏母猪同期分娩试验

应用前列腺素类似物氯前列烯醇对100头配种后112－113d的妊娠健康大约克夏母猪进行同期分娩控制试验。结果表明，肌肉注射0.05、0.10和0.20mg氯前列烯醇可分别使90％、95％和90％的母猪在用药后16.0-28.0h分娩,用药母猪的产程明显缩短,压死仔猪的比例明显下降,该药对母猪的生产性能无明显影响。     

The induction of parturition in sows using prostaglandin F2alpha

Intramuscular injections (10 mg) of prostaglandin F2alpha were administered to 19 pregnant sows in one herd on either the 112th or 113th day of gestation and a similar number of untreated sows served as controls. Induced sows for up to 6h after injection generally showed more walking, drinking defaceating and postural changes. Over the last 20 h prepartum they spent more time lying and urinated more frequently. Mean interval from injection to onset of parturition in treated sows was 24.5 h and 16 of them commenced farrowing during the working day, compared with 6 in the control group. Induction of parturition did not influence litter size at birth, piglet body-weights at birth or 14 days of age, the incidence of the mastitis, metrititis agalactae syndrome, re-breeding interval of the sow or size of the subsequent litter at birth. Farrowing time was significantly longer (6.48 h v 4.08 h) for treated sows and litter pre-weaning mortality was higher but not significantly so. Most piglet deaths in each group resulted from overlaying or starvation but mortality from anaemia and septicaemia occurred only in the treated group. It is considered that the technique could have practical application on well-managed intensive pig units.     

The induction of parturition in sows using prostaglandin F2auml;

Intramuscular injections (10mg) of prostaglandin F2ä were administered to 19 pregnant sows in one herd on either the 112th or 113th day of gestation and a similar number of untreated sows served as controls. Induced sows for up to 6h after injection generally showed/more walking, drinking defaceating and postural changes. Over the last 20h prepartum they spent more time lying and urinated more frequently. Mean interval from injection to onset of parturition in treated sows was 24.5h and 16 of them commenced farrowing during the working day, compared with 6 in the control group. Induction of parturition did not influence litter size at birth, piglet bodyweights at birth or 14 days of age, the incidence of the mastitis, metrititis agalactae syndrome, re-breeding interval of the sow or size of the subsequent litter at birth. Farrowing time was significantly longer (6.48h v 4.08h) for treated sows and litter pre-weaning mortality was higher but not significantly so. Most piglet deaths in each group resulted from overlaying or starvation but mortality from anaemia and septicaemia occurred only in the treated group. It is considered that the technique could have practical application on well-managed intensive pig units.     

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。     

应用激素诱导母羊发情的效果观察

东北细毛羊为短日照发情动物,1年1胎,除妊娠、哺乳时间外,1年中仍有4-5个月处于休情状态,每年的7-11月份才发情。为了使绵羊产羔后尽早发情、配种,提高生产效率,我们应用了CRID装置,PMSG促性腺激素和LRH-A3促性腺激素释放激素,复合孕酮制剂,对母羊进行诱导发情试验,并对发情配种效果进行了观察,取得了一些可靠数     

诱导母猪同期分娩的试验

在工厂化养猪条件下,要求严格按工艺流程有节奏地进行养猪生产,药物诱导母猪同期分娩作为调控繁殖节律的技术之一,已成为工厂化养猪业的一个重要研究课题,这一技术在国外养猪生产中已广为应用,国内近年来也进行了这一技术在生产中的应用研究.     

Aggressive behavior of sows at parturition

Sows, especially primiparous, may show aggressive behavior at parturition against their own piglets, resulting in wounding or death of the piglets. Frequency, environmental influences and heritability of aggressive behavior were studied in two data sets. The first (923 first litters) was collected at an experimental farm and the other (925 first litters) came from a pig breeding organization. Frequency of aggressiveness ranged, depending on its definition, from 7 to 12%. Fixed effects of year, season and feeding level of the gilt during the rearing period did not affect the frequency of aggressiveness. A regression of aggression on postpartum sow weight was found, suggesting that low weight at first farrowing might predispose sows to aggressive behavior. Coefficients for backfat and litter size were positive but nonsignificant. Heritability of aggressiveness on the underlying normal scale, estimated from the paternal half-sib component of variance, averaged .12 for the first data set, and .25 for data set II. Estimates from daughter-dam regression were .49 and .87 for the two data sets, respectively. A simulation study indicated that this difference might be due to maternal effects. A simple application would be to select boars and gilts from non-aggressive sows only. Response to selection would be rather slow if the frequency of aggressive behavior is low. At frequencies that are too high from an economic point of view, estimation of breeding values, combining own performance and(or) data from relatives, is required.     

产仔季节对深县母猪繁殖性能的影响

为了研究不同季节对深县母猪繁殖性能的影响,选用辛集市正农牧业有限公司2012年1月至2015年12月间的深县母猪的繁殖记录,统计分析不同产仔季节对深县母猪的各个繁殖性状。结果显示:深县母猪在春季的总产仔数最高,显著高于夏、冬两季(P0.05);春季产仔母猪数最多,显著高于夏季(P0.05);深县仔猪的初生窝重、初生个体重、断奶个体重在秋季最佳;断奶窝重在春季达到最佳;春、夏、秋季的断奶成活率显著(P0.05)高于冬季。结果表明:深县母猪在春、秋两季的繁殖性能较好。     

Effect of feeding thyrotropin-releasing hormone to lactating sows

Two experiments were conducted to assess the effects of feeding thyrotropin-releasing hormone (TRH) during lactation on sows. In Exp. 1, sows were fed 0, 1, 10, 100 or 1,000 mg TRH on d 10.8 +/- .4 (mean +/- SE) after parturition. Blood samples were taken from sows every 30 min from -2 h to 8 h and at 10, 12 and 18 h from feeding. Consumption of 100 or 1,000 mg TRH increased mean serum concentrations of thyroxine (T4; P less than .001), 1,000 mg TRH increased growth hormone (GH; P less than .06) and 100 or 1,000 mg TRH increased prolactin (PRL; P less than .01), but insulin (INS; P greater than .10) was unaffected by TRH. Serum concentrations of T4 were elevated within 2 to 4 h after feeding TRH and remained elevated for 12 to 18 h. Concentrations of GH and PRL began to increase immediately after feeding 100 or 1,000 mg TRH and remained elevated for 6 and 8 h, respectively. In Exp. 2, sows were fed 0 or 200 mg TRH from d 111 of gestation to weaning at 27.1 +/- .3 d of lactation. Consumption of TRH elevated concentrations of T4 at all stages of lactation and increased respiration rate on d 10 and d 20, heart rate on d 20, and milk production on d 20 of lactation. Consumption of TRH did not influence number of pigs born, number born alive, survival rate during lactation, sow body weight, heartgirth, backfat depth, feed disappearance, or milk production on d 10 of lactation. Piglets nursing sows fed TRH were similar in weight to piglets nursing sows not fed TRH on d 0 and 5 of lactation, but they were heavier on d 10 (P less than .07), 15 (P less than .001), 20 (P less than .001) and 27 (P less than .0001). Sows fed TRH took longer (P less than .001) to return to estrus after weaning than control sows. Results indicated that feeding TRH elevated T4, GH and PRL and that feeding TRH for the duration of lactation increased milk production on d 20 of lactation and increased weaning weights, but it delayed estrus after weaning.