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1.
The present study investigated daily sperm output and sperm morphology of fresh semen in eight Swedish Warmblood stallions aged 5–8 years. They were used for artificial insemination, and their fertility during the breeding season of semen collection exceeded 60% per cycle. One ejaculate of semen was collected daily for 10 consecutive days from each stallion. The gel-free volume was measured, and the sperm concentration was assessed with a Bürker chamber. The volume of gel-free fraction was multiplied by the sperm concentration to give the total number of spermatozoa (TSN). Sperm morphology was examined in ejaculates collected on days 2, 5 and 10. An aliquot from each ejaculate was fixed in 1 ml formol–saline immediately after collection and examined under a phase-contrast microscope (magnification 1000×) to assess morphological abnormalities. Furthermore smears were prepared and stained according to Williams (carbolfuchsin–eosin) for a more detailed examination of the sperm heads under a light microscope (magnification 1000×). Analysis of variance was applied to data. Total spermatozoa number decreased progressively during the first 8 days of collection, and daily sperm output (DSO) was calculated as mean TSN of collections on days 8–10, being 6.4 × 109 spermatozoa. The overall percentages of morphologically normal spermatozoa in ejaculates collected on days 2, 5 and 10 were above 70%, being significantly lower in ejaculate 2 (68.6%) compared with ejaculates 5 and 10 (72.9% respectively 75.3%).  相似文献   

2.
The objective was to investigate whether it is possible to improve the quality of stallion semen, with respect to sperm morphology and chromatin integrity, both of which have been linked to fertility, using either density gradient centrifugation (DGC) or a new method, hereby named single layer centrifugation (SLC). The two methods of colloidal centrifugation were evaluated using 38 ejaculates from 10 stallions. Sperm morphology, subjective motility and sperm chromatin integrity were compared in uncentrifuged samples and in centrifuged sperm preparations. The proportion of morphologically normal spermatozoa varied between stallions (p < 0.001) and was increased by both methods of colloidal centrifugation (median value before centrifugation 67.5%; after SLC 78%; after DGC 77%; p < 0.001). The incidence of certain abnormalities was reduced, e.g. proximal cytoplasmic droplets were reduced from 12.9% to 8.8% (p < 0.001), and mid-piece defects from 5.3% to 1.4% (p < 0.05). Similarly, sperm motility and chromatin integrity were significantly improved (p < 0.001), with no difference between the two centrifugation methods. Centrifugation through colloids can enrich the proportions of stallion spermatozoa with normal morphology and normal chromatin structure in sperm preparations. The new method, SLC, was as effective as DGC in selecting motile stallion spermatozoa with normal morphology and intact chromatin. SLC, being simpler to use than DGC, would be appropriate for routine use by stud personnel to improve stallion sperm quality in insemination doses.  相似文献   

3.
The standard procedure for assessing the breeding potential of a stallion includes the parameter total number of spermatozoa classified as morphologically normal. This study investigated sperm morphology of fresh semen in randomly chosen Estonian (E, n = 8) and Tori (T, n = 7) breed stallions with proven fertility. Two ejaculates were examined from each stallion. An aliquot from each ejaculate was fixed in 1 mL formol-saline immediately after collection and examined with phase-contrast microscope at a magnification 1000x for all types of morphological abnormalities. Furthermore smears were prepared and stained according to Williams (carbolfuchsin-eosin) for a more detailed examination of the sperm heads with light microscope at a magnification 1000x. Analysis of variance was applied to the data, and results are presented as LSmeans (+/- SE). One T stallion that had a disturbance in the spermatogenesis and one 22-year-old E stallion were not included in the analyses. The T stallions had on average 57.5 +/- 4.1% and the E-stallions 74.4 +/- 3.8% morphologically normal spermatozoa (p = 0.012). In 4 of 7 T stallions and 7 of 8 E stallions both ejaculates had > 50% morphologically normal spermatozoa. There was a significant difference between breeds in mean percentage of proximal droplets (17.3 +/- 2.7% and 2.9 +/- 2.5% for T and E stallions, respectively; p = 0.003).  相似文献   

4.
The objective of this research was to improve the techniques in processing chilled and frozen‐thawed horse semen. In a preliminary experiment (Exp. I), different techniques for sperm selection and preparation [Swim‐up, Glass wool (GW) filtration, Glass wool Sephadex (GWS) filtration; Percoll] were tested for their suitability for equine spermatozoa and results were compared with the routine procedure by dilution (Exp. I). In the main experiment (Exp. II), two sperm preparation techniques (GWS, Leucosorb®) refering to the results of Exp. I and a previous study of our group (Pferdcheilkunde 1996 12, 773) were selected for processing complete ejaculates either for cooled‐storage or cryopreservation. In a third experiment (Exp. III), pregnancy rates from inseminations with semen processed according to the techniques tested in Exp. II were compared with those obtained with semen processed according to routine procedures. In Exp. I (six stallions, six ejaculates/stallion), between 48 and 92% of spermatozoa were lost following the different sperm selection procedures (p < 0.05). Preparation of sperm increased percentage of progressively motile spermatozoa (pms) [Swim‐up, GW, GWS vs dilution, Percoll (p < 0.05)] and decreased percentage of sperm head abnormalities [Swim‐up, GW, GWS vs dilution, Percoll (p < 0.05)] probably by not improving the quality of individual cells, but by elimination of spermatozoa of inferior quality. In Exp. II (eight stallions, three ejaculates/stallion) Leucosorb® and GWS procedures allowed the filtration of large volumes (extended ejaculates) for routine laboratory practice. GWS and Leucosorb® filtration resulted in increased motility, membrane integrity and sperm viability after storage of spermatozoa until 48 h at +5°C when compared with control (diluted) and centrifuged semen (p < 0.05). Significantly more spermatozoa were recovered after centrifugation (87.8 ± 15.4%) compared with GWS (63.5 ± 18.6%) and Leucosorb® filtration (53.6 ± 22.3%). GWS or Leucosorb® procedure resulted in successful cryopreservation of stallion semen without centrifugation for removal of seminal plasma. The per cycle conception rate of inseminated mares using 200 × 106 pms transferred within 8 h after collection of semen was not affected by GWS filtration or Leucosorb® separation when compared with centrifugation (n.s.; Exp. III). In conclusion, GWS and Leucosorb® filtration results in the improvement of semen quality and should be considered as a method for stallion semen processing. Additional studies are needed for the evaluation of potentially higher fertilizing ability of stallion spermatozoa separated by techniques for sperm selection.  相似文献   

5.
In an attempt to evaluate the possible relationship between the microbial flora in the stallion ejaculate and its ability to freeze, three ejaculates from five stallions were frozen using a standard protocol. Before freezing, an aliquot was removed for bacteriological analysis. Bacterial growth was observed in all the ejaculates studied. The isolated microorganisms were: Staphylococcus spp. and Micrococcus spp. (in all the stallions), β-haemolytic Streptococcus (in stallions 3 and 4), Corynebacterium spp. (in stallions 1, 3–5), Rhodococcus spp. (in stallion number 2), Pseudomonas spp. (in stallion number 1) and Klebsiella spp. (in stallions 1, 3 and 5). The presence and richness of Klebsiella and β-haemolytic Streptococcus in the ejaculate were related to two sperm variables post-thaw, namely the proportion of dead spermatozoa (ethidium+ cells; r = 0.55, p < 0.05) and the amplitude of lateral displacement of the sperm head (ALH, μm; r = −0.56, p < 0.05), respectively. The degree of growth of Corynebacterium spp. in the ejaculate was positively correlated with the percentage of spermatozoa showing high caspase activity post-thaw (r = 0.62, p < 0.05). The presence and number of colonies of β-haemolytic Streptococcus were negatively correlated (r = −0.55, p < 0.05) with low sperm caspase activity. It is concluded that the microbial flora of the equine ejaculate may be responsible for some of the sublethal damage experimented by the spermatozoa during cryopreservation.  相似文献   

6.
A careful evaluation of daily sperm output (DSO) and seminal parameters is indicative of the potential fertility of the animal and at the same time is useful for maximization of the reproductive activity. The aim of this article was to evaluate the seminal parameters, testicular volume (TV) calculated by ultrasound measurements, DSO, and any eventual relationship between these in Ragusano donkey jackasses. Eight Ragusano donkey stallions underwent a morphometric evaluation of the testes by ultrasound to calculate the TV, and daily semen collection for 10 consecutive days. TV ranged from 250 to 500 cm3 and no significant differences could be observed between the left and right testes. Only ejaculates from 4 to 10 days were analyzed, given that there was evidence that the sperm extragonadal reserve interfered with the total number of sperm in ejaculates during the early days. DSO in the Ragusano donkey ranged from 7 to 23 × 109 sperms. The seminal parameters showed high values of motility, viability, and low abnormality percentages. Age, TVs, and sperm parameters were not significantly correlated. The correlation between TV and DSO was poor (P = .1) in this study and this may suggest that TV and DSO might simply not be highly correlated in the donkey.  相似文献   

7.
Seminal and testicular characteristics were compared in 19 three-year-old and 23 two-year-old Quarter Horse stallions. Semen was collected, and testicular evaluations made on all stallions once in April or May and again 60 days later. Semen was collected from stallions twice, one hour apart, at each evaluation. Average testicular tone and scrotal width were greater in three-year-olds than in two-year-olds. Ejaculates of three-year-olds had higher motility scores (66% vs 47%) sperm movement (3.2 vs 2.4), normality (77 vs 71), and total number of normal, motile spermatozoa per ejaculate (4.3 × 109 vs 2.2 × 109). Two-year-olds had twice as many cytoplasmic droplets (11% vs 5%) as three-year-olds. Average sperm concentrations per ml of gel-free semen and gel-free volume of ejaculates were not different. Volume of ejaculate and motility of spermatozoa were positively correlated with pregnancy rate, whereas percent cytoplasmic droplets was negatively correlated with pregnancy rate in both groups of stallions. Pre- and post-ejaculatory urethral, seminal, and preputial cultures were examined for pathologic organisms on all stallions. Eighteen of 42 had positive cultures for Klebsiella spp., Pseudomonas spp., β-Strep spp., or E. coli. Nine two-year-olds and 3 three-year-olds had positive cultures for Klebsiella spp. All but one of these stallions were housed on wood shavings and allowed limited exercise. Three-year-old stallions had superior seminal quality as compared with two-year-olds.  相似文献   

8.
Reasons for performing study: An improvement in sperm quality after single layer centrifugation (SLC) has been seen in previous studies using small sample sizes (for example, n = 10 stallions). There is a need to investigate whether this improvement is repeatable over several breeding seasons with a larger number of stallions (n ≥ 30 stallions). Objective: To make a retrospective analysis of the results of SLC performed on more than 250 sperm samples (176 ejaculates) from 31 stallions in 3 consecutive breeding seasons. Methods: Sperm quality (motility, proportion of morphologically normal spermatozoa and the proportion of spermatozoa with undamaged chromatin) was assessed before and after SLC. Results: All parameters of sperm quality examined were significantly better in sperm samples after SLC than in their unselected counterparts (P<0.001 for each parameter). The yield of spermatozoa obtained after SLC was influenced by the type of extender used and also by the concentration of spermatozoa in the original ejaculate, with fewer spermatozoa being recovered when the loading dose contained a high concentration of spermatozoa. The optimal concentration was approximately 100 × 106/ml. Sperm concentration in the samples loaded on to the colloid influenced the sperm yield while the type of semen extender affected sperm quality and survival. Furthermore, the scaled‐up SLC method was found to be suitable for use with a range of ejaculates, with similar sperm kinematics being observed for standard and scaled‐up preparations. Conclusions: SLC consistently improved the quality of stallion sperm samples from a large number of ejaculates. The method could be scaled‐up, allowing larger volumes of ejaculate to be processed easily from a wide range of stallions.  相似文献   

9.
The traditional stripping procedure for collecting fish semen is associated with the risk of urine contamination, which may significantly affect semen quality and quantity. The use of a catheter as an alternative method for semen collection may overcome this problem. Therefore, this study compared Caspian brown trout (Salmo trutta caspius) semen parameters (i.e. sperm density, seminal plasma osmolality, motility parameters of spermatozoa analysed using computer‐assisted sperm analysis and fertility) between the traditional stripping method and the use of a catheter. All parameter values of the semen collected with a catheter were significantly higher (p < .05; density = 7.67 ± 1.02 × 109 ml?1 and osmolality = 279.28 ± 32.84 mOsm kg?1) than those collected with stripping method (density = 4.85 ± 0.47 × 109 ml?1 and osmolality = 216.42 ± 20.75 mOsm kg?1). Semen collected with a catheter was characterized by higher spermatozoa motility compared with sperm collected via stripping. Similarly, the fertilization ability of sperm collected with a catheter was significantly greater (p < .05) than sperm collected with the traditional stripping method. In conclusion, collection of sperm with a catheter was shown to effectively reduce urine contamination and is therefore recommended for the collection of Caspian brown trout sperm.  相似文献   

10.
Eight pony stallions were paired by estimated daily sperm output (DSO) and randomly assigned to one of two treatments in a randomized block experiment. Stallions received 44 μg/kg BW estradiol cypionate (ECP) or an equivalent volume of physiological saline solution on alternate days during the breeding season. Blood samples collected immediately preceding each injection were assayed for luteinizing hormone (LH), estradiol-17β (E2) and testosterone (T). Semen was collected twice weekly, 3.5 days apart, to evaluate sperm motility and total number of sperm per ejaculate. Prior to and after 4, 8 and 12 weeks on treatment, semen was collected once daily for 7 days to determine DSO. Data were separated into 9 periods (10 days each) for statistical analysis and subjected to analysis of variance for a randomized block design to determine treatment effects.There were no differences (p>.05) between groups for DSO or LH prior to initiation of treatment. Testosterone was higher (p<.05) in ECP stallions compared with C stallions prior to treatment and at all time points measured. As expected, E2 was higher (p<.05) in the ECP stallions compared to C stallions after 20 days (period 2) of treatment and for the remainder of the experiment. However, E2 was higher (p<.05) in the C group prior to treatment, but there was no difference between the groups after 10 d of treatment (period 1). ECP stallions had higher (p<.05) DSO than C stallions after 30 d on treatment. After 40 and 50 d (periods 4 and 5), ECP stallions demonstrated higher (p<.05) total sperm per period than C stallions. This was preceded by higher (p<.05) LH values for ECP stallions than for C stallions after 10 and 20 d (periods 1 and 2). No differences were found between the ECP and C groups for LH between 30 and 60 d. Although numerically higher, no significant differences (p>.05) were seen after 60 days for DSO or after 60, 70 or 80 days for total sperm per period. ECP stallions had higher (p<.05) DSO and total sperm per period after 90 d than C stallions. Additionally, LH remained significantly higher (p<.05) in the ECP group after 60 days (periods 7, 8 and 9). Elevated LH concentrations in ECP stallions demonstrated that estrogen treatment did not inhibit LH secretion in this study.  相似文献   

11.
To investigate effects of thermally-induced testicular degeneration on hormonal and seminal parameters in stallions, the scrotum was insulated for 36 hours in two mature (5-year-old mixed breed and 11-year-old Throughbred) stallions. Semen was collected daily for 10 days (DSO) prior to, and at intervals after, scrotal insulation. When DSO determinations were not being made, semen was collected 3 times weekly. Jugular blood samples were collected at 15-minute intervals for 6 hours from each stallion prior to, and at intervals after, scrotal insulation. A mouse interstitial cell testosterone assay was modified to quantify biologic activity of equine luteinizing hormone (BLH) in plasma samples. Immunoactive luteinizing hormone (ILH) and testosterone (T) concentrations were determined in plasma samples by routine RIA procedures. Percentages of progressively motile and morphologically normal spermatozoa began to decrease by 1 to 2 weeks postinsulation, reached nadir values at 3 to 3-1/2 weeks postinsulation, and returned to preinsulation values by 7 weeks postinsulation. Total number of spermatozoa and total number of progressively motile, morphologically normal spermatozoa in ejaculates at DSO returned to normal by 8 weeks postinsulation in stallion 2 and 12 weeks postinsulation in stallion 1. Concentrations of BLH and ILH increased, and while T concentrations decreased, immediately postinsulation. The increase in ILH concentrations was greater than the increase in BLH concentrations, resulting in a decrease in the BLH:ILH (B:I) ratio. Following the peak in LH secretion immediately postinsulation, LH concentrations gradually decreased while T concentrations increased. The B:I ratio was elevated from 1 to 13 weeks postinsulation compared to immediately postinsulation. In addition to changes in spermatozoal quality in ejaculates, stallion response to scrotal insulation included increased secretion of luteinizing hormone and impaired Leydig cell function (as determined by reduced testosterone concentration in circulating plasma). The proportion of biologically active LH secreted in response to thermal testicular injury increased during the recovery phase.  相似文献   

12.
High dilution rates have been documented as detrimental for boar spermatozoa, shortening their lifespan (Centurion et al. 2003, Biol Reprod 69: 640–646). Addition of seminal plasma (SP) to semen extenders, or selenium (Se) and vitamin E (VE) in diet of boars could increase motility of highly diluted spermatozoa (HDS). The aim of this work was to evaluate the effect of seminal plasma on sperm motility of HDS from boars feed with Se and VE. Sixteen 12 month-old boars were designed to one of four dietary treatments: (i) control, Se 0 ppm–VE 0 IU/kg; (ii) Se 0–VE 250; (iii) Se 0.5–VE 250 and (iv) Se 0.5–VE 0. Boars were treated for 8 weeks before semen collection. Sperm rich fractions from each boar were diluted to 5 × 106 sperm/ml in PBS medium and incubated at 37°C with or without 10% SP. The measurements were done at 0, 2 or 5 h. Data were analyzed as a mixed model for a factorial design [2 (Se) × 2 (VE) × 2 (SP) × 3 (h)]. Percentage of sperm motility (PSM) increases significantly (p < 0.001) with addition of Se (81.3 ± 1.52), VE (81.0 ± 1.62) and SP (81.5 ± 1.57) vs control (73.4 ± 1.61). There was significant interaction Se × VE (p < 0.001) and Se × VE × SP (p < 0.05) in PSM. However, PSM was affected significantly by time (0 h 83.4 ± 1.92; 2 h 80.7 ± 1.92 and 5 h 67.9 ± 1.92; p < 0.001). There was significant interaction SP × Time (p < 0.05) in PSM. These results indicate that Se, VE and SP improve seminal viability. Addition of 10% of SP maintains PSM at least during 5 hours.  相似文献   

13.
Contents
The value of routine evaluation of bull semen was analysed for 117 AI bulls placed in two studs. Data from semen analysis of a total of 1635 ejaculates was compared statistically with the nonreturn rates of the bulls. The semen parameters which were significantly correlated to nonreturn rates were the motility of the freshly collected ejaculates (p = 0.0140) and post-thaw motility (p = 0.0075). The total number of motile sperm in the inseminate ranged from 10.9 to 19.3 × 106 and according to previous reports the effects of low motility should be fully 'compensated' when doses above 10 × 106 sperm/dose are used for insemination. In conclusion, the motility of freshly collected semen does not appear to be 'compensation' and a low percentage of motile sperm in an ejaculate may indicate other dysfunctions of the population of motile cells. Furthermore, post-thaw motility appears to correlate significantly with nonreturn rates. The largest proportion of the variation was explained by the breed of the bull and stud (42.2% of the variation), whereas the two motility parameters explained 10% of the total variation in nonreturn rates. Objective and precise evaluation of sperm motility in combination with other semen traits are needed to improve breeding efficiency. Although microscopic evaluation of sperm motility correlates with nonreturn rates of bulls, the methods are subjectively assessed and inaccurate and therefore do not allow a satisfactory prediction of fertility.  相似文献   

14.
Myeloperoxidase (MPO) is a pro‐oxidant enzyme associated with decreased motility in thawed equine semen. This study aimed to describe MPO concentration, activity and subunits in raw and thawed semen and to correlate these data with motilities in raw and thawed semen. Semen samples from five stallions were collected four times. Motilities were assessed in raw and thawed semen. MPO assays were performed in raw seminal plasma, raw sperm‐rich pellet and thawed semen. Total and active MPO concentrations were, respectively, assayed by enzyme‐linked immunosorbent assay and specific immunological extraction followed by enzymatic detection. MPO subunits present in semen were characterized by Western blot. Purified active MPO was added in saline solution and freezing extender to control its activity during freezing procedure. Differences between medians were determined using Kruskal–Wallis test, and correlations were determined using Spearman's test for nonparametric data. Active MPO concentration was low in seminal plasma and thawed semen, but high in pellet (p = 0.0058), as the opposite relation was observed for total MPO concentration (p < 0.0001). In seminal plasma and post‐thaw semen, inactive 86‐kDa MPO precursor was mainly observed. Purified MPO activity was decreased in the extender (p = 0.0286). MPO activity in pellet was highly correlated with thawed progressive motility (r = ?0.5576, p = 0.0086). Inactive MPO precursor and unknown low molecular weight inactive MPO precursor subunits explain low MPO activity in semen. Major MPO activity was observed in pellet, and post‐thaw loss of activity is partially explained by MPO inactivation in extender. Thawed semen motility was negatively correlated with MPO activity in pellet, becoming a potential freezability predictor.  相似文献   

15.
The objective of the study was to assess apoptosis and DNA defragmentation in equine semen diluted and chilled to +4°C. Semen was collected from nine fertile stallions, including four Arabian thoroughbreds and five coldbloods. Examinations were carried out immediately after semen collection (0) and at five storage times (24, 48, 72, 96 and 120 h). The basic semen evaluation was performed in terms of volume, sperm concentration, viable sperm percentage, progressive motility and morphology. Using flow cytometry, DNA defragmentation and cell membrane integrity of spermatozoa were determined. The results of basic tests did not demonstrate significant differences amongst stallions, except for progressive sperm motility, which was significantly higher (p < 0.05) in the semen of Arabian stallions. In the semen of the same stallions, a significant decrease in the percentage of alive spermatozoa was observed at 72, 96 and 120 h of storage, whereas a significant increase in the number of spermatozoa with DNA defragmentation was found after 24 h storage. In the semen of coldblood stallions, significantly reduced live spermatozoa percentage was observed at 96 and 120 h, while increased DNA defragmentation was observed at 48 h. These findings demonstrated that the semen of Arabian stallions chilled to +4°C retained original characteristics until 24 h of storage, whereas in coldbloods, these were preserved up to 48 h of storage.  相似文献   

16.
Sperm motility is an indicator of male fertility because of its importance for sperm migration through the female genital tract and for gamete interaction at fertilization. This study analyses the relationship between computer assisted semen analysis (CASA) motility patterns and sperm migration of rams in ruminant cervical mucus. In experiment 1, spermatozoa extended with sperm analysis medium (SAM) and seminal plasma were compared in terms of motility. In experiment 2, 56 semen samples were collected either with artificial vagina (AV) or electroejaculator to be compared in terms of motility performance. In experiment 3, 104 ejaculates collected by AV from 26 males were analysed via the CASA system to characterize their motility patterns. In experiment 4, ejaculates from pairs of rams (20 rams in total) were simultaneously assessed for mucus migration (ovine, caprine, bovine) and motility patterns to evaluate the correlations between both parameters. Semen collected by AV and extended in SAM allows the most reliable assessment for sperm motility. Ram spermatozoa move fast and follow a linear trajectory compared with other ruminants. Continuous line velocity (VCL) and average path velocity (VAP) are the only sperm kinematic parameters that presented significant positive correlations with the ability to migrate in sheep cervical mucus (p < 0.05). Continuous line velocity, VAP, straight line velocity and linearity are highly significantly related with migration efficiency in goat cervical mucus (p < 0.01) and only lateral head displacement is negatively related to sperm migration in bovine cervical mucus (p < 0.05). These results suggest that specific kinematic parameters confer the ability of spermatozoa to colonize and migrate through epithelial mucus with different rheological properties.  相似文献   

17.
Contents Five tropically adapted buck breeds extensively managed in Ethiopia were studied to determine possible effects of breed and age on body size and testicular traits. In all, 177 bucks were selected following stratified random sampling, and evaluated in three age groups: <14 months (young), 14–19.5 months (intermediate) and 19.6–24 months (old). The breeds studied were Arsi-Bale (AB; N = 35), Central Highlands (CH; N = 33), Afar (N = 35), Boran (N = 36) and Woito-Guji (WG; N = 38). In all the three age groups, Boran and CH bucks were the heaviest (p < 0.05), Afar were the lightest, and AB and WG were in between. The highest body weight (BW) was achieved in the intermediate age group for Afar, but in the oldest age group for the other breeds. In the youngest age group, scrotal circumference (SC) was the widest (p < 0.05) for Boran and CH and the narrowest for Afar, AB and WG, while in the intermediate and the oldest age groups, Boran showed the widest SC. Boran, WG and CH had higher (p < 0.05) testicular weight (TW) than Afar and AB in the youngest age group. Boran retained the highest (p < 0.05) TW in the intermediate and the oldest age groups, while in the oldest age group WG and AB medium TW and Afar had the lowest TW. However, Afar had the highest TW expressed as percentage of BW. SC was well correlated with TW (p < 0.001; r  = 0.74) and BW (p < 0.001; r  = 0.61), indicating a linear, positive association between BW and TW (p < 0.001; r  = 0.51). In conclusion, body size and testicular traits of Ethiopian bucks under an extensive management system are influenced differently by breed and age group.  相似文献   

18.
The aim of this study was to investigate the effect of gonadotrophin-releasing hormone (GnRH) immunisation on mature stallions that had been used for breeding. Four Standardbred stallions were used in the study: 3 experimental animals and 1 control animal. Semen was collected regularly, i.e. twice/week, during the 4 months prior to the experimental period. The stallions were immunised against GnRH with a GnRH-BSA conjugate. Equimune was used as the adjuvant. The stallions were immunised on 5 occasions, 4 at 2 week intervals, and the fifth 4 weeks after the fourth. Blood samples were taken once a week for analysis of GnRH antibody titre and every third week for testosterone and oestrone sulphate analyses. Semen was collected once a week, and libido and sexual behaviour were observed. Ejaculate volume, sperm concentration, total number of sperm in the ejaculate, sperm motility and sperm morphology were evaluated. Testicular size was measured once a week. At the end of the study, the stallions were castrated, and a histological examination of the testes performed. All immunised stallions produced antibodies against GnRH, and plasma testosterone concentration decreased. However, the effect of immunisation varied between stallions. In 2 of the stallions, high levels of antibodies were found, while in the third, the level was moderate. Four weeks after the first immunisation, a decrease in libido was observed. Two months after the first immunisation, marked changes in semen quality were observed in the 2 stallions with high antibody titres. Fourteen weeks after the first immunisation, the total number of sperm/ejaculate had decreased from >8.6 x 10(9) to <2.7 x 10(9), sperm motility from >59 to <10% and the frequency of morphological normal spermatozoa had decreased from >60 to <14%. The dominating abnormalities were abnormal head shapes, proximal cytoplasmic droplets and detached heads. In the third stallion, only slight changes in semen quality were found. No changes were observed in the control stallion. Decreases in testicular size were noted in all of the experimental stallions. Pronounced histological alterations in the testes were observed in 2 of the stallions. It is concluded that the vaccine was effective in stimulating production of GnRH antibodies and in suppressing testicular function and androgen secretion. However, there was an individual variation in the responses among the stallions and, further, libido was not totally suppressed.  相似文献   

19.
The goal of this study was to evaluate the occurrence of macrophages in rooster semen and to investigate their impact on the spermatozoa quality. Ross 308 breeder males (n = 30) with no evidence of genital tract infections were used to determine the concentration of macrophages using fluorescently conjugated acetylated low‐density lipoprotein (AcLDL). Subsequently, the roosters were divided into two groups on the basis of semen macrophage concentration, and semen quality was compared in two heterospermic samples. We applied computer‐assisted semen analysis (CASA) system to determine motility parameters. Fluorescence microscopy and flow cytometry were used to evaluate occurrence of apoptotic and dead spermatozoa. Spermatozoa fertility potential was examined after intravaginal artificial insemination of hens. Eighteen roosters (control group) contained 0.2–3% of macrophages within spermatozoa population and ten roosters (macrophage group) had 10–15% of macrophages. Males from macrophage group had lower (p < 0.05) motility parameters (total and progressive movement, velocity curved line) and increased concentration of dead spermatozoa detected by flow cytometry and fluorescence microscopy (p < 0.001 and p ? 0.05, respectively). Differences (p < 0.05) between fluorescent microscopy and flow cytometry in results on spermatozoa apoptosis and viability were observed. No significant difference was found between groups in fertility of spermatozoa. In conclusion, the higher presence of macrophages in rooster semen may have a negative effect on some parameters of rooster spermatozoa evaluated in vitro. Furthermore, our study suggests that flow cytometry allows more precise examination of spermatozoa viability and apoptosis in a very short time compared with the fluorescent microscopy.  相似文献   

20.
A QTL detection experiment was performed in French dairy cattle to search for QTL related to male fertility. Ten families, involving a total of 515 bulls, were phenotyped for ejaculated volume and sperm concentration, number of spermatozoa, motility, velocity, percentage of motile spermatozoa after thawing and abnormal spermatozoa. A set of 148 microsatellite markers were used to realize a genome scan. First, genetic parameters were estimated for all traits. Semen production traits were found to have moderate heritabilities (from 0.15 to 0.30) while some of the semen quality traits such as motility had high heritabilities (close to 0.60). Genetic correlations among traits showed negative relationships between volume and concentration and between volume and most quality traits such as motility or abnormal sperm while correlations between concentration and these traits were rather favourable. Percentages of abnormal sperm were negatively related to quality traits, especially with motility and velocity of spermatozoa. Three QTL related to abnormal sperm frequencies were significant at p < 0.01. In total, 11 QTL (p < 0.05) were detected. However, the number of QTL detected was within the range of expected false positives. Because of the lack of power to find QTL in this design further analyses are required to confirm these QTL.  相似文献   

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