The anti-proteolytic activity of blood and ovarian follicular fluid in sheep after stimulation with serum gonadotropin (PMSG) and administration of Antisergon]

The synthesis and secretion of trypsin (trypsin model serine protease) inhibitors are regulated in ovarian follicles by gonadotropins. The superovulation stimulations with 400 IU FSH, 1000 IU PMSG, 1000 IU HCG, 750 IIU PMSG + 750 IU HCG influence in a different way the trypsin inhibiting activities (TIA) of blood plasma (BP) (Figs 1 and 2) and follicular fluid (fig. 3); this points to a possibility of local effects. An increase in the average values of TIA in BP was statistically significant during the whole experiment: P less than 0.05 to P less than 0.001 (following the administration of PMSG+HCG, or PMSG, and HCG); Antisergon administered in 68 hours after PMSG reduced this increase. The changes in the fraction of low-molecular TIA in BP (after BP treatment with perchloric acid) were of converse nature; a decrease in the average values ranged from P less than 0.02 to P less than 0.001 (following PMSG or other stimulations). Antisergon did not influence this decrease. The changes observed on particular days of the trial (Figs. 1 and 2) also indicate different effects of the preparations, mainly of the component LH, which resulted in the occurrence of large nonovulating follicles (greater than 10 mm--"cystic" ones). No such follicles were observed in nonstimulated ewes and after FSH stimulation. The administration of antisergon (goat's antiserum against PMSG) 68 hours after PMSG administration did not prevent their creation. The TIA of follicular fluid (FF) of antral follicles was on average tenfold in comparison with that of blood plasma; and the TIA FF of follicles greater than 10 mm was higher (up to P less than 0.001) than the TIA FF of follicles less than 10 mm. The administration of Antisergon in shorter intervals following PMSG administration (12, 24, 48 and 58 hours) influenced the average values of TIA BP in 120 hours (since PMSG administration) in dependence on time (Tab. I). The effects of Antisergon administered in 12 and 24 hours after PMSG administration on the TIA BP were insignificant if it was administered in 48 and 58 hours the TIA BP increased (P less than 0.02; P less than 0.001) in comparison with the interval of 12 hours. The TIA FF of follicles less than 5 mm, 5-10 mm and greater than 10 mm varied in dependence on the time intervals of Antisergon administration (Fig. 4). The statistical significance of these changes in shown in Tab. II.(ABSTRACT TRUNCATED AT 400 WORDS)     

Morphologic picture of the ependyma of the 3d cerebral ventricle in ewes after hormonal stimulation

The ependyma in the infundibular region of the third cerebral ventricle was studied. Ageline sponges (20 mg per animal) were applied to nine ewes. On the thirteenth day after the removal of sponges, 750 I. U. PMSG was administered intramuscularly to three ewes, 1000 I. U. PMSG to another three, and the remaining three ewes were left without this treatment. Six ewes were the control. After embedding in paraffin, the material obtained from four control sheep and all the test sheep was stained with haematoxylin-eosine, material from another two control animals was impregnated by the method after Golgi-Cox. The ependyma in the infundibular region of anoestric ewes has a single layer and is cubic to cylindrical; it is only in the recessus infundibuli that it forms two to four layers. After the administration of Ageline, or in combination with PMSG, ependyma can be observed to react within the whole infundibular region of the third cerebral ventricle, but the most expressive reaction is recorded in the caudal part of the middle third of infundibulum where a transient type of cells (between ependymal cells and tanycytes) was found in the control animals after impregnation (they have cilia and one to two short and one long processes). After Ageline administration, ependymal cells in the middle third stretch out like in the anoestric period. The administration of 20 mg Ageline and 750 I. U. PMSG gave rise to low digital excrescences, the ependyma is undulated (pseudo-stratified) or contains small deposits of multiplied cells. After the administration of 20 mg Ageline and 1000 I. U. PMSG, the middle third contained, besides subependymal serous infiltrate, also large digital excrescences, probably filled with a serous fluid, and the surface of the subependyma and ependyma is eroded, containing proliferated deposits of ependymal cells of different thickness. Everywhere proliferation occurs, the surface layer of ependymocytes is desquamated into the cerebrospinal fluid. The histological picture described in the present paper probably suggests an increased secretory activity of ependymal cells after the administration of hormonal preparations. It is confirmed by these results that ependyma is involved in the hypothalamo-hypophyseal control of the sexual activity of sheep.     

The dose precision of PMSG in young and old sows in the process of biotechnical ovulation synchronization. 1. Comparison of diagnostic laparotomy

Treatment was applied, on two farms, to 272 gilts and 169 adult sows, 24 hours after discontinuation of Suisynchron application to the gilts or weaning of piglets of adult sows. Included were 600, 800 or 1,000 IU of PMSG for the gilts and 750, 1,000 oder 1,250 IU of the same batch (Pregmagon-Dessau) for the adult sows for ovarian stimulation. This was followed by application of 500 IU of HCG to the gilts or 300 micrograms Gn-RH vet. "Berlin-Chemie" + 300 IU HCG to the adult sows for synchronised ovulation. Laparotomy was performed on the gilts on the fifth day from PMSG application and on the adult sows on the fourth day. Average ovariotropic stimulation was "mild" in response to lower doses (14.8 follicles in gilts and 20.4 follicles in adult sows) but was "pronounced" in response to medium doses (19.4 or 22.7 follicles, respectively). The pharmacological concept of "mild" exogenic ovarian stimulation by low dosage at the threshold of effectiveness should deserve more attention, last but not least, for breeding aspects. The two groups of animals on both farms differed considerably from one another with regard to reactivity, which cannot be etiologically interpreted for the time being.     

对C57BL／6小鼠超排效果的研究

本文以近交系C57BL／6小鼠为实验对象．研究注射不同剂量的PMSG和hCG对小鼠超排效果的影响。取C57BL／6小鼠各30只,按照注射剂量不同分为A、B、C三组,每组10只,A组注射PMSG2．5IU,HCG2．5IU,B组注射PMSG5．0IU,HCG5．0IU,C组注射PMSG7．5IU,HCG7．5IU。每只小鼠腹腔注射PMSG,间隔48h后分别注射HCG进行超数排卵,再与性成熟同系公鼠合笼,次日早上检查阴道栓．有栓雌鼠用颈椎脱臼法处死。在实体显微镜下由输卵管膨大部冲卵．收集卵母细胞置于盛有M2培养液的表面皿中检查计数．分析超排效果。结果表明。C57BU6小鼠B组的平均取卵数极显著高于A组的平均取卵数（P〈0．05）;B组的平均取卵数显著高于C组的平均取卵数（P〈0．05）;C组与A组的平均取卵数差异不显著（P〉0．05）。     

Morphologic and biochemical changes in the hypothalamus in hormonally stimulated sheep

The effect of exogenous hormonal preparations (PMSG, SG, PMSG + PGF2 alpha and FSH) was studied as exerted on neurosecretion and on changes in the nuclear volume of nucleus paraventricularis, nucleus ventromedialis, nucleus infundibularis and nucleus tuberomamillaris, and on histological changes in the third cerebral ventricle. Changes in catecholamine concentrations were determined in the rostral, medial, and caudal hypothalamus of the ewes. The study was performed with 28 ewes of the Slovak Merino breed during the oestrus period. The oestrus was synchronized by the Agelín vaginal tampons (Spofa). The ewes of four experimental groups were stimulated by the administration of 1000 I.U. PMSG (Antex-Leo), 1000 I. U. Serum Gonadotropin (Bioveta Ivanovice na Hané), 1000 I. U. PMSG with 250 micrograms Oestrophan inj. (Léciva Praha), and 450 I. U. Folistiman (VEB Arzneimittelwerk Dresden, GDR). The brain samples were processed by common histological methods. A caryometric analysis was performed at 3000-fold magnification and by measurement of 200 cells of one sample. The data were subjected to mathematical processing after Fischer and Inke (1956). The amount of neurosecretory material was evaluated by light microscopy (Nakahara, 1963). The multiplication of neurosecretion in the hypothalamic nuclei testifies to the fact that the administration of hormonal preparations stimulates the function of hypothalamic structures, which corresponds with the results of the caryometric analysis. It also ensues from the results that the administration of serum gonadotropins (PMSG and SG) at the dose of 1000 I. U. results in a statistically significant decline (P less than 0.001) of the concentrations of norepinephrine in the rostral, medial and caudal hypothalami of the ewes, although the PMSG preparation has a more pronounced effect when compared with SG. The hormonal stimulation with PGF2 alpha and with FSH causes no significant changes in the concentration of norepinephrine in the hypothalamus of the ewes. As norepinephrine is considered as a neurosecretion inhibitor, the multiplication of neurosecretion in the hypothalamus nuclei after stimulation with serum gonadotropins correlates with the decline of hypothalamic norepinephrine concentrations.     

金黄地鼠超数排卵模型的建立

为探讨金黄地鼠超数排卵效果的影响因素,采用孕马血清促性腺激素(PMSG)和人绒毛膜促性腺激素(HCG)对成年雌性金黄地鼠进行超数排卵研究。结果表明,采用40 IU PMSG+40 IU HCG剂量组合的超排效果优于30 IU PMSG+30 IU HCG剂量和20 IU PMSG+20 IU HCG组合;90日龄~150日龄的90 g~150 g的金黄地鼠超数排卵效果最好;人绒毛膜促性腺激素注射后20 h是超排鼠处死取卵的最佳时间,获卵最多。     

The effect of the seasons on the ovarian response in sheep after the administration of the serum gonadotropin, PMSG

In the autumn oestrus season, 20 Slovak Merino ewes were exposed to synchronization of oestrus, treated with the PGF2alfa at doses 125 micrograms (Oestrophan, inj. Spofa). followed by an injection of PMSG at doses 1000 IU (Antex Leo Denmark) and 50,000 IU of Vitamin A (Axerophtol Spofa). 23 anoestrus ewes were synchronized with an intravaginal sponges containing 20 mg of chlorsuperlutine (Agelin, Spofa) for 12 days and after sponge withdrawal, the ewes were injected with 750 and 1000 IU of PMSG (Antex Leo Denmark). Ovulatory response was observed and the possibility of ova recovered from the genital organs in ewes after synchronization of oestrus and superovulation in oestrus season. Higher values of the total follicular response (CFO), and the average number of ovulation (PO) after administering equal doses of PMSG were found out both in anoestrus ewes (CFO 6.62 +/- 4.24; PO 4.25 +/- 4.52) and in oestrus ewes (CFO 2.70 +/- 2.10; PO 2.60 +/- 1.74; resp. CFO 2.80 +/- 1.83; PO 3.4 +/- 3.0), if the ewes were treated with PMSG together with vitamin A. The average number of ova flushed was higher in anoestrus ewes (3.0-0.5) than in oestrus ewes (1.67-3.75). In both trials the equal ratio in the number of released ova was gained from ewes of experimental groups (83-88% of the total number). After ova flushing from the genital organs in ewes of the experimental groups most ovas were found in the isthmatal part of the uterine tube (36-60%). On the basis of gained results it was concluded, that synchronized oestrus ewes on receiving PMSG in anoestrus season the ovarial response was more significant than in autumn breeding season.     

Changes in the biometry of the sex organs of sheep after estrus synchronization and superovulation in the breeding period

In twenty ewes of the Slovak Merino breed coming from a demonstration farm at Zemplínska Teplica, to the age of two-three years biometrical variations of the sex organs and overall follicular response to PMSG and PGF2 alpha administration were investigated in the autumn period (October-November). In the ewes of all groups the heat was synchronized by i. m. administration of PGF2 alpha (Oestrophan Spofa) at a dose of 125 micrograms in the interval of 11 days. On the ninth day the ewes of the second and fourth group were given 1000 i. u. of PMSG (Antex Leo, Denmark), the ewes of the third group 750 i. u. of PMSG. The ewes of the third and fourth group were administered at the same time 50,000 i. u. vitamin A (Axerophtol Spofa) (each group). The weight and dimensions of the sex organs were investigated. The results demonstrate that the administration of PMSG in the mating period increases significantly the weight of oviducts and horns of uterus in the ewes while there are no variations of the weight of the other sex organs and of their length, or it is lower than in the ewes of the control group. The overall follicular response was not influenced by the higher weight of ovaries.     

The effect of PMSG on the trypsin inhibitory activity of the blood and cervical mucus and on the reproductive organs in sheep during anestrus

The effect of the doses of 750, 1000, and 1500 I. U. PMSG (Antex Leo) on changes in the trypsin-inhibition activities (TIA) of the blood plasma and cervical mucus of ewes was found to vary: a) in the times (from PMSG administration) of recording the minimum values of total TIA (72, 48, 24 hours); b) in the values of the average total TIA on individual days of the trial (40.3-141.4% of the control values); c) in the fractions of low-molecular TIA after administration of 750 and 1500 I. U. PMSG, the fractions exhibited minimum values after 24 hours, and of 1000 I. U. after 72 hours (53.0 and 60.4, and 69.7% of the control values, respectively); d) in the highest values of the fractions of low-molecular TIA recorded after 96 hours (96.1-183.7% of the control values); e) in the average values for 96 hours of the trial, which ranged from 64.1% (1500 I. U.) to 77.1% (750 I. U.) for total TIA and from 89.6% (750 and 1000 I. U.) to 122.8% (1500 I. U.) for low-molecular TIA; f) in the ratio of atretic and non-atretic (A/N) tertiary follicles, which grew with increasing PMSG doses; this was indirectly correlated with the average values for total TIA; g) in the weights of uteri and ovaria which increased from 176.8 to 322.3% of the control values after the stimulation; h) in the epithelium thickness of cervix and cervical glands increasing from 118% to 316% of the control values; i) in the average TIA values of cervical mucus ranging from 53.3 to 125% of the control values.     

PMSG对甘肃高山细毛羊同期发情和繁殖率的影响

在甘肃省肃南县康乐乡对甘肃高山细毛羊应用阴道栓与孕马血清促性腺激素(PMSG) 结合处理,结果表明,不同注射剂量和处理方式对母羊的同期发情和繁殖率均有影响,在埋栓后12.5 d注射550 IU PMSG并在放栓后14 d撤除阴道栓后的0-48 h发情率显著高于其他试验组(P<0.05);在埋栓后13 d注射600 IU PMSG同时撤除阴道栓的试验组繁殖率最高(P<0.05)。但综合繁殖率和经济效益考虑,在埋栓后间隔12.5 d注射550 IU PMSG并在放栓后14 d撤除阴道栓0-48 h的试验组效果最好,平均每只母羊净收入可达773.7元。     

The effect of hormonal stimulation on the follicle population in the ovaries of ewes during estrus and anestrus

In the oestral and anoestral periods, 129 ewes of the Slovak Merino breed were treated with different doses of the stimulants PMSG, PGF2 alpha, HCG, SG and FSH after synchronization by means of Ageline tampons. In the anoestral period, PMSG doses of 750 and 1000 i. u. were found to increase the number of tertiary follicles from 12.3 to 17.2 and 18.6, whereas the dose of 1500 i. u. was found to reduce this number from 18.6 to 13.5. PGF2 alpha increases the average number of tertiary follicles from 12.3 to 22.2 and when it is combined with 750 i. u. PMSG, the increase is to 29.3 tertiary follicles. At higher PMSG doses the ratio of atretic (A) to non-atretic (N) tertiary follicles rose and the number of ovulations increased from 2.5 to 4.0. After synchronization with Ageline and administration of PMSG at the doses of 750 and 1000 i. u., the number of tertiary follicles increased from 16.0 to 18.4 and the number of ovulations from 3.1 to 5.7; the number of atretic tertiary follicles showed no change. In the oestral period, the dose of 1000 i. u. PMSG administered after PGF2 alpha reduced the number of tertiary follicles from 18.9 to 14.5 and increased the number of ovulation from 1.6 to 2.6; an increase was also recorded in the number of atretic tertiary follicles.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of vitamin A on trypsin inhibition activity of the blood and cervical mucus after the effects of hormones on the ovaries of sheep in the estrus period

Vitamin A (50,000 I. U.), administered after oestrus synchronization by PGF2 alpha (2 X 125 micrograms; 1st and 11th day) together with PMSG (750 and 1000 I. U.), had a stronger influence on the changes in the trypsin-inhibition activities (TIA) of the blood plasma, as compared with the effect of PMSG. The changes in the average TIA values within 120 hours after the administration of the stimulating dose were also observed more frequently to depend on vitamin A. After administration of 1000 I. U. PMSG, an increase was recorded only in the values of the fraction of low-molecular TIA, whereas the administration of the combinations of PMSG + vitamin A resulted in an increase of all the TIA's under study. This increase was directly correlated with an increased number of non-atretic tertiary follicles, with an increased number of ovulations (at the same dose of PMSG), and with a reduced ratio of changes in the concentration of progesterone (P) and 17-beta oestradiol (E): P/E = 1.1 after the administration of 1000 I. U. PMSG, P/E = 0.81 after I. U. PMSG + vitamin A, and P/E = 0.90 after 1000 I. U. PMSG + vitamin A. The increase in the average TIA of the cervical mucus is due to the increased secretory activity of the cervical glands rather than to the multiplication of these glands after ovary stimulation.     

Possibilities of ovulation synchronization in puberty-induced gilts

Puberty was induced in 39 clinically prepuberal gilts (two groups of three sub-groups each) by parallel but locally separated application of 500 IU PMSG ("Maretropin") and 250 IU HCG ("Gonadex"), with the view to testing ways to synchronise ovulation. Seventy-two hours were allowed to elapse, before 24 animals received another application of 500 IU HCG and 15 animals 250 IU HCG. The animals were slaughtered in consecutive groups of study ovulation and histolotically examined to disclose endometrial processes. Ovulations were found to be well synchronised in the recipients of a second injection of 500 IU HCG. Only sub-threshold effects with no synchronised ovulation were recorded from the animals that had received a second dose of 250 IU HCG. A second injection of 500 IU HCG should be given not until something between 78 and 82 hours after puberty induction for optimum follicle maturation and adequate proliferation of the endometrium.     

Quantitative micromorphological study of the ovaries in sheep after estrus synchronization and superovulation in the autumn mating season

The quantitative micromorphological changes of tertiary follicles and corpora lutea (CL) were studied in ewes in the autumn mating season after oestrus synchronization, induced by administration of PGF2 alpha (Oestrophan Spofa) at a rate of 125 micrograms, and after superovulation, induced by administration of PMSG (Antex Leo, Denmark) at a rate of 1000 I. U., or PMSG at rates of 750 and 1000 I. U. together with 50,000 I. U. vitamin A (Axerophthol Spofa). The highest number of ovulations was obtained in ewes treated with 1000 I. U. together with vitamin A (3.4 +/- 3.0) and after administration of 1000 I. U. PMSG alone (2.6 +/- 2.74). The highest number of tertiary follicles was recorded in ewes after administration of PGF2 alpha. The proportion of tertiary atretic follicles was the highest in ewes after administration of PMSG (64.6%). The occurrence of the luteinizing form of atresia was recorded only in ewes treated with PMSG (4% of the total number of atretic follicles). Using the caryometric analysis of the luteal cells of corpora lutea, the ewes of the experimental groups had two-peak variation curves; this corresponds to the theory of the presence of two luteal types in the tissue of the corpus luteum in ewes. As determined morphometrically, the smallest proportion of connective tissue out of the total volume of ewes' ovaries was found after administration of 1000 I. U. PMSG together with vitamin A. Administration of vitamin A together with PMSG had a favourable influence on the over-all follicular response, on the average number of ovulations, and on the proportion of non-atretic follicles.     

不同剂量生殖激素对小鼠超排效果的影响

为了探讨孕马血清促性腺激素(PMSG)和人绒毛膜促性腺激素(HCG)对小鼠超数排卵的最佳组合剂量、最佳注射时间间隔,本试验以成熟实验小鼠为试验动物,分别采用不同剂量PMSG(5IU、7.5IU、10IU、12.5IU)与不同剂量HCG(5IU、7.5IU、10IU、12.5IU)组合注射小鼠进行排卵效果研究,并以44h、46h、48h、50h的间隔时间对小鼠进行超数排卵处理试验。结果表明,(10+10)IU剂量组合处理的见栓小鼠平均获卵数最高(10.3枚);在注射间隔为48h试验组中见栓小鼠平均获卵数最高(8.4枚)。提示本试验条件下,小鼠超排中PMSG与HCG组合剂量为10IU、注射时间间隔为48h时超排效果较好。     

Changes in antiproteolytic activity in blood and ovarian follicular fluid in 3 breeds of sheep after stimulation of superovulation]

Serine proteases help to regulate the ovarian cycle at different levels and they are subjected to the control of gonadotropic hormones and protease inhibitors. Superovulation stimulations influence the activities of trypsin inhibitors (model serine protease) in blood plasma (BP) and in follicular fluid (FF), and also in dependence on the breed. Trypsin inhibiting activities were determined from the reduced rate of trypsin hydrolysis of a chromogenic substrate (TAPA) and they were determined in percent. A change in absorbancy at 405 nm = 1.0 after 10-minute incubation at 25 degrees C and pH = 8.05 was taken as 100%. The incubation mixture as a sample contained 100 microliters blood plasma or 10 microliters follicular fluid, diluted with gammaglobulin at 1:10. The differences in the trypsin inhibiting activities (TIA) of BP in ewes of the Merino, Tsigai and Wallachian breeds were insignificant, but Agelin synchronization (20 mg chlorsuperlutin per vaginal swab) induced statistically significant differences. The lowest TIA BP was recorded in the Tsigai breed (T), P less than 0.001 in comparison with the Wallachian (W) and Merino (M) breeds. Following the administration of 1,500 IU PMSG, the TIA BP within 120 hours decreased in W (P less than 0.001), it increased in T (P less than 0.1) and in M the changes in the TIA BP were insignificant. The average numbers of ovulations increased from 2.25 +/- 2.5 to 3.0 +/- 1.2 in W; from 0.25 +/- 0.43 to 2.5 +/- 1.6 in T and from 0.00 +/- 0.0 to 2.5 +/- 2.3 in M. Following the single administration of 2,000 IU PMSG after Agelin synchronization, the changes in M ewes were also insignificant, and there were no different responses in pregnant (1st to 2nd month) and nonpregnant ewes. In pregnant T ewes the TIA BP increased after Agelin synchronization and stimulation (P less than 0.01), in nonpregnant ewes these changes were not significant. In W lambing ewes the TIA BP increased (P less than 0.001), the effects of Agelin were greater than those of PMSG. The TIA of follicular fluid (FF) of antral follicles were on average tenfold if compared with BP. After hormonal treatment of ovaries, the TIA FF mostly increased at different levels of statistical significance. The TIA FF of follicles less than 10 mm were lower than in follicles greater than 10 mm (P less than 0.001 for M and W, P less than 0.1 for T).(ABSTRACT TRUNCATED AT 400 WORDS)     

大鼠卵巢对不同超排处理的反应

将大鼠19只分为4组,第1、2、3组各5只,分别用PMSG 50 IU+HCG 60 IU、FSH50 IU+LH60 IU和P MSG50 IU连续处理3次;第4组4只(对照组),注射生理盐水0.5 mL.以上各组均采用腹腔注射,每次注射间隔时间24 h,最后一次注射后24 h剖检,测量卵巢体积、重量和排卵数.结果表明,不同试验组卵巢体积明显比对照组大(P<0.05),卵巢重量也有增加,但差异不显著(P<0.05).不同试验组都引起排卵,第1组排卵数最多,第2组最少,但差异不显著.     

Progesterone plus PMSG Priming in seasonally anovulatory lactating Sarda ewes exposed to the ram effect

The aim of this trial was to evaluate the effectiveness (fertility and lambing) of priming with a single injection of progesterone plus PMSG in anovulatory lactating Sarda ewes subjected to the ram effect (RE) in spring. Thirty ewes (P4 group) were i.m. injected with 30 mg progesterone and 500 IU PMSG 36 h before ram introduction (d 0). This treatment was compared to a 12-day treatment with fluorogestone acetate intravaginal sponges that was followed by injections of 350 IU PMSG upon sponge withdrawal (FGA group, n=30). All ewes responded to RE, showing plasma progestrone concentrations >1 ng/mL between d 6 and 12 (FGA) or 6 and 9 (P4). Eighty-nine percent of the P4 ewes conceived at first ovulation, and 11% conceived following a short estrus cycle. Lambings occurred on d 150.4 +/- 3.9, and the lambing rate was 100%. The fertility of the FGA ewes was 83% for the induced ovulation and was 7% for the second ovulation after a normal cycle. The FGA ewes lambed on d 149.8 +/- 4.4, and the lambing rate was 83%. Two abortions were recorded for the FGA ewes, which had higher prolificacy than the P4 group (2.2 +/- 0.8 vs. 1.8 +/- 0.4, respectively; P<0.05). Both fertility and the lambing rate were high in both groups, with a high degree of estrus synchronization, and there were no significant differences between the groups. We concluded that priming of lactating Sarda ewes in spring with P4+PMSG before RE is an effective and competitive method (cheaper and more practical than FGA+PMSG) of inducing fertile ovulations in these ewes.     

PMSG对母兔卵巢机能的影响

以三种不同剂量的国产孕马血清促性腺激素(PMSG)对28只成年哈白母兔进行处理，剂量分别为30IU，50IU和80IU，间隔48小时后耳静脉一次性注射人类绒毛膜促性腺激素(HCG)，剂量均为80IU，再隔48小时后手术冲卵，观察母兔卵巢动态变化。结果表明三种剂量30IU、50IU和80IU处理后的母兔平均排卵点数分别为9．5个、10．8个和15．2个，其中以80IU的PMSG剂量组的排卵点个数为最高和其他两组比较差异显著(P<0．05)；48小时后各组的卵巢上可见卵泡数分别平均为43.0个、33.4个和35.9个，其中以30IU的PMSG组的未成熟卵泡数为量多，和其他两组比较差异显著(P<0.05)，各组的充血卵泡数分别为2.5个、2.0个和9.4个。80IU的PMSG剂量组的充血卵泡高于30IU和50IU剂量组，差异极显著(P<0.     

Influence of PMSG and time of artificial insemination on fertility of progestogen-treated sheep in confinement

The need for pregnant mates' serum gonadotropin (PMSG) in breeding confined sheep by artificial insemination (AI) at progestogen-synchronized estrus was assessed in 152 adult crossbred ewes brought into season by a controlled light regimen. One-half of the ewes received 500 IU PMSG after intravaginal progestogen treatment; all ewes were inseminated either 54, 57 or 60 h after sponge removal or at 54 and again at 60 h. Based on progesterone determinations 18 d after AI, conception rates with single insemination 54, 57, or 60 h and double insemination at 54 and 60 h were 76, 72, 47 and 72%, respectively, among ewes receiving PMSG, compared to 17, 22, 47 and 43%, respectively, among ewes not give PMSG (P less than .01) Lambing rates were higher (P less than .01) with PMSG (67, 67, 37 and 61%) than without PMSG (11, 11, 26 and 33%). While there was only a small increase (.06 less than P less than .05) in litter size with PMSG, fecundity decreased (P less than .01) from 1.4 to .3 when PMSG was not used. These data indicate that, even with controlled lighting to induce estrous activity, additional stimulation of ovulation by PMSG at progestogen-synchronized estrus is necessary for normal fertility when confined sheep are bred by AI.