豫西地区小尾寒羊的繁育技术探讨

对豫西地区小尾寒羊的繁殖生理特性进行了观察,其发情周期为16.83±0.52d,发情持续期为29.50±5.23h产后发情时间为47.30±12.56d,产后配种时间为65.36±13.40d,妊娠期为149.2±1.45d。提出了提高小尾寒羊繁殖成活率的技术措施,指出了在繁育推广过程中应注意的4个方面的问题。     

山羊同期发情处理后发情时间、LH峰及排卵时间间隔的研究

试验比较了16-次甲基甲地孕酮(MGA)和氟孕酮(FGA)对安徽白山羊进行同期发情处理后发情、LH峰值及排卵的时间间隔,结果表明:MGA处理组开始发情的时间(80.6±3.5)h较FGA处理组(41.3±1.3)h长,而且差异极显著(P<0.01);同情发情处理结束到LH峰出现、到排卵以及LH峰出现到排卵的时间间隔,MGA组为(93.5±2.2)h、(117.9±2.9)h和(24.4±1.1)h,FGA组为(55.5±2.3)h、(76.4±1.5)h和(20.8±0.7)h,两组间差异均达显著水平(P<0.05);同期发情处理结束后开始发情到LH峰出现的时间间隔、开始发情到排卵的时间间隔以及血清LH峰持续时间MGA组、FGA组分别为:(13.9±1.4)h和(14.3±0.8)h,(37.3±2.1)h和(35.0±0.5)h,(12.0±0.6)h和(12.6±0.3)h,两组间差异均不显著。     

银狐繁殖期血浆主要激素变化及其对繁殖功能的调控

通过放射免疫测定技术测定母银狐发情前期和发情期外周血浆雌二醇-17β[E2]、孕酮(P4)浓度以及公狐睾酮(T)浓度,并分析这些技术的变化及其对繁殖功能的调控.结果表明,银狐初配前2～3d,E2浓度达峰值(240.85±39.98)pg/mL,在母狐接受跨时E2浓度降至(146.95±38.21)pg/mL,而在发情前期和发情期,其孕酮浓度范围是0.91～77.43ng/mL,峰值是(54.77±23.66)ng/mL,在雌二酮峰值时,孕酮浓度为(28.57±21.21)ng/mL,配种时,P4浓度(33.12±22.56)ng/mL,初配后4d(排卵结束),P4达(48.28±34.84)ng/mL.公狐配种期,T浓度范围(127.2±444.4)pg/mL,,峰值是(341.2±103.2)pg/mL.     

胚胎移植受体山羊同期发情方案的研究

对山羊进行3种同期发情处理,处理Ⅰ为C IDRS+PMSG(100 U)+PG(0.1 mg),处理Ⅱ为C IDRS+PMSG(200 U)+PG(0.1 mg),处理Ⅲ为PG(0.1 mg)。结果发现,撤栓后0~24 h处理Ⅰ的发情率(27.76±0.62)%与处理Ⅱ的发情率(35.00±5.00)%差异不显著(P>0.05),但均显著高于处理Ⅲ(3.62±0.12)%(P<0.05);撤栓后24~48 h和48~72 h处理Ⅰ(35.31±1.40)%和(5.86±0.73)%、处理Ⅱ(56.67±3.33)%和0%和处理Ⅲ(18.07±1.94)%和(14.45±1.94)%的发情率之间均差异显著(P<0.05);在撤栓后0~72 h,处理Ⅰ(68.05±1.66)%和处理Ⅱ(91.67±8.33%)的发情率均显著高于处理Ⅲ(36.14±3.88)%P<0.05,但是处理Ⅰ、Ⅱ之间显著不差异(P>0.05)。另外在手术中观察山羊卵巢发现,处理Ⅰ、Ⅱ和Ⅲ有较好黄体的山羊比率分别为(52.15±1.42)%、(46.67±3.33)%和(62.88±2.43)%,处理Ⅰ和Ⅲ高于处理Ⅱ,并且处理Ⅱ和处理Ⅲ之间差异显著(P<0.05)。试验结果表明,采用2次优化PG法既可提高发情率,又可使受体羊黄体率达到较好水平。     

寒区马鹿发情鉴定与最佳输精时间的确定

为使寒区马鹿人工授精有标准可循,并提高其受胎率,对2007年大兴安岭地区马鹿人工输精记录进行了分析。结果表明：生产中,寒区马鹿发情鉴定采取＂公鹿试情为主,人为观察为辅＂综合判定的方式比较准确。人工输精最佳时机是发情末期母鹿拒绝试情公鹿爬跨前的1h到拒绝爬跨后的3h。这一个时段母鹿外观特征主要变化是由兴奋转为安静,从接受公鹿爬跨转为拒爬,外阴肿胀基本消退、颜色呈淡红或暗紫色。     

同期排卵处理母牛体温和活动量变化规律及效果分析

为探究同期排卵处理母牛体温和活动量变化规律及不同同期排卵技术处理效果，指导同期排卵技术优化。本研究自动监测了18头20月龄左右同期排卵（GnRH-PG-GnRH）处理荷斯坦母牛和17头产后40~60 d预同期排卵（PG-PG-GnRH-PG-GnRH）处理荷斯坦母牛的体温和活动量，应用自动检测系统进行母牛发情监测。结果发现，同期排卵处理母牛发情时阴道温度平均升高（0.43±0.20）℃，持续（12.37±2.73）h；活动量平均升高（18.28±18.61）倍，持续（11.00±1.68）h；排卵时阴道温度平均下降（0.20±0.10）℃，持续（11.00±1.68）h。自动化发情监测显示，同期排卵处理母牛7头发情并排卵；预同期排卵母牛GnRH处理前全部发情排卵。两种同期排卵处理，虽可改变母牛性周期进程，促进母牛性周期同步化，但均难以使母牛性周期完全同步。因此，将同期排卵-定时输精和发情鉴定技术科学结合才能取得更好的繁殖效果。     

神木县黄牛繁殖规律及其影响因素的探讨

对1134头配种母牛的登记资料用生物统计处理，井用t检验进行显著分析。结果表明，神木黄牛平均初配年龄为2.30岁，最佳繁殖年龄为4～7岁，发情周期为22.30d，发情持续期为(40.68±9.78)h，配种受胎率为56.2％。但由于月份、年龄、输精次数、发情阶段的不同，母牛繁殖受胎率略有差异。     

宁夏滩羊发情周期血液中促黄体素(LH)、孕酮、雌二醇——17β含量的测定

用放射免疫测定法测定了宁夏滩羊母羊(13只)外周血清中促黄体素(LH)、孕酮及雌二醇—17β的含量及其变化。血清LH的含量,在黄体期,其值很低,为5.0±0.41ng/ml,到发情开始后约6—12小时增至75.13±17.64ng/ml。孕酮含量的变化,在周期的黄体期,其值最高为2.84±0.10ng/ml;而在发情开始到发情后第二天最低0.52±0.06ng/ml。雌二醇—17β的含量是在发情开始前6—24小时时上升的;其值的变化范围是从黄体期的14.86±1.24Pg/ml到发情开始时的38.7±5.8Pg/ml。     

不同因素对绵羊同期发情的影响

用CIDR(阴道栓)和PMSG(孕马血清促性腺激素)处理小尾寒羊、蒙古绵羊、小尾寒羊和东北绵羊的杂交品种,注射PMSG后24h引入试情公羊,以便确定母羊是否发情。实验结果表明:在繁殖季节,不同品种绵羊的同期发情率无显著差异(P>0.05);季节影响小尾寒羊的同期发情效果;阴道栓放置时间的长短影响同期发情率,以12～14d为宜;用450UPMSG处理羊比400U的只平均排卵数稍高(1.545±0.741n=299,1.505±0.647n=88),但不存在统计学上的差异(P>0.05).     

牦牛发情规律及外周血孕酮、17-β雌二醇水平

牦牛发情集中在7月中旬至9月下旬。发情周期平均20.95±5.13d。发情持续时间在24h以内的占69%超过1d的占31%最长可达96h。发情率为66.7%(n=225),其中空怀牛和带犊牛分别为92.1%和50%。未带犊牛发情期17-β雌二醇平均为231±100pg/mL,黄体期孕酮平均为0.43±0.07ng/mL。每日挤乳1次的带犊牛,孕酮及17-β二醇分别为0.26±0.08ng/mL和61±26.0pg/mL。     

青海藏羊,马鹿血清中HBsAg的检测

采用人乙型肝炎ＥＬＩＳＡ试剂盒，检测青海地区藏羊及马鹿血清中乙型肝炎表面抗原。结果：藏羊血清中ＨＢｓＡｇ阳性率为１０％，马鹿血清中未查出。     

马鹿Zfx/Zfy基因的克隆及序列分析

根据GenBank中公布的牛Zfx/Zfy基因的mRNA序列,设计特异性引物,对马鹿Zfx/Zfy基因进行扩增,并对该序列进行分析。结果表明,克隆得到马鹿Zfx基因序列长为2 115 bp,GenBank登录号为KP257294.1,编码696个氨基酸;Zfy基因序列长为2 406 bp,GenBank登录号为KU041539,编码801个氨基酸。依据Zfx/Zfy基因氨基酸序列构建进化树,分析表明,马鹿Zfx基因与人的亲缘关系较近,与聚为一类的野牛、藏羚羊、虎、家猫、家牛、家犬、绵羊的亲缘关系稍远;Zfy基因与家牛、野牛、藏羚羊、绵羊的亲缘关系较近,与其他动物及人的亲缘关系较远。本研究首次克隆了马鹿Zfx/Zfy基因,为研究该基因蛋白质的结构和功能奠定了基础。     

Cloning and Sequence Analysis of Zfx/Zfy Gene in Cervus elaphus

Specific primers were designed according to the mRNA sequence of Bos taurus Zfx/Zfy genes provided in GenBank.Zfx/Zfy sequences of Cervus elaphus were cloned and analyzed.The results showed that the cloned Zfx gene sequence of Cervus elaphus was 2 115 bp (GenBank accession No:KP257294.1) that encoded 696 amino acids,the cloned Zfy gene sequence was 2 406 bp (GenBank accession No:KU041539) that encoded 801 amino acids.The phylogenetic trees of Zfx and Zfy amino acid were obtained using the Neighbor-Joining method of DNAStar software.Analysis showed that Zfx of Cervus elaphus was closely related to Homo sapiens,compared with Bison,Pantholops hodgosoniiand,Panthera tigris,Felis catus,Bos taurus,Canis lupus familiaris,Ovis aries.Zfy of Cervus elaphus was closely related to Bos taurus,Bison,Ovis aries,Pantholops hodgosonii compared with others.Zfx/Zfy genes of Cervus elaphus were cloned and sequenced for the first time,and this research provided a foundation for further studying the structure and biological functions of the proteins.     

Estrous Characteristics and Pregnancy Rates of Beef Heifers Administered Two Synchronization Protocols,

Two estrous synchronization protocols were used to determine their effect on estrous characteristics, synchronization rates, and pregnancy rates in nulliparous beef heifers on a commercial cow-calf operation in western New Mexico. Fifty-three Red Angus and Angus × Hereford heifers were sorted by age and BW to compare heifers treated with gonadotropin-releasing hormone (GnRH) 7 d before treatment with prostaglandin F_2α [PGF_2α; SelectSynch (SS); n = 26] and heifers treated with two administrations of PGF_2α 14 d apart [Targeted Breeding™ (TB) (Pharmacia, Kalamazoo, MI); n = 27). An androgenized cow fitted with a chin-ball marker was placed in each pen of heifers, and a HeatWatch (HW) transmitter (DDx, Inc., Denver, CO) was attached to each heifer to monitor estrous characteristics. Heifers were artificially inseminated after estrus was determined by HW. Number of standing events tended (P=0.12) to increase for TB heifers compared with SS heifers (54.4 ± 7.4 and 37.5 ± 7.7, respectively). Duration of estrus was increased (P<0.05) in TB heifers (16.0 ± 1.3 h) compared with SS heifers (11.6 ± 1.3 h). However, overall synchronization and pregnancy rates were similar (P>0.10) between protocols. Androgenized cows identified 53% of the estruses detected by HW. When utilizing synchronization protocols, radiotelemetric estrous detection systems may identify more heifers in estrus than androgenized cows. Intensity of estrus was increased in TB heifers compared with SS heifers; however, synchronization and pregnancy rates were not influenced by synchronization protocol.     

天山马鹿清原品系经济效益计算和分析

依据中国农业科学院农业经济研究所 1991年 8月确立的“农业科研成果经济效益计算分析” ,并结合马鹿饲养业的特殊性 ,计算出天山马鹿清原品系选育成果已获经济效益 2 2 72万元 ,还可能产生经济效益2 116万元、年经济效益 2 93万元和科研投资年均纯收益率     

微卫星标记分析5种鹿类动物群体遗传多样性

利用15个微卫星标记对麋鹿、黇鹿、梅花鹿、黄麂、马鹿5种鹿类动物群体DNA多态性进行测定,共检测到95个等位基因,平均等位基因数和群体有效等位基因数分别为6..3333±2.7946个和4.7089±1.8355个,平均期望杂合度为0.5790±0.1025,平均多态信息含量为0.4483±0.1050。群体间的平均遗传分化为29.4%（P〈0.001）,构建5种鹿类动物群体的系统聚类图,结果基本一致,黄麂、马鹿和梅花鹿聚为一大类,黇鹿和麋鹿为一类或各自成为一类。     

Relationship between endogenous estradiol-17 beta and estrous behavior in heifers

Thirty-five Holstein heifers were used to examine the relationship between endogenous estradiol-17 beta and estrous traits. During a non-superovulation period (NSP), estrous cycles were synchronized and during the periovulatory stage blood samples were collected every 6 h for 120 h for subsequent determination of estradiol-17 beta and progesterone. In addition, continuous observation for estrous behavior was performed for 98 h. A gonadotropin-induced superovulation period (SP) was begun 12 d after estrus was detected during NSP. Heifers were injected with FSH twice daily for 4 d and single injections of prostaglandin were given on d 14 and 15. Beginning at d 14, blood samples were collected every 6 h for 120 h for subsequent determination of estradiol-17 beta and progesterone. Continuous observation for estrous behavior was performed for 98 h. Peak estradiol-17 beta was greater during SP than during NSP (49.0 +/- 3.1 vs 12.9 +/- 3.0 pg/ml serum). Thirty-three and 31 of the 35 heifers were in estrus during NSP and SP, respectively; duration of estrus was 2.3 h longer during SP than during NSP. However, number of behavioral interactions during estrus did not differ between NSP and SP. In conclusion, estrous traits were similar, whereas peak estradiol-17 beta concentrations were markedly different between NSP and SP.     

Letter to the editor

Extract

Madam:- We would like to report an observation which we have made recently whilst investigating an epidemic of rye grass staggers in Canadian wapiti (Cervus elaphus mannitobensis) in Fehruary of this year.     

Duration of estrus induced after GnRH‐PGF2α protocol in dairy heifer

Estrous expressions in dairy cows have been shortened and weakened. Dairy heifers, on the other hand, may not have had such changes in estrous signs as observed in cows, since they have less stresses than cows. The aim of this study was to describe the duration of estrus in a herd of dairy heifers. A total of 56 Holstein Friesian heifers estrus was synchronized using two different hormonal protocols. They were checked for primary and secondary estrous signs with the help of heat detection devices for 48 h at an interval of 4 h starting at 16.00 hour, one day after PGF_2α treatment. Onset and end of standing estrus during 48 h observation period was recorded in 35 of the 44 heifers coming into estrus within 5 days after PGF_2α treatment during the observation period. The duration of standing estrus on the average (±SD) was 9.7 ± 5.3 h. Percentage of heifers with standing estrus longer than 12 h was 40%, and 53% showed standing estrus only for 4–8 h. It is indicated that duration of estrus in dairy heifers has been shortened recently.