Proportion Of Abnormal Spermatozoa Research Articles

Dissecting the relationship between artificial insemination success and bull semen quality in the arid region of Tiaret (Algeria)

Despite being subject to prior assortment, frozen bull sperms commercialized for artificial insemination may present certain morphological defects. The present study aims (i) to assess the artificial insemination success of the most common cattle breeds in Algeria and (ii) to evaluate the possible effects of commercialized bull’s semen quality on this operation. Artificial insemination was assessed through four years of field monitoring by inseminating different cattle breeds of normal fertility. However, semen quality was evaluated using light microscopy by measuring viability, motility, and morphological abnormalities of spermatozoa. Field study revealed a high percentage of normal calving in red and white Holstein breed (44.83 %) against the high percentage of embryonic mortality (46.43 %) and calving with a malformation (10.71 %) in Montbéliarde breed. Semen quality assessment revealed that sperm viability and motility were higher in Holstein breeds than in Montbéliarde. Furthermore, significant differences between semen bulls were found in the proportion of abnormal spermatozoa; a higher rate of sperms with the abnormal head was observed in the black and white Holstein breed (69.3±10.98 %). However, the percentage of abnormal sperms with tail defects was higher in the Montbéliarde breed (67.5±10.74 %). The lousy quality of the selected semen and/or the poor handling and storage of frozen semen constitute a determinant factor that hinders the success of artificial insemination in the arid region of Tiaret (Algeria).

Sperm divergence in a passerine contact zone: Indication of reinforcement at the gametic level.

Postcopulatory sexual selection may promote evolutionary diversification in sperm form, but the contribution of between-species divergence in sperm morphology to the origin of reproductive isolation and speciation remains little understood. To assess the possible role of sperm diversification in reproductive isolation, we studied sperm morphology in two closely related bird species, the common nightingale (Luscinia megarhynchos) and the thrush nightingale (Luscinia luscinia), that hybridize in a secondary contact zone spanning Central and Eastern Europe. We found: (1) striking divergence between the species in total sperm length, accompanied by a difference in the length of the mitochondrial sperm component; (2) greater divergence between species in sperm morphology in sympatry than in allopatry, with evidence for character displacement in sperm head length detected in L. megarhynchos; (3) interspecific hybrids showing sperm with a length intermediate between the parental species, but no evidence for decreased sperm quality (the proportion of abnormal spermatozoa in ejaculates). Our results demonstrate that divergence in sperm morphology between the two nightingale species does not result in intrinsic postzygotic isolation, but may contribute to postcopulatory prezygotic isolation. This isolation could be strengthened in sympatry by reinforcement.

Lycopene-loaded nanoliposomes improve the performance of a modified Beltsville extender broiler breeder roosters

Antioxidants may ameliorate the effects of the freeze-thawing stress on cryopreserved spermatozoa. Lycopene is an effective antioxidant yet to be tested for rooster sperm cryopreservation and nanoliposomes, a technology recently applied to sperm cryopreservation, could improve conservation and antioxidant delivery to spermatozoa. Therefore, we evaluated the effect of 0.1, 0.2, and 0.3 mM lycopene and lycopene-loaded nanoliposomes (LnL) on the cryopreservation of rooster sperm in Beltsville extender. Post-thawing evaluation included sperm motility, membrane integrity, abnormal morphology, mitochondria activity, apoptotic status, malondialdehyde (MDA) and antioxidant activities: Glutathione peroxidase (GPx), superoxide dismutase (SOD) and total antioxidant capacity (TAC). Total and progressive motility, membrane integrity and mitochondria activity were higher with 0.2 mM lycopene and LnL (P < 0.05), compared to 0.1 and 0.3 mM (lycopene and LnL) and the control group. The 0.2 mM lycopene and LnL showed a lower percentage of apoptotic sperm and increased GPx activity and TAC when compared with the other treatments, and reduced MDA levels when compared to 0.3 mM (lycopene and LnL) and control. Supplementation did not significantly affect activities of SOD or the proportion of abnormal spermatozoa. A fertility trial showed that 0.2 mM lycopene increased the proportion of fertile and hatched eggs in comparison to the control, especially when using nanoliposomes. Therefore, the supplementation of the Beltsville extender with 0.2 mM lycopene could improve the quality of rooster spermatozoa after freeze-thawing, and the combination with nanoliposomes seems promising in order to improve the performance of existing approaches.

Relationship between morphological abnormalities in commercial bull frozen semen doses and conception rate.

Commercial doses of frozen bull semen for artificial insemination may have a certain percentage of morphological defects, despite being subject to prior selection. The aims of this study were to determine the prevalence of morphological abnormalities in commercial doses (n=55, r=2) of dairy and beef bulls, from AI Centers and to determine the possible existence of differences between them, regarding the percentage of abnormal spermatozoa. At least 200 spermatozoa per sample were evaluated using Bengal Rose stain (3%m/v) and light microscopy (×1000 magnification). The mean percentage of abnormal sperm samples from dairy breeds was 7.19%±4.91% and from beef breeds was 15.83%±9.28%. Significant differences between biotypes were found in the proportion of abnormal spermatozoa, abnormal heads and abnormal midpieces; it could be due to different selection pressure. It was observed that the percentage of abnormal spermatozoa was not a good fertility level predictor for the commercial samples of frozen bovine semen used in this study. In both biotypes, the midpiece abnormalities were the most frequent, mainly its distal flexion (compensable defect). This could be as a result of the effects of freezing and thawing on spermatozoa.

Cypermethrin reversibly alters sperm count without altering fertility in mice

Administration of cypermethrin (CYP), orally by gavage (3 doses: 1.38, 2.76, and 5.52 mg/kg body weight) to mice either for 6 (D1) or 12 (D2) weeks caused a significant reduction in epididymal spermatozoa count and an increase in abnormal spermatozoa count when compared to controls. These counts returned to normal levels 6 weeks after cessation of 1.38 or 2.76 mg/kg body weight (BW) treatment either after D1 or D2. In 5.52 mg/kg BW treated mice the counts returned to normal levels following D1 but not after D2. Mice in all the treatment groups showed normal fertility. Weight of the litter born to mice mated with CYP treated (all three doses) males either in D1 or D2 was significantly lower than controls whereas gestation period and litter size did not significantly vary from controls. This is the first report revealing that CYP as low as 1.38 mg/kg BW adversely affects spermatogenesis and that the effect is reversible up to 2.76 mg/kg BW/kg BW exposure for 3 months. The results further reveal that despite reduction in sperm count and increase in proportion of abnormal spermatozoa, normal fertility is possible. Hence, in reproductive toxicity evaluation of pesticides, fertility test alone is misleading.

Reproductive characteristics of Ethiopian highland sheep: II. Genetic parameters of semen characteristics and their relationships with testicular measurements in ram lambs

A study was conducted to investigate the effect of season on, and to estimate heritabilities of, and genetic correlations among, semen and spermatozoa characteristics and the relationship of these characteristics with measures of testicular or scrotal size in 6-, 9- and 12-month old ram lambs of Menz and Horro sheep breeds indigenous to Ethiopian highlands. A total of 278 ram lambs with substantial pedigree information were involved in the study. There was improvement in all semen and spermatozoa traits with age, the means at 12 months being consistently superior to values at 6 and 9 months of age. There were no significant breed differences in any of the traits studied, except semen volume at 9 months (0.67, S.E. 0.07 for Horro versus 0.39, S.E. 0.05 ml for Menz) and proportion of dead spermatozoa at 12 months (0.18, S.E. 0.03 versus 0.23, S.E. 0.02, respectively). Season was significant ( p<0.05) for most of the traits studied, and differences were attributed primarily to nutrition. Semen collected in the wet season had higher spermatozoa concentration while samples collected in the dry season had higher proportion of abnormalities. After correcting for differences in total spermatozoa abnormalities, the wet season (of collection) had the highest spermatozoa output (volume×concentration) in 12-month old ram lambs. Heritability estimates varied substantially in magnitude, ranging from zero to over 0.4. Traits with non-trivial heritability estimates were mass motility at 9 months (0.32, S.E. 0.11), individual motility at 9 months (0.32, S.E. 0.12) and at 12 months (0.16, S.E. 0.12) and proportion of abnormal spermatozoa at 9 months (0.35, S.E. 0.13). Genetic correlations among semen and spermatozoa characteristics, as well as correlations with testicular measurements, were medium to high and generally favourable, but were associated with large standard errors. The genetic correlations of scrotal circumference with semen volume (0.55, S.E. 0.11), mass motility (0.62, S.E. 0.20), individual motility (0.54, S.E. 0.12), concentration (0.25, S.E. 0.04) and proportion of abnormal spermatozoa (−0.75, S.E. 0.24) in 12-month old rams indicated that selection based on this trait, which is highly heritable and easy to measure and can be measured early in life, should have appreciable favourable correlated response in semen quality and spermatozoa production.

Seasonal variations of semen quality in male goats: Study of sperm abnormalities

The type, frequency and seasonal variation of sperm abnormalities in male goats inhabiting in Mediterranean region were evaluated. Semen was collected twice a week with an artificial vagina from 9 10-month-old Murciano-Granadina male goats weighing 41 to 48 kg. Distal cytoplasmic droplets and acrosomal damage were the predominant abnormalities. Increase in age (10 to 27 months) did not reveal itself as a main effect on the occurrence of sperm abnormalities. All types of sperm abnormalities studied showed significant (P<0.01) seasonal variation. The poorest quality semen was collected during winter and spring. In spite of a seasonal variation in sperm quality, semen of Murciano-Granadina goats in the Mediterranean area is good all year long, since the proportion of abnormal spermatozoa was well within the accepted range for normal fertility.

Morphology of spermatozoa bound to the zona pellucida of human oocytes that failed to fertilize in vitro.

The morphology of spermatozoa bound to the zona pellucida (ZP) of 264 oocytes that had failed to fertilize in 58 in vitro fertilization procedures was studied by light microscopy. The percentage of spermatozoa with normal morphology bound to the ZP (mean 77, range 8-100) was significantly higher than in the insemination medium (mean 42, range 2-80). The abnormal spermatozoa bound to the ZP had small oval (47%), pyriform (46%), amorphous (5%) and tapering (2%) heads. Other abnormalities of morphology were not observed in ZP-bound spermatozoa. The mean rates of binding to the ZP of spermatozoa with normal morphology (44, 95% confidence limits 42-46, number bound/ZP/10(5)/ml inseminated) were much higher than for abnormal spermatozoa with small oval 6.5 (5.5-7.6), pyriform 5.9 (4.8-7.3), amorphous 1.0 (0.5-2.0) and tapering 2.5 (1.2-5.3) heads. The morphologically abnormal forms not found on the ZP were infrequent in the insemination medium (tail defects, large oval, round, pin and duplicate heads and cytoplasmic droplets) but upper 95% confidence limits for standardized binding ratios of less than 60% indicated that these were unlikely to bind to the zona with rates approaching those of normal spermatozoa (standardized binding ratio 180%). A large number of uniformly normal spermatozoa bound to the ZP when the percentage normal morphology in the insemination medium was greater than 40%. The proportions of abnormal spermatozoa in the insemination medium. Spermatozoon head dimensions were measured with a micrometer in samples from 14 patients. While there were no consistent changes in all samples, the means for head width and area were significantly larger and the ratio of the length to width was smaller for spermatozoa on the ZP than for those in the insemination medium. The head length and ratio of length to width of spermatozoa in samples with good morphology were significantly less than in samples with poor morphology. The percentage of spermatozoa with normal morphology, motility and the ratio of head length to width in the insemination medium were positively correlated with the percentage of spermatozoa with normal morphology bound to the ZP. Logistic regression analysis showed that the diagnosis of tubal infertility and the rate of binding of spermatozoa with normal morphology to the ZP were positively related to fertilization rates in vitro while the rate of binding of spermatozoa with pyriform heads was negatively related. In conclusion. human ZP are highly selective for spermatozoa with normal morphology. The frequency of binding of abnormal spermatozoa to the ZP was mainly dependent on semen quality.(ABSTRACT TRUNCATED AT 400 WORDS)

Sperm head abnormalities in relation to the age and strain of mice.

Sperm abnormalities were examined in the samples of the uterine contents collected after copulation. Male mice of the inbred C57BL/Kw (C57), CBA/Kw (CBA) and KE strains were tested at the ages of 6, 7, 8 and 10 weeks. Severely misshapen spermatozoa were produced by 6-week-old males of all strains: 30% of spermatozoa had 'thread-like' heads, devoid of Feulgen-positive material; the total proportion of abnormalities was lowest in CBA males. During maturation the percentages of abnormalities dropped rapidly and the proportion of drastically misshapen spermatozoa diminished in favour of less severe deformations. The frequency distribution of abnormal sperm types was strain specific for adult males but not for very young males. Large spermatozoa were seen in samples from young CBA and KE males (0.5-2%) and sporadically in 10-week-old CBA males. A negative relationship between body weight and the severity of abnormalities was seen for young, but not adult, males reared in litters of different size. No sperm deterioration was noticed in the first year of life of 5 KE males tested every 3 months until death, but a male surviving to 15 months had increased (38%) proportions of abnormal spermatozoa.

The relation of semen and vaginal mucus traits to fertility in the Australian Merino

Data relating semen traits and vaginal mucus scores in 515 ram years and 4190 first inseminations to subsequent lambing performance of ewes were analysed by a range of statistical methods. The results showed there to be an important curvilinear effect of mucus score at insemination time and linear effects of scores for motility and consistency of semen in the ejaculates used. These effects operated both on fertility and on fecundity. There appeared also to be smaller linear effects of volume of semen inseminated per ewe and estimates of the proportion of abnormal spermatozoa in ejaculates collected before the insemination season on fecundity and probably on fertility. The effects of age of ewe on fecundity to a single insemination are in contrast with the usual effects of age on lambs born under natural mating. In our material two-tooth ewes produced 5–6% more lambs from a single insemination than did older ewes. It is suggested that, while older ewes are more sexually active and shed increased numbers of ova, the reproductive tract becomes a less favourable environment for initiation and completion of pregnancy with increasing age.

Temperature Shock in Chicken Spermatozoa

Semen used in this study was collected from eighteen White Leghorn males. After the collected semen was thoroughly mixed with a glass rod, it was placed in a water bath at 25°C. Samples of undiluted semen (1.5ml) or diluted semen (1.6ml, 4-fold dilution with a Wilcox's buffer) were cooled at different cooling rates in order to determine whether chicken spermatozoa are subject to temperature shock produced by placing the samples at 25°C into cooling baths at 5.0 and -2°C. After the shock treatments, the diluted semen was centrifuged at 1, 200 R.C.F. for 5 minutes, supernatant discarded and resuspended to the original volume in the buffer just before insemination. In fertility tests White Leghorn hens were inseminated with 0.1ml of the undiluted semen or the reconcentrated semen. All precautions were taken against temperature shock during the collection and insemination of the semen. Results obtained are as follows.1) When the undiluted semen was cooled rapidly to 5°C as described above and stored for 60 minutes at that temperature, there was no change in fertility (94.2%), whereas a rapid cooling to 0 and -2°C resulted in lowered fertility (74.2 and 45.5%, respectively: P<0.01). When the undiluted semen was cooled slowly to -2°C at a rate of 0.5°C per minute and stored for 0, 30 and 60 minutes at the temperature, a slight decrease with the lapse of time with no significant decrease in fertility was observed through the storage periods (93.9, 85.0 and 82.5%, respectively). It was concluded, therefore, that chicken spermatozoa are subject to temperature shock.2) The effect of temperature shock on fertility was completely prevented by the 4-fold dilution of semen with the buffer.3) There was little change in motility of spermatozoa in any of the semen samples cooled rapidly to -2°C, whereas a significant increase (P<0.05) in the proportion of abnormal spermatozoa after the shock treatment was observed with the undiluted semen as compared to the diluted semen.

I.—Genetics of Gametes. I. A Quantitative Analysis of Five Characteristics of Rabbit Spermatozoa

SynopsisInformation is presented on some ways in which spermatozoa vary within a mammalian species, and on the relative importance of non-genetic factors affecting this variation. The work is basic to current researches in this laboratory on the genetics of mammalian spermatozoa. Five characteristics of rabbit spermatozoa were examined in permanent nigrosin-eosin preparations: the incidence of stained spermatozoa and the incidence of spermatozoa lacking the acrosomal cap, both related to the fertility of semen; the length, breadth and area of the spermatozoan head. Various factors have been studied that potentially affect these characteristics, with emphasis on variation attributable to technique and observation. The effects of the factors have been recorded in quantitative form and, in the light of the present work, suggestions have been made for the design of future experiments. Experimental and statistical procedures are described. Observations on variation due to biological causes include a separation of the variance between the males of a litter from the variance between the litter means. It has also been shown that the average length of the spermatozoan head in the vas deferens remains virtually unchanged in the ejaculate. Mensuration characteristics (length, breadth and area) are better adapted to objective analysis than are enumeration characteristics (proportions of abnormal spermatozoa).

Effect of Techniques of Preparing Semen Smears for Staining on The Morphology of Bull Spermatozoa

DETERMINATION of the proportion of morphologically abnormal spermatozoa in stained semen smears was formerly considered as one of the best means of estimating the potential fertility of a breeding male (Williams and Savage, 1925; and Moench and Holt, 193I). More recently, the reliability of this method has been questioned (Dougherty and Ewalt, 1941 ; Herman and Swanson, 1941; and Lasley and Bogart, 1943). Little recent evidence has been obtained to show direct correlation between the proportion of abnormals and relative fertility in the bull (Trimberger and Davis, 1942; and Mercier, 1946) but no proof is yet available that abnormals need no longer be considered in routine semen examination. Direct evidence on this question is needed. Before sound evidence can be obtained easy and precise methods by which the proportion of abnormal spermatozoa in bull semen can be determined routinely in any laboratory need to be developed. Work in this laboratory revealed that the procedures used in preparing smears for staining might have an influence on the proportion of tailless heads and abnormally-formed spermatozoa observed.