Assessment of pubertal development of boars derived from ultrasonographic determination of testicular diameter

At the onset of puberty, seminiferous tubules rapidly increase in diameter, thereby occupying a greater proportion of the testis, resulting in a rapid increase in testicular size. The objective of the current studies was to evaluate ultrasonography for assessing testicular diameter, as a basis for ranking boars relative to their extent of pubertal development. In the initial study, prior to castration at 4, 5, 6, or 7 mo of age, testicular length and diameter were assessed by ultrasonography in 160 anesthetized boars. After castration, testes were weighed. Mean diameter of seminiferous tubules and percentage of the testis occupied by tubules were determined by histological evaluations of all testes. Testicular volume was calculated from length and diameter and was correlated with testicular weight (P < 0.001; r ≧ 0.78) within each of the four age groups. At 4 and 5 mo of age, testicular diameter correlated positively (P < 0.001) with diameter of seminiferous tubules; this relationship was not significant at older ages. In two subsequent studies, testicular diameter determined ultrasonographically in conscious boars was highly correlated (r > 0.8) when assessed twice on the same day, or when diameter of the right was compared with diameter of the left testis. Similarly, testicular diameter obtained initially at 92 d of age correlated positively (P < 0.001) with the diameter observed at older ages, but the magnitude of the relationship decreased as time between evaluations increased. These findings supported ultrasonographic determination of testicular diameter during early pubertal development, as a means to rank boars of similar chronological age for extent of pubertal development.     

Expression of FGF2 and TGFalpha and testis morphology during testicular hypertrophy subsequent to hemicastration in the neonatal boar

The objective was to ascertain fibroblast growth factor-2 (FGF2), epidermal growth factor (EGF), and transforming growth factor-alpha (TGFalpha) mRNA expression and testis morphology during accelerated testicular growth after hemicastration in the neonatal boar. On Day 10 after birth (Day 0), boars were assigned to control (n = 28), no treatment; hemicastrated (n = 28), left testis removed. The right testis in both groups (n = 7) was removed on Days 5, 10, 15, and 20. Expression of mRNA for FGF2, EGF, and TGFalpha was determined by qRT-PCR using TaqMan. Testicular morphology was determined on Day 15. On Day 10, hemicastrated boars had a greater (P = 0.01) testis weight (6.2 +/- 0.8 g; mean +/- SEM) than controls (4.3 +/- 0.4 g) and on Day 15 testis weight in hemicastrated boars (8.8 +/- 0.8 g) was twice (P < 0.01) that of control boars (4.2 +/- 0.3 g). Seminiferous tubule volume was approximately doubled in hemicastrated boars (P < 0.01) and was associated with an increase (P < 0.01) in Sertoli cell number. Interstitial compartment volume was greater (P < 0.01) in hemicastrated boars. Leydig cell numbers were similar (P = 0.14) but volume was greater (P < 0.01) for hemicastrates. There were no differences (P > 0.05) between control and hemicastrated boars in TGFalpha or FGF2 expression on Day 5 or Day 10, and EGF was not detected. It was concluded that upregulation of TGFalpha or FGF2 expression is not a pre-requisite for enhanced testicular growth and increased Sertoli cell proliferation that occurs subsequent to hemicastration in the neonatal boar.     

Spermatogenesis in azoospermic,formerly cryptorchid men. Use of needle aspiration techniques

OBJECTIVE: To assess the use of testicular needle aspiration techniques to evaluate fertility potential in azoospermic, formerly cryptorchid men. STUDY DESIGN: Fifteen consecutive adult azoospermic, formerly cryptorchid patients (eight unilateral and seven bilateral) were examined by needle aspiration techniques, fine (FNA) and large needle (LNAB) testicular aspiration biopsy, for cytologic and histologic analysis. Five of the 15 subsequently underwent surgical biopsy for attempted assisted fertilization. RESULTS: Spermatozoa or spermatids were detected by FNA cytology or LNAB histology in one or both testicles in 87.5% of the unilateral and 28.6% of the bilaterally affected, formerly cryptorchid patients (P = .041, Fisher's exact test). The addition of LNAB to FNA identified spermatids in one patient with unilateral cryptorchidism and only Sertoli cells on FNA cytology. Furthermore, LNAB differentiated testicles with the cytologic finding of only Sertoli cells into those with or without diffuse fibrosis. In the five patients in whom assisted fertilization was attempted, the needle aspiration techniques predicted the presence or absence of spermatozoa in the subsequent surgical biopsy. CONCLUSION: The two needle aspiration techniques can be used to assess the fertility potential of azoospermic, formerly cryptorchid men and to select patients for assisted fertilization.     

Prevalence of chlamydiae in boars and semen used for artificial insemination

Although there are indications for venereal transmission of chlamydiae in pigs, direct diagnostic evidence on the presence of these bacteria in boars and boar semen in particular is still incomplete. We investigated boars from two studs (A, B) in semen (A: n = 174; B: n = 100) and faeces (A: n = 174; B: n = 24) for chlamydiae using ompA-PCR and partial ompA gene sequencing. Additionally, blood serum was examined for chlamydial antibodies using an indirect ELISA (A: n = 171; B: n = 62). Chlamydiae were found in 9 (5.2%) and 24 (24.0%) semen specimens, and in 71 (40.1%) and 2 (8.3%) faecal samples from boars of stud A and B, respectively. Regarding individual chlamydial species, Chlamydophila psittaci and Chlamydia suis were identified most frequently, with the former predominating in semen (in 23 out of 33 positive samples) and the latter in faeces (68/73). In contrast, Chlamydophila pecorum was found only sporadically. Chlamydial antibodies were detected in 80 (46.8%) and 6 (9.7%) boars of stud A and B, respectively. No correlation was observed between the data from serology and PCR of semen or faeces in either of the studs. In conclusion, detection of chlamydiae in semen of boars suggests a potential for venereal transmission. Whether the high overall prevalence of chlamydial infections reflects a general situation in boars needs to be investigated. Serological testing failed to identify boars shedding chlamydiae in their semen.     

Early sexual maturity in local boars of Northeastern India: age-related changes in testicular growth, epididymal sperm characteristics and peripheral testosterone levels

The present study reports the age related changes in the peripheral testosterone levels, testicular and epididymal growth and development and cauda epididymal spermiogram in local pigs of Northeastern India, which attain sexual maturity around 3 months of age. Local boars (n = 20) were castrated at monthly intervals from 2 to 6 months of age (4 boars per month) to study the testicular growth and development and the epididymal spermiogram. Blood samples, collected from local boars (n = 6) at monthly intervals from 2 to 6 months of age, were analyzed for testosterone levels by radioimmunoassay. Compared to Hampshire boars, significantly (P < 0.05) high testosterone levels were observed in the local boars as early as 2 months of age. The mean (± SEM) level of testosterone in the local boars at 2, 3 and 4 months of age was 11.89 ± 1.52, 20.45 ± 1.33 and 20.38 ± 2.0 ngml⁻¹, respectively. Though there was consistently significant (P < 0.05) difference in the body weight between Hampshire and local pigs, the same was not observed in case of testicular weight except at 3 and 6 months of age. In line with the above observation, the testis:body weight ratio (gram testis per kg body weight) was significantly (P < 0.05) higher in the local boars compared to the Hampshire boars at any time of observation, which ranged from 0.8 to 1.0 in case of Hampshire and from 2.3 to 3.0 in local boars. The sperm concentration in the cauda epididymal fluid of local boars at 2, 3 and 6 months of age was 2255 ± 186.6, 3685 ± 103.8 and 4325 ± 146.2 million/ml, respectively and the sperm motility, viability and total abnormality was 73.3, 75.2 and 6.2%, respectively at 3 months of age. Taken together, the testosterone level, testicular growth and development and epididymal spermiogram indicate the trait of early sexual maturity in the local pigs as compared to Hampshire.     

Pituitary and Leydig cell function in boars actively immunized against gonadotrophin-releasing hormone

Crossbred boars were (a) immunized against GnRH conjugated to human serum globulin (200 micrograms GnRH-hSG) in Freund's adjuvant at 12 weeks of age and boosted at weeks 18 and 20 (N = 10), (b) served as controls and received hSG only in adjuvant (N = 10), or castrated at weaning (N = 10). At 24 weeks of age (immediately before slaughter), the boars were challenged with saline or pig LH (1 microgram/10 kg body weight). After slaughter, fresh testicular fragments were incubated with pig LH (0.05 and 0.2 ng/2 ml medium) to assess the effects of immunization on Leydig cell function. Pituitary contents of LH and FSH, and testicular LH receptor content were also measured. The results indicated that plasma LH and testosterone concentrations, pituitary LH content, testicular LH receptor content, testis and sex accessory organ weights were significantly reduced in GnRH-immunized boars compared to hSG-adjuvant controls. However, plasma and pituitary FSH content were not affected by high antibody titres generated against GnRH. The testicular testosterone response to exogenous LH in vivo and in vitro was significantly reduced (P less than 0.05) in GnRH-immunized boars. These results indicate that active immunization against GnRH impairs pituitary and Leydig cell functions in boars.     

Mitochondrial haplotypes of European wild boars with 2n = 36 are closely related to those of European domestic pigs with 2n = 38

Wild boars from Western Europe have a 2n = 36 karyotype, in contrast to a karyotype of 2n = 38 in wild boars from Central Europe and Asia and in all domestic pigs. The phylogenetic status of this wild boar population is unclear, and it is not known if it has contributed to pig domestication. We have now sequenced the mtDNA control region from 30 European wild boars (22 with a confirmed 2n = 36 karyotype) and six Asian wild boars (two Hainan and four Dongbei wild boars) to address this question. The results revealed a close genetic relationship between mtDNA haplotypes from wild boars with 2n = 36 to those from domestic pigs with 2n = 38. Thus, we cannot exclude the possibility that wild boars with 2n = 36 may have contributed to pig domestication despite the karyotype difference. One of the European wild boars carried an Asian mtDNA haplotype, and this most likely reflects gene flow from domestic pigs to European wild boars. However, this gene flow does not appear to be extensive because the frequency of Asian haplotypes detected among European wild boars (c. 3%) were 10-fold lower than among European domestic pigs (c. 30%). Previous studies of mtDNA haplotypes have indicated that pig populations in Europe and Asia have experienced a population expansion, but it is not clear if the expansion occurred before or after domestication. The results of the present study are consistent with an expansion that primarily occurred prior to domestication because the mtDNA haplotypes found in European and Asian wild boars did not form their own clusters but were intermingled with haplotypes found in domestic pigs, indicating that they originated from the same population expansion.     

Differences in aromatase activity between Leydig cells from the scrotal and abdominal testis in the naturally unilateral-cryptorchid boar

In an earlier study, estrogen production was much lower in Leydig cells from the abdominal than from the scrotal testis in naturally occurring unilateral cryptorchidism in the boar. A more direct assessment of aromatase activity was made in thirty-two mature male pigs to examine this observation further, using nonradioactive androstenedione (delta 4A 1.0 x 10(-6) M - 1.5 x 10(-5) M) and [1 beta, 2 beta-3H] delta 4A as substrates. Purified Leydig cells were prepared from normal boars and from unilaterally and bilaterally cryptorchid animals. Combined estrone sulfate (E1S) and estrone (E1) formation from delta 4A were measured by radioimmunoassay. Little or no estrogen secretion was seen with cells from the abdominal testis in unilaterally cryptorchid boars (n = 7), and E1S formation from delta 4A was 6- to 14-fold higher for scrotal cells (n = 6). Aromatase activity as reflected in percent conversion of substrate to [3H]-labeled water was clearly lower in cells from the abdominal testis (1.10 +/- 0.08 and 11.22 +/- 0.7%, respectively, p less than 0.01, n = 6). No marked reduction was noted for unilaterally cryptorchid boars with an inguinally located testis (10.18 +/- 0.27 and 13.09 +/- 0.58% for inguinal and scrotal testes, respectively, n = 3). Concentrations of E1S in testicular arterial and venous blood (n = 9) gave additional evidence of lower estrogen production by the undescended testis of the cryptorchid boar. It was concluded that lower aromatase activity is present in Leydig cells of the abdominal testis.     

Pubertal development of the boar: age-related changes in testicular morphology and in vitro production of testosterone and estradiol-17 beta

The responsiveness of testicular tissue, in terms of testosterone (T) and estradiol-17 beta (E2) production, to human chorionic gonadotropin (hCG) stimulation in vitro was assessed during pubertal development of the boar. A morphometric investigation was conducted concurrently to quantitate Leydig cell and seminiferous tubule changes in the testes of developing boars. Testicular volume percentage of seminiferous tubules increased from 36% at 40 days of age to a maximum of 72% at 190 days of age. Increases in tubular diameter were from 65 micrometers at 40 days of age to 236 micrometers at 250 days of age. Testicular volume percentage of Leydig cells decreased from 40% at 40 days of age to 10% at 250 days of age. Leydig cell number increased rapidly to 130 days of age, remained constant through 160 days, and then increased steadily to 220 days of age. Volume per Leydig cell changed little from 40 to 130 days of age, increased by 75% at 160 days, and declined thereafter. Total Leydig cell weight increased steadily from 40 to 160 days of age and then declined slightly. The capacity of Leydig cells for T production and testicular tissue for E2 production was greatest (P less than 0.05) after hCG stimulation in boars that were 130 and 160 days of age. In addition, sensitivity, as judged by the regression coefficient of T or E2 production per Leydig cell on log dosage of hCG was greater (p less than 0.05) for T at 130 days of age and for E2 at 160 days of age. The data presented support the hypothesis that one factor in pubertal development of boars is an increased capacity and sensitivity of the testes to gonadotropin stimulation.     

Immunological castration temporarily reduces testis size and function without long-term effects on libido and sperm quality in boars

The objective was to determine the effects of immunization against gonadotropin-releasing hormone on reproductive characteristics in boars. A total of 72 boars were used in a randomized design with three treatments: single immunization (SI) (10 weeks of age) or double immunization (DI) (10 and 15 weeks of age) with Improvest® and intact controls (no Improvest®; CNT) (n=24/group). At 10, 15, 20, 25 and 40 weeks of age, blood was collected and serum harvested to evaluate testosterone concentrations. Testosterone concentrations were less for DI boars compared with CNT boars and SI boars at 20 and 25 weeks (P<0.001), but not at 40 weeks of age. At week 25, 18 pigs (n=6/group) were sacrificed and testes were removed, weighed and measured, and seminiferous tubules were examined and scored using histological slides of testes parenchyma. A sample of neck fat was assessed for boar taint aroma. All testicular measurements and weights and seminiferous tubule scores were less for DI boars compared with SI and CNT boars (P<0.001). More (P<0.05) SI and CNT boars had detectable boar taint aroma than DI boars. Libido was assessed at 32, 36, 47, 60 and 63 weeks of age and semen collected at 60 weeks of age was analyzed for indicators of quality. There were no effects of treatment (P=0.41) or treatment by week (P=0.71) on libido. Semen volume, gel weight and total number of sperm cells, determined in a subset of boars (n=3/treatment), were not different among treatments. Sperm concentration was greater for DI than SI (P=0.01), and tended to be greater for DI compared with CNT (P=0.10). Sperm motility tended to be greater for DI boars compared with CNT boars (P=0.066). In conclusion, our results show that there are no long-term effects of immunocastration on reproductive characteristics in boars.     

The effect of lutalyse on the training of sexually inexperienced boars for semen collection

The objective was to determine if i.m. treatments of lutalyse (PGF2alpha; dinoprost tromethamine salt) expedited the training of sexually inexperienced boars for semen collection. Lean-type, terminal-line boars (n = 40; 177.4 +/- 2.4 day of age and 112.8 +/- 2.0 kg body weight) that had not previously experienced natural mating were utilized. Boars were moved individually twice weekly for 6 weeks (total of 12 training sessions) to a semen collection room equipped with an artificial sow. Upon entering the semen collection room, boars received i.m. treatments of either deionized water (4 ml, n = 10) or lutalyse at doses of 5 mg (n = 10), 10 mg (n = 10), or 20 mg (n = 10), and subsequently received a libido score of 1-5 (1 = no interest in the artificial sow; 5 = mounting artificial sow and allowing semen collection). The percentages of boars successfully trained for semen collection during the experimental period were similar (P > 0.05) for controls (20%) and boars receiving 5 mg (30%), 10 mg (20%), or 20 mg (10%) of lutalyse. Average libido score for boars receiving 10 mg lutalyse (2.35 +/- 0.08) was greater (P < 0.05) than for controls (2.14 +/- 0.06). In summary, lutalyse increased libido scores, but did not affect the number of boars trained for semen collection.     

Testicular fine needle aspiration cytology for the diagnosis of azoospermia and oligospermia

OBJECTIVE: To evaluate qualitative and quantitative cytologic features on testicular fine needle aspiration biopsy in the diagnosis of azoospermia and oligospermia and to correlate cytologic and histologic diagnoses. STUDY DESIGN: In this prospective study, 50 infertile males selected from the infertility clinic of Guru Tegh Bahadur Hospital were studied. Fine needle aspiration cytology (FNAC) smears from both testes of 27 azoospermic and 23 oligospermic patients (sperm count < 10 million per milliliter) were stained with May-Grünwald-Giemsa and Papanicolaou stain. Differential counting of 500 spermatogenic cells was done, and the number of Sertoli cells per 500 germ cells was determined for calculating the spermatic index and Sertoli cell index, respectively. FNAC and testicular biopsy were performed under local anesthesia as a minor surgical procedure. RESULTS: Six groups were identified on FNAC smears from azoospermic patients: I. normal spermatogenesis (8), II. hypospermatogenesis (2), III. maturation arrest (2), IV. Sertoli cells only (6), V. atrophic pattern (7), and VI. Leydig cell predominance (2). In oligospermic patients two groups were identified: I. those with normal spermatogenesis (4), and II. those with subnormal spermatogenesis (19). Correlation with histopathologic examination was seen in 81.5% azoospermic and 65.2% oligospermic patients. CONCLUSION: Qualitative and quantitative evaluation of testicular FNAC provides useful information on both azoospermic and oligospermic patients. FNAC performed under local anesthesia is an acceptable outpatient procedure that consistently yields sufficient diagnostic material in all patients.     

Circulating concentrations of luteinizing hormone, testosterone, and growth hormone after naloxone treatment in sexually mature boars

The effects of naloxone, an antagonist of opioid peptides, on circulating concentrations of luteinizing hormone (LH), testosterone, and growth hormone (GH) were determined in sexually mature boars. Blood samples were collected at 15-min intervals for three hr from five crossbred boars. Two hr after initiation of blood sampling, boars received an i.v. challenge of naloxone (1 mg/kg body weight; n=2) or 0.9% saline (n=3). Twenty-four hr later the experiment was repeated, but boars that previously received naloxone received saline and vice versa. A time by treatment interaction (p=0.09) was detected for concentrations of LH in serum, and levels of LH were greater (p<0.03) after treatment with naloxone compared to saline. Concentrations of testosterone in serum were affected by time (p<0.01), but not treatment (p= 0.59) or treatment by time (p=0.74). A treatment by time interaction (p=0.02) was detected for serum GH concentrations. Levels of GH increased in saline-treated boars (p<0.01), but not in boars receiving naloxone (p>0.1). Our results are consistent with the theory that opioid peptides suppress LH secretion and stimulate GH release in sexually mature boars.     

Influence of pre- and post-pubertal grazing regimes on adult testicular morphology in extensively reared corriedale rams

The aim of the present study was to determine whether pre- and post-pubertal young rams on different grazing regimes, resulting in differences in live weight (LW), would show corresponding differences in testicular growth or testicular morphometry that could influence the reproductive traits of these rams upon reaching adulthood. Forty-one spring-born Corriedale rams were reared on either native pasture (low feeding level, Group L, n=22) or improved pasture (higher feeding level, Group H, n=19) from 1 to 7 months of age. Thereafter, half the animals in the native-pasture group were placed on improved pasture and vice versa, thus creating an additional four differential-grazing treatment groups (Groups LL, n=11; LH, n=11; HL, n=10; and HH, n=9). Animals were managed in this way until 18 months of age. Half the animals from each group were then castrated and their testes were subjected to morphometric analysis. The remaining animals (Groups LL, n=6; LH, n=6; HL, n=5; and HH, n=4) were managed together until 30 months of age (from 18 to 27 months on native pastures and from 27 to 30 months of age on improved pastures, at a stocking rate of two to three rams per hectare), whereupon they were also castrated for testicular morphometry. LW and scrotal circumference (SC) were recorded every 60 days. The stereological analysis of testicular parenchyma included counts of elongated spermatids and Sertoli cells. Differences (P<0.001) in LW were observed between feeding levels, even at 30 months of age. Differences (P<0.001) in SC existing at the end of the differential treatment (18 months of age) disappeared (n.s.) soon after. Most differences (P<0.05) in testicular morphometry existing at the end of the differential treatments were no longer significant 1 year later. It is concluded that changes in grazing management during pre- and post-pubertal periods can induce short-lived differences in testicular post-natal growth in Corriedale rams but do not influence testicular morphology or function later in life.     

Interrelationships of porcine X and Y chromosomes with pituitary gonadotropins and testicular size

Endocrine and testicular responses to unilateral castration on 1, 10, 56, or 112 days of age were characterized in 132 Chinese Meishan (MS) x White composite (WC) crossbred boars in which testicular size associates with a quantitative trait locus (QTL) on X chromosome. At 220 days of age, testicles of boars unilaterally castrated on Day 1 or 10 weighed more and had greater total daily sperm production (DSP) than one testicle of bilaterally intact boars (P < 0.05); compensation did not double these two responses. Boars with MS alleles at the X chromosome QTL had smaller testicles, darker colored parenchyma, and lower total DSP than boars with WC alleles (P < 0.05). The MS alleles engendered greater (P < 0.05) plasma FSH and LH during puberty than WC alleles. Plasma FSH increased (P < 0.05) within 48 h of unilateral castration on Days 1, 10, and 56. Subsequent increases occurred earlier during puberty (P < 0.05) after unilateral castration at younger ages than after unilateral castration at older ages. Pubertal increases in plasma FSH and LH were greater (P < 0.05) in boars with MS alleles than in those with WC alleles for the X chromosome QTL. Breed of Y chromosome had no effect on testicular traits, FSH, testosterone, or estrone. For LH, boars with an MS Y chromosome had greater (P < 0.01) plasma LH across all ages than boars with a WC Y chromosome. We conclude that a gene or groups of genes that reside on the porcine X chromosome regulate testicular development and pubertal gonadotropin concentrations.     

PGF2alpha facilitates the training of sexually active boars for semen collection

The objective was to determine the effects of PGF2alpha on the training of sexually active boars (i.e., boars experienced with natural mating) to mount an artificial sow for semen collection. Boars were moved to a semen collection pen twice weekly for 4 wk. After entering the pen, boars received im treatment with 10 mg PGF2alpha (n = 7) or 2 mL deionized water (n = 7). Boars were classified as trained when after a successful collection, the animals mounted the artificial sow and allowed semen collection on the next scheduled day without first receiving an injection of PGF2alpha or deionized water. The semen from 6 of 7 PGF2alpha-treated boars and 2 of 7 control boars was collected during the first exposure to the artificial sow (P < .03). After 4 training sessions, 7 of 7 PGF2alpha-treated boars and 4 of 7 controls were successfully trained (P < .05). The number of false mounts (mounting artificial sow but not allowing semen collection) per session was lower (P < .07) for PGF2alpha-treated boars (.6 +/- 1.0), compared to boars receiving deionized water (3.9 +/- 1.0) or trained boars receiving no treatment (3.4 +/- .7). Reaction time (elapsed time after entering collection pen until the start of ejaculation) was lower (P < .04) for PGF2alpha-treated boars (267.4 +/- 63.4 sec), compared to boars treated with deionized water (628.4 +/- 98.3 sec) or boars receiving no treatment (440.4 +/- 46.4 sec). In summary, use of PGF2alpha facilitated the training of sexually active boars to mount an artificial sow for semen collection.     

Effects of prostaglandins and prostaglandin synthesis inhibitors on sexual behavior in boars

Experiments were conducted investigating the effects of prostaglandins and prostaglandin synthesis inhibitors on libido in boars. In Experiment 1, two prostaglandin products were compared with regard to expediting the training of boars for semen collection. On each of five consecutive days, boars received i.m. treatment with saline, dinoprost tromethamine or cloprostenol sodium (n=12/group). On each of day 1 (p=0.06), day 2 (p<0.05), and day 3 (p<0.05), but not on day 4 or 5 (p>0.1), the percentage of boars collected after dinoprost tromethamine, but not cloprostenol sodium, was greater than controls. In Experiments 2 and 3, libido in boars that were trained previously for semen collection was assessed after treatment with prostaglandin synthesis inhibitors, testing the hypothesis that endogenous release of prostaglandin is necessary for expression of sexual behaviors. In Experiment 2, boars treated with flunixin meglumine (n=12) had suppressed (p<0.01) levels of 15-ketodihydro-prostaglandin-F(2) (PGFM) in serum but characteristics of libido were similar (p>0.1) to controls (n=12). In Experiment 3, boars were administered indomethacin orally (n=12) or served as untreated controls (n=12). Indomethacin decreased (p<0.01) serum levels of PGFM, increased (p<0.05) the number of false mounts (mounting artificial sow but dismounting before an ejaculate was collected), and tended (p=0.09) to lengthen the interval between entering the collection pen and the start of ejaculation. These results suggest that prostaglandin synthesis and release is necessary for the complete display of normal sexual behaviors in boars.     

Morphometric studies on mink testicular tissue

The mink, a seasonal breeder of great economic importance, shows a high incidence of male infertility. This problem has forced investigators to find methods of assaying male mink infertility. In this study, morphometric studies have been performed on testicular tissue of a total of 31 males eliminated from breeding after testicular palpation, sperm test, and estimation of serum testosterone concentrations. Males having low sperm quality or disturbed testicular development (n=24) had significantly (p<0.01) lower numbers of spermatocytes, spermatids, and freefloating luminal spermatozoa. compared with males with good sperm quality (n=7). No differences were found in the numbers of spermatogonia, Sertoli, and Leydig cells. Other morphometric parameters such as mean diameter, mean area, mean volume, percentage of area, and surface area per volume of nuclei are also presented for each cell type in the testis. It may be concluded that the sperm test is best suited for assessing fertility in mink. Severe disturbances in testicular development can be detected by testicular palpation and serum testosterone measurements.     

Embryo outcome in Y-chromosome microdeleted infertile males after ICSI

A prospective study involving 118 infertile Japanese couples to assess the embryo outcomes in both azoospermic and oligoasthenoteratoazoospermic (OAT) patients with Y-chromosome microdeletion. The men were divided into two groups; azoospermia (n = 27), and OAT, sperm concentration <5 x 10(6)/ml (n = 91). They were investigated for Y-chromosome microdeletions by a polymerase chain reaction (PCR) amplification of the Y-chromosome-specific sequence tag site (STS). The embryo outcomes of patients found to have Y-microdeletion were determined. The frequency of microdeletion was 8.8% (9) and two had microdeletions distal to DAZ. The mean fertilization rate and the cleavage rate in the eight cycles of both azoospermic and oligospermic patients were 59.3 and 87.5%, respectively. The percentages of grade 1 & 2 embryos, > or =6 cells embryos, and blastocyts were 51.7, 65.6, and 45.3%, respectively. Three pregnancies resulted from the eight cycles (37.5%). CONCLUSION: in Y-chromosome microdeletion cycles in which sperm cells were available for intracytoplasmic sperm injection (ICSI), embryo outcome was comparable to conventional IVF.     

Assessment of boar semen quality in relation to fertility with special reference to methanol stress

The relationship between various semen evaluation tests and fertility in fertile and subfertile artificial insemination (AI) boars was examined. In total, 36 boars, 19 Finnish Landrace and 17 Yorkshire, were included. The average value of three ejaculates extended in an X-cell extender from each boar was used in the analysis. Based on nonreturn results (NR60d, later referred to nonreturn rate, NR%), the boars were divided into two groups: those with poor fertility (NR% < 80, n = 19) and those with normal or above average nonreturn rates (NR% = 83, n = 17). Semen quality was determined after 1 and 7 days of storage at 17 degrees C. Sperm motility before and after each methanol stress was assessed both subjectively and using a computer-assisted semen analyzer (CASA). The sperm cells were stained with calcein AM and propidium iodide and evaluated for plasma membrane integrity under an epifluorescence microscope. Propidium iodide and Hoechst 33258 dyes were used in parallel to stain sperm cells for fluorometric analysis with an automatic fluorometer. Sperm morphology was evaluated in stained smears. The percentage of sows reported as not having returned to estrus within 60 days after AI (nonreturn rate, NR%) and litter size of primiparous and multiparous farrowings were used as measures of fertility. Of the parameters analyzed, only CASA-assessed total sperm motility and methanol-stressed total sperm motility correlated significantly (P < 0.05) with nonreturn rate. Those tests presenting the highest correlation with nonreturn rate were CASA-assessed total motility (r = 0.54, P < 0.01) and subjective sperm motility (r = 0.52, P < 0.01) after 7 days of storage. The highest correlation with fertility at 1 day of storage was shown by methanol-stressed total sperm motility assessed with the CASA (r = 0.46, P < 0.01). The only semen parameter that correlated significantly (r = 0.37, P < 0.05) with litter size of multiparous farrowings was viability of seven-day stored semen stained with Hoechst 33258 and analyzed with a fluorometer. The methanol stress test described here could serve as a rapid test whose results could be used to predict NR% better than motility.