牛冷冻精液不同有效精子数输精效果的研究

[目的] 肉牛种业为肉牛生产发展的基础和前提,种公牛是肉牛业发展的“芯片”,直接关系到生产的质量和效率。为提高优秀种公牛的利用率和区域覆盖率,适当降低每剂量冷冻精液的有效精子数量,同时能够确保其输精受胎率不受影响而进行该研究。[方法]制作含有效精子数分别为8ｘ10₆^、4ｘ10₆^、2ｘ10₆^,三组牛冷冻精液,用上述冷冻精液进行输精试验,比较输精效果。[结果] 有效精子数为8ｘ10₆^、有效精子数为4ｘ10₆^、有效精子数为2ｘ10₆^,三个试验组间其人工输精后受胎率进行了比较。研究结果表明,输精总受胎率差异不显著,降低有效精子数,其输精受胎率未受影响。[结论]降低每剂冷冻精液的有效精子数量(2~8ｘ10₆⁾在适当范围内,其输精受胎率差异不显著。     

确保种公牛冷冻精液有效精子数方法的研究

确保种公牛冷冻精液有效精子数方法的研究吴企胜（辽宁省畜牧技术推广站沈阳１１００１５）刘作伟（辽宁省农业开发世行贷款项目办）郭世权（辽宁省冷冻精液站）前言有效精子数是牛冷冻精液８项重要质量指标之一。《牛冷冻精液国家标准》（ＧＢ４１４３－８４）中明确规定...     

降低牛细管冷冻精液前进运动精子数对受胎率影响的初步研究

降低单剂冷冻精液中的精子数量,并保证理想的配种受胎率,是有效提高优秀种公牛利用效率的重要手段之一。本研究通过降低牛冷冻精液每剂量中的前进运动精子数,对其人工输精后的情期受胎率进行了比较,并对气候因素、不同种公牛以及不同的输精人员对受胎率的影响进行了比较,研究结果表明,当每剂量中前进运动精子数分别为200万、400万时,冷冻精液人工输精后,第一情期受胎率分别为57．36％、56．45％,三次总情期受胎率分别为61．15％、61．83％,与每剂量中前进运动精子数800万时均差异不显著（60．2（1％、64．32％）;当牛冷冻精液每剂量直线运动精子数分别为200万、400万时,输精季节为第二季度,第一情期受胎率与三次总情期受胎率均高于其他三个季度。因此,当每剂量中前进运动精子数降低到200万时,不影响其人工输精后的情期受胎率。     

牛冷冻精液有效精子数检测

牛冷冻精液中,呈直线前进运动的精子数(在输的时间视为有效精子数),直接影响受胎效果。因此《牛冷冻精液》国家标准(简称“国际”)作了明确规定。细管:每支(下限)1000万个,颗粒:每粒(下限)1200万个,安瓿:每支(下限)1500万个,并作为精液品质评定指标,要求定期捡查。经长期定期检查,可为生产单位提供了科学     

提高牛冷冻精液人工授精受胎率的体会

牛冷冻精液人工授精技术具备较高的科技含量,它属于综合性实用技术,要想提高受胎率,必须选取合格的精液,并且正确保存和解冻,做好发情鉴定工作,选择合适的时间输精。只有将各个环节的工作做好,才能够确保受胎率的提升。本文主要分析牛冷冻精液人工授精受胎率的方法。     

降低牛冷冻精液单剂量直线运动精子数对情期受胎率影响的研究

降低单剂冷冻精液中的精子数量,并保证理想的配种受胎率,是有效提高优秀种公牛利用效率的重要手段之一：本研究通过降低牛冷冻精液每剂量中的前进运动精子数,对青年牛及成母牛进行人工输精后的情期受胎率进行了比较。研究结果表明,每剂量前进精子数由800万降低到200万,体外培养4h,不会影响其在体外的活率。当每剂量中前进运动精子数降低到200万时,不影响青年牛及成母牛人工输精后的第一情期受胎率。     

降低牛细管冷冻精液有效精子数对受胎率影响的试验报告

利用冷冻精液改良本地黄牛的推广工作,从20世纪70年代末、80年代初在我国各地普遍开始。经过近30多年的黄牛改良工作的进展,使全国各地黄牛的初生重、生长发育、产肉、产奶等生产性能都有了较大幅度的提高,为广大农牧民增收奔小康起到了重大作用。考虑到家畜育种工作的长期性、复杂性和改良品种的发展方向,充分利用和发挥优良品种个体的遗传基因,     

母猪倒骑式按摩输精法的应用效果研究

研究的目的是验证猪常规人工授精中倒骑式按摩法输精方法的效果,分析配种后受胎率与产仔数.在断奶发情的实验母猪发情鉴定表现定立表现时,采用倒骑式按摩法输精技术,实施子宫颈人工授精.按摩母猪乳房时间为30～60 s.输精完成后继续倒骑60 s.试验组与对照组相比,母猪发情表现主要集中在72 h到96 h之间,母猪断奶处理12...     

In vitro evaluation of cryopreserved bovine sperm and its relation to field fertility in fixed‐time artificial insemination

This study aimed to assess characteristics of bovine cryopreserved sperm and evaluate its relation to field fertility in fixed‐time artificial insemination (FTAI). Semen samples of 16 bulls were used to inseminate 811 Nellore cows, and four of these bulls were also used to inseminate 101 Nellore heifers. Samples of the same ejaculate used for FTAI from each bull were analysed in the laboratory after thawing. Sperm motility and vigour were subjectively assessed by light microscope, and integrity of the plasma and acrosome membranes, and H₂O₂ production were evaluated by flow cytometer. Relation among sperm characteristics and pregnancy rate of cows and heifers were evaluated by univariate and multivariate logistic regression. Subjective sperm motility and vigour did not affect the probability of pregnancy in cows or heifers. In univariate analysis for pregnancy in cows, sperm traits related to acrosome injury positively affected probability of pregnancy mainly when associated with plasma membrane integrity; H₂O₂ production seems to be less important than plasma membrane integrity in affecting probability of pregnancy. In multivariate analysis, sperm traits related to injured acrosome positively affected probability of cow and heifer pregnancies while intact acrosome was negatively related to cow pregnancy. Intact plasma membrane and high H₂O₂ production were positively related to cow pregnancy but negatively related to heifer pregnancy. Results suggest that a capacitation‐like status of the acrosome may benefit probability of pregnancy in cows.     

Investigation of in vitro measurable sperm attributes and their influence on electroejaculated bull semen with a fixed‐time artificial insemination protocol in Australian Bos indicus cattle

Increasing use of fixed‐time artificial insemination (FTAI) in beef cattle production has presented an opportunity for the use of fresh or chilled semen as an alternative to standard cryopreserved semen. The objective of this study was to examine in vitro sperm function and pregnancy rate of electroejaculated semen, chilled and stored for 48 hr, compared to conventionally cryopreserved semen with an optimized FTAI protocol in Brahman cattle. Semen from three Brahman bulls was collected, and aliquots were extended in either chilled (at 5°C) or frozen (LN₂) in a Tris‐egg yolk extender base with 2.4% or 7.0% glycerol, respectively. Semen samples were assessed 48 hr after collection or post‐thaw and warming, for sperm motility, in vitro sperm function and fertilizing ability, and used in a FTAI programme. The overall pregnancy rates was significantly different (p < .01) after FTAI with frozen (n = 173; 53.2%) and chilled semen (n = 174; 31.6%). In contrast, the in vitro sperm assessment showed that the chilled semen had significantly faster motility (p < .05), a higher proportion of progressively motile spermatozoa (p < .05), with significantly higher proportions of acrosome intact, viable spermatozoa (p < .01). This study showed that reasonable pregnancy rates in Brahman cattle can be achieved using FTAI with chilled semen collected using electroejaculation and stored for up to 48 hr. However, improvements in semen extenders are required in consideration of semen collection method to improve the longevity of sperm fertilizing ability to significantly increase FTAI output using chilled storage of bull semen.     

Quantifying sperm egg interaction to assess the breeding efficiency through artificial insemination in guinea fowls

• 1. Guinea fowl hens were inseminated weekly once with two doses of spermatozoa (75 million and 100 million) in two different diluents, Beltsville poultry semen extender (BPSE), and Instruments for Veterinary Medicine (IMV), each with and without pre-insemination vaginal douching. Per cent fertility, hatchability, dead germ, dead in shells along with data on sperm egg interaction and vaginal microbial counts were recorded.

• 2. Artificial insemination had significantly improved the per cent fertility and hatchability compared to natural mating. Dose dependent improvement in fertility was noticed with both diluents.

• 3. There was a beneficial effect of vaginal douching, which was more pronounced at lower insemination doses.

• 4. For optimum fertility and hatchability in guinea fowl, insemination of 75 million spermatozoa diluted in BPSE once in 4 d and 100 million spermatozoa diluted in BPSE or IMV once in 5 d coupled with vaginal douching is recommended.

     

提高奶牛细管冻精精子活力的试验研究

为了提高奶牛细管冻精精子的活力,试验探索了稀释液种类、最佳熏蒸距离、最佳冷冻温度、最佳熏蒸时间、不同解冻温度及时间对精子活力的影响。结果表明:精子在由柠檬酸钠和果糖组成的稀释液中存活时间长,在三羟甲基氨基甲烷稀释液中冷冻后精子活力高于其他稀释液;牛细管冻精最佳熏蒸距离为2.5 cm,时间影响不显著(5～10 min均可);用50℃温水解冻15 s的精子活力比其他解冻温度和时间时的精子活力要好。     

猪0.5 mL细管冻精不同解冻方法精子质量的研究

利用计算机辅助精子分析系统(CASA)结合顶体完整率(NAR)的检查,研究了长白猪0.5 m L细管冻精4种解冻程序后精液的质量,综合评价不同解冻方法。结果表明:1)精子冷冻-解冻后在曲线速度(VCL)、直线速度(VSL)、平均路径速度(VAP)、直线性(LIN)、前向性(STR)、鞭打频率(BCF)以及A+B类精子比例的检测性状上降低,差异极显著(P0.01);精子头侧摆幅度(ALH)也显著减小(P0.05),活率(Motile rate)变化差异不显著(P0.05);2)四组解冻程序中,38℃20 s解冻组的活率(Motile rate,MR)、VSL、VCL、STR、A+B精子比例指标均极显著(P0.01)优于42℃20 s、50℃15 s、62℃5 s解冻组,VAP、LIN与NAR差异不显著(P0.05);3)Topsis综合评价的结果表明38℃20 s组在孵育2 h、4 h、6 h之后检测性状优于其他解冻组。由此推论,虽然解冻后精子在运动参数发生较大变化,但是38℃20 s的解冻效果优于其他解冻条件。     

Combined cryopreservation of canine ejaculates collected at a one-hour interval increases semen doses for artificial insemination without negative effects on post-thaw sperm characteristics

A limiting factor in canine artificial insemination (AI) is the low number of insemination doses obtained per ejaculate. In this study, semen was collected from dogs (n = 28) either once and frozen directly after collection or the same dogs were submitted to a dual semen collection with a 1-hr interval and the two ejaculates were combined for cryopreservation. We hypothesized that combining two ejaculates increases semen doses per cryopreservation process without negative effects on semen characteristics. Total sperm count was lower in semen from a single semen collection in comparison with the combination of the first and second ejaculate of a dual semen collection (p < .001). The percentage of motile and membrane-intact spermatozoa determined by computer-assisted sperm analysis (CASA) in raw semen did not differ between single and combined dual ejaculates and was reduced (p < .001) by cryopreservation to the same extent in single (motility 73.7 ± 1.8%, membrane integrity 65.6 ± 2.2%) and combined dual ejaculates (motility 72.7 ± 2.3%, membrane integrity 64.6 ± 2.5%). The percentage of spermatozoa with morphological defects increased after cryopreservation (p < .001) but was similar in single and combined dual ejaculates. The CASA sperm velocity parameters decreased with cryopreservation (p < .001) but did not differ between single and combined dual ejaculates. The number of insemination doses increased from 2.7 ± 0.4 for single to 4.7 ± 0.8 for combined dual ejaculates (p < .01), based on 100 million motile spermatozoa per frozen-thawed semen dose. In conclusion, combining two ejaculates collected at short interval for one cryopreservation process increases the number of AI doses without compromising semen quality.     

提高牛人工授精受胎率技术

文章从母牛繁殖机能、冻精质量、冻精解冻的温度、时间及方法、母牛发情鉴定、黄牛和水牛繁殖的差异、输精方法、输精时间、榆精部位、技术培训和养牛综合配套技术等方面阐述了提高黄牛、水牛冻精配种受胎率的技术措施。