首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
In this study, semen samples from 25 bulls that had passed a breeding soundness evaluation were analyzed for the presence or absence of a 31-kDa protein, known as fertility-associated antigen (FAA), on spermatozoal membranes. Eighteen bulls had FAA on sperm (FAA-positive) and seven were devoid of FAA on sperm (FAA-negative). A single ejaculate from each bull was extended and frozen with 25 to 30 x 10(6) sperm in .5-mL straws. Crossbred replacement heifers (n = 865) were estrus-synchronized and artificially inseminated either at timed AI or 12 h after they were detected in estrus. Mature cows (n = 285) were inseminated 12 h after they were detected in estrus during a 45-d AI period. Pregnancy rates (pooled) to first AI service for females (n = 764) inseminated with FAA-positive sperm were 65.6% and were 49.7% for females (n = 386) inseminated with FAA-negative sperm (P < .005). Among the estrus-synchronized replacement heifers, pregnancy rates to synchronized AI service for heifers (n = 550) inseminated with FAA-positive sperm were 62% and were 45.7% for heifers (n = 315) inseminated with FAA-negative sperm (P < .005). These data indicate that pregnancy rates to first AI service at spontaneous and synchronized estrus are higher when using semen from bulls with detectable FAA on spermatozoal membranes compared to semen from bulls devoid of FAA on membranes. Fertility-associated antigen is an important determinant for fertility potential of sperm from bulls to be used in AI breeding programs.  相似文献   

2.
Effect of narrow sperm head shape on fertility in cattle   总被引:1,自引:1,他引:0       下载免费PDF全文
Seven experiments were done in feedlot heifers to determine the importance of various degrees of narrowness of the sperm head on fertility in feedlot heifers. Frozen semen used in these experiments was selected to be normal in all respects except for very high numbers of a single specific type of sperm head aberration. Semen with the sperm aberration in question and control semen were selected to be as similar as possible in dose and postthaw viability so that differences in fertility would be attributable to the morphological variant under study. Fertilization rates were determined by collecting embryos from the reproductive tracts of superovulated heifers which had been slaughtered seven days after insemination. Pregnancy rates and rates of embryonic loss were studied in estrus-synchronized heifers by repeated transrectal ultrasound examinations from day 22 to day 55 after insemination. Reproductive tracts were collected and examined after slaughter at 60 days postinsemination.

The combined results of these experiments show that a moderate degree of sperm head narrowness, in the absence of other seminal signs of a disturbance of spermatogenesis, is not detrimental to fertility. However, extreme narrowness of the postacrosomal region of the sperm head of most spermatozoa, as was found in two bulls without other seminal signs of a disturbance of spermatogenesis, resulted in significantly reduced fertility. The data suggest that, although a decision between normal and abnormal sperm morphology may contain a degree of subjectivity, of the defects studied only sperm with extreme narrowness of the post-acrosomal region are likely to reduce fertility.

  相似文献   

3.
The morphology of sperm in raw semen was compared with that of the live sperm in semen which had been frozen and thawed. The thawed semen was stained with 6-carboxyfluorescein diacetate and propidium iodide and examined by fluorescence microscopy; smears of the raw semen were stained with eosin and nigrosin. Thirty-four ejaculates from 24 bulls of various breeds were examined. There were fewer abnormal heads, detached heads, coiled tails and proximal cytoplasmic droplets/pseudodroplets in the thawed semen than in the raw semen, there was no change in the number of bent tails, but the number of distal cytoplasmic droplets/pseudodroplets increased. There were no significant differences in morphology between ejaculates which passed or failed the osmotic resistance test after thawing, but failed batches tended to have more distal cytoplasmic droplets/pseudodroplets.  相似文献   

4.
A crossbred bull heterozygous for a double centric fusion was produced. At 14 months of age, semen volume and sperm characteristics were normal. Cytologic and ultrastructural evidence of spermatid degeneration was found coincident with abundant, apparently normal, sperm formation. Implications for the early detection of centric fusion in young bulls are discussed.  相似文献   

5.
As electroejaculation (EEJ) is prohibited for use on unanaesthetized animals in Sweden, there is a need for an alternative method of semen collection from bulls in the field. The aim of the present study was to evaluate the use of transrectal massage (TM) of the ampullae to collect semen from yearling beef bulls under field conditions in Sweden. Transrectal massage was performed on 52 yearling beef bulls. Volume of semen collected, duration of procedure, percentage progressively motile sperm, and sperm concentration were measured. Smears were prepared for sperm morphology examination. Semen samples were obtained from 47 of 52 bulls. Mean volume was 3.2 ml (SD +/- 3.7), mean duration of collection was 7.4 min (SD +/- 2.8), mean percentage progressively motile sperm was 43.5% (SD +/- 29.2) and mean concentration was 201.9 x 10(6) spermatozoa/ml (SD +/- 278 x 10(6)). Twenty-three of the 52 bulls were slaughtered 3-4 days after semen collection and aliquots of the cauda epididymal contents were collected for sperm morphology examination. The percentages of proximal droplets, abnormal tails and abnormal midpieces were significantly higher (p < 0.05) and the percentage of detached heads was significantly lower (p < 0.05) in the post-mortem samples compared with those in the TM samples. However, importantly there was no significant difference between the two sample types in the percentages of abnormal heads. This study demonstrates that semen can be collected from yearling beef bulls by TM. We think that TM constitutes a useful tool, when semen collection with EEJ or artificial vagina (AV) is not possible under field conditions, when included in the bull breeding soundness evaluation (BBSE) protocol. However, further studies are needed, and presently being carried out, to evaluate if semen samples collected by TM are comparable with semen samples collected by AV.  相似文献   

6.
7.
Frozen-thawed sexed semen from six bulls (Holstein) was used for studying their efficiency in an in vitro fertilization (IVF)-programme and to compare their ultrastructure with in vitro produced bovine blastocysts produced with non-sorted sperm. Progressive motility of sorted spermatozoa, their IVF rate, development of produced blastocysts and the ultrastructure of the blastocysts were analysed. The cleavage rates of sexed sperm of bulls (groups S1, S2 and S4) were significantly lower than that of unsorted control sperm (P < 0.01). Blastocyst development at day 7 of the sexed semen groups varied between 3.5% and 28.8% versus 33.6% for non-sexed semen. The individual blastocyst yield with sexed semen of group S5 (28.8%) was similar to the mean blastocyst production of the non-sexed control spermatozoa (C, 33.6%; P > 0.05). The remaining five sexed sperm groups resulted in significantly lower developmental rates of blastocysts on day 7 (S1, 4.9%; S2, 0%; S3, 0%, S4, 3.5%; S6, 25.8%, P < 0.01). Group S2 showed microbiological contamination in 50% (four of eight) and S3 in 100% of the experiments (eight of eight). Progressive motility of sexed sperm was significantly lower than that of unsorted sperm (S1, 48 +/- 12.0%; S2, 41 +/- 11.9%; S3, 39.0 +/- 9.9%; S4, 42 +/- 4.6%; P < 0.01; S5, 72 +/- 7.1% and S6, 64 +/- 9.3; P < 0.05 versus C 82 +/- 4.6%). The percentage of progressive motile spermatozoa showed a good correlation with the developmental capacity of blastocysts (r(2): >0.70), the regression parameter was significant (P < 0.01). Furthermore, with a straw containing 10 x 10(6) sexed spermatozoa significantly lower number oocytes was fertilized than with the same concentration of non-sexed sperm (P < 0.01). Our results demonstrate that the suitability of sperm sorting for in vitro fertilization (IVF) is lower than no sexed sperm. Our ultrastructural studies showed that blastocysts produced with flow-cytometrically sex-sorted spermatozoa possessed deviations in the number and structure of organelles like mitochondria, rough endoplasmic reticulum (ER) and nuclear envelope. These morphological alterations may be responsible for compromised development that observed in embryos produced with sex-sorted spermatozoa. Thus, we conclude that sperm sex sorting can markedly affect the efficiency of an IVF-programme.  相似文献   

8.
The effect of trypsin on the fertilizing capacity of bull semen was investigated as part of the evaluation of the addition of trypsin to semen as a method for destroying or inactivating infectious agents. Parts of the ejaculates from four bulls were treated with 0.3% trypsin solution. Both the treated and untreated aliquots of semen were frozen, thawed and used for the artificial insemination of superovulated heifers. Two hundred and thirty ova and embryos were collected from 22 heifers on day 7 after oestrus (insemination). One hundred and ten out of 164 (67%) embryos and ova from 15 heifers inseminated with trypsin-treated semen were classified as of transferable quality compared to 46 out of 66 (70%) in the control group of 7 heifers (p>0.05). There was no difference in the proportion of fertilized ova or degenerated embryos resulting from the control or trypsin-treated samples of frozen-thawed semen, which is consistent with results obtained previously using fresh semen.  相似文献   

9.
本试验选择亚热带气候条件下广州地区的娟姗公牛和荷斯坦公牛各5头,比较两个品种公牛的精液品质(采精量、原精密度、原精活力、细管精液产量、冻后活力、低渗膨胀率及穿透率)。研究表明,荷斯坦公牛每次采精的采精量(16.14±0.06 mL)和细管精液产量(189.17±3.11支)都极显著地高于娟姗公牛(4.74±0.05 mL,158.46±2.64支)(P<0.01);娟姗公牛的原精密度(8.95±0.08亿/mL)极显著地高于荷斯坦公牛(8.32±0.07亿/mL;P<0.01);娟姗公牛原精活力(0.731±0.004)高于荷斯坦公牛(0.729±0.003),但两者差异不显著(P<0.05);娟姗公牛精液的冻后活力(0.355±0.003)极显著高于荷斯坦公牛(0.339±0.003;P<0.01);娟姗公牛冷冻精液的低渗膨胀率(34.50%±0.49%)显著高于荷斯坦公牛(31.21%±0.59%;P<0.01);娟姗公牛冷冻精液对去透明带仓鼠卵的穿透率(84.51%±13.83%)显著高于荷斯坦公牛(81.52%±6.13%;P<0.05)。  相似文献   

10.
The appearance and incidence of sperm abnormalities was studied in 115 ejaculates, collected periodically over 1 year covering all seasons from five mature, healthy swamp buffalo (Bubalus bubalis) bulls reared under tropical conditions and serving as the current source of semen for artificial insemination (AI) in Thailand. Light microscopy of stained smears was used to investigate sperm head shape morphology, while unstained wet smears were used to examine other sperm abnormalities. The most commonly found morphological aberrations were pear-shaped spermatozoa, knobbed acrosomes, proximal cytoplasmic droplets, simple bent tails and coiled tails under the head, whose ultrastructure (scanning electron microscopy) corresponded to what has been found in other species of bovidae, including varieties of buffalo. The mean prevalence (as least squares mean +/- SEM) of sperm abnormalities was low (below 15%), corresponding to healthy spermiograms. The younger bulls (<10 years old, n = 3) had less abnormalities than the older ones (10.1 +/- 0.6% versus 14.1 +/- 0.8%, P < 0.001, n = 2), including abnormalities of sperm head shape (1.1 +/- 0.3% versus 3.6 +/- 0.3, P < 0.001), acrosome defects with knobbed acrosomes (1.1 +/- 0.2% versus 1.2 +/- 0.3%, P < 0.001), spermatozoa with proximal cytoplasmic droplets (2.7 +/- 0.1% versus 1.4 +/- 0.2%, P < 0.001), defective mid-pieces (0.2 +/- 0.1% versus 0.3 +/- 0.1%) and abnormal sperm tails (3.1 +/- 0.3% versus 5.7 +/- 0.4%, P < 0.001). The within-bull effect of the year solely affected the incidence of pear-shaped spermatozoa while the incidences of abnormal contour, variable size of sperm head shapes, abnormal mid-piece and simple bent tail among bulls were affected by ejaculate (week of collection). Interaction between age and ejaculate affected only the prevalence of spermatozoa with proximal cytoplasmic droplets. In conclusion, the types of defects encountered were similar to those found in other bovidae, with a very low prevalence over the year the AI sires were followed through.  相似文献   

11.
Diagnostic ultrasonography has been widely used for examination of the reproductive tract of female cattle, but more sparingly in bulls. Typical clinical ultrasonographic examinations of bull testes are unlikely to affect semen quality or sperm production. The ultrasonographic anatomy of bull testes and accessory sex glands has been reported. Although testicular echogenicity increased (i.e. the parenchyma appeared more white) as a bull approached puberty, echogenicity was not superior to scrotal circumference as a predictor of puberty. Ultrasonography can be used to detect and characterize testicular pathology. It is noteworthy that areas of increased echogenicity (testicular fibrosis) are common, especially in young bulls, but are not associated with decreased semen quality (e.g. percentage of morphologically abnormal sperm). Neither visual evaluation nor computerized pixel analysis of testicular ultrasonic echotexture was consistently predictive of semen quality in bulls. Therefore, we concluded that the primary clinical use of ultrasonography in assessment of reproductive function in the bull is characterization of grossly detectable lesions in the testes and scrotum.  相似文献   

12.
Using stochastic simulation, the effect of using sexed semen to cow dams (CD) in a dairy cattle breeding scheme, with or without use of multiple ovulation and embryo transfer (MOET) to bull dams (BD), on annual genetic gain at the population level was examined. Three levels of sexed semen were combined with three levels of MOET: no sexed semen, sexed semen to the best CD and sexed semen to all heifers, combined with no MOET, MOET on all BD and MOET randomly on 20% of the BD. In total, nine scenarios were compared. The simulated population was monitored for 30 years and included 450 herds with 100 cows each. Each year 50 young bulls (YB), 10 active sires and 215 BD were selected on best linear unbiased prediction estimated breeding values by truncation selection across the simulated population, and the YB were tested within the population. Use of sexed semen alone gave a positive increase in the annual genetic gain of 2.1% when used on the best CD and 2.7% when used on all heifers, but only the latter was statistically significant. The increased annual genetic gain was caused by a larger contribution from the CD to the BD. Use of sexed semen together with MOET on BD increased the annual genetic gain by 1.8-2.5% compared with schemes without sexed semen and MOET on all BD. Performing MOET on all BD enables selection of offspring with high Mendelian deviations, which increase the annual genetic gain. Use of sexed semen decreased the genetic lag between the sires and the CD by 12-14% when used on the best CD and by 6% when used to all heifers. The decrease in the genetic lag is caused by the increased selection intensity of the cow dams.  相似文献   

13.
Mondal  Santu  Bhakat  M.  Singh  A.  Mohanty  T. K.  Abdullah  M.  Yadav  S. K.  Kumar  R. 《Tropical animal health and production》2019,51(7):1823-1827

Zebu bulls are a shy breeder and they exhibit optimum libido in the presence of females with estrus phase. Continuous semen collection with the use of male dummy leads to lack of adequate sexual stimulation. Therefore, the present study was designed to test the effect of estrus-specific molecule(s) for effective sexual preparation of donor bulls. The bulls were divided into normal and poor libido group, five bulls in each group by taking 1-month control study data after collecting the information of individual bull’s sexual behaviour during semen collection by regular semen collector. The bulls were never being exposed to female animals and semen was collected by an artificial vagina. The ten animals were exposed to a glycerol-water solution (50/50 v:v) as control and then exposed to estrus-specific molecules one by one. The estrus-specific molecules like squalene, 1-iodoundecane, acetic acid, coumarin, propionic acid, oleic acid, and 2-butanone were purchased from Sigma-Aldrich Company, USA, and the molecules were solubilised individually in a non-pressurised aerosol dispenser as 1.0% concentration in glycerol-water solution (50/50, v:v). Identical bulls were used as the control and exposed to each molecule one by one by giving a refractory period of 14 days. A nasal spray of acetic acid or 2-butanone significantly (p < 0.05) reduced reaction time (RT) and total time taken to ejaculate (TTTE) in normal libido bull group. Semen volume, sperm concentration, and the total number of sperm per ejaculation obtained did not show significant improvement in the normal libido group of bulls after the application of estrus-specific molecules as compared to the control. In poor libido group, acetic acid, oleic acid, and 2-butanone application showed significant (p < 0.01) improvement in RT and TTTE as compared to the control group, whereas semen production variables like sperm concentration and total sperm output per ejaculation increased significantly (p < 0.05) except semen volume. There was significant (p < 0.01) reduction in RT (%) and TTTE (%) after the application of acetic acid followed by 2-butanone and oleic acid. The sperm concentration and total sperm output per ejaculation were more after the application of each molecule but significant increase (p < 0.05) in sperm concentration was observed with 2-butanone (11.42%), acetic acid (11.42%), and oleic acid (10.13%), whereas total sperm output per ejaculation increased significantly (p < 0.05) only after the application of acetic acid and 2-butanone (24.75% and 26.84%). Hence, it can be concluded that acetic acid, 2-butanone, and oleic acid are effective for better sexual preparation of Sahiwal bulls and total sperm output per ejaculation.

  相似文献   

14.
Bulls shedding bovine viral diarrhoea virus (BVDV) in semen and simultaneously having a high concentration of circulating antibodies may cause reproductive problems and spread the viral infection within cattle populations. To investigate this in detail, three heifers were inseminated with BVDV‐infected semen from a non‐viraemic, seropositive Holstein–Friesian bull, named `Cumulus'. One control heifer was inseminated with semen from a healthy bull that was free of BVDV. All four heifers remained clinically healthy throughout the experiment. The conception succeeded in the control animal and in two of the three heifers inseminated with semen containing BVDV. The heifer with the failed conception was the only one that became systemically infected with BVDV. This animal was deemed non‐pregnant by ultrasonic examination on day 34 after insemination and showed no signs of subsequent oestrus during the entire experimental period. At slaughter, 42 days after insemination, there were no histopathological changes in the ovaries and virus was not detected in ovarian tissue. The fact that seronegative dams served with semen from persistently infected bulls have occasionally produced persistently infected calves together with the present findings and the fact that non‐viraemic, seropositive bulls can constantly shed BVDV, suggest that the use of semen from such bulls in BVDV‐free herds could have far‐reaching consequences, especially if it led to the birth of persistently infected (P1) calves.  相似文献   

15.
不同季节和气候条件对种公牛精液品质的影响的研究   总被引:1,自引:0,他引:1  
[目的]研究不同季节气候条件对种公牛精液品质的影响。[方法]从采精种公牛中随机抽出5头,选取气温最高(7月份)最低(1月份)和适中温度(4,9月份)进行试验,分别对不同时期所采得的精液进行检测。[结果]在最高温度月份7月份(25℃)时5头种公牛的平均精液量为5.88mL,原精活率67.2%,精液密度16.64亿/mL,冻后活率33.8%,生产冻精数143.4剂,精子畸形率23%。1月份环境温度平均在-11.2℃时,5头种公牛的精液量平均为5.7mL,原精活率66.8%,精液密度13.3亿/mL,冻后活率37.4%,生产冻精数为275.8剂,精子畸形率17.8%。在4,9月份环境温度12℃时精液量为6.6mL,原精活率73.2%,精液密度16.92亿/mL,冻后活率41.8%,生产冻精数404.4剂,精子畸形率12.6%。精液量之间差异显著(P〈0.05),原精活率之间差异显著(P〈0.05),精子畸形率之间差异显著(P〈0.05)。冻后活率和冻精生产数差异不显著。[结论]环境温度过高或者过低都会影响精液品质,种公牛在适宜的温度下生产的精液品质也会更加优良,种公牛在温度较高的条件下生产精液品质比在低温条件下还要差,种公牛最适宜的生产温度为12℃~16℃。  相似文献   

16.
This study was conducted to evaluate the response of Bali bulls (Bos javanicus) to different semen collection methods and their effects on fresh and post‐thawed semen quality. The collection methods employed were electro‐ejaculation (EE), transrectal massage (RM) and RM followed by EE (RM + EE). A total of 25 untrained Bali bulls (age between 2 and 4 years old) were subjected to the different semen collection methods. Fresh semen samples from all the 25 bulls were evaluated for volume, pH, general motility, live/dead ratio and abnormality using the conventional method. For fresh and frozen samples collected by EE and RM from 10 bulls, computer‐assisted semen analysis system was used for precise quantitative measurement of motility, velocity and forward progression. Accucell photometer was used to measure sperm concentration in all samples, regardless fresh and frozen. Semen samples were obtained 100% of the attempts using EE, 84% using RM and 96% using RM + EE. There were no differences among the collection methods for fresh semen quality characteristics, including motility, morphology and viability, but pH and volume were higher for EE than RM and RM + EE. Higher sperm concentration was observed in semen collected by RM than the other two methods. Different age groups (2–3 and >3–4 years old) of the bulls did not show significant differences in volume, pH, sperm concentration, percentages in motility, live/dead ratio and normal sperm morphology. The quality of semen for general and progressive motility, VAP, VSL and VCL and acrosomal integrity after thawing was higher for RM than EE. In conclusion, Bali bulls appeared to respond best to EE and the combination of RM + EE than RM, as a method of semen collection, with a shorter time of stimulation required. Differences in age of the Bali bulls did not affect the semen quality.  相似文献   

17.
[目的]通过比较夏南牛和法系夏洛来的精液品质,探索中原地区肉牛改良的适合品种。[方法]选择中原地区的夏南牛和法系夏洛来种公牛各5头,比较两个品种种公牛的精液品质(采精量、原精密度、原精活力、细管产量、冻后活力、精子畸形率)。[结果]表明:夏南牛公牛精液品质极显著的高于夏洛来牛。[结论]夏南牛公牛更适应中原地区的气候条件...  相似文献   

18.
奶牛性控冻精人工授精影响因素研究   总被引:2,自引:0,他引:2  
用分离X和Y精子的性控精液进行人工授精是控制家畜性别之最简单可行的方法.然而,低密度性控精液输精效果还不如常规人工授精,许多技术环节都有待改进.以常规冻精和稀释常规冻精为对照,研究解冻方法、输精时间和部位、不同精液来源和输精员以及育成和经产牛等因素对性控冻精人工授精妊娠率的影响.结果显示,精液解冻水浴温度和持续时间对人工授精效果有显著影响,性控精液对解冻水浴温度更敏感;性控冻精和稀释常规冻精比常规冻精对输精时间要求更严格;3种精液输精到排卵卵泡同侧子宫角基部受胎率都显著高于输精于子宫体和同侧子宫角前端;3种精液育成牛受胎率(80%)都显著高于经产牛(50%);于输精同时注射促排卵素3号明显提高性控冻精受胎率;经严格挑选、能够从事胚胎移植操作的技术熟练输精员之间性控冻精受胎率差异不显著;在所设计的不同条件下,性控冻精与稀释同样倍数的常规冻精行为相似,说明精子分离过程没有对精子造成特殊损伤.研究结果说明,精确控制人工授精各个技术环节可以实现消除性控与非性控、低密度与高密度精演之间的差别,获得高妊娠率.  相似文献   

19.
选用83头14~15月龄的育成母牛分成两组,试验1组选小以牛冷冻精液配种,试验2组对公牛不进行筛选,即用大、小型公牛的冷冻精液本性中。另选46头18月龄的母牛作为对照组,称其为晚配件,也行人工授精,所用公牛与试验2组相同。试验结果表明,早配的试验1组与晚配件相比投产月龄提前4.1个月/头,可提高乳牛终身产奶量,创造出显著的经济效益,每头可增收节支2373元,胎衣不下率减少2.3%,产活犊率提高3%  相似文献   

20.
选择在广州地区亚热带气候条件下2岁~6岁的娟姗公牛5头,观察其精液品质(采精量、原精密度、原精活力以及细管精液产量)在全年不同月份的变化情况.结果表明:娟姗公牛的每次采精量和细管精液产量在气温较高的7~9月份会因为采精频率的减少而增加,10月份会因为周采精频率增加而使每次采精量和细管精液产量有明显减少;娟姗公牛的原精密度在气温适宜的2月份和采精频率较低的8月份会出现两个高峰值;娟姗公牛的原精活力在气温较高的月份会出现明显的下降趋势,2月份气温适宜时原精活力最好.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号