影响荷斯坦牛胚胎移植受胎率因素的研究

为进一步提高荷斯坦牛冷冻胚胎移植受胎率,本研究对西安市奶牛育种中心2009~2013年期间的胚胎移植数据进行统计分析,侧重讨论了黄体位置、胚胎日龄及移植季节对受胎率的影响。结果表明,三年平均胚胎移植受胎率为53%;左右黄体受胎率分别为52%、55%,不同黄体位置对受胎率影响不显著(P0.05);早期桑葚胚、致密桑葚胚、早期囊胚的受胎率分别为40%、56%、62%,胚胎发育阶段对受胎率影响显著(P0.05);春、秋、冬季受胎率分别为60%、48%、52%,移植季节对受胎率影响不显著(P0.05)。     

影响母猪受胎率因素的分析

通过在永靖县玉丰猪场调查不同季节、不同的配种方式、不同查情方式、人为因素和其他因素对母猪受胎率的影响调查,分析了影响母猪受胎率的因素。结果表明,不同季节母猪的受胎率情况不同,夏季温度高时受胎率相对较低,不同的配种方式以及发情时间的不同也对母猪受胎率提高有影响,人为因素对提高母猪受胎率的作用十分重要。     

影响西门塔尔母牛情期受胎率因素的分析

为探讨影响新疆地区西门塔尔母牛情期受胎率的因素,本试验采用SAS 8.1对影响情期受胎率的配种季节、与配公牛和母牛年龄3个因素进行最小二乘方差分析,各水平间进行Duncan多重比较并分析不同水平对情期受胎率的影响。结果表明,不同配种季节对西门塔尔母牛情期受胎率影响极显著(P<0.01),春季西门塔尔母牛情期受胎率极显著低于夏季、秋季、冬季(P<0.01),冬季情期受胎率最高(64.7%),而春季情期受胎率最低(40.0%);与配公牛对西门塔尔母牛情期受胎率无显著影响(P>0.05);母牛年龄对西门塔尔母牛情期受胎率的影响极显著(P<0.01),随着母牛年龄的逐渐增加情期受胎率有降低的趋势。依据本研究结果,可针对各影响因素合理有效的调控,从而提高母牛的情期受胎率,最终提高牛场经济效益。     

黑头萨福克绵羊胚胎玻璃化快速冻胚移植效果分析

本试验应用玻璃化胚胎冷冻方法进行黑头萨福克绵羊胚胎冷冻和移植,比较了受体羊卵巢上黄体数量、受体羊的体况、移植胚胎的数量对受体受胎率的影响。受体羊卵巢上有一个黄体的移植受胎率42.7%与有2~3个黄体受体羊移植受胎率44.4%无显著差异;受体的体况对受胎率有显著影响,中上等(含中等)体况水平的受体的受胎率47.2%显著高于中下等的受体的受胎率43.0%(P0.05);使用玻璃化胚胎冷冻法的冷冻解冻胚胎移植受胎率54.2%显著高于常规胚胎冷冻法的冻胚移植受胎率44.0%(P0.05);移植1枚桑葚胚(1M)的受胎率47.5%略高于移植1枚囊胚(1B)的受胎率44.3%(P0.05)。因此,受体羊黄体数、冷冻桑葚胚和囊胚对胚胎移植受胎率没有显著影响,而受体中上等(含中等)体况水平和玻璃化胚胎冷冻法冷冻解冻胚胎移植受胎率显著提高。     

利用普通药物提高难孕母牛人工授精受胎率的观察

对屡配不孕的133头母牛(分6个组)利用普通药物在输精前或同时进行灌注,受精122头,总受胎率84.2%。第1组(Pc NaCl法)受胎率为65.7%,第2组(Pc Ps NaCl法)受胎率为55.5%,第3组(Oxt Pc法)受胎率为60%,第4组(Oxt法)受胎率为71.4%,第5组(Atp法)受胎率为43.7%,第6组(7%Gs Pc Ps法)受胎率为50%,可提高母牛的人工授精受胎率的方法是4(Oxt法)、1(Pc NaCl法)、3(Oxt Pc法)。     

哈萨克羊冷冻胚胎移植试验

通过对哈萨克羊胚胎移植试验数据的分析,表明管理水平的高低与移植受胎率的高低成正相关;环境温度的高低对胚胎移植受胎率有一定影响,室温在17℃和25℃时的受胎率分别为44.44％和47.25％;移植双胚可显著提高受胎率,移植单胚和双胚的受胎率分别为47.02％和50％;受体羊重复利用对移植受胎率有严重不良影响,重复利用的受体羊受胎率仅为21.42％,初次利用受体羊受胎率46.09％.     

影响新西兰兔受胎率的因素分析

为了分析影响新西兰兔受胎率的因素,提高新西兰兔繁殖率,从仔兔选留、饲喂方式、不同月份受胎率变化三个方面,阐述影响新西兰兔受胎率的高低。选取妊娠母兔60只,分3组,仔兔选留分别为7、8、9只,测定受胎率;另外选取妊娠母兔60只,分2组,饲喂方式分别为自由采食、分餐饲喂,测定受胎率;同时统计2016年全年配种记录,对不同月份受胎率进行统计分析。结果表明:仔兔选留9只受胎率显著低于选留7、8只的母兔;自由采食和分餐饲喂之间没有显著差异;受胎率6、7月份最低,分别为71. 15%、70. 45%,显著低于其他月份,春季、秋季、冬季受胎率均高于夏季。由此得出母兔每窝选留8只,同时对母兔进行自由采食,并控制夏季饲养环境可确保新西兰兔繁殖的最佳性能。     

广西水牛发情特点及适时输精

几年来,我区牛品种改良工作取得了显著成绩,配种受胎率不断提高,黄牛的配种受胎率达75%以上.但是水牛配种受胎率比较低,本交的受胎率只有60%左右,冻配受胎率仅45%左右.     

提高受体黄牛移植受胎率试验

为提高受体黄牛移植受胎率,探索合理的饲养管理条件,本试验将受体牛随机分为6组.分别为对照、注射亚硒酸钠、维生素V<,ADE、HCG和饲料中增加6%的能量和蛋白,各组均采用两次注射PG的同期发情的方法.结果显示,注射亚硒酸钠、维生素V<,ADE、HCG能够提高受体移植受胎率,受胎率分别为57.1±2.45%、58.3±1.61%、59.2±3.13%,与对照组(受胎率为48.3±2.33%)之间差异显著(P<0.05);在一定营养水平下,饲料中增加5%的能量和蛋白未能提高受体移植受胎率,受胎率分别为56.9±3.57%、47.6±1.20%,与对照之间差异不显著(P>0.05).受体牛子宫黄体状况也是影响移植受胎率的重要因素,受体牛的子宫生理状况是A级(移植受胎率达到55.8%)与B级(移植受胎率达到45.9%)差异显著(P<0.05),A级与C级(移植受胎率达到6.7%)差异极显著(P<0.01).结论是,全价营养、合理管理、较好的子宫黄体生理状况是影响受胎率的主要因素.     

如何提高奶牛受胎率

在良好的饲养管理条件下,奶牛的第一情期受胎率可达到60%以上,年总受胎率达到85%～90%.但是目前我省多数奶牛场和奶牛小区受胎率偏低,严重影响了我省奶牛生产和奶农积极性. 影响奶牛受胎率的因素很多,包括饲养管理、生理、环境、遗传、产科疾病和人工授精员的技术等.其中饲养管理和人工授精技术是影响受胎率的主要原因.     

饲料营养对母牛繁殖率影响效果研究

通过对妊娠后期（后１４２ｄ）母牛、带犊哺乳母牛的不同阶段饲料营养配合试验，探讨母牛的饲养技术方案。选择条件大致相同的妊娠后期母牛３６头，随机分为试验１、２组和对照组各１２头。试验１组和试验２组根据妊娠月份及粗饲料种类不同，粗饲料日喂量各有所调整，对照组牛则采用当地的传统饲养方式。试验结果，试验１组母牛产仔成活１１头，哺乳期平均１１７ｄ，断奶成活１０头，繁殖成活率８３．３％，母牛产后开始发情时间平均     

通过测定生殖道黏液导电性确定小尾寒羊配种时机的观察研究

通过使用羊排卵测定仪准确掌握不同繁殖期小尾寒羊的排卵期,旨在有效提高母羊的受孕率。选择1.5~3.5周岁和4~6周岁小尾寒羊空怀期繁殖母羊各30只,利用羊排卵测定仪测定发情期内母羊生殖道黏液电阻值,研究其变化规律,发现1.5~3.5周岁母羊组发情持续时间较短,电阻值下降和上升均较快;而4~6周岁母羊组发情持续时间较长,电阻值下降较快但其上升曲线较为曲折。比较处于不同阴道黏液电阻值范围的母羊人工授精后的受孕率发现,4~6周岁的羊群组比1.5~3.5周岁的羊群组可受孕范围宽,但1.5~3.5周岁的羊群组在可受孕电阻值范围内受孕率明显高于4~6周岁的羊群组。该研究结果提示,不同年龄小尾寒羊母羊阴道黏液电阻值变化幅度不同,发情周期内电阻值下降到最低点后再上升时期为小尾寒羊的排卵期,适宜配种,该时期为母羊配种受孕率高。     

Changes in sexual behavior and fecal steroid hormone concentrations during the breeding season in female Hokkaido brown bears (Ursus arctos yesoensis) under captive condition

The longitudinal changes in fecal steroid hormone concentrations and sexual behavior in 2 mated/pregnant and 3 non-mated female Hokkaido brown bears were investigated during the breeding season. Behavioral estrus (standing) lasted for 14 and 32 days in the mated females and for 25 to 36 days in the non-mated females. In non-mated females, sexual behavior, such as female-female mounting and masturbation, was observed for several days before and after the estrous period. In mated females, mean fecal estradiol-17beta concentrations were higher in the estrous period than in the post-estrous period, while fecal progesterone concentrations were higher in the post-estrous period than in the estrous period. The similar trends of steroid hormone changes were observed in the non-mated females.     

Effect of adding different levels of rumen protected choline to the diet on productive and reproductive performance of female goats and growth of their kids from birthing to weaning

Forty female goats in the third parity were randomly divided into four similar groups. The experiment was started 20 days before mating and lasted until the end of the suckling period for 60 days and weaning their kids. The first group were fed diet without supplementation and kept as control while in the second, third and fourth groups, each doe was fed diets with rumen protected choline (RPC) at the rate of 10, 20 and 40 g/day, respectively. Results showed that number of doe kidding twins and triplets and litter weight of kids born per group increased with increasing the level of RPC in the diet of goats and viability rate of born kids during the suckling period improved due to RPC supplementation in the diets of their mothers. Duration of estrous, days from weaning to estrous, days from kidding to estrous and kidding interval decreased significantly, while conception rate increased due to adding RPC. Milk choline concentrations and total choline secretion though milk were progressively increased significantly with increasing the level of RPC supplementation. Live body weight and daily body gain of their suckling male and female kids at weaning increased significantly with increasing RPC levels in the diets of their mothers.     

Ovarian follicular growth, function and turnover in cattle: a review

Studies in cattle assessing changes in number and size of antral follicles, concentrations of estradiol, androgens and progesterone in serum and follicular fluid, and numbers of gonadotropin receptors per follicle during repetitive estrous cycles and postpartum anestrus are reviewed. The rate of growth of small follicles (1 to 3 mm) into larger follicles increases as the estrous cycle progresses from d 1 to 18 (d 0 = estrus). Size of the largest antral follicle present on the ovary also increases with advancement of the estrous cycle. Most large follicles (greater than 10 mm) persist on the ovarian surface for 5 d or more between d 3 and 13 of the bovine estrous cycle. After d 13, most of these large follicles are replaced more frequently by new growing follicles (turnover) with an increased probability for recruitment of the ovulatory follicle after d 18. More research is needed to determine the time required for growth of bovine follicles from small to large antral size and evoke recruitment of the ovulatory follicle. Factors that regulate selection of the ovulatory follicle are unknown but may involve increased frequency of LH pulses in blood, altered blood flow and(or) changes in intrafollicular steroids and proteins. Quantitative evaluation of ovarian follicles indicated occurrence of consistent short-term changes in fluid estradiol and numbers of luteinizing hormone receptors in cells of large follicles only during the pre-ovulatory period. Presumably, low concentrations of follicular estradiol found during most of the estrous cycle are not due to a lack of aromatizable precursor or follicle-stimulating hormone receptors. Follicular fluid concentrations of progesterone increase only near the time of ovulation. Little is known about changes in follicular growth, turnover and function during postpartum anestrus in cattle. However, preliminary data suggest that the steroidogenic capacity of large follicles changes markedly during the postpartum period.     

寒区马鹿繁殖规律研究

为探明寒区马鹿的繁殖规律,对大兴安岭地区107头马鹿繁殖情况进行统计,结果表明:寒区马鹿发情时间主要集中在10月4日~11月14日;发情周期为(17.33±5.23)d;妊娠期(242.54±5.28)d,变化范围231~253 d;发情持续期(21.21±4.45)h,变化范围17.00~27.17 h,其中发情初期(5.41±2.27)h,发情盛期(15.52±4.10)h,发情末期(1.80±0.76)h。     

东北半细毛羊发情周期的观察

在繁殖季节，对准备用作胚胎移植受体的280只适龄东北细毛羊母羊进行了为期126d的定时定点观察，并结合胚胎移植手术对其卵巢类型进行了观测，结果表明7月下旬－－11月下旬间，各月上、中、下旬羊的发情率为17％－64％，发情周期为16．98d(15.00-17.36d)，发情持续期为19.67h(14.62－25.84h），功能黄体及功能黄体＋卵泡型卵巢类型占85．5％。     

Sonographic evaluation of thyroid morphology during the normal estrous cycle in the Indo-Pacific bottlenose dolphin (Tursiops aduncus)

Physiologic changes occurring in the thyroid in response to the estrous cycle have been noted in companion animals. However, in bottlenose dolphins, the influence of different reproductive states on thyroid morphology remains unclear. Sonography was used to evaluate the variations of thyroid morphology for nine consecutive estrous cycles of four sexually mature, female Indo-Pacific bottlenose dolphins (Tursiops aduncus). The estrous cycle was divided into two phases for evaluation: the follicular and luteal phases. To compare changes associated with sex, thyroid volumes were measured in the different phases during the estrous cycle of female dolphins and were compared to the ultrasound examinations of the four male dolphins measured over a 2-mo period. In males, there was no significant difference in thyroid volume during the study period (P > 0.05). The thyroid volume measured in combining all estrous cycle phases of the female dolphins was significantly larger than that measured in the male dolphins (P < 0.05). A difference in thyroid volume during the estrous cycle was observed, with the thyroid volume during the follicular phase significantly smaller (P < 0.05) than that of the luteal phase, and is possibly related to the influence of female sex steroids. Thyroid volume variability during estrus should, therefore, be taken into account when examining the thyroid gland of female dolphins.     

生殖周期小鼠输卵管粘膜糖复合物结合特性

为了解输卵管粘膜糖复合物的特点和变化规律,用４种酶标植物凝集素（ＣｏｎＡ、ＳＢＡ、ＲＣＡ１２０、ＷＧＡ）作探针,研究了小鼠发情周期、妊娠早期（７ｄ）、产后（１ｄ）的输卵管粘膜凝集素结合糖复合物染色特性的变化。结果发现,输卵管粘膜与ＣｏｎＡ、ＳＢＡ、ＲＣＡ１２０的结合,无论在发情周期还是妊娠早期（７ｄ）及产后（１ｄ）,均有波动,而与ＷＧＡ的结合始终保持最强阳性。提示输卵管粘膜凝集素结合特性的变化,可能与生殖周期激素的波动和胚泡的调节有关。     

Effects of Calf Removal at Parturition on Postpartum Ovarian Activity in Zebu (Bos indicus) Cows in the Humid Tropics

To assess endocrine and morphological responses of ovaries to total weaning at parturition, 6 Zebu (Bos indicus) cows 5 years or older were investigated. Following parturition, blood samples were collected daily during the first month and twice weekly thereafter until day 60 to determine concentrations of progesterone (P₄) and prostaglandin F_2α metabolite.It took between 25 to 32 days to complete uterine involution.The prostaglandin metabolite remained elevated for a mean period of 14.2 days (range, 4-21) postpartum. Five of the animals resumed cyclicity with a short estrous cycle starting between days 7 to 34 and lasting between 7 and 14 days. No estrous behavior was recorded prior to the short estrous cycles, but subsequent normal-length estrous cycles were all preceded by signs of estrus. In the 1 animal that resumed cyclicity with an estrous cycle of normal length on day 37 (length 20 days), the cycle was preceded by estrous behavior.Progesterone concentrations reached a mean maximum of 4.8 nmol liter⁻¹ during the short estrous cycles, and prostaglandin metabolite concentrations peaked while P₄ concentrations were decreasing. P₄ concentrations reached a mean maximum of 12.2 nmol liter⁻¹ during the estrous cycles of normal length. The interval from parturition to the first estrous cycle of normal length varied between 16 and 48 days, and the length of the cycle was 18 to 22 days.Starting 2 days postpartum, ovaries from 5 of the cows were scanned by ultrasonography every second day until day 30 postpartum. Medium-sized follicles were detected between days 4 to 7 postpartum in 4 of the scanned cows that later had short estrous cycles. The time between parturition and the appearance of the first dominant follicle was 7.6 days (range 6-10 days). The interval between parturition and the appearance of the first ovulatory-sized follicle was 10.2 days (range 8-13 days). In 3 of the scanned cows this ovulatory-sized follicle ovulated.We conclude that cyclic ovarian activity in Zebu cows can start early in the postpartum period in the absence of offspring, and that short luteal phases, not preceded by estrous behavior, may play an important role in establishing normal postpartum ovarian activity.