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。     

饲粮锌、硒和维生素E水平对后备母猪生长发育及生殖激素的影响

选择日龄、体况较一致的二元杂(长白×约克)后备母猪27头,采用L9(34)正交表安排试验,共9个试验组,每组3个重复。饲粮锌、硒和维生素E均设置3个水平,分别为:锌(45.0mg/kg,85.0mg/kg,125mg/kg);硒(0.10mg/kg,0.25mg/kg,0.40mg/kg);维生素E(15IU/kg,30IU/kg,45IU/kg),目的是研究饲粮微量元素锌、硒和维生素E对后备母猪生长发育和血清生殖激素参数的影响规律。结果表明在喂给含锌量85mg/kg,含硒量0.25mg/kg,含维生素E量45IU/kg饲粮时:(1)后备母猪的初次发情时间最早,分别为(187.4±6.6)d,(185.9±8.4)d,(189.1±7.3)d(P<0.05);(2)血清雌激素及孕激素浓度在不同日龄情况下均显示最高水平(P<0.05或P<0.10)。综合所考察的参数,后备母猪饲粮中含锌85mg/kg,含硒0.25mg/kg,含维生素E45IU/kg是适当的组合用量。     

母猪试情车侧翻和侧滑运动稳定性分析与试验研究

针对在猪场狭小特定环境下如何通过猪场狭小的过道空间,将种公猪运送到发情母猪面前,让母猪嗅到种公猪身上的气味、看到种公猪、甚至触碰到种公猪,进而提高母猪的情趣;再通过人工授精,提高母猪受孕率,提出了无线遥控母猪试情车,分析了无线遥控母猪试情车的机械结构及工作原理,建立了试情车侧翻侧滑模型;通过试验,得出试情车的相关参数,仿真分析质心高度、轮距宽度和后车体重量占整车重量比例等参数改变对试情车侧翻和侧滑稳定性的影响;理论计算试情车空载和满载时,在水平路面上以最大转弯角度行驶时发生侧翻和侧滑的最大速度;并通过试验验证试情车以最大角度转弯行驶,低于理论计算的速度时,是否会发生侧翻和侧滑现象;为提高试情车运行时侧翻侧滑稳定性及结构上的改进优化提供理论指导.     

奶牛宫颈粘液CMPx,CMEC与发情及排卵的关系

选取３０头健康黑白花奶牛，在发情期不同时间测定宫颈粘液过氧化物酶（ＣＭＰｘ）的活性及电导率（ＣＭＥＣ），以探讨ＣＭＰｘ、ＣＭＥＣ与发情及排卵的关系。结果表明，ＣＭＰｘ在卵泡成熟期明显下降，与卵泡初期及排卵初期的酶活性差异极显著（Ｐ＜０．０１）；而ＣＭＥＣ在卵泡初期、卵泡成熟期及排卵初期变化不显著（Ｐ＞０．０５）。本研究提示，ＣＭＰｘ在奶牛发情期有特定的变化规律，可以作为预告排卵的指标     

不同时间引入公羊对非繁殖季节诱导卡拉库尔母羊同期发情的试验

将90只处于乏情期的卡拉库尔母羊随机分为两组，统一使用孕激素合剂处理与阴道海绵孕酮埋植12d和肌注PMSG，对两组母羊在不同时间引入处理公羊。结果表明，发情前2d引处处理公羊组97.8%母羊表现发情，第1和第2情期产羔母羊数占处理母羊数的93.3%，其中第1情期产羔母羊数占处理母羊数的48.9%，产羔的综合效果优于发情当日引入处理公羊组。     

Pseudopregnancy in Saanen Goats (Capra hircus) Raised in Northeast Brazil

The prevalence of pseudopregnancy over 44 months was investigated in 23 Saanen goats raised in Northeast Brazil during continuous oestrous cycling (cyclic group) or after synchronization of oestrus (synchronized group). The goats were monitored by ultrasonography and their plasma progesterone profile. The overall prevalence of pseudopregnancy was 30.4% (7/23). In the cyclic group, 28.6% (4/14) of goats showed pseudopregnancy, while in the synchronized group the prevalence was 33.3% (3/9). There was no significant difference between the groups (p>0.05). The mean (+/- SD) length of pseudopregnancy, as shown by the progesterone profile, was 121.6 +/- 33.5 days, ranging from 70 to 155 days. The study defined the prevalence of pseudopregnancy in Saanen goats raised in Northeast Brazil for the first time. This finding identified a major problem for this breed, as without treatment such animals remain unproductive until the spontaneous resolution of the condition. More research seems desirable to ascertain the prevalence of this condition in other breeds in this region of Brazil.     

甜玉米金玉甜1号制种父母本花期及栽培密度研究

为了获得金玉甜1号高产制种的父母本最佳播期差以及母本最佳载培密度,研究了甜玉米金玉甜1号制种父母本的花期相遇以及栽培密度对其制种产量的影响。结果表明,金玉甜1号春季制种父本比母本迟播18～20 d,父母本花期达到最佳相遇。在父母本花期正常相遇的前提下,金玉甜1号制种母本的最适栽培密度为4.76万株/hm2。     

不同处理方法对新疆褐牛同期发情效果的影响

为新疆褐牛胚胎移植和人工授精选择高效的同期发情方法。经直肠检查,具有功能性黄体的新疆褐牛母牛149头,采用CIDR+FSH+PG、孕酮海绵栓+PMSG+PG、1次肌肉注射PG、2次肌肉注射PG、GnRH+PG方法进行同期发情处理,比较不同处理方法同期发情的效果。结果表明:1次肌肉注射PG与CIDR+FSH+PG、孕酮海绵栓+PMSG+PG、2次肌肉注射PG、GnRH+PG方法的同期发情率分别为48.28%与80.65%、75.00%、75.00%、72.41%,差异显著(p0.01)。可见处理方法以2次肌肉注射PG法为好,同期发情率高,简单易操作且成本低。     

用荷斯坦奶牛性控精液生产体内性控胚胎

采用荷斯坦奶牛X性控冻精和超数排卵技术结合生产奶牛性控胚胎,以建立高效、低成本的体内性控胚胎生产方法。研究发现,使用CIDR和Cue-Mate进行奶牛同期发情处理,发情率分别为90.9%和100%(P<0.05),且Cue-Mate的发情时间更加集中;加拿大的FOLLTROPIN-V和中国科学院动物研究所的FSH对奶牛超排效果影响不显著,分别为头均胚胎数10.08枚±8.08枚、头均可用胚胎数2.38枚±3.07枚和头均胚胎数6.57枚±4.31枚、头均可用胚胎数2.00枚±1.88枚,无显著差异(P>0.05);奶牛发情后12h～14h和16h～19h人工授精,分别获得头均胚胎数10.25枚±5.53枚、头均可用胚胎数5.33枚±4.52枚和头均胚胎数10.13枚±6.93枚、头均可用胚胎数5.88枚±6.26枚,无显著差异(P>0.05)。但是未受精胚胎数差异显著(27对7,P<0.05)。     

Relation of reproductive performances and rectal palpation for luteum function of heifers 7 days after estrus

Diagnosis of corpus luteum (CL) function by rectal palpation (RP) has been widely used for recipient selection of embryo transfer (ET), a technology essential for genetic improvements in cattle. To examine the accuracy of RP diagnosis method, the relationship between RP‐based CL function and reproductive performance was compared in this study. In Experiment 1, CL of Holstein heifers on day 7 after estrus was classified into functional or hypoplastic by RP, and the results were compared with ultrasonographic (US) images and plasma progesterone (P4) levels. As a result, heifers with functional CL judged by RP had a mean maximum CL diameter of 20.1 ± 3.1 mm on US and a mean P4 concentration of 8.1 ± 2.3 ng/mL. These values were significantly greater than those of heifers with hypoplastic CL (12.4 ± 5.4 mm, 4.0 ± 2.8 ng/mL) (P < 0.001). In Experiment 2, the length of the estrus cycle was examined between functional CL and hypoplastic CL. The rate of heifers with a normal estrus cycle length with 18–25 days was significantly lower with hypoplastic CL than with functional CL (16/24 vs. 43/46, P < 0.01). In Experiment 3, 543 inseminated heifers were similarly classified by CL function by RP 7 days after estrus. The heifers with functional CL showed higher pregnancy rate compared with the heifers with hypoplastic CL (75.2 vs. 47.9%, P < 0.0001). Finally, the CL function of 66 heifers was examined by RP on day 7 post‐estrus, and ET was performed in 49 (74.2%) heifers with functional CL. As a result, 27 (55.1%) of them became pregnant. Taken together, these results reconfirm that RP on day 7 after estrus is useful for selection of heifers with functional CL.