Accessory corpora lutea formation in pregnant Hokkaido sika deer (Cervus nippon yesoensis) investigated by examination of ovarian dynamics and steroid hormone concentrations

Generally, sika deer conceive a single fetus, but approximately 80% of pregnant females have two corpora lutea (CLs). The function of the accessory CL (ACL) is unknown; moreover, the process of ACL formation is unclear, and understanding this is necessary to know its role. To elucidate the process of ACL formation, the ovarian dynamics of six adult Hokkaido sika deer females were examined ultrasonographically together with peripheral estradiol-17β and progesterone concentrations. ACLs formed in three females that conceived at the first estrus of the breeding season, but not in those females that conceived at the second estrus. After copulation, postconception ovulation of the dominant follicle of the first wave is induced by an increase in estradiol-17β, which leads to formation of an ACL. A relatively low concentration of progesterone after the first estrus of the breeding season is considered to be responsible for the increase in estradiol-17β after copulation.     

Factors affecting plasma prolactin concentrations throughout gestation in high producing dairy cows

The aim of the present study was to investigate possible relationships between plasma concentrations of prolactin and the following factors throughout gestation in lactating dairy cows: photoperiod, season, milk production, Neospora caninum-seropositivity, twin pregnancy, and plasma concentrations of pregnancy associated glycoproteins-1 (PAG-1), progesterone and cortisol. Pregnancy was diagnosed by trans-rectal ultrasonography on Day 40 post-insemination and by palpation per rectum on Days 90, 120, 150, 180 and 210 or until abortion in aborting cows. Blood samples were collected from each animal immediately before each pregnancy diagnosis. The study population was comprised of 73 non-aborting (54 Neospora-seropositive cows) and 20 aborting cows (all Neospora-seropositive) cows. In non-aborting cows, GLM repeated measures of analysis of variance revealed that lactation number and days in milk had no effect on plasma prolactin concentrations throughout gestation, whereas high plasma prolactin concentrations were significantly associated with high plasma levels of cortisol and PAG-1, with Neospora-seropositivity, positive photoperiod (increasing day length), twin pregnancy, and with low plasma progesterone concentrations. An interaction among plasma prolactin, plasma cortisol and milk production was observed in that plasma prolactin concentrations differed significantly throughout gestation and were highest in high-producing cows with high cortisol levels. In Neospora-seropositive non-aborting versus aborting cows, mean prolactin concentrations failed to differ on Days 40, 90, 120, 150 and 180 of pregnancy, whereas prolactin values were significantly lower (P = 0.03) in aborting animals on Day 210 of pregnancy. Our results indicate that a positive photoperiod and Neospora-infection lead to increased plasma prolactin concentrations throughout gestation. Reduced prolactin concentrations detected in Neospora-seropositive aborting cows compared to non-aborting animals suggests a protective effect of prolactin in N. caninum infection.     

早期妊娠猕猴孕激素水平的检测

利用全自动化学发光免疫分析仪检测正常未妊娠的与不同孕期猕猴血清中雌二醇及孕酮的分泌水平。结果表明孕5d、10d、25d、30d血清孕酮比正常猕猴的分泌水平有非常明显的上升（P〈0.01）,孕15d也有显著的上升（P〈0.05）;孕15d、20d的雌二醇分泌水平比正常组有非常显著升高（P〈0.01）,而孕5d、10d、2...     

不同时期小鼠血浆中孕激素的变化

[目的]了解不同妊娠期、泌乳期小鼠血浆中孕激素水平的变化。[方法]通过放射免疫法测定血浆中孕激素的水平。[结果]妊娠期内孕激素的水平先升后降,而在泌乳期内孕激素水平较稳定。[结论]不同时期体内孕激素的水平受多种因素的影响。     

锰对白耳鸡血浆LH雌激素孕酮含量的影响

对经含 Mn9(Ⅰ组)、59(对照组)、209(Ⅲ)PPm 日粮处理的产蛋母鸡用放射免疫测定法检测血浆中 LH,雌激素和孕酮的合量。结果表明:血浆 LH 的平均值,实验各期Ⅰ组是2.24±0.18ng/ml,对照组是2.59%±0.22ng/ml,Ⅲ组是1.91±0.09ng/ml,Ⅲ纽非常显著地低于对照组(P<0.01),排卵用期中Ⅰ组为1.54±0.21ng/ml,对照组为1.75±0.26ng/ml,Ⅲ组为1.41±0.24ng/ml;血浆雌激素平均值,实验各期对照组是161.20±8.36pg/ml,高于Ⅰ组的102.39±5.72pg/ml(P<0.01)和Ⅲ组的120.52±7.75pg/ml(P<0.01),排卵周期中对照组为82.84±10.37Pg/ml,高于Ⅰ组的61.82±7.09和Ⅲ组81.04±12.22pg/ml;血浆孕酮平均值,实验各期Ⅰ组为1.28±0.12ng/ml,低于对照组的1.77±0.11ng/ml(P<0.01)和Ⅲ组的1.58±0.10ng/ml(P<0.05),排卵周期中Ⅰ组是三组中最低的;在排卵周期中各组都在排卵前8小时出现血浆雌激素峰值,在排卵前4小时出现血浆 LH、孕酮峰值,但Ⅰ、Ⅲ组的血浆 LH,雌激素和孕酮峰值水平与对照组比,明显降低,这可能是由于 Mn 缺乏或过多引起产蛋率下降的原因。本文还对高 Mn 或低 Mn 日粮引起血浆 LH 水平下降的机理进行了讨论。     

氟孕酮在提高奶牛受胎率上的应用

[目的]为了解决奶牛的繁殖障碍,特别是高产奶牛产后不发情或屡配不孕的问题。[方法]介绍以牛欢氟孕酮阴道海绵栓为核心组合的“二次发情配种法”,综述氟孕酮在提高奶牛受孕率上的研究与应用进展。[结果]结果表明:奶牛第一情期受胎率达到65%左右,其余牛经1个情期后自然发情配种,2次总发情率95%,受胎率90%,效果明显。[结论]该技术值得推广,解决了奶牛的繁殖障碍问题,促进了奶牛业的发展。     

特定电磁波对激发产后奶牛发情、配种效果及有关性腺激素变化的观察

 特定电磁波（TDP）辐射器，通过电热激发，可产生2-25μm红外光谱，其峰值为9μm，具有对生物体有益的特异生物效应，目前在中国已广泛地应用。奶牛产后乏情达3个月以上且无卵泡发育者，用特定电磁波（TDP）居髎穴区照射，照射组（30头）在照射的21天内16头发情，对照组（30头）在此期间仅1头发情，两者比较，差异极显著；经3个情期配种，照射组16头发情牛中15头妊娠（第一情期配种8头妊娠），对照组1头发情牛经3个情期配种没有妊娠，两者比较，差异极显著。用放射免疫方法测定经照射发情16头奶样中雌二醇（E#-2）和孕酮（P#-4）含量变化曲线与正常发情牛周期中两种性腺激素含量变化规律一致，对照组牛奶样中雌二醇（E#-2）和孕酮（P#-4）没有规律性变化。     

常用实验动物血清雌二醇和孕酮的测定及比较

目的测定NIH、BABL/C、C57BL/6J小鼠、SD、Wistar大鼠和长爪沙鼠等几种常用实验动物的血清雌二醇(E2)和孕酮(P)水平,为动物生殖和胚胎工程等方面的研究提供基础资料。方法用放射免疫分析法测定上述动物生产前后血清雌二醇(E2)和孕酮(P)水平,进行统计学处理和比较。结果在未生产动物中,血清E2、P的含量与特定物种的体重呈正相关的趋势(p<0.01);血清P的含量在动物生产前后变化较大,生产过动物均高于未生产动物(p<0.01)。结论动物血清E2、P的含量具种属特异性;但在已生产动物中似无明显关联。血清P的含量变化与其在动物体内的正常分泌及生理功能相对应。     

Relationship of Progesterone,Bovine Pregnancy-Associated Glycoprotein-1 and Nitric Oxide with Late Embryonic and Early Fetal Mortalities in Dairy Cows

The aim of the present study was to determine the relationship of progesterone (P4), bovine pregnancy-associated glycoprotein-1 (bPAG-1) and nitric oxide (NO) levels with late embryonic (LEM; day 28 to day 42) and early fetal mortalities (EFM; > day 42 to day 56) in dairy cows. Transrectal ultrasonography (6–8 MHz) was performed in 100 Holstein-Friesian cows at days 28, 42 and 56 after artificial insemination (AI; day 0) to diagnose pregnancy and to monitor the fate of the embryo. After ultrasound scanning of each cow, a milk sample was collected for assessment of P4 by an ELISA test and a blood sample was collected for assessment of bPAG-1, by using a double-antibody radioimmunoassay, and serum NO metabolites (nitrate + nitrite). Based on ultrasonographic examinations and bPAG-1-RIA, 41 of 100 inseminated cows were confirmed pregnant at day 28 after AI. Nine cows suffered of LEM, and 6 cows suffered of EFM and the overall pregnancy loss rate was 36.6% (15/41) between days 28 and 56 of pregnancy. By logistic regression analysis, there were no significant relationships between the level of P4 and bPAG-1 at day 28 after AI and the occurrence of LEM and EFM. Also, there were no significant relationships between the levels of P4 and bPAG-1 at day 42 and the occurrence of EFM. On the other hand, a significant relationship (P<0.05) was found between NO level at day 28 and the occurrence of LEM. In conclusion, measurement of the serum NO concentration at day 28 of pregnancy might help to predict the outcome of pregnancy by day 42 in dairy cows but further studies are needed to confirm this.