人工授精五步法对提高母猪受胎率、产活仔数的影响

目前,人工授精技术已得到一些大中型猪场的充分肯定。针对我国规模化猪场生产中,对人工授精技术的研究、推广和应用工作起步晚,发展不均衡,为此,北京养猪育种中心推出人工授精五步法操作规程,通过试验数据及统计分析表明,五步法有效提高了母猪受胎率和产活仔数,促进了规模化猪场生产水平提高。     

应用催产素提高猪人工授精效果试验

试验选用健康状况良好的经产母猪(长大和大长)212头,随机分为2组,对照组106头,试验组96头,试验组的处理方法为,母猪出现"静立反射"后8～12小时,用20IU摧产素(PRL)一次肌注,3～5分钟后实施第一次人工授精(AI),随后相继间隔8～12小时进行第二和第三次人工授精.对照组不作任何药物处理,仅在发情后8～12小时后进行自然交配(NS)一次,随后相继间隔8～12小时进行两次人工授精,即"本交/人工/人工"配种方式(NS/AI /AI).试验结果表明,试验两组跟对照组的配种分娩率和窝均产活仔数差异均不显著(P＞0.05),两组母猪断奶后发情均正常.该试验表明在人工授精前用催产素处理母猪在生产中是确实可行的,我们现正进行较大规模推广.     

仿真刺激对母猪人工授精效果分析

本试验针对农村散养母猪户和小规模母猪养殖场,在没有公猪的情况下,通过仿真刺激后输精来提高母猪的繁殖性能。试验分对照组（直接给发情母猪输精）和试验组（仿真刺激后给发情母猪输精）,试验结果表明,试验组比对照组配种受胎率提高10％,母猪的配种分娩率、窝均总产仔数分别提高7．8％和多产仔猪1．5头,经显著性检验,差异极显著（P〈0．01）。该技术值得在农户大群生产中推广。     

提高母猪繁殖力的技术措施

提高母猪繁殖力关键是提高母猪年产仔窝数和母猪窝产活仔数。 1 提高母猪年产仔窝数 1.1 缩短母猪的哺乳期 首先实行仔猪早期断奶。试验证明,仔猪28d断奶与35d断奶相比,28d断奶对母猪断奶后的发情时间和断奶后仔猪发育无不良影响,对于个别窝仔猪开料 早,发育较好的仔猪可采取23～24日龄断奶的办法。其次是实行分批断奶。对于体质瘦弱的母猪和后备猪实行提前断奶,保证这些母猪断奶后及时发情配种。     

提高母猪人工授精受胎率的初探

猪的人工授精是充分利用优良种公猪,加速生猪杂交改良,提高经济效益的有效措施。由于母猪人工授精受胎率受品种、年龄、受精输配时间等多种因素影响,往往导致母猪输精后复配量大,受胎率不高,畜主对母猪的人工授精不放心。为了掌握输配关     

提高母猪人工授精受胎率的措施

实施养猪“三优”(优化繁育体系、优化饲料配合、优化饲养方式)计划项目建设过程中,部分乡镇牲猪人工授精配种站(点)存在着种公猪饲养管理粗放,采、输精操作技术粗疏,精液的处理方式不科学等急需解决的实际问题。推广普及人工授精技术,提高母猪受胎率,力求技术操作规范化、设施配套化、服务完善化,需采取得力措施。     

猪人工授精技术推广情况调查报告

<正>猪人工授精技术是指利用人工辅助器械,采取种公猪精液,经过实验室检查、处理和保存,再用输精器械将合格的种公猪精液输入发情母猪生殖道内的一种配种方法。这一技术是现代国内外养猪业中     

对纯种母猪人工授精工作的体会

笔者从１９６５年开始从事家畜人工授精工作至今。先后给朝鲜猪、巴克夏、大约克、长白猪等多个外来品种的母猪实施人工授精,均获得成功。现又对黎塘供水站猪场作技术指导。于１９９７年,配种长约杂母猪３２头。受胎率８５％,平均窝产９８头。有的读者反映说瘦肉型母...     

人工授精技术的指导原则

人工授精成功的合格水平是公母比应在1：100以上．受胎率应达85％，分娩率达80％，窝产总数和活仔数与自然交配相当．优秀的水平应达到1头公猪配250～350头，受胎率95％-97％．分娩率89％-90％产活仔数．比自然交配时高0．5～1头。     

提高初产母猪产活仔率的技术措施

<正> 桐庐县良种场是一个年提供8000头供港活中猪的出口猪场,繁殖母猪群在420头左右,年更新率约为20～25%.每年约有100头新母猪投入生产,然而头胎母猪流产、死胎、空怀等繁殖障碍给生产带来了严重损失.同时,近年来由于香港市场对中猪品种质量要求的改变,迫使该场投资35万元,历经二年多的品种改良工作,采用二个外来纯种猪的杂交母猪,仅1991年新母猪投产就达310头,占全场总母猪群的75%,因此初产母猪产活仔数的高     

Monitoring training success using a lactate-speed relationship

Monitoring training by measuring blood lactate content is a well-known procedure in sports physiology. Because of the difficulties in standardizing a test procedure in field studies, this method is fraught with considerable problems when applying it to race horses. The aim of the present study was to develop a test procedure which is able to give evidence about the training state of different race horses after nonidentical test-loads. Under almost identical environmental conditions, the level of blood lactate was determined in five trotters which were kept in training. Immediately after the single phases of a three-stage test procedure (handicap: 'small', 'medium' and 'high' load for the animals chosen at the discretion of the coach) blood samples were drawn. The lactate value was set in relation to the speed of each animal. A curve of the equation y = y0 + e(k + b*x) was fitted with r2 > 0.93 to these data. With the aid of this equation, the 'comparative speed', V, was calculated; this is the arithmetic mean of the velocities V4, V8 and V20, obtained by inserting the appropriate values for (imaginary) lactic acid concentrations in the formula. With the aid of V it was possible to detect both an increase and a decrease in physical fitness. In this way, animals tested together on one date, as well as the development of one animal tested on several dates, can be scored. Advantages and limitations of the method are discussed in detail.     

Relationship between oxidative stress and the success of artificial insemination in dairy cows in a pasture-based system

This study was designed to evaluate whether the outcome of artificial insemination (AI) was affected by the metabolic and oxidative status of dairy cows. Seventy-nine inseminations in 40 cows, were classified, on the basis of blood progesterone (P4) and pregnancy-associated glycoprotein (PAG) concentrations and clinical confirmation of pregnancy into, three categories: (1) positive (AI+, resulted in pregnancy, n=26; 33%), (2) negative (AI-, did not result in pregnancy, n=49; 62%), and (3) embryonic mortality (EM, n=4; 5%). Reactive oxygen metabolites, biological antioxidant potential, oxidative stress index, body condition score, glucose, total proteins, albumin, urea, non-esterified fatty acids (NEFAs), cholesterol, triglycerides, haptoglobin and advanced oxidative protein products (AOPPs) were measured on the day of AI (day 0), and 30 and 42days later. Cows with EM had lower BCS scores (2.5) than AI+ (2.8) and AI- (2.9) cows (P<0.05). During the post-partum period, body condition score (BCS) increased and NEFAs decreased (P<0.05) suggesting a recovery from the negative energy balance (NEB). The only significant differences found were that the mean concentration of AOPPs was higher and that of albumin lower in EM cows than in AI+ and AI- (P<0.05) animals. Plasma concentration of reactive oxygen metabolites and biological antioxidant potential were not related to AI outcome. Further studies are required to confirm this finding and to clarify the role of oxidative status on cows' fertility.     

Influence of inducing luteal regression before a modified fixed-time artificial insemination protocol in postpartum beef cows on pregnancy success

Most fixed-time insemination protocols utilize an injection of GnRH at the beginning of the protocol to initiate a new follicular wave. However, the ability of GnRH to initiate a new follicular wave is dependent on the stage of the estrous cycle. We hypothesized that administering PGF(2α) 3 d before initiating a fixed-time AI protocol would improve synchrony of follicular waves and result in greater pregnancy success. Therefore, our objective was to determine whether inducing luteal regression 3 d before a fixed-time AI protocol would improve control of follicular turnover and pregnancy success to fixed-time AI. Multiparous crossbred cows at 3 locations (n = 108, 296, and 97) were randomly assigned to 1 of 2 treatments: 1) PGF(2α) [25 mg; intramuscularly (i.m.)] on d -9, GnRH (100 μg; i.m.) and insertion of a controlled internal drug-releasing device (CIDR) on d -6, PGF(2α) (25 mg; i.m.) and CIDR removal with PGF(2α) (25 mg; i.m.) at CIDR removal on d 0 (PG-CIDR) or 2) GnRH (100 μg; i.m.) and insertion of a CIDR on d -5 and CIDR removal with PGF(2α) (25 mg; i.m.) at CIDR removal and 4 to 6 h after CIDR removal (5-d CIDR). Cows were time-inseminated between 66 and 72 h (PG-CIDR) or 70 to 74 h (5-d CIDR) after CIDR removal, and GnRH was administered at the time of fixed-time AI. At location 1, ovulatory response to the first injection of GnRH was determined by ultrasonography at the time of GnRH and 48 h after GnRH administration. Among cows with follicles ≥10 mm in diameter, more (P = 0.03) PG-CIDR-treated cows ovulated after the initial GnRH injection (88%, 43/49) compared with the 5-d CIDR-treated cows (68%, 34/50). Pregnancy outcome was not influenced by location (P = 0.96), age of the animal (P = 1.0), cycling status (P = 0.99), BCS (P = 1.0), or any 2-way interactions (P ≥ 0.13). However, pregnancy success was influenced by synchronization protocol (P = 0.04). Pregnancy outcome was greater (P = 0.04) for the PG-CIDR protocol (64%) compared with the 5-d CIDR protocol (55%). In summary, control of follicular turnover was improved by inducing luteal regression 3 d before initiation of a fixed-time AI protocol, and pregnancy success was improved with the PG-CIDR protocol compared with the 5-d protocol.     

Effect of environmental factors on estrus synchronization and artificial insemination success in farmers flock in sheep under semi-arid tropical region

Environmental cues in the different seasons might influence the estrus and lambing percentages. The present study was conducted to assess the effect of environmental factors on estrus synchronization (ES) and artificial insemination success in sheep . During the period from 2012 to 2017, a total of 1,197 ewes of Kheri and Malpura breeds of 34 farms originating from 10 villages were synchronized for estrus and then fixed-time artificial insemination (FTAI) was done. Oestrous synchronization was done by intravaginal progesterone sponges and eCG protocol. Fixed-time cervical insemination was performed 48 and 56 hr after sponge removal in ewes exhibiting estrus, using liquid chilled semen containing 100 million sperm per dose of Patanwadi/Malpura rams. Mean sunshine hours, maximum and minimum ambient temperatures, temperature amplitude, mean relative humidity (RH), temperature-humidity index (THI), mean temperature during sponge-in to sponge-out—12-day period, sponge-out and next day, AI day and AI to next 15 days have been calculated. The estrus response and lambing percentage were higher (p < .05) when ES and FTAI were done during hot-humid with rainfall season. Successful (p < .05) ES occur when the minimum temperature was higher in cold-humid season, and the sunshine hour was higher in hot-humid with scanty rainfall season during sponge-in to sponge-out period. The success of the lambing percentage was higher (p < .05) when maximum temperature, minimum temperature, mean temperature and THI was higher on the day of AI and the next 15-day period, irrespective of the season. The success of FTAI indicates the adaptability of the local breed to tolerate the harsh climate of the hot semi-arid region without much hindrance in lambing percentages.     

Equine artificial insemination

Artificial insemination is an effective technique for improving utilization of the stallion while maintaining normal conception rates in the mare. However, procedures for collection, evaluation, and insemination of semen must be followed carefully to achieve good results. Techniques for preservation of equine semen in the liquid or frozen state could potentially allow for more widespread use of genetically superior stallions. Further acceptance of artificial insemination and the use of cooled or frozen transported semen by breed registries is needed before this will occur. More work is needed to perfect methods of semen preservation, even though semen from some stallions can be cooled or frozen quite successfully at the present time.