Effect of various injection times in ovulation stimulation in gilts following previous biotechnical puberty induction

A conclusion derived from the slaughter of 69 gilts was that no role was played by the time intervals tested between puberty induction, using 500 IU of PMS and 250 IU HCG, and subsequent action to stimulate ovulation. Very good follicle maturation and follicle formation as well as the usual uterus and ovary weights were observed, no matter whether 500 IU of HCG were injected to stimulate ovulation 54, 72 or 78 hours after puberty had been induced. Ovulation was very efficiently synchronised by 500 IU of HCG in all three groups in which the ovulation figures relative to follicle formation 120 hours from puberty induction were 92.6, 94.6 or 92.7 per cent.     

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.     

Attempts at biotechnical induction of puberty in young female pigs. 2. Effects of various time intervals between one puberty induction with PMS and HCG to the following estrus synchronization on estrus and ovulation in animals about 190 days old

A biological engineering approach to induce puberty in 125 young female fattening pigs aged 190 days was undertaken on the basis of a mixture of 500 IU PMS (Prolosanserum, Dessau) with 250 IU HCG (Gonabion, Dresden). The injections were made subcutaneously. Pronounced oestrus symptoms were recorded from the external genital organs of 80% of the probands up to ten days after injection, associated with toleration in 52.8% of them. Toleration usually started on the fourth to sixth days after injection. Cycles began to develop in 57.1% up to the next oestrus period. Animals with -/x weight increase per die of 400 g exhibited lower responses. Results in terms of heat and ovulation were lower along with shorter intervals, when oestric synchronisation was undertaken 53, 32, and 17 days after the induction of puberty (20 days Suisynchron, Bernburg; 750 IU PMS).     

Induction of estrus and ovulation in the bitch, using exogenous gonadotropins

The capability of pregnant mare serum (PMS) and human chorionic gonadotropin (HCG) to induce estrus and ovulation was tested in mature, anestrous bitches. The PMS was given for 10 consecutive days in 1 of 3 regimens: 500 IU/day (experiment 1), 250 IU/day (experiment 2), or 20 IU/kg/day (experiment 3). The HCG was given as a single 500-IU dose on experimental day 10. Controls were given saline solution. Vaginal smears were collected on days 1, 3, 5, 7, 9, and 12 by jugular venipuncture, and the plasma was assayed for progesterone concentration by radioimmunoassay. On day 13, the bitches were euthanatized, ova were flushed from the uterine tubes (oviducts), and the ovaries were collected and prepared for microscopic examination. Fourteen of 25 bitches treated with PMS and HCG showed estrus and ovulated. Proestrus (vaginal bleeding) commenced between experimental days 7 and 10. Estrus commenced on day 9 or 10. Progesterone increased from approximately 1 ng/ml on day 1 to more than 6 ng/ml on day 12. Numbers of ovulation sites on both ovaries were 4.7 +/- 1.1 and 4.6 +/- 0.5 (mean +/- SEM) in those given the daily doses of 500 and 250 IU of PMS and 9.8 +/- 1.5 in experiment 3 bitches. Eleven hormone-treated dogs and 7 saline-treated dogs did not show any detectable response. Neither cystic nor unovulated, luteinized follicles appeared on the ovaries.     

The course of ovulation in gilts after the partial replacement of HCG by GnRH for ovulation stimulation

The ovulation status and the amount of ovulated follicles were determined in 3 experiments from 197 gilts which had been given differentiated treatment and which were subsequently slaughtered. Ovulation stimulation produced high synchronisation effects, as compared to untreated animals. Partial substitution proved possible of Gn-RH vet. "Berlin-Chemie" for 500 I.U. of HCG which were generally used to stimulate ovulation, since the amount of ovulated follicles 169 hours from the last application of Suisynchron premix was in all 3 cases above the specified value of 85.0 per cent even after injection of 300 I.U. HCG/300 micrograms Gn-RH.     

Orientation studies of ovulation release in mice to test gonadotropic preparations. 2. FSH, PMSG and Gn-RH activity

The doses of FSH (follicle-stimulating hormone), PMSG (pregnant mare serum gonadotrophin), and gn-RH (gonadotrophin-releasing hormone) effective in terms of triggering ovulation were determined in a mouse ovulation test. Varying doses of the above preparations were subcutaneously injected, 48 hours after overstimulation by injection of 0.5 or 1.0 IU of PMSG. The animals were sacrificed for examination, after another 18-20 hours had passed. Roughly 50 per cent of all animals treated (threshold) in one and the same dosage group (n = 5) had ovulated in response to 0.02-0.1 IU of FSH per animal. The following FSH and PMSG dosages are recommended: 0.02, 0.04, 0.06, 0.08, and 0.1 IU of FSH, 0.6, 1.0, 1.4, 1.8, 2.2, 2.6, 3.0 IU of PMSG. When mouse ovulation tests were used in orientation studies, ovulation was regularly induced by Gn-RH doses per animal between 0.01 and 1.0 micrograms. Dosage spacings or increments should be specified with higher accuracy by further studies.     

Endocrine pathogenesis of postweaning anestrus in swine: response of the persistently anestrous sow to hormonal stimuli

The endocrine function of the individual components of the hypothalamo-hypophyseal-ovarian axis of the postweaning anestrous sow was evaluated by monitoring the sow's response to exogenous estradiol, gonadotropin releasing hormone (GnRH), and gonadotropins. Sows (4 to 6/group) not returning to estrus by 42.8 +/- 3.1 days after weaning were assigned to 1 of the following treatments: 10 micrograms of estradiol benzoate (EB)/kg of body weight; 200 micrograms of GnRH, 1,000 IU of pregnant mare's serum gonadotropin (PMSG); 1,000 IU of human chorionic gonadotropin (HCG); or 4 ml of saline solution plus 2 ml of corn oil. A preovulatory-like surge of luteinizing hormone [(LH) greater than 12 hours in duration] was observed in all weaned sows treated with EB. All EB-treated sows exhibited estrus and ovulated but none conceived. Sows given GnRH had transiently increased (less than 3 hours) LH concentrations that were not associated with estrus or ovulation. Treatment with PMSG caused an increase in peripheral concentrations of 17 beta-estradiol that was followed by an LH surge, estrus, ovulation, and conception. Treatment with HCG caused an increase in circulating concentrations of 17 beta-estradiol that was accompanied by a surge of LH in some sows and ovulation in all sows. Not all sows treated with HCG exhibited estrous behavior, but conception occurred in 2 of 3 sows that were mated at estrus. None of the sows treated with saline plus corn oil had consistent changes in circulatory concentrations of 17 beta-estradiol or LH and none exhibited estrus or ovulated.(ABSTRACT TRUNCATED AT 250 WORDS)     

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.     

Changes in the hypothalamus and adjacent ependyma after hormonal stimulation of the ovaries in ewes]

Superovulation treatment leaves alternations in the controlling regions of the hypothalamus and in the adjacent ependyme after ovulation. The test ewes were synchronized with Agelin (20 mg chlorsuperlutin in one vaginal sponge) and stimulated (after the removal of the sponges) with 750 IU PMSG + 750 IU HCG and with 1000 IU HCG and 750 IU PMSG + 5 ml Antisergon (goat antiserum against PMSG), administered 68 hours after PMSG (i.e. 40 hours after HCG). The control ewes were in different stages of the ovarial cycle. The experimental ewes were killed 120 to 130 hours after the start of stimulation. Routine histological techniques were used to treat the brain samples; this treatment was followed by assessment under light microscope. The ependyme epithelium of the third cerebral chamber was studied under scanning microscope. Preparations with different FSH:LH ratios had different effects on the nucleus ventromedialis. Antisergon administration influenced the secretion of NPV (prevented persistent stimulation), which was observed after administration of PMSG + HCG. On the surface of the lower part of the third cerebral chamber the administration of Antisergon slowed the formation of the miniblebs. Supraependyme cells disappeared after stimulation for superovulation.     

Oestrus synchronisation and fertility in black Bengal goats following administration of progesterone/prostaglandin and gonadotrophins.

Oestrus synchronisation, fertility and kidding behaviour were studied in 44 Black Bengal goats. They were divided into six experimental groups: group 1, control; group 2, progesterone; group 3, progesterone, pregnant mare serum gonadotrophin (PMSG) and human chorionic gonadotrophin (HCG); group 4, prostaglandin F2 alpha (PGF2 alpha); group 5, PGF2 alpha, PMSG and HCG; group 6, PMSG and HCG. There was 100 per cent synchronisation of oestrus in the groups treated with progesterone, progesterone with PMSG and HCG, and prostaglandin with PMSG and HCG. In the other two treated groups the synchronisation was between 66 and 75 per cent. In the control group only 50 per cent of the animals came into oestrus during the period of observation. The duration of oestrus varied between 19 and 24 hours except in group 5 where it was 40.87 hours. Animals came on heat between 95 and 137 hours after treatment except in group 5 where the interval was only 18.87 hours. A maximum fertility of 75 per cent was observed in group 4 while the kidding percentage was greatest in group 2. There appeared to be no beneficial effect of superovulation on the number of kids produced. Gestation length was similar in all the groups.     

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.     

Effects of biotechnical management procedures on blood parameters in gilts. 2. Protein-bound iodine and copper

Two groups of twelve gilts each kept on platforms were synchronised in two passes over 20 days, using 100 mg Suisynchron per animal and die followed by PMS treatment (1,000 I.U. Intergonan) and HCG treatment (250 I.U.). Complement fixation occurred five days after the first hormone application and was followed twelve to 15 days later by another phase of treatment, using Gravigonan (250 I.U. follicle-stimulating hormone (FSH), 500 I.U. HCG, 1 mg oestradiol benzoate in 10 ml serum of swine). Blood samples were continuously drawn during the various phases of treatment and cycle from the above animals as well as from 20 gilts synchronised in the above way and from another 20 untreated gilts. Protein-fixed iodine and copper levels were assessed from those samples. The protein-fixed iodine and copper levels of the blood were significantly reduced (P less than 0.01) by synchronisation, using Suisynchron. None of the two parameters was particularly affected by PMS and HCG treatments. Blood-borne protein-fixed iodine and copper was increased by administration of gonabione. Both parameters went up further during full oestrus at which date they were higher in untreated animals than in synchronised. (Protein-fixed iodine: 3.50/226micrograms/100 ml; P less than 0.01; copper: 0.283/0.234 mg/100 ml; P less than 0.01).     

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。     

Regression of induced corpora lutea by human chorionic gonadotropin in prepuberal gilts

The effect of daily injections of human chorionic gonadotropin (HCG) on luteal maintenance in hysterectomized prepuberal gilts induced to ovulate and in hysterectomized mature gilts was studied. Twenty-four pre-puberal gilts, 120 to 130 d of age, were induced to ovulate with 1,000 IU pregnant mare serum gonadotropin followed 72 h later with 500 IU HCG. Nine of the 24 prepuberal gilts (bred controls) were artificially inseminated on d 0 (d 0 = d after HCG). Mature gilts that had displayed one or more estrous cycles of 17 to 22 d were used (d 0 = onset of estrus). All gilts, except the bred controls, were totally hysterectomized on d 6 to 9 and their corpora lutea (CL) marked with charcoal. From d 10 through 29, eight prepuberal and 10 mature hysterectomized gilts received daily injections of 500 IU HCG in saline while seven prepuberal and eight mature hysterectomized gilts received daily injections of saline vehicle. Jugular blood samples were quantitated by radioimmunoassay for estrogen and 13,14-dihydro-15-keto prostaglandin F2 alpha (PGFM), a metabolite of prostaglandin F2 alpha. One bred control gilt was pregnant on d 30, indicating that the prepuberal gilts used in the experiment were prepuberal. All mature gilts and six of seven prepuberal gilts that received saline had maintained CL to d 30. Eight of 10 mature gilts that received HCG had maintained CL to d 30, while only two of eight (P less than .05) prepuberal gilts that received HCG maintained CL to d 30. All gilts receiving HCG had numerous follicles and accessory luteal structures.(ABSTRACT TRUNCATED AT 250 WORDS)     

Prevention of anestrus in sows after the 1st and 2d parturition

The procedure of prevention of anoestria after the weaning of piglets was verified in 389 experimental and 332 control sows of the Prestice breed. The set of animals under study included 77 experimental and 122 control primiparae, 68 experimental and 71 control secundiparae, and 244 experimental and 139 control multiparae (i.e. sows with three or more parturitions). The experimental sows were treated with 1000 IU of serum gonadotropin ad usum vet.-Bioveta-(PMSG) the first day after the weaning of piglets and with 300 IU of chorion gonadotropin (HCG) in the Praedyn inj. Spofa preparation together with 1 ml of Dirigestran inj. Spofa (40 micrograms LHRH) 72 hours later. Control sows were not treated with hormones. The treated primiparae and secundiparae respectively, had a significantly higher percentage of oestrus onset within 10 days after weaning and lower occurrence of anoestria over 10 days after weaning by 31.25 per cent (P less than 0.001), and 21.36 per cent (P less than 0.02) respectively as compared with untreated controls. In the set of secundiparae, the studied hormonal treatment speeded oestrus onset by a significant (P less than 0.01) shortening of the interval from weaning to the first insemination by 0.79 day and by a more frequent onset of oestrus within only 5 days after weaning of piglets. The values of the other criteria of reproduction studies, i.e. percentage of pregnancies after the first insemination, total number of born piglets and number of liveborn piglets converted per one litter in treated primiparae and secundiparae did not differ significantly (P greater than 0.05) from the control.(ABSTRACT TRUNCATED AT 250 WORDS)     

Experiments in biological engineering to induce puberty in young female swine. 4: Ovulation period after puberty in animals aged about 200 days, using different combinations of gonadotropic hormones

44 prepuberal gilts were treated with gonadotropic combinations and investigated for ovarian dynamics. 400 PMS + 200 HCG (Suigonan-Vemie) induced ovulations at the 4th day p.i., 100 FSH + 100 HCG resp. 200 FSH + 200 HCG at the 6th day p.i. At the 8,-11th day p.i. the PMS/HCG-treated animals showed corp. lut, in 100, the FSH/HCG-treated in 50 resp. 87% of the cases. A second injection of 250 HCG 3 days after 200 FSH + 200 HCG increased the number of animals which had ovulated. Zystic ovaries (larger than or equal to 11 mm) developed in all groups. Declaration of gonadotropins in "international units".     

Dinoprost 14-day oestrus synchronisation schedule for dairy cows

Oestrus and ovulation were synchronised in 82 lactating Friesian dairy cows with two injections of dinoprost, and the cows were inseminated 72 and 96 hours after the second injection. Twenty-one of the 41 cows (51 per cent) which had a 14-day interval between the dinoprost injections conceived to the inseminations, compared with 18 of the 41 cows (44 per cent) which had an 11-day interval between the injections.     

Effects of biotechnical management procedures on blood parameters in gilts. 3. Lipids

Suisynchron treatment was applied to platform-kept gilts over 20 days. The dosage was 100 mg per animal and die. This was followed by 1,000 I.U. PMS and 250 I.U. HCG. Artificial insemination was applied five days after the first hormone administration and followed by one Gravigonan injection after another twelve to 15 days. Blood samples were drawn from those animals as well as from 20 gilts synchronised in the above way and another 20 untreated gilts from a production unit during the various phases of treatment and cycle. Those samples were used for assessment of cholesterol, lipoid-P, free fatty acids, triglyceride, and beta-lipoproteids. The levels of free and total cholesterol went up along with Suisynchron feeding, whereas lipoid-P and beta-lipoproteids declined. Free fatty acid levels went down with significance (P less than 0.01), and triglycerides increased (P less than 0.05). Cholesterol levels were not altered by PMS/HCG administration. The levels of lipoid-P, free fatty acids, and beta-lipoproteids rose to their magnitudes prior to Suisynchron treatment. Tirglycerides rose by 50 per cent. At the time of full oestrus triglyceride levels doubled (P less than 0.01). Unimportant rises were recorded also for cholesterol, beta-lipoproteids, free fatty acids, and lipoid-P. In animals with spontaneous oestrus all lipid parameters were ligher than in sows with full oestrus after synchronisation.     

Timing of induction of ovulation in mares treated with Ovuplant or Chorulon

Reliable induction of timed ovulation is an important managerial tool in any horse-breeding operation. Not only does breeding close to ovulation increase pregnancy rates when using cooled, frozen, or poor-quality semen, but it also reduces the number of inseminations needed per cycle, resulting in a more efficient breeding program. To better predict ovulation time in the long estrus period of the mare, one could increase the frequency of transrectal palpations and ultrasounds and/or implement hormonal therapies to induce ovulations. However, previous studies have been unclear on the exact timing of ovulation of mares treated with human chorionic gonadotropin (Chorulon, Intervet Inc, Millsboro, DE) or deslorelin acetate (Ovuplant, Pharmacia and UpJohn Co, Kalamazoo, MI). This study was designed to determine the timing of ovulation after Ovuplant or Chorulon treatment in normal cycling mares presented to the veterinary clinic. In addition, the pregnancy rates were determined for mares bred when a single insemination, using frozen or chilled semen, was performed at a fixed time (36 hours) after Ovuplant or Chorulon treatment. Thirty-two mares were given a subcutaneous injection of 7.5 mg of prostaglandin F2α (Lutlyse, Ft Dodge Animal Health, Ft Dodge, IA) 5 days after the last ovulation and were examined every 48 hours until estrus was detected based on a dominant follicle and the presence of endometrial edema as determined by ultrasonographic examination. Group 1 (N = 12) was treated intravenously with 2,500 units of Chorulon, and group 2 (N = 20) was treated subcutaneously with Ovuplant as soon as mares were determined to be in estrus. Once treated all mares were examined by rectal palpation and ultrasound at 0, 12, 24, 28, 30, 32, 34, 36, 38, 40, 42, 44, 48, 60, 72, 84, 96, hours or until ovulation was detected. Ovulation rate in response to Chorulon was 83.3% at 48 hours, 91.6% at 72 hours, and 100% at 96 hours. All of the mares in the Ovuplant-treated group had ovulated by 48 hours. Chi-square analysis of the data showed a significant (P < .01) variation in the distribution of ovulation times between mares treated with Chorulon and mares treated with Ovuplant. This study provides enough evidence to support the hypothesis that timing of ovulation is a more reliable event in mares treated with Ovuplant compared with those treated with Chorulon.     

Effect of age and physical or fence-line boar exposure on estrus and ovulation response in prepubertal gilts administered PG600

Boar exposure has been used for estrus induction of prepubertal gilts, but has limited effect on estrus synchronization within 7 d of introduction. In contrast, PG600 (400 IU of PMSG and 200 IU of hCG; Intervet, Millsboro, DE) is effective for induction of synchronized estrus, but the response is often variable. It is unknown whether boar exposure before PG600 administration might improve the efficiency of estrus induction of prepubertal gilts. In Exp. 1, physical or fence-line boar contact for 19 d was evaluated for inducing puberty in gilts before administration of i.m. PG600. Exp. 2 investigated whether 4-d boar exposure and gilt age influenced response to PG600. In Exp. 1, 150-d-old prepubertal gilts were randomly allotted to receive fence-line (n = 27, FBE) or physical (n = 29, PBE) boar exposure. Gilts were provided exposure to a mature boar for 30 min daily. All gilts received PG600 at 169 d of age. Estrous detection continued for 20 d after injection. In Exp. 2, prepubertal gilts were allotted by age group (160 or 180 d) to receive no boar exposure (NBE) or 4 d of fence-line boar exposure (BE) for 30 min daily before receiving PG600 either i.m. or s.c. Following PG600 administration, detection for estrus occurred twice-daily using fence-line boar exposure for 7 d. Results of Exp. 1 indicated no differences between FBE and PBE on estrus (77%), age at puberty (170 d), interval from PG600 to estrus (4 d), gilts ovulating (67%), or ovulation rate (12 corpora lutea, CL). Results from Exp. 2 indicated no effect of age group on estrus (55%) and days from PG600 to estrus (4 d). A greater (P < 0.05) proportion of BE gilts expressed estrus (65 vs. 47%), had a shorter (P < 0.05) interval from PG600 to estrus (3.6 vs. 4.3 d), and had decreased (P < 0.05) age at estrus (174 vs. 189 d) compared with NBE. Ovulation rate was greater (P < 0.05) in the BE group for the 180-d-old gilts (12.7 vs. 11.9 CL) compared with the NBE group. However, age group had no effect on ovulation (77%) or ovulation rate (12 CL). Collectively, these results indicate that physical boar contact may not be necessary when used in conjunction with PG600 to induce early puberty. The administration of PG600 to 180-d-old gilts in conjunction with 4 d prior fence-line boar exposure may improve induction of estrus, ovulation, and decrease age at puberty.