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1.
Improved sperm selection techniques are needed to increase the efficiency of equine-assisted reproduction. Single layer centrifugation (SLC) of spermatozoa has been shown to improve the quality of stallion sperm samples. In this study, the functionality of selected stallion spermatozoa was tested by intracytoplasmic sperm injection of equine oocytes after selection by SLC through Androcoll-E or by discontinuous density gradient centrifugation (DGC) through Redigrad and Tyrode's medium with added albumin, lactate, and pyruvate. The mean cleavage rates of the injected oocytes from SLC- and DGC-selected spermatozoa were 67% and 66%, respectively, whereas the proportion of blastocysts developing from cleaved oocytes was 28% and 22%, respectively (P > .05, not significant). An incidental finding was that there was a tendency for SLC-selected spermatozoa to have a higher percentage of spermatozoa with normal morphology than DGC (70% ± 22% vs. 58% ± 38%) and for more blastocysts to be obtained from subfertile ejaculates (21 [19.6%] vs. 15 [14.4%], respectively). In further experiments, stallion spermatozoa bound to hyaluronan, although binding may depend on the semen extender and sperm treatment as well as incubation time. In conclusion, SLC-selected stallion spermatozoa function normally when injected into oocytes. SLC may potentially be better than DGC at selecting spermatozoa from subfertile ejaculates, but this effect needs rigorous investigation with a much larger sample size. Use of the hyaluronan-binding assay for assessing the potential fertility of stallion spermatozoa may be useful but requires further evaluation.  相似文献   

2.
Although several selection techniques are available for processing spermatozoa, only colloid centrifugation has been used to any extent in this field, starting with density gradient centrifugation and progressing more recently to single-layer centrifugation (SLC). SLC through a species-specific colloid has been shown to be effective in selecting spermatozoa with good motility and normal morphology from stallion semen. The method is easier to use and less time-consuming than density gradient centrifugation, and has been scaled-up to allow whole ejaculates to be processed in a practical manner. The potential applications of SLC in equine breeding are as follows: to improve sperm quality in artificial insemination doses for “problem” ejaculates, to increase the shelf life of normal sperm doses, to remove pathogens (viruses, bacteria), to improve cryosurvival by removing dead and dying spermatozoa before freezing or after thawing, to select spermatozoa for intracytoplasmic sperm injection, and to aid conservation breeding.  相似文献   

3.
Reasons for performing study: A new, simpler, technique of colloidal centrifugation has recently been developed, designated single layer centrifugation (SLC). This technique requires evaluation by comparison with a density gradient for its ability to select the best quality spermatozoa and its practicality of use on studfarms. Objective: To compare the effect of 2 methods of colloidal centrifugation, density gradient centrifugation and single layer centrifugation, on stallion sperm motility, yield and survival, using freshly collected extended stallion semen. Methods: Aliquots of extended stallion semen from 10 stallions (38 ejaculates) were processed by the 2 methods of colloidal centrifugation. For both uncentrifuged and centrifuged samples, sperm yield was calculated and subjective sperm motility assessed over several days to provide an estimate of sperm survival. Some stored semen samples, held at 4°C overnight, were also available for testing. Results: For fresh, extended semen, a similar recovery yield of motile spermatozoa was seen for the 2 methods of preparation for single layers and density gradients, respectively. Sperm motility and survival rate were significantly improved by colloidal centrifugation compared to unprocessed ejaculate, without any significant difference between methods (SLC vs. gradient). However, the yield was reduced by 18–20% when cold‐stored semen was used for centrifugation compared to fresh semen; and more variation between ejaculates was observed than for fresh ejaculates. Again, sperm motility and sperm survival were improved in the centrifuged sperm preparations compared to stored, unprocessed ejaculates. Potential relevance: The 2 colloid centrifugation techniques produce equivalent sperm preparations in terms of sperm quality. However, the SLC method would be more practical and convenient for use in the field.  相似文献   

4.
The objectives of this study were 1) to compare pregnancy rates resulting from 2 methods of insemination using low sperm numbers and 2) to compare pregnancy rates resulting from hysteroscopic insemination of 5 x 106 nonsorted and 5 x 106 spermatozoa sorted for X- and Y-chromosome-bearing populations (flow sorted). Semen was collected with an artificial vagina from 2 stallions of known acceptable fertility. Oestrus was synchronised (June to July) in 40 mares, age 3-10 years, by administering 10 ml altrenogest orally for 10 consecutive days, followed by 250 microg cloprostenol i.m. on Day 11. All mares were given 3000 iu hCG i.v. at the time of insemination to induce ovulation. Mares were assigned randomly to 1 of 3 treatment groups: mares in Treatment 1 (n = 10) were inseminated with 5 x 10(6) spermatozoa deposited deep into the uterine horn with the aid of ultrasonography. Mares in Treatment 2 (n = 10) were inseminated with 5 x 10(6) spermatozoa deposited onto the uterotubal junction papilla via hysteroscopic insemination. Mares in Treatment 3 (n = 20) were inseminated using the hysteroscopic technique with 5 x 10(6) flow sorted spermatozoa. Spermatozoa were stained with Hoechst 33342 and sorted into X- and Y-chromosome-bearing populations based on DNA content using an SX MoFlo sperm sorter. Pregnancy was determined ultrasonographically at 16 days postovulation. Hysteroscopic insemination resulted in more pregnancies (5/10 = 50%) than did the ultrasound-guided technique (0/10 = 0%; P<0.05) when nonsorted sperm were inseminated. Pregnancy rates were not significantly lower (P>0.05) when hysteroscopic insemination was used for sorted (5/20 = 25%) and nonsorted spermatozoa (5/10 = 50%). Therefore, hysteroscopic insemination of low numbers of flow sorted stallion spermatozoa resulted in reasonable pregnancy rates.  相似文献   

5.
Seminal plasma (SP) contains several types of compounds derived from the epididymides and accessory glands. The aim of this study was to examine the protein composition of different ejaculate fractions. Trial I: fractionated ejaculates were collected from two normal and two subfertile stallions. Samples containing pre‐sperm fluid and the first sperm‐rich jets (HIGH‐1), the main sperm‐rich portion (HIGH‐2), the jets with low sperm concentrations (LOW), and a combined whole‐ejaculate (WE) sample was centrifuged, and the SP was filtered and frozen. A part of each SP sample was stored (5°C, 24 h) with spermatozoa from HIGH‐2 and skim milk extender. Sperm motility was evaluated after storage in extender mixed with the stallion’s own SP or SP from one of the other stallions (sperm from a normal stallion stored in SP from a subfertile stallion and vice versa). Protein composition was analysed using reverse‐phase liquid chromatography (RP‐HPLC), N‐terminal sequencing and mass spectrometry. The area‐under‐the‐curve (AUC) was used for quantitative comparison of proteins within fractions. Trial II: semen samples were collected from seven stallions. Fractions with the highest (HIGH) and lowest (LOW) sperm concentrations and WE samples were examined using SDS‐PAGE and densitometry. No significant differences emerged between fractions in the AUC‐values of the Horse Seminal Protein‐1 (HSP‐1) and HSP‐2 peaks, or the peak containing HSP‐3 and HSP‐4 (HSP‐3/4). Levels of HSP‐1, HSP‐2 and HSP‐3/4 were not significantly correlated with total sperm motility, progressive sperm motility or average path velocity after storage. Significant differences between ejaculate fractions in the amount of different protein groups present in SP were not found in Trial I; but in Trial II, the proteins in the 60–70 kDa range were more abundant in LOW than in HIGH and WE, indicating that this band contained proteins derived mainly from the seminal vesicles, which produce most of the SP in LOW.  相似文献   

6.
REASONS FOR PERFORMING STUDY: To compensate for the wide variation in the freezability of stallion spermatozoa, it has become common veterinary practice to carry out repeated ultrasonography of the ovaries of oestrous mares in order to be able to inseminate them within 6-12 h of ovulation with a minimum of 300-500 x 10(6) frozen-thawed spermatozoa. Furthermore, in order to achieve satisfactory fertility, this requirement for relatively high numbers of spermatozoa currently limits our ability to exploit recently available artificial breeding technologies, such as sex-sorted semen, for which only 5-20 x 10(6) spermatozoa are available for insemination. OBJECTIVES: This study was designed to evaluate and compare the efficacy of hysteroscopic vs. conventional insemination when low numbers of spermatozoa are used at a single fixed time after administration of an ovulation-inducing agent. METHODS: In the present study, pregnancy rates were compared in 86 mares inseminated once only with low numbers of frozen-thawed spermatozoa (3-14 x 10(6)) at 32 h after treatment with human chorionic gonadotrophin (hCG), either conventionally into the body of the uterus or hysteroscopically by depositing a small volume of the inseminate directly onto the uterotubal papilla ipsilateral to the ovary containing the pre-ovulatory follicle. RESULTS: Pregnancy rates were similarly high in mares inseminated conventionally or hysteroscopically with 14 x 10(6) motile frozen-thawed spermatozoa (67% vs. 64%). However, when the insemination dose was reduced to 3 x 10(6) spermatozoa, the pregnancy rate was significantly higher in the mares inseminated hysteroscopically onto the uterotubal junction compared to those inseminated into the uterine body (47 vs. 15%, P < 0.05). CONCLUSIONS: When inseminating mares with <10 x 10(6) frozen-thawed stallion spermatozoa, hysteroscopic uterotubal junction deposition of the inseminate is the preferred method. POTENTIAL CLINICAL RELEVANCE: Satisfactory pregnancy rates are achievable after insemination of mares with frozen-thawed semen from fertile stallions 32 h after administration of human chorionic gonadotrophin (Chorulon). Furthermore, these results were obtained when mares were inseminated with 14 x 10(6) progressively motile frozen-thawed spermatozoa from 2 stallions of proven fertility.  相似文献   

7.
Slow-cooled stallion spermatozoa, with and without seminal plasma removed by centrifugation, were diluted in Kenney's extender (KE) containing nonfat dry skim milk with glucose and antibiotics or in KE supplemented by adding a modified high-potassium Tyrode's medium (KMT). Four ejaculates from each of four stallions were collected and divided factorially across these four treatments. Percentage of motile sperm, path velocity, and linearity immediately after treatment (0 h) and after storage at 4 degrees C for 24, 48, and 72 h were evaluated objectively by use of a HTM-2030 sperm motility analyzer. Stallions were a significant source of variation (P less than .01) throughout. After sperm had cooled, effects of stallion, extender, centrifugation, and their interactions were all found to be significant (P less than .01). The motility at 0, 24, 48, and 72 h for centrifuged KE was 74, 47, 39, and 24%; for uncentrifuged KE was 76, 56, 50, and 37%; for centrifuged KMT was 76, 75, 72, and 64%; and for uncentrifuged KMT was 80, 50, 26, and 13%, respectively. The extender x centrifugation interaction, after 24, 48, and 72 h of storage, accounted for half or more of the variation. Whereas centrifugation of semen extended in KE seemed to be harmful to sperm, motility of sperm extended in KMT after centrifugation was remarkably conserved for 72 h and was superior to all other treatments (P less than .05). This extender is promising for preserving liquid stallion semen when it must be transported before use in artificial insemination.  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 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   

10.
Conception rates for mares bred with transported-cooled and fresh stallion semen were collected over a 4-yr period (1998–2002) for two stallions. Both stallions stood at a commercial breeding farm. Semen from both stallions was used immediately after collection on the farm and after 24 to 48 h of cold storage when transported to locations in the U.S. and Canada. Semen for insemination of mares located on the farm was extended with a commercially available skim milk glucose extender (SKMG). Spermatozoal motility following cold storage for spermatozoa diluted in SKMG extender was unacceptable. Thus, semen from both stallions was centrifuged, and spermatozoa were resuspended in SKMG supplemented with modified PBS. In a previous study, the percentage of motile spermatozoa increased following centrifugation and reconstitution of the sperm pellet in SKMG-PBS as compared with semen dilution in SKMG (Stallion A: 15% vs 47%; Stallion B: 18% vs 43%). In the current study, 22 of 25 (88%) and 3 of 4 (75%) mares conceived with transported-cooled semen from Stallions A and B, respectively. Conception rates for mares inseminated with transported semen did not differ (P>0.05) from those inseminated on the farm with fresh semen. These data illustrate that stallion owners can modify standard cooled semen processing procedures and semen extender composition to improve post-storage spermatozoa motility and to obtain acceptable fertility.  相似文献   

11.
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   

12.
With the aim of investigating properties of stallion seminal plasma to eventually improve semen-handling techniques, sperm motility and plasma membrane integrity were analysed in different fractions of the ejaculates after storage. Semen was collected using a computer-controlled automated phantom that separates the ejaculates into five successive cups. Samples containing seminal plasma and skim milk extender were compared with samples stored in skim milk extender after the removal of seminal plasma by centrifugation. Fractionated ejaculates were stored cooled for 24 h after dilution with extender (Expt 1) or frozen in liquid nitrogen (Expt 2). In Expt 1, cup 1 was pre-sperm fluid, cups 2 and 3 sperm-rich fractions, and cup 4 sperm-poor fractions. In Expt 2, cups 1 and 2 were sperm-rich fractions, and cups 3 and 4 sperm-poor fractions. One sample (WE) represented the whole ejaculate in both experiments. Motility parameters were determined with a Hamilton-Thorn Motility Analyzer, and plasma membrane integrity was assessed using carboxyfluorescein diacetate and propidium iodide staining and fluorescence microscopy. The removal of seminal plasma lowered motility values, but not plasma membrane integrity, in both experiments. No significant differences between cups were observed after cooled storage. The cups differed significantly in most post-thaw motility parameters, and the sperm-rich fraction showed higher post-thaw motility than the whole ejaculate.  相似文献   

13.
Little information is available on the quality of stallion spermatozoa after sex sorting. The objectives of the present study were to assess the quality of sex‐sorted stallion spermatozoa and determine its fertilizing ability after hysteroscopic low dose insemination. Ejaculates from four stallions were collected and sorted by a MoFlo SX® flow cytometer/sperm sorter. Before and after sorting, spermatozoa were evaluated for motility by Computer Assisted Sperm Analysis, viability (SYBR 14‐propidium iodide), mitochondrial function (JC‐1) and acrosomal status (fluorescein isothiocyanate Pisum sativum agglutinin conjugated). A fertility trial was carried out on four mares (seven oestrous cycles) by hysteroscopic insemination, depositing 5 × 106 X‐bearing spermatozoa. Sex sorting resulted in a significant decrease (p < 0.001) in all motility characteristics. Sperm viability and percentage of spermatozoa with functional mitochondria were not affected by the sorting process, while the percentage of reacted spermatozoa was higher (p < 0.01) for non‐sorted than sorted spermatozoa. Pregnancy rate was 28.6% (2/7) after low dose hysteroscopic insemination. Only one pregnancy was carried to term with the birth of a healthy filly. In conclusion, despite the reduction in sperm motility, sex sorting did not impair stallion sperm viability and mitochondrial activity immediately post‐thaw; moreover, the sexed spermatozoa retained the ability to fertilize in vivo.  相似文献   

14.
REASONS FOR PERFORMING STUDY: A method of removing equine arteritis virus (EAV) from equine semen used for artificial insemination is urgently needed. Recent medical studies suggest that a double semen processing technique of density gradient centrifugation followed by a 'swim-up' can provide virus-free sperm preparations for assisted reproduction. OBJECTIVES: To investigate the use of the double semen processing technique to obtain virus-free sperm preparations from stallion semen containing EAV. METHODS: Aliquots of an ejaculate from an uninfected stallion were spiked with virus and processed by the double processing technique. The sperm preparations were tested by PCR for the presence of EAV. The procedure was repeated using an ejaculate from a known shedding stallion, testing processed and unprocessed aliquots by PCR and virus isolation. RESULTS: Virus-free sperm preparations were obtained using the double sperm processing technique. The 'swim-up' step is apparently required to ensure complete virus removal. CONCLUSIONS: The double semen processing technique is potentially a useful and simple tool for the removal of EAV from the semen of shedding stallions. POTENTIAL RELEVANCE: The inclusion of density gradient centrifugation and 'swim-up' in protocols for the processing of semen for artificial insemination could help prevent the transmission of viral diseases carried in semen, such as EAV.  相似文献   

15.
Seminal plasma (SP) is a mixture of contents from the testes, epididymides and accessory sex glands. The sperm concentration is highest in the first few jets, or fractions, of the ejaculate, and the composition of SP varies between these fractions because accessory gland secretions are released in a specific order. The aim of this study was to compare the levels of Na, Cl, K, Mg, Ca, inorganic phosphate (Pi) and the enzymes alkaline phosphatase (AP), acid phosphatase (ACP) and β‐glucuronidase (BG) in the different fractions of the ejaculate and in different stallions. All semen collections were done using a computer‐controlled phantom that collects the ejaculatory jets separately in five cups. The cups with the highest (HIGH) and the lowest (LOW) sperm concentration were analysed. In Trial I, semen was collected from three reproductively normal stallions. In Trial II, ejaculates of two reproductively normal stallions were compared to those of two subfertile stallions. In Trial III, semen was collected from seven stallions with varying reproductive history. The sperm‐rich fractions contained the highest levels of AP, ACP, BG and inorganic phosphate, and the values were positively correlated to the sperm concentration. Significant differences between the subfertile and the fertile stallions pairs in HIGH : LOW ratios were found in Pi and Cl concentrations. The highest concentrations of Ca and Mg were found in the last fractions with low sperm concentrations, with no significant differences between the fertile and the subfertile stallion pairs. The concentrations of K, Na and Cl were similar in HIGH and LOW fractions and in whole ejaculate samples. Pre‐sperm fluid contained the highest concentrations of Na and Cl. Some of the possible variation in storage tolerance between ejaculates and ejaculatory fractions could perhaps be explained by differences in the composition of SP.  相似文献   

16.
This study was conducted to investigate the effect of glutathione-supplemented INRA82 extender on miniature Caspian stallion sperm quality during storage at 5°C. A total of 12 ejaculates from three stallions (four ejaculates from each stallion) were collected and diluted with INRA82 extender that included different concentrations of glutathione (0 [INRA-G0], 5 [INRA-G5], and 10 mM [INRA-G10]) and stored for 48 hours at 5°C. Sperm motility (computer-assisted sperm analysis), plasma membrane integrity (eosin–nigrosin staining) and functionality (hypo-osmotic swelling test), and malondialdehyde (MDA) level were determined during storage at 5°C. The results showed that the sperm total and progressive motility and plasma membrane integrity and functionality in all extenders were significantly decreased with increasing storage time. However, the MDA level in all extenders was significantly increased with increasing storage time. Also, the results showed that most of the evaluated sperm quality parameters in the present study, with the exception of MDA, were significantly greater in INRA-G5 than in INRA-G0 and INRA-G10 after 24 and 48 hours of storage at 5°C. We have concluded that supplementation of INRA82 with 5 mM glutathione can improve miniature Caspian stallion sperm quality during storage at 5°C by increasing total and progressive motility, plasma membrane integrity and functionality, and decreasing the MDA level compared with INRA-G0 and INRA-G10. More advanced in vitro evaluations and artificial insemination are required to reveal the exact effects of INRA-G5 on miniature Caspian stallion sperm quality and its fertilizing ability.  相似文献   

17.
Cooling of equine semen obtained from some stallions results in lower seminal quality and viability when the seminal plasma (SP) is present. The objective of this study was to evaluate the effect of the removal of SP using a Sperm Filter on the viability of cooled stallion semen. For this purpose, 31 stallions were used. Their ejaculates were divided into three groups: CN, semen was diluted with an extender; FLT, SP was removed by filtration; and CT, SP was removed by centrifugation and cooled to 15°C for 24 hours. Sperm kinetics and plasma membrane integrity were evaluated immediately after collection (T0) and after 24 hours of refrigeration (T1). No difference (P > .05) was noted at T1 for total sperm motility (TM), progressive sperm motility, or plasma membrane integrity when semen samples from all the stallions were analyzed. However, when samples from stallions termed “bad coolers” were analyzed (TM = <30% at T1), a difference was observed in TM and progressive sperm motility for CN compared with FLT and CT at T1. Sperm recovery was greater when SP was removed using the filter (FLT) to that when the SP was removed by centrifugation (CN) (89% vs. 81%). Thus, we concluded that filtering with a Sperm Filter is an efficient and practical method for removal of SP from stallion ejaculates, with lower sperm loss than centrifugation. We also found that the presence of SP reduces the quality and viability of cooled semen from stallions whose semen is sensitive to the process of refrigeration.  相似文献   

18.
REASONS FOR PERFORMING STUDY: The success rate of artificial insemination following the freezing of stallion semen is limited; therefore, improving the stallion semen quality after the freezing and thawing process is a necessary objective. OBJECTIVES: To investigate the influence of glass bead column separation on the freezability of stallion semen. HYPOTHESIS: Glass beads in a column separator remove damaged and dead spermatozoa in the ejaculate during centrifugation. METHODS: In total, 50 ejaculates from 6 Lipizzaner stallions were studied. Each ejaculate was divided into 2 parts, one half processed following standard procedure and the second half used for the column separation procedure. After freezing, semen quality was evaluated using standard tests for motility, morphology and viability of semen. RESULTS: Motility and progressive motility of the column-separated (CS) semen were significantly higher (P < 0.001) before freezing and immediately, 24 and 48 h after thawing. A significant increase (P < 0.001) in the percentage of hypoosmotic positive spermatozoa was observed in CS samples. The percentage of total morphological changes in the separated samples before and after freezing was significantly lower (P < 0.001) compared with samples prepared using the standard procedure. A substantial decrease (P < 0.001) was found in the percentage of spermatozoa with damaged acrosomes. However, the percentage of spermatozoa with coiled tails was increased in the separated samples (P < 0.001). CONCLUSIONS: Column separation before freezing has a positive effect on the quality of thawed equine semen. POTENTIAL RELEVANCE: The quality of CS frozen/thawed samples indicates their potential use for increasing insemination success in mares.  相似文献   

19.
In this work, we studied retrospectively the influence of several factors on semen quality of the Spanish Purebred (SPB) stallion. Among these factors, we considered stallion age, season, and interval between two consecutive collections. The semen was collected from 11 SPB stallions (634 ejaculates). Semen quality was evaluated based on volume, concentration, and motility of the ejaculates. Results showed that the semen collected in autumn and winter was more concentrated in comparison with that collected in spring and summer, when the volume of ejaculate was the highest. Those ejaculates collected from younger stallions were characterized by having the smallest volume and the highest sperm concentration. When incorporating an SPB stallion into a program of artificial insemination, it is important to take into account all of these factors to achieve the maximum reproductive potential of the animal.  相似文献   

20.
In our experience, the testicular dysfunction that develops in aged stallions is typically progressive, contributing to a gradual deterioration in sperm output and quality over 2-4 years. As the ability to produce sufficient numbers of normal sperm in ejaculates declines, so do pregnancy rates until the stallion eventually becomes so subfertile that it is no longer commercially feasible to continue breeding. However, more intensive breeding management can sometimes result in pregnancy rates (per cycle and per season) that are sufficient to justify breeding of the aged stallion to a diminishing number of mares during the period of declining fertility.  相似文献   

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