[Effect of vaccination against GnRH (Bopriva®) in the male pubertal calf]. / Wirkung einer Impfung gegen GnRH (Bopriva®) beim männlichen pubertären Kalb.

The objective of this experiment was to investigate the effectiveness of a newly developed bovine anti-GnRH vaccine (Bopriva®, Pfizer Animal Health, Australia). A total of 12 peripubertal bull calves aged between 6 and 8 months were used, 2 randomly selected animals served as controls. Animals were vaccinated twice at an interval of 4 weeks with 1ml of Bopriva® (400 µg GnRH-protein-conjugate) subcutaneously in the neck and observed for a total of 36 weeks. Scrotal circumference was measured every week and blood samples were also taken weekly for the determination of testosterone and GnRH antibodies. Three months after the second injection (booster), 5 animals were slaughtered and their testes histologically examined. GnRH antibody titers rapidly began to rise after the second vaccination and reached peak values 3 weeks later. Testosterone concentrations decreased to values below 0.5 ng/ml serum 1 week after the booster and remained at this low level for at least 10 weeks. The following increase of testosterone occurred individually within 11 and 23 weeks after the booster injection. Histological examination of testes in vaccinated animals showed an incomplete spermatogenesis with impaired or no production of spermatids and a reduced diameter of seminiferous tubules. From our results we conclude that in the peripubertal bull two injections with the new bovine anti-GnRH vaccine 4 weeks apart is effective in suppressing testicular growth and testosterone secretion during at least 10 weeks after the booster injection.

[Suppression of reproductive cyclicity by active immunization against GnRH in the adult ewe]. / Unterdrückung der Fortpflanzungsaktivität durch aktive Immunisierung gegen GnRH beim adulten weiblichen Schaf.

The objective of the present study was to evaluate the effect of an anti-GnRH vaccine on cycling activity in the adult ewe during the breeding season. For the experiments 22 cycling White Alpine sheep, aged between 2 and 4 years, were randomly divided into a treatment and control group of 11 animals, each. Sheep of the treatment group were immunized twice at an interval of 4 weeks with 2 ml (400microg GnRH-protein conjugate) of Improvac (Pfizer Animal Health, Australia) subcutanously in the neck. Sheep of the control group received the same amount of saline solution. Blood progesterone concentrations were measured weekly from 3 weeks before to 32 weeks after first immunization and anti-GnRH titers were determined monthly. All vaccinated ewes ceased cycling within 2 - 8 weeks after first immunization. Plasma progesterone was suppressed for a minimum of 12 weeks (2 ewes) with individual variation of 14 (1 ewe), 25 (1 ewe) and more than 25 weeks (7 ewes). Four animals resumed cyclicity while 7 animals remained suppressed until the end of the study. Antibody titers peaked one month after the booster injection and thereafter continuously dropped until the end of the study (8 months after first immunization) to values between 10.9 and 40.8 % binding. From our results it can be concluded that two vaccinations with Improvac 4 weeks apart suppress cycling activity in adult ewes for at least 12 weeks. The inhibitory effect on ovarian activity, however, varies individually and may last more than 31 weeks.

[Effects of straw handling during storage on semen quality in the bull]. / Auswirkungen der Handhabung von Pailletten während der Lagerung auf die Qualität von Stiersamen.

The aim of the present study was to investigate the influence of semen handling by different inseminators on quality of frozen-thawed bovine semen. For this study a total of 10 ejaculates were collected from 7 bulls and semen stored frozen for 7 months in vessels of 10 inseminators each, in three different regions of Switzerland (A, B and C). After storage motility and acrosome integrity (live spermatozoa with intact acrosomes) were measured in frozen-thawed semen by computer-assisted sperm analysis (CASA) and flowcytometry, respectively. In addition, the 56 days non-return rate (NRR) was determined for each inseminator and the relation between NRR of single inseminators and semen quality examined. Results demonstrate that motility as well as acrosome integrity of stored frozen semen were significantly influenced by the specific delivery system used in the different regions and by the ejaculate. After storage of straws in region B semen motility was significantly (P < 0.05) lower than in region C. In region B the percentage live and acrosome intact spermatozoa as well as the NRR of the inseminators were significantly (P < 0.05) lower than in region A. Motility and acrosome integrity of semen stored by single inseminators were significantly correlated with the inseminator's NRR. We conclude that the quality of frozen semen clearly varied between inseminators of the three regions with an impact on NRR.

Influence of long-term treatment with equine somatotropin (EquiGen) on gonadal function in stallions with poor semen quality.

The aim of the present study was to investigate the spermatogenic and Leydig cell activity in stallions with impaired semen quality after treatment with equine somatotropin. Experiments were performed using 18 adult clinically healthy stallions with poor semen quality which did not pass breeding soundness evaluation. The animals were randomly divided into a treatment (n = 9) and a control (n = 9) group. Over a period of 90 days, nine stallions received a daily intramuscular injection of 10 mg recombinant equine somatotropin (EquiGen, BresaGen Limited, Adelaide, Australia) and 9 control animals were injected with the same amount of physiological saline solution. During and until 2 months after treatment, semen characteristics and daily sperm output as well as plasma testosterone concentrations were determined monthly in all stallions. In addition, testosterone concentration measurement after stimulation with hCG was performed in all animals immediately before and at the end of the treatment period as well as 2 months later. Our results demonstrate that equine somatotropin (EquiGen) given daily in a dose of 10 mg per animal during 90 days had no significant effect neither on plasma testosterone concentrations and hCG-induced testosterone release nor on semen quality parameters in adult stallions with poor semen characteristics.

Influence of estradiol on adrenal activity in ovariectomized cows during acute stress.

Stress-dependent activation of the hypothalamo-pituitary-adrenal axis (HPA) can compromise reproductive function in animals and humans. In addition, it has been shown that estrogens are also capable of influencing the activity of the adrenal cortex. The objective of this study was to evaluate the effect of estradiol (E2) on adrenocortical secretion of cortisol and progesterone as well as on pituitary LH-release in cows during stress. Five ovariectomized Brown Swiss cows were exposed to acute restraint stress (2-h immobilization in a trimming chute), either with or without E2 treatment. Blood samples were taken every 15 min during a 5-h period for determination of cortisol progesterone and LH. Our results demonstrate that during the 2-h stress period mean cortisol concentrations significantly (P < 0.05) increased in all cows independent of E2 treatment. Mean progesterone concentrations also increased during stress, but the effect was only significant in E2-untreated cows. In contrast to cortisol and progesterone, mean LH values decreased in all animals during stress, but the decline was not significant. However, significantly lower mean LH values were seen at the end of the stress period comparing to values before stress. In cows without stress, E2 treatment had no significant effect on mean values of all three hormones analyzed. From our results it can be concluded that in ovariectomized cows (a) acute stress increases cortisol and progesterone secretion but decreases LH release and (b) the stress induced adrenocortical and pituitary responses were clearly attenuated under the influence of estradiol.

Influence of repeated treadmill exercise on quality and freezability of stallion semen.

The objective of this study was to investigate changes of quality and freezability of stallion semen in response to repeated acute treadmill exercise. Ejaculates from 11 stallions were collected, evaluated and frozen weekly during four periods of 4 weeks each defined as before (period 1), during (period 2) and after (periods 3 and 4) intense exercise. In fresh semen the gel-free volume, sperm concentration, motility, normal sperm and sperm with major defects (acrosome defects, nuclear vacuoles, abnormal heads, midpiece defects and proximal droplets) were evaluated. In frozen-thawed semen, motility as well as viability (SYBR-14/PI) were examined. In period 2, all stallions were exercised on an indoor high speed treadmill twice a week (total of eight sessions) using an incremental workload test. Heart rate was monitored telemetrically during exercise and blood samples were taken for determination of cortisol, testosterone and lactate. Results of our investigation demonstrate that heart rate and the plasma concentrations of cortisol, testosterone and lactate significantly (P < 0.05) increased during each exercise session. Furthermore, significantly more major sperm defects were present in periods 3 (69.5+/-2.1%) and 4 (66.8+/-2.1%) than in periods 1 (62.2+/-2.4%) and 2 (62.5+/-2.2%). Acrosome defects increased towards the end of exercise but improved 3 weeks later to values observed before exercise. In frozen-thawed semen, motility was significantly lower in period 2 (45.4+/-2.3%) compared to period 4 (51.6+/-1.7%) and viability was significantly lower in period 2 (49.2+/-2.0%) than in periods 1 (53.8+/-2.1%) and 4 (53.7+/-1.6%). Our results clearly demonstrate that in the stallion repeated strenuous treadmill exercise can negatively influence semen quality and freezability.

Effect of exercise and suspensory on scrotal surface temperature in the stallion.

In this study, the effect of exercise (treadmill, riding) on scrotal surface temperature (SST) in the stallion with and without suspensory was evaluated. Experiments were carried out between September and November 2004 using 12 Franches-Montagnes stallions from the National Stud in Avenches (Switzerland). Each stallion performed a standardized incremental treadmill and a ridden test with and without suspensory. The intensity of exercise was monitored by heart rate and blood lactate concentration. For SST measurements, special thermistors were developed and affixed to the most ventral part of the scrotum over each testis. SST was recorded telemetrically at 1min intervals. Our results show that type of exercise (treadmill/ridden) and suspensory (with/without) significantly influenced SST. The mean SST level was higher during treadmill (32.2+/-0.02 degrees C) than during ridden exercise (30.4+/-0.03 degrees C) and mean SST differences between stallions with and without suspensory were smaller in treadmill (0.4 degrees C) than in ridden (2 degrees C) exercise. These findings clearly demonstrate that ambient airflow, which was higher during ridden exercise, is important and effective in SST regulation. In order to prevent possible thermal damage to spermatogenic cells we recommend removing the suspensory immediately after exercise.

Influence of immunization against GnRH on reproductive cyclicity and estrous behavior in the mare.

The aim of this study was to evaluate the effect of active immunization against GnRH on ovarian activity, plasma progesterone and estradiol concentrations and on estrous behavior in adult mares. Eighteen cyclic mares were randomly divided into a treatment and control group. Nine mares were immunized twice with 2 mL (400 microg GnRH-protein conjugate) of a GnRH-vaccine (Improvac, CSL Limited, Australia) administered intramuscularly, 4 weeks apart. Control mares received the same amount of saline solution. Ovaries and uterus of all mares were examined weekly by ultrasonography from 3 weeks before to 60 weeks after first immunization. Thereafter, vaccinated mares were evaluated monthly until 100 weeks after first vaccination. In addition, mares were teased with a stallion for assessment of estrous behavior and blood was collected for progesterone, estradiol-17beta and GnRH antibody titer determination. Results demonstrate that vaccination against GnRH significantly (P<0.05) influenced all parameters, except estradiol-17beta concentration. All vaccinated mares ceased reproductive cyclicity (plasma progesterone <1 ng/mL, follicles <3 cm) within 8 weeks after the first injection and ovarian activity remained suppressed for a minimum of 23 weeks. Five mares resumed cyclicity (follicles >3 cm, progesterone >1 ng/mL) while three mares showed only follicular activity (follicles >3 cm) and one mare remained completely suppressed for the entire duration of the study. In spite of ovarian suppression, four mares expressed sporadic and one mare continuous estrous behavior. In conclusion, reproductive cyclicity in adult mares can be successfully suppressed by immunization against GnRH but the timing of resumption of cyclicity is highly variable and estrous behavior may occur in spite of ovarian suppression.

Histomorphological and immunohistochemical findings in testes, bulbourethral glands and brain of immunologically castrated male piglets.

The aim of this study was the histological and immunohistochemical evaluation and comparison of testicular, bulbourethral and brain tissue in immunized and intact control boars. Fourteen male piglets, aged between 10 and 16 weeks, were vaccinated twice subcutaneously 4 to 5 weeks apart with Improvac, an anti-GnRH vaccine. The pigs were sacrificed 1 to 16 weeks following the second injection. Testicular weight was recorded and various tissue samples were collected and fixed in formalin and Bouin's fixative for histological examination. In addition, 2 boars were immunized five times and slaughtered 60 weeks after the last injection. Histological and immunohistological studies performed on testes and epididymes showed clear signs of atrophy in the immunized animals and a significant reduction in paired testes weight was seen in treated boars. Microscopically, the mean diameter of the seminiferous tubules was markedly reduced. Spermatogonia as well as few spermatocytes were visible between the Sertoli cells and Leydig cells were atrophic. None or only few spermatozoa were detected in the epididymis. The bulbourethral glands of immunocastrated pigs were smaller than in control pigs and showed histological evidence of atrophy. Immunohistological detection of LH and FSH in the pituitary gland of treated and control boars showed no quantifiable difference in the amount of these two gonadotropins and no lesions were visible in the hypothalamus and the pituitary gland. From our findings it can be concluded that the anti-GnRH vaccine Improvac induces severe atrophy of testes and bulbourethral glands in immunized pigs. This effect appears to be reversible, depending on the immune response of each animal and the time elapsed after the last booster injection.

Influence of vedaprofen (Quadrisol) on quality and freezability of stallion semen.

The objective of this study was to evaluate the effect of the non-steroidal anti-inflammatory drug (NSAID) vedaprofen (Quadrisol) on quality and freezability of stallion semen. Experiments were performed using 22 Franches Montagnes stallions from the National Stud in Avenches (Switzerland) randomly divided into a control and test group. Vedaprofen was given orally to all stallions of the test group at the recommended therapeutic dose (initial dose of 2mg/kg followed by 1mg/kg body weight every 12h) for 14 days. Control animals received the same amount of carrier substance. During treatment, blood samples of five stallions in both test and control group were collected for PGF(2 alpha)-metabolite (PG-metabolite) determination. Ejaculates from all stallions were collected and cryopreserved weekly for 14 weeks from September to December. Concentrations of PG-metabolite, PGF and PGE were measured in the seminal plasma of ejaculates collected 2 weeks before, during and 2 weeks after treatment. In fresh semen the volume, concentration, motility and number of normal sperm and sperm with major defects (acrosome defects, abnormal heads, nuclear vacuoles, proximal droplets, midpiece defects) were evaluated. In frozen-thawed semen samples motility as well as viability (SYBR-14/PI) were tested and the hypoosmotic swelling test (HOS) was performed. Results demonstrate that vedaprofen had no effect on blood plasma concentration of PG-metabolite but significantly inhibited both, PGF and PGE concentrations in seminal plasma. Furthermore, all quality parameters in fresh and frozen-thawed semen were not affected by vedaprofen treatment but the time of semen collection had a significant (P<0.05) effect on motility, normal sperm and sperm with nuclear vacuoles in fresh semen.

Fertility in heifers and cows after low dose insemination with sex-sorted and non-sorted sperm under field conditions.

The present study was performed to test fertility after low dose insemination with sexed and non-sexed sperm in dairy cattle under field conditions in Switzerland. Spermatozoa were stained with Hoechst 33342 and sorted by flow cytometry. A total of 132 heifers and cows were inseminated with 2 x 10(6) X-bearing, frozen-thawed sperm (A) and 91 animals were inseminated with the same dose using non-sorted, frozen-thawed sperm (B). Pregnancy examination by ultrasound was performed twice, 30-40 days (PE1) and 70-90 days (PE2) after insemination. The pregnancy rates after PE1 were 33.3% (9/27) and 59.3% (16/27) in heifers (P=0.05) and 27.6% (29/105) and 28.1% (18/64) in cows (P>0.05) for groups A and B, respectively. Embryonic losses between PE1 and PE2 in heifers were 11.1% (1/9) and 0% (0/16) and in cows 17.2% (5/29) and 5.6% (1/18), the differences between groups A and B not being significant (P>0.05). Calving rates in heifers were 29.6% (8/27) and 57.8% (15/26), whereas in cows 22.1% (23/104) and 23.4% (16/63) gave birth to calves (for both groups P>0.05). The sex ratio was different (P<0.05) between A (85.3%) and B (58.6%). From our results it can be concluded that conception rates of sorted and non-sorted semen are similar using an insemination dose of 2 x 10(6). Fertility may be increased by improving sexing technology and animal management.

Twenty-four-hour secretory pattern of cortisol in the bull: evidence of episodic secretion and circadian rhythm.

A single antibody RIA method for measurement of plasma cortisol concentrations in the bull is described. Antisera were obtained from rabbits immunized against cortisol-3-oxime-bovine serum albumin. By this technique, peripheral cortisol levels were determined in seven adult bulls (one blind) during 24- and 48-h periods, with blood collections every 30 min. Statistical evaluation of the 24-h profiles using time series analysis revealed that cortisol is secreted episodically throughout the day-night cycle (range, 0.4-9.7 ng/ml). Despite individual variability in both frequency and amplitude of secretory episodes, a distinct circadian secretion pattern was recognized. After dividing the 24 h into three 8-h time periods (I, 0900-1700 h; II, 1700-0100 h; III, 0100-0900 h), a depressed secretory activity with small episodic bursts not exceeding 3.5 ng/ml plasma consistently occurred during time period II. Increased cortisol secretion with high fluctuating levels was evident during time periods I and III. Maximum cortisol concentrations greater than 8 ng/ml were noticed in the morning at the onset of daylight, whereas lowest values were recorded in the evening when darkness began. Results from this study indicate that there is a temporal correlation between the rhythm of cortisol secretion and the light-dark cycle in the bovine species.

Sensitive fluorimetric method based on sequential injection analysis technique used for dissolution studies and quality control of prazosin hydrochloride in tablets.

This report introduces a fully automated flow system for drug-dissolution studies based on the coupling of the sequential injection analysis (SIA) technique with a conventional dissolution apparatus. The methodology described was used for monitoring of dissolution profiles of prazosin hydrochloride (PRH) in pharmaceutical formulation. The very sensitive fluorimetric detection of PRH was performed at lambda(ex)=244 nm (lambda(em)>or=389 nm). Under the optimal conditions, the calibration curve was linear over the range 0.02-2.43 mg x l(-1) of PRH with R.S.D. 1.89, 1.23, and 1.80% (n=10) when determining 0.02, 1.22, and 2.43 mg x l(-1) of PRH in standard solutions, respectively. Equation of the calibration curve was calculated giving the following values: F=4.108 c-3.9 (n=6), r=0.9996. Detection limit was calculated 0.007 mg x l(-1) of PRH. The dissolution test of Deprazolin tablets was programmed for 60 min, with a continuous sampling rate of 70 h(-1) under conditions required by USP 26. Results obtained by SIA technique compared well with HPLC standard method.

Seasonal changes of semen quality and freezability in Franches-Montagnes stallions.

The objective of this study was to investigate seasonal changes of semen quality parameters in Franches-Montagnes stallions and to compare the freezability of ejaculates collected in autumn and winter. Experiments were performed using 15 stallions from the National Stud Farm in Avenches (Switzerland). Ejaculates were collected and evaluated every month during 1 year as well as cryopreserved in autumn and winter (September to February). In fresh semen the gel-free volume, concentration, motility and morphology (normal sperm, major defects, vacuoles and acrosome defects) were evaluated and in frozen-thawed semen the motility as well as the viability (SYBR-14/PI) were performed. To analyse seasonal differences four periods of 3 months each were defined as autumn (September, October, November), winter (December, January, February), spring (March, April, May) and summer (June, July, August). During the 1-year experiment all fresh semen quality parameters demonstrated a clear seasonal and individual pattern. The gel-free volume was significantly (P<0.05) higher in spring and summer compared to autumn and winter while sperm concentration was significantly (P<0.05) lower in spring than at any other time of the year. Total sperm number was significantly (P<0.05) higher and sperm motility significantly (P<0.05) lower in summer than in other seasons. Regarding sperm morphology, normal sperm was significantly (P<0.05) higher in autumn than in winter and summer and major defects were lowest (P<0.05) in autumn. In frozen-thawed semen motility was significantly (P<0.05) improved in the ejaculates collected in autumn compared to winter, while viability showed no obvious differences. Our results clearly demonstrate that individual and seasonal differences occurred in semen quality of Franches-Montagnes stallions. Ejaculates collected in autumn (September, October, November) demonstrated good quality, especially regarding sperm morphology, and were more suitable for cryopreservation because of better motility in frozen-thawed semen collected during autumn than in winter.

Seasonal changes in semen quality and freezability in the Warmblood stallion.

The objective of this study was to investigate seasonal changes in stallion semen quality and to determine the best time for semen cryopreservation. Experiments were performed using 10 Warmblood stallions from the National Stud Farm in Avenches (Switzerland). Ejaculates were collected and frozen every other week during 1 year from January to December 1999. Volume, concentration, and motility, and the number of morphologically normal sperm and sperm with major defects (abnormal heads, acrosome defects, nuclear vacuoles, proximal droplets, abnormal midpieces) were evaluated. For all frozen-thawed semen samples motility as well as viability (SYBR-14/PI) was tested, and the hypoosmotic swelling test (HOS) was performed. To analyze seasonal differences 4 periods of 3 months each were defined: autumn (September, October, November), winter (December, January, February), spring (March, April, May) and summer (June, July, August). During the 1 year experiment all semen quality parameters showed a clear seasonal pattern. The volume, total sperm count and motility in fresh semen were significantly higher (P<0.05) in summer than in winter, while sperm concentration was significantly lower in summer compared to the other seasons. Regarding morphology, normal sperm was significantly lower (P<0.05) in summer than at any other time of the year and higher values (P<0.05) were found for major defects in summer than in spring and autumn. In frozen-thawed semen motility was significantly (P<0.05) improved in autumn when compared to spring and summer. Viability was lowest in summer and differed significantly (P<0.05) from other seasons. The HOS test revealed significantly more (P<0.05) membrane damaged spermatozoa in winter than in spring, summer and autumn. Our results demonstrate that in our climatic conditions clear seasonal differences occur in semen quality of fresh and frozen-thawed semen and that cryopreservation of stallion semen should preferably be performed in autumn.

Semen characteristics after vasectomy in the ram.

The objective of this study was to monitor the changes in semen characteristics in vasectomized rams and to determine if infertility was present 14 days after vasectomy. Experiments were performed using five cross-breed rams, aged between 18 and 30 months. Semen was collected weekly by artificial vagina from 2 months before to 5 months after vasectomy. After sexual rest for 10 days, vasectomy was performed by the cranial midscrotal approach. In all ejaculates the volume, concentration, total sperm number, motility and morphology (normal spermatozoa, loose heads) were determined and sperm viability (SYBR-14/PI) was evaluated in all semen samples collected after vasectomy. In the first ejaculate obtained 14 days post vasectomy all rams showed a significant (P < 0.05) drop in mean volume (from 1.2 to 0.5 mL), total sperm count (from 5176.8 to 51.1 x 10(6)) and morphologically normal sperm (from 84.1 to 15.7%), when compared to the last prevasectomy collection. We could also demonstrate a positive correlation (r = 0.89) between the individual cumulative total number of spermatozoa after vasectomy and the scrotal circumference measured before vasectomy. Sperm motility and viability could never be demonstrated after vasectomy and normal spermatozoa continuously decreased concomitant with an increase in loose heads. On post mortem examination 5 months after surgery, spermatocele formation and multiple sperm granulomas were present in all five rams. Our results show that in the first ejaculate collected by artificial vagina 14 days after vasectomy, no motile and viable spermatozoa could be detected. Despite weekly collections during a 5-month period after sterilization, azoospermia could never be achieved.

Influence of Eqvalan (ivermectin) on quality and freezability of stallion semen.

The objective of this study was to evaluate the effect of Eqvalan (ivermectin) on stallion semen quality and freezability. Experiments were performed using 22 Freiberger stallions, randomly divided into a control and test group. Semen was collected once a week for 17 weeks from October 1997 to February 1998. Eqvalan was given orally to all stallions of the test group at a therapeutic dose of 0.2 mg ivermectin/kg. Besides measuring the scrotal width, ejaculates were collected to determine the volume, concentration, and the motility and morphology (normal sperm, major defects, vacuoles and acrosome defects). In addition, the motility and viability (fluorescence staining with propidium iodide/SYBR-14) were tested in all frozen-thawed semen samples. During the experimental period, stallions treated with Eqvalan had significantly better concentration (P < 0.0001) and motility (P < 0.0001) in fresh semen compared to control animals. After freezing-thawing, the motility (P < 0.0001) and viability (P = 0.0003) of semen also increased significantly for treated stallions. Regarding morphology, normal sperm (P < 0.0001), major defects (P = 0.0027) and vacuoles (P = 0.0236) were significantly better in the Eqvalan group. In addition to group differences we also observed a time effect on morphological parameters as shown by a decrease of normal sperm and an increase of major defects in both groups during the experiment. Our results demonstrate that a single oral application of Eqvalan did not negatively influence the quality and freezability of stallion semen in the nonbreeding season. Rather, it seems that Eqvalan has a favorable effect on stallion fertility as most sperm parameters examined were significantly improved in treated animals compared to control.

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.

[Case report: varicocele in a ram]. / Fallbericht: Varikozele beim Widder.

In a 7 year old ram a partly fluctuating mass proximal to the left testicle was diagnosed as varicocele. On ultrasound examination non-echogenic tortuous areas were present. Spermatologic examination revealed an oligozoospermia and an oligokinespermia. Considering the poor prognosis, the ram was slaughtered and the diagnosis of varicocele could be verified on post mortem examination.