外源激素PMSG提高滩羊繁殖率初探

采用阴道栓塞、PMSG和加强饲养管理相结合的方法,对63只空怀滩母羊进行两个胎次125只次的处理,结果表明,①注射PMSG时间与撤栓的时间间隔以撤栓同时或提前12小时效果较好.②配种季节250 u和非配种季节300 uPMSG能有效地诱导滩母羊的同期发情并增加母羊的排卵数.③采用适宜的外源激素处理基本实现了滩羊一年两产并诱导一产多羔,母羊年繁殖率达187.3%,年只均繁殖成活羔羊1.59只,母羊只均增加收入66.62元.按两年三产计算,年繁殖率为142.1%.     

滩羊多羔性能的RAPD标记研究

用RAPD技术和混合分离分析 (BSA)方法对双羔家系的 2 6只滩羊和对照系的 2 5只单羔滩羊进行了RAPD检测。发现 :OPB1 7-530、OPB1 9-92 6和OPB2 0 -1 4 2 6三条DNA片段仅出现在多羔家系的母本及多羔母本与单羔父本杂交产生的部分后代中 ,而在对单羔羊的逐个检测中未出现这三条片段。据此可以推断三个DNA分子标记与多羔性能主基因可能相关。作者系统优化组合出了能使滩羊基因组DNA稳定扩增的RAPD体系     

提高小尾寒羊繁殖率的综合措施

每年各季发情、高繁殖率和1年2产是小尾寒羊的突出特点。在饲养管理中,利用小尾寒羊常年发情,缩短繁殖周期,掌握一胎多羔技术,可以提高繁殖率,是饲养小尾寒羊获取收益的关键所在。影响小尾寒羊繁殖率有许多因素。在生产实践中只有对诸多因素进行正确分析,并采取相应有效的对策,才能获取最大的产出。     

宁夏滩羊血清转铁蛋白多态性及双羔性能的研究

采用垂直板聚丙烯酰胺凝胶电泳,对宁夏滩羊双羔羊实验组及对照组群体进行血清转铁蛋白（Ｔｆ）多态位点的检测。共发现６个表现型（基因型）,受３个等显性基因控制（Ｔｆ＾Ａ,Ｔｆ＾Ｂ,Ｔｆ＾Ｃ）,通过计算基因频率,得出宁夏滩羊双羔羔羊实验组与对照组Ｔｆ的基因频率有显著差异,其中含有Ｔｆ＾Ｃ基因的宁夏滩羊有较高的双羔性能。     

提高小尾寒羊繁殖率六要点

<正>(一)选择多羔公母羊留种双羔或多羔具有遗传性,在选留种公母羊时,其上代公母羊最好是一胎双羔或多羔以上的后备羊群中所选出的。这些具有良好遗传基础的     

双羔技术对提山区牧场绵羊繁殖率作用的试验

试验一：在山区牧场采用双盖苗处理８００只母羊，试验结果：小群中水剂双羔苗提高双羔率平均为３５．６５％（１８％－６０％）；油剂双羔苗平均为２２．４２％（１３．６％－３１．２５％）。大群中水剂和油剂双羔苗提高双羔率分别为３２．５％和２０．８％。结果表明，水剂苗明显比油剂苗要好（Ｐ＜０．０１）。试验二：采用双羔苗处理１８６５只母羊，分两种处理。结果表明，注射双羔苗后，激素处理并不影响双羔苗的作用。在大群     

应用激素提高母牛繁殖率效果研究

应用激素诱导母牛超数排卵,提高母牛繁殖率。选择３个试验组合,即ＦＳＨ＋ＬＨＲＨ－Ａ３试验组、ＰＭＳＧ＋ＡＰＭＳＧ试验组和三合激素＋ＬＨ试验组。选择条件大致相同的空怀母牛３６头,随机分为３组,每组各１２头,饲养管理基本一致。结果ＦＳＨ＋ＬＨＲＨ－Ａ３试验组母牛１２头,情期受胎９头,受胎率７５．０％,产犊１２头,其中产双胎３头,双胎率为３３．３％;ＰＭＳＧ＋ＡＰＭＳＧ试验组母牛１２头,情期受胎８头,受     

滩羊冬羔春羔生产效果对比试验

为了探讨优良地方品种滩羊最佳产羔季节,从生产发育、羔羊成活率和经济效益3个方面进行研究试验结果表明,试验组羔羊平均初生重3．66kg,1月龄体重8．80kg,3月龄体重16．78kg;对照组羔羊平均初生重3．42kg,1月龄体重9．60kg,3月龄体重18．25kg。冬羔初生重大于春羔,而断奶期生长速度低于春羔。冬羔的成活率为97．5％,春羔为95．8％。3月龄冬羔每只收入402．72元,春羔每只收入401．5元。春羔虽然断奶期日增重高于冬羔,但综合羔羊成活率、经济效益等因素,在甘肃省景泰县饲养优良绵羊品种滩羊冬羔的生产效果和经济效益优于春羔。     

The effects of exogenous growth hormone on follicular steroid secretion and ovulation rate in sheep.

Growth hormone (GH) has diverse actions in many tissues, including the follicle. This paper summarizes three experiments that examined the effects of GH and insulin-like growth factor (IGF)-I on the ovary. Ewes given oGH and pregnant mane serum gonadotrophin were compared with control and pregnant mane serum gonadotrophin-treated ewes. Ewes, with synchronized cycles, were given varying doses of pregnant mane serum gonadotrophin and/or oGH to determine if oGH is able to augment ovulation rate (Experiment 1). Experiments 2 and 3 used the ovarian autotransplant model. Ewes were infused via the ovarian artery with oGH (Experiment 2) or insulin-like growth factor I (IGF-I) (Experiment 3). Both were administered for 12 hr on Day 10. In Experiment 2, ewes were given intravenous gonadotropin releasing hormone (150 ng i.v.) at -2.5 and 10.5 hr relative to infusion. Ovarian and jugular venous blood was collected every 15 min from -30 to 150 min relative to gonadotropin releasing hormone. In Experiment 3, luteolysis was induced at the end of infusion. Ovarian and jugular venous blood was collected every 3 hr from before and until 84 hr after the infusion. Estradiol and androstenedione were assayed in ovarian venous plasma and GH in jugular venous plasma. In Experiment 1, treatment with oGH increased the jugular venous concentration of GH. However, in Experiment 2 treatment with oGH via the ovarian artery did not increase jugular venous GH but did increase ovarian venous GH. Treatment with oGH had no effect on ovulation rate (Experiment 1) or the secretion of androstenedione and estradiol (Experiment 2). Infusion of IGF-I (Experiment 3) increased the secretion of estradiol during the follicular phase. These data show that short-term treatment of sheep with GH had no in vivo effects on the follicle and that IGF-I was a potent stimulator of follicular steroidogenesis in vivo.     

Luteinizing hormone and growth hormone secretion in ewes infused intracerebroventricularly with neuropeptide Y

Neuropeptide Y (NPY) provides an important hypothalamic link between nutritional status and neuroendocrine mechanisms regulating growth and reproduction. The objective of the following series of experiments was to determine the effects of single or continuous administration of NPY on secretion of luteinizing hormone (LH) and (or) growth hormone (GH). In experiment 1, four ovariectomized (OVX) ewes and four OVX + estrogen-treated ewes each received, in a 4 x 4 Latin Square arrangement of treatments, a single injection of 0, 0.5, 5, or 50 microg NPY via an intracerebroventricular (i.c.v.) cannulae to determine the effects on secretion of GH. NPY significantly elevated serum GH at the 50 microg dose regardless of estrogen exposure (P = 0.003). In experiment 2, eight OVX ewes were infused i.c.v. with NPY or saline (n = 4/trmt) continuously for 20 h in a linearly increasing dose, ending at 50 microg/h NPY. Blood samples were collected via jugular cannulae every 10 min during hour -4-0 (interval 1, pre-treatment), hour 6-10 (interval 2) and hour 16-20 (interval 3) relative to the initiation of infusion (0 h). Mean LH and LH pulse frequency were lower in NPY- versus saline-infused ewes during intervals 2 and 3 (P < 0.01), but NPY had no discernable effect on serum GH (P > 0.10). In experiment 3, four OVX ewes were continuously infused with NPY as in experiment 2, except that the maximum 50 microg/h dose was achieved after only 10 h of infusion. Blood samples were collected every 10 min, beginning 4 h before and continuing until 4h after the NPY infusion. Mean serum LH changed significantly over time (P = 0.0001), decreasing below pre-treatment levels by hour 3 of NPY infusion (P < 0.01), and returning to pre-treatment concentrations following the end of infusion (P > 0.15). Serum GH also changed significantly over time (P < 0.001). Mean GH levels tended to be greater than pre-treatment levels by hour 2 of infusion (P < 0.08), but thereafter returned to basal levels. Serum GH also increased following the end of NPY infusion (P < 0.03). From these data we conclude that NPY exerts a persistent inhibitory effect on secretion of LH, and may stimulate the secretion of GH during the initiation and cessation of infusion of NPY. These observations support a role for NPY in mediating the effects of undernutrition on both LH and GH, and also provide evidence for potential mechanisms by which leptin, acting through NPY, may stimulate the secretion of GH.     

不同月份产羔母羊泌乳期生殖激素与生长激素监测

为了解不同月份生产的奶山羊泌乳期生殖激素与生长激素(GH)变化规律,随机抽取1、3、5和8月份分娩的奶山羊各10只,于分娩后0 d、7 d、1~8个月(每月的第15天)时采集母羊静脉血,分离血清,采用ELISA试剂盒检测母羊外周血中催乳素(PRL)、卵泡刺激素(FSH)、促黄体生成素(LH)、雌激素(E₂)、孕酮(P₄)和GH水平变化。结果显示:不同月份产羔母羊泌乳期间外周血中同一激素的动态变化趋势一致;在整个泌乳期间,1、3、5、8月份产羔母羊PRL、FSH、LH、P₄、E₂、GH含量的动态变化范围分别为446.17~221.72 ng·L^-1、9.49~3.82 U·L^-1、351.17~218.16 pg·mL^-1、4086.83~3568.15 pmol·L^-1,33.74~22.30 ng·L^-1、30.36~11.57μg·L^-1;不同月份产羔母羊外周血中GH水平在相同泌乳期均无显著差异(P>0.05),FSH水平在0 d有显著差异(P<0.05),P₄水平在8个月时有显著差异(P<0.05),PRL水平在泌乳的0 d和2、3、8个月时有显著差异(P<0.05),LH水平在泌乳的0 d、2个月时有显著差异(P<0.05),E₂水平在泌乳0 d、3个月和8个月时有显著差异(P<0.05)。结果表明:奶山羊产羔月份的不同对泌乳期间的激素水平有一定的影响,但动态变化趋势一致。     

Successful fostering of orphan lambs by non-pregnant ewes induced to lactate using exogenous hormone treatment

Six nonpregnant ewes were induced to lactate by an exogenous hormone treatment lasting 6 weeks. At the end of the treatment one alien lamb was adopted by each ewe. Each ewe was initially indifferent to the alien lamb and required only mild restraint to allow the lambs to suck successfully. Maternal interest subsequently increased and strong ewe-lamb bonding was evident by 80 minutes (n=1), 10 hours (n=4) or 24 hours (n=1) in different cases. The lambs required supplementary milk for 4-6 days while milk production by the ewes increased to adequate levels. Thereafter they were reared entirely by the ewes. Another four nonpregnant ewes were induced to lactate by a similar hormone treatment and were then hand-milked thrice daily for 23 weeks. One alien lamb was then removed after 10-30 minutes. The ewes were then injected subcutaneously with 5 mg of oestradiol-17beta and were placed in fostering stocks. After a further 3-5 hours the lambs were re-introduced. Strong ewe-lamb bonding occurred during the subsequent 10 hours in all cases. All 10 lambs were reared successfully by these ewes until at least 3 months of age, when observations stopped. It was concluded firstly that nonpregnant ewes induced to lactate artificially will adopt and rear orphan lambs successfully, provided that additional milk is given to meet shortfalls during the first 4-6 days; and secondly that a 5 mg injection of oestradiol-17beta may facilitate fostering of lambs by ewes in established lactation whether the lactation is induced artificially or not.     

A radiographic method for measuring the effect of exogenous hormone therapy on uterine involution in ewes.

Twenty-six pluriparous Suffolk ewes were used to monitor the effects of four hormone treatments on the rate of uterine involution, which was assessed by means of radio-opaque markers and radiography. The close correlation between measurements of the genital tract in live sheep and after slaughter indicated that this method of monitoring uterine involution was acceptably accurate. Uterine involution was complete by about 29 days after lambing. None of the hormone treatments with progesterone, oestradiol-17 beta, prostaglandin F2 alpha or an oxytocin analogue, administered shortly after lambing, had any effects on the rate of uterine involution. There was no correlation between the duration of increased plasma concentrations of 13.14 dihydro-15-keto-prostaglandin F2 (PGFM) and the rate of uterine involution.     

Successful fostering of orphan lambs by nonpregnant ewes induced to lactate using exogenous hormone treatment

Six nonpregnant ewes were induced to lactate by an exogenous hormone treatment lasting 6 weeks. At the end of the treatment one alien lamb was adopted by each ewe. Each ewe was initially indifferent to the alien lamb and required only mild restraint to allow the lambs to suck successfully. Maternal interest subsequently increased and strong ewe-lamb bonding was evident by 80 minutes (n=l), 10 hours (n=4) or 24 hours (n=l) in different cases. The lambs required supplementary milk for 4–6 days while milk production by the ewes increased to adequate levels. Thereafter they were reared entirely by the ewes. Another four nonpregnant ewes were induced to lactate by a similar hormone treatment and were then hand-milked thrice daily for 2-3 weeks. One alien lamb was then introduced to each ewe. All four ewes were aggressive towards the lambs which were removed after 10–30 minutes. The ewes were then injected subcu- taneously with 5 mg of oestradiol-17β and were placed in fostering stocks. After a further 3–5 hours the lambs were re-introduced. Strong ewe-lamb bonding occurred during the subsequent 10 hours in all cases. All 10 lambs were reared successfully by these ewes until at least 3 months of age, when observations stopped. It was concluded firstly that nonpregnant ewes induced to lactate artificially will adopt and rear orphan lambs successfully, provided that additional milk is given to meet shortfalls during the first 4–6 days; and secondly that a 5 mg injection of oestradiol-17β may facilitate fostering of lambs by ewes in established lactation whether the lactation is induced artificially or not.