The effect of various doses HCG on ovulation stimulation in gilts following previous biotechnical puberty induction

The effects of various doses of human chorionic gonadetropine (HCG) to stimulate ovulation in 86 gilts in which puberty had been induced by administration of 500 IU of pregnant mare serum (PMS) and 250 IU of HCG were established by slaughter. Only 26.9 per cent of the group without HCG had completed ovulation 120 hours from puberty induction, but 93.5 per cent had done so in the group which had received additional 500 IU or HCG 78 hours after the PMS/HCG injection. Ovulation was completed by 71.4 per cent of those sows which had been stimulated, using 250 IU of HCG. More accurate timing of ovulation in animals of one and the same group can be helpful in better insemination timing.     

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).     

Appearance of the uterine specific proteins following induction of ovulation in prepubertal gilts.

The appearance of the uterine specific proteins following induction of ovulation in prepubertal gilts is described. 12 gilts each at 3, 4, and 5 months of age were allotted randomly to 1 of 2 treatment groups prior to induction of ovulation: 1) saline treated and 2) human chorionic gonadotropin (HCG) treated (400 IU daily from Days 12 through 16 of the induced cycle). Ovulation was induced with HCG following treatment with pregnant mare serum gonadotropin and the day of ovulation was designated as Day 1. All the gilts were laparotomized and uteri infused with phosphate-buffered saline on Day 16 to obtain uterine protein secretions. Plasma progesterone levels on Day 11 and observations made at laparotomy indicated that only 1 gilt 3 months of age failed to ovulate. The number of corpora lutea, plasma progesterone, total recoverable uterine protein, and uterine specific protein on Day 16 were markedly affected by the age of the gilt. These same characteristics, except uterine specific protein, were additionally affected by HCG treatment. Total recoverable uterine protein and uterine specific protein in saline and HCG-treated gilts at 3, 4, and 5 months of age were 6.3 and 1.5, 10.4 and 2.8; 38.8 and 15.2, 51.6 and 15.9; 20.4 and 7.7, 47.8 and 14.6 mg, respectively. Polyacrylamide slab gel electrophoresis showed that HCG-treated gilts at 3 months of age and both saline- and HCG-treated gilts at 4 and 5 months of age generally produced the purple basic protein and the complete profile of the low molecular weight acidic proteins during the induced cycle.     

不同定时输精程序处理对有无初情期后备母猪发情及妊娠的影响

为探讨有无初情期和不同定时输精程序处理对后备母猪发情及妊娠的影响,随机选择182头有初情期和193头无初情期的后备母猪,其中将182头有初情期后备母猪分为3组,对照组(C1组,62头)、烯丙孕素组(A1组,60头)、烯丙孕素+孕马血清促性腺激素(PMSG)+促性腺激素释放激素(GnRH)组(APG1组,60头);193头无初情期后备母猪分为对照组(C2组,63头)、烯丙孕素组(A2组,65头)、烯丙孕素+PMSG+GnRH组(APG2组,65头),并且比较不同组间后备母猪的发情集中度、发情率、妊娠率等。结果显示:无初情期A2、APG2组经程序处理后分别于停药后第5～9天、第6天集中发情,有初情期A1组、APG1组母猪于停药后第6～9天、5～6天集中发情;烯丙孕素可显著提高有初情期后备母猪A1组发情率与妊娠率(P0.05),APG1与APG2组的发情率与妊娠率极显著高于C1组、C2组(P0.01),且APG1、APG2组间差异极显著(P0.01);隐性发情后备母猪妊娠率APG1、APG2组间无显著差异(P0.05)。结果表明:有无初情期显著影响后备母猪定时输精处理的效果,利用定时输精程序处理后可使母猪发情集中度、发情率、妊娠率均显著提高。     

The course of ovulation in gilts after the use of two GnRH injections for ovulation stimulation

The status of ovulation and amount of ovulated follicles in 410 gilts which had received differentiated pretreatment produced evidence to the feasibility of substitution of HCG by Gn-RH vet. "Berlin-Chemie" to stimulate ovulation. Yet, 2 injections are necessary with an adequate interval between them and with appropriate dosage. The highest synchronisation effect in all experimental variants was obtained from 350 and 750 micrograms of Gn-RH with 50 minutes in between or 750 plus 750 micrograms of Gn-RH with an interval of 40 minutes. Ovulation was most reliably stimulated by 500 I.U. of HCG.     

Effect of elevated ambient temperatures on puberty in gilts

Effects of elevated ambient temperature on puberty and related physiological responses were studied in 40 gilts. Group 1 (n = 20) gilts were born in September and Group 2 (n = 20) gilts were born in March. Gilts were placed in environmentally controlled chambers at 140 d of age. After a 10-d acclimation period at 20 degrees C, 35% relative humidity (RH), and 12 h light (L)/12 h dark (D), gilts within each group were randomly assigned to one of two treatments: control (C; 15.6 degrees C, 35% RH, 12 h L/12 h D) or heat stress (HS; 33.3 degrees C, 35% RH, 12 h L/12 h D). Daily detection of estrus with a boar began at 180 d of age and continued for 50 d. All gilts not reaching puberty by 230 d of age received 1,000 IU pregnant mare serum gonadotropin (PMSG) and 7 d later were examined by laparotomy. Rectal temperatures (REC) and respiration rates (RESP) were taken twice daily. Food intake (FI) and water usage (WC) were recorded daily. Blood samples were collected weekly and BW recorded at 150, 190, and 230 d of age. No differences (P greater than .05) were observed due to season of birth. Heat-stressed gilts had greater (P less than .001) REC and RESP and consumed more (P less than .01) water than C gilts. Food intake and ADG were not different between treatments (P greater than .05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Histological findings on the uterus of gilts following synchronized ovulation

Histological studies were undertaken with the view to testing uterus structure and function of gilts following synchronised ovulation by means of different PMSG doses. All proband groups received 500 I.U. HCG. All histomorphological, histochemical, and histometric checks revealed 500 I.U. PMSG to be too low a dosage, whereas the optimum amount was found to be between 750 and 1,000 I.U. PMSG. The uterine glands of all treated animals in all three groups were less favourably developed than those of the untreated controls. The best morphologico-histochemical pattern was observed following administration of 750 I.U. PMSG.     

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.     

The effect of transportation/relocation on cortisol, CBG and induction of puberty in gilts with delayed puberty

Twenty-seven Swedish purebred Yorkshire gilts were transported 12 km to the clinic. In 8 gilts (Group A), blood samples were drawn in connection with transportation, while in the remaining 19 gilts (Group B) no samples were drawn at this time. After transportation the gilts were examined by laparoscopy and catheterized. Blood samples were then drawn 3 times and oestrus detection was performed twice daily. After 1 week the laparoscopy was repeated.Twenty gilts (74 %) showed oestrus within 1 week, on average 5.4 days (4–7.5 days) after transportation. Elevated oestradiol-17β levels were seen in those gilts approximately 2 days after transportation. The Cortisol level was significantly higher (p < 0.001) on day 1 (the day of transportation) than on day 2 and a markedly higher level of Cortisol was seen on days 1 and 2 in the gilts which did not show oestrus (2 gilts), compared with the gilts in which oestrus was induced (6 gilts) by transportation. The difference was significant on day 2 (p < 0.05). The CBG level was significantly decreased (p < 0.001) on day 2 for all 8 gilts. During day 3 to day 8 there was no difference in the Cortisol level between days (groups A and B, 27 gilts), and no differences were seen in the levels of Cortisol and CBG between gilts showing (20 gilts) and not showing oestrus (7 gilts). The hypothesis propounded that the higher levels of Cortisol on days 1 and 2 inhibited induction of oestrus in those gilts which did not show oestrus after transportation.     

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.     

Effect of biotechnical management procedures on blood parameters in gilts. 1. Acid and alkaline phosphatase

Three independent experiments were conducted with cyclic gilts kept under different conditions (2 x 12 on platforms and 100 from production unit), i.e. hormonally unaffected or under the usual conditions of synchronised oestrus (100 mg Suisynchron per animal and die over 20 days followed by 1,000 I.U. PMS and again followed, three days later, by 250 I.U. HCG). Blood samples were repeatedly drawn from the jugular vein and brachiocephalic vein during phases of treatment and oestrus. Acid and alkaline phosphatases were determined immediately in the plasms, and the results were calculated by variance analysis. Synchronisation, using Suisynchron, proved conducive to lowering with significance (P less than 0.01) the levels of acid and alkaline phosphatases. All changes in phosphatase values were not in full conformity within the experiments during the other phases of treatment. Phosphatase levels were not affected by discontinuation of Suisynchron nor by administration of Gn hormone. The levels of acid and alkaline phosphatases in biotechnically treated animals appeared to be lower than those in animals with spontaneous oestrus at the time of full oestrus. While the findings were of period-specific significance (P less than 0.01), the results obtained from the individual animal failed to provide specific information, since gaps were too wide between animals and between animals, on the one hand, and periods, on the other (P less than 0.01).     

Influence of manure gases on puberty in gilts

To determine whether manure gases can influence onset of puberty in gilts, 42 crossbred gilts were reared from 10 to 40 wk of age on concrete slats over a 1.22-m deep pit that was drained and refilled with clean water biweekly (clean group). Forty-one gilts were reared over a similar type pit where manure was allowed to accumulate (control group). Treatments were in two separate rooms of the same building with similar feeding, water, floor space, lighting and room temperature. Ventilation fans with timer controls in each room were set so fans in the clean environment ran twice as long as fans in the control environment. Aerial concentrations of ammonia in the control room were fourfold higher than in the clean room (21 vs 5 ppm), while aerial concentrations of hydrogen sulfide were similar. Average daily gain and feed efficiency were similar for both groups [.69 vs .72 kg/d (P = .31) and 1.61 vs 1.54 kg feed/kg gain (P = .52)]. From 20 to 40 wk of age, all gilts were exposed to a mature boar three times weekly, utilizing four boars in rotation. Blood samples were collected weekly from each gilt by venipuncture and analyzed for progesterone to establish time of first ovulation. A greater proportion of gilts in the clean group attained puberty by 24 to 26 wk (P less than .05) and 27 to 29 wk of age (P less than .10) compared with the control group.(ABSTRACT TRUNCATED AT 250 WORDS)     

Influence of norgestomet in combination with gonadotropins on induction of estrus and ovulation in prepubertal gilts.

Our objective was to determine whether priming with the progestogen norgestomet for 9 d would enhance estrual and ovulatory responses of prepubertal gilts to PG600 (400 IU eCG + 200 IU hCG). Gilts (140 to 190 d old) were assigned by litter, age, and weight to one of three treatments: 1) 9 d of norgestomet implant with an injection of PG600 after implant removal on d 9 (N+PG; n = 43); 2) no implant and an injection of PG600 on d 9 (PG; n = 36); or 3) neither implant nor PG600 (control; n = 29). Beginning on d 0, gilts were exposed once daily to a boar and checked until estrus was observed or until d 45 after the start of the experiment. Ovaries were examined for number of corpora lutea (CL) after estrus or at 45 d. Greater proportions of N+PG (63%, P < .05) and PG (69%, P < .01) gilts expressed estrus than did controls (34%), but proportions did not differ between N+PG and PG (P > .10). Among gilts in estrus following treatment with N+PG or PG, 100% showed estrus within 6 d after PG600 injection. For gilts that expressed estrus within 45 d, the average age at estrus was reduced (P < .05) by PG to 172 +/- 2 d compared with 182 +/- 4 d for controls. Average age at estrus did not differ (P > . 10) between PG and N+PG (177 +/- 2 d). Greater proportions of N+PG (82%; P < .001) and PG (65%; P < .001) gilts ovulated than controls (13%), but proportions did not differ between N+PG and PG (P > .10). The number of CL (20 +/- 2) was not affected by treatment and ranged from 2 to 71. There was no increase in ovarian cysts in response to treatment. Results indicated that norgestomet before PG600 did not enhance estrus expression or ovulation compared with PG600 alone, but use of PG600 increased the proportions of gilts that expressed estrus and ovulated compared with controls.     

Relationship between two morphological types of ovaries and their follicular microscopic population before puberty and their ensuing follicular development and ovulation rates at puberty in gilts

A population of ovarian follicles was studied in 32 gilts with two morphological types at four physiological stages. Left ovaries were serially sectioned (10 microns), and follicles (greater than .19 mm) were counted and measured by histological technique. In Exp. 1, prepuberal gilts that maintained the grape-type (GT) or other-type (OT) of ovaries at 140 and 160 d of age as determined by laparoscopy had their population of follicles studied at 165 d of age and compared with that on d 3 of the first puberal estrus in gilts that maintained the same ovarian type (GT or OT) at 140, 160 and 180 d of age. In Exp. 2, gilts that maintained the same ovarian types at 140, 160 and 180 d of age were compared at d 19 and 3 of the first and second puberal estrus, respectively. At 165 d of age, OT ovaries contained a greater number of classes 3 (.63 to 1.12 mm) and 4 (1.13 to 2.00 mm) nonatretic (less than 4 pycnotic bodies) follicles than GT (P less than .01), whereas at d 3 of the first puberal estrus, their mean number became comparable between the two ovarian types (P greater than .1) and similar to 165-d GT ovaries. At 165 d of age, atretic follicles formed 19.6% and 10.7% of the population of antral follicles in OT and GT ovaries (P less than .05) whereas at puberty 17.5% and 19.6% atresia was observed in the same two groups, respectively (P greater than .10).(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of prepubertal consumption of zearalenone on puberty and subsequent reproduction of gilts

Forty-eight prepubertal gilts (178.7 +/- 4.1 d; 94.2 +/- 4.1 kg), 16 in each of three trials, were assigned randomly to receive 0 (C) or 10 ppm zearalenone (Z) daily in 2.5 kg of a 14% protein finishing ration for 2 wk. Blood samples were collected at 20-min intervals for 4 h 1 wk after the start of the experiment and 1 wk after Z was withdrawn. Two weeks after Z was withdrawn, gilts were exposed to mature boars 15 min per day for 3 wk. Gilts in estrus were mated to two different boars 12 h apart. Twice each week, blood was sampled and analyzed for progesterone to establish age of puberty. Age at puberty differed (P = .008) among replicates but was similar (P = .13) between Z and C gilts within each replicate. Mean serum concentrations of LH were suppressed (P = .025) during consumption of Z (.25 vs .42 ng/ml) but were similar (P = .16) to concentrations in C gilts 1 wk after Z was withdrawn (.35 vs .45 ng/ml). Frequency and amplitude of LH secretory spikes did not differ (P greater than .50) between Z and C gilts during either sampling period. Mean serum concentrations of FSH were similar (P = .25) between Z and C gilts. Number of corpora lutea and live fetuses were similar (P = .29 and P = .94, respectively) between Z and C gilts. Fetal weights were greater (P = .025) and crown to rump length tended to be greater (P = .10) in fetuses from Z gilts.(ABSTRACT TRUNCATED AT 250 WORDS)