Sperm Quality in Holstein Bulls Friesian and Brahmans of Frozen Semen Commercially

The aim of this study was to assess sperm quality (motility, viability and acrosomal integrity) sperm from commercially frozen semen straws two breeds of bulls Bos taurus (holstein Frisian) and Bos indicus (Brahman). 9 commercial straws 0.5 ml of Holstein bull semen and 9 Brahman bull were thawed, they were kept for two hours at room temperature and motility, viability and acrosomal integrity (NAR) was assessed. The results were 30% motility, viability 40% and 30% of NAR in the Holstein breed. Brahma race for motility 40%, 50% and 40% viability was obtained NAR. In conclusion, according to the results of the variables analyzed, the Brahman breed in sperm quality was better than the Holstein breed;however, the results of both races meet minimum standards of quality sperm for use in artificial insemination (AI) field level.

Effects of Storage Temperature on the Effective Activity of Straw Frozen Semen after Thawing

The aim was to discuss the optimal storage environment and proper insemination time after thawing of 0.25 mL straw frozen semen. Straw frozen semen was thawed at 40 ℃ for 20 s, and then stored at 0 -4 ℃, 14 - 16 ℃, 25 -27 ℃ for 2, 4, 6, 8 and 10 h, respectively. The sperm motility was detected. After thawing, semen was stored at 0 - 4 ℃ and 14 - 16 ℃ for 10 h. Their sperm motilities （0.434 ±0. 016 7 and 0.423 ±0.019 6） had no significant differences （P 〉 0.05） with initial thawing motility （0.441 ± 0.030）. Sperm motility reduced as the storage time prolonged at 25 -27 ℃. Sperm motility after 6 h had signifi- cant differences with that of initial thawing motility （P 〈 O. 05 ）, and sperm motilities after 8 and 10 h showed extremely significant differences （P 〈 0.01 ）. Thus, sperm motility after thawing was still very high after stored at 0 -4 ℃ and 14 - 16 ℃ within 10 h, which met the requirements for insemination. Under this temperature and time ranges, sperm could be carried over long distances, which had small effects on sperm quality and reached the expected insemination effects. However, under the temperature of 25 - 27 ℃, semen should be used for insemination within 6 h after thawing.

Development of Annexin V Technology for Removal of Dead Spermatozoa from Bovine Spermatozoa and Its Application in Frozen Sexed Semen Production

[Objectives]This study was conducted to develop a molecular marker immunomagnetic bead sorting technology method that can specifically identify dead spermatozoa.[Methods]This study first confirmed the specific binding of Annexin V to dead bovine spermatozoa,and tried to remove dead spermatozoa in semen combining with the immunomagnetic bead technology,so as to improve the separation efficiency of target spermatozoa in the process of sex-controlled semen preparation on a flow cytometer.[Results]The spermatozoon motility,membrane integrity and mitochondrial activity after sorting and the rate of dead spermatozoa during the on-machine X/Y separation were all improved to different degrees(P<0.05),indicating that the technical process design could effectively remove some dead spermatozoa,and there was no significant effect on frozen sexed semen prepared from the separated X or Y spermatozoa(P>0.05),indicating that the technical process did not cause additional damage to the spermatozoa.[Conclusions]Combining the specificity of Annexin V with the immunomagnetic bead method could effectively remove dead spermatozoa from bovine spermatozoa,and significantly reduce the rate of dead spermatozoa in bovine permatozoa during sex-controlled separation(P<0.05).The method developed can effectively improve the production efficiency of frozen sexed semen of dairy cows,reduce the production cost,and promote the industrial application of the product.

Effects of DHA-enriched hen egg yolk and L-cysteine supplementation on quality of cryopreserved boar semen

The objective of the present study was to determine the effects of docosahexaenoic acid （DHA）-enriched hen egg yolks and L-cysteine supplementation on the qualities of the cryopreserved boar semen. A total of 15 ejaculates from 5 Pietrain boars were divided into 4 groups according to the compositions of the freezing extenders used, that is, normal hen egg yolk （group Ⅰ）, DHA-enriched hen egg yolk （group Ⅱ）, normal hen egg yolk with 5 mmol L^-1 of cysteine supplementation （group Ⅲ） and DHA-enriched hen egg yolk with 5 mmol L1 of cysteine supplementation （group Ⅳ）. The semen was cryopreserved using controlled rate freezer and was thawed at 50℃ for 12 s. Progressive motility, sperm viability, acrosome integrity and functional integrity of sperm plasma membrane of the post-thawed semen were evaluated. The supplementation of L-cysteine in the freezing extender alone （group Ⅲ） improved progressive motility （P 〈 0.05）, and the supplementation of L-cysteine in combination with DHA-enriched hen egg yolk （group Ⅳ） improved both progressive motility （P 〈 0.05） and acrosome integrity （P 〈 0.01）. The use of DHA-enriched hen egg yolk alone （group Ⅱ） did not enhance any of the post-thawed semen qualities （P 〉 0.05）. In conclusion, the supplementation of antioxidant L-cysteine alone or in combination with DHA-enriched hen egg yolk significantly improved the post-thawed semen qualities, especially progressive motility and acrosome integrity.

Resazurin reduction and other tests of semen quality and fertility of bulls

Aim: This study was undertaken to compare the reduction in color of two dyes methylene blue (MBRT) and resazurindye (RRT) with other tests of bull semen quality and to examine their relationship to fertility. Methods: One hundredsixty-four ejaculates from 59 bulls were examined, processed, and used for 30 016 inseminations. Results: Bulls usedin artificial insemination have been selected for high semen quality and fertility, and semen from these bulls averaged80.6 % unstained sperm, only 11% had abnormalities, and fertility ranged from 64 %to 76 %. The MBRT and RRTwere run with standardized sperm numbers to prevent sperm concentration from influencing the dye reduction time. Ashort RRT was correlated with higher fertility ( r = -0.26) but MBRT was not correlated ( r = -0.05, P >0.0,5).The correlations were low, but axe typical and reflect the statistical effect of the large binomial variance associated withpregnancy or nonpregnancy being coded as 1 or O. Conclusion: The fact that the RRT was significantly correlated withfertility when sperm numbers were standardized, and published reports that resazurin is useful for monitoring other semencharacteristics, indicate that this dye may provide valuable information not given by other simple laboratory tests. (AsianJ Androl 1999 Sep; 1: 109 - 114 )

Effect ofDiospyros kakienriched extender on cattle bull sperm parameters and conception rate

Objective:To explore the effect of Diospyros kaki on cattle spermatozoa during chilling and cryopreservation.Methods: Five milliliter of blended Persimmon (Diospyros kaki) flesh was added to 45 mL TCF to obtain 10% stock solution. Kaki enriched extender (KEE) was prepared by adding to TCF in concentrations 0.0/5.0 mL (control, 0%), 0.5/4.5 mL (1%), 1/4 mL (2%), 1.5/3.5 mL (3%), 2.0/3.0 mL (4%), 2.5/2.5 mL (5%), 3.0/2.0 mL (6%), 3.5/1.5 mL (7%), 4.0/1.0 mL (8%), 4.5/0.5 mL (9%) and 5.0/0.0 mL (10%) to obtain a final volume 5 mL in each tube. Whole egg yolk was added to each tube to obtain KEE with 20% egg yolk (KEEY), all tubes were centrifuged to get rid of debris. Semen was added to the supernatants in other tubes. Extended semen was subjected to evaluation (motility, alive sperm and intact sperm membrane (HOST) %) in both chilled and cryopreserved semen. Conception rate was carried out.Results:Sperm motility was significantly (P<0.0001) kept high after 11 d of chilling with the concentration 1%, 2%, 3%, 4%, 5% as compared to the control (41.67±1.67, 41.67±1.67, 40.00±0.00, 41.67±1.67 and 41.67±1.67, respectively) and also non-significantly kept high at the other concentrations up to 9 d of chilling. Addition of KEE had significantly (P<0.0033) improved post thawing sperm motility % with the concentrations 1, 2, 3, 4, 5 and 6% as compared to the control (51.67±5.27, 55.00±3.16, 48.33±1.05, 45.00±3.96, 57.00±2.50, 55.00±5.00 and 43.33±5.11 respectively).While the other concentrations exhibit no effect. Addition of KEE maintained alive sperm%, abnormalities% and % of intact spermatozoa membranes (HOST %) as good as the control with all concentrations of kaki used in our study. The conception rate upon using frozen semen in insemination showed higher conception rate in concentrations of 2%, 4% and 6 % KEE in cattle.Conclusion: It could be concluded that some concentrations ofDiospyros kaki improved bull semen quality post-chilling and post-freezing.

Impact of silymarin enriched semen extender on bull sperm preservability

Objective:To explore the effect of silymarin on bull spermatozoa during cooling and cryopreservation. Methods: Pooled bull semen were diluted by Tris-Citrate-Fructose egg yolk diluents, purified silymarin powder (obtained from the milk thistle silybum marianum), purchased from Unipharma, Al Obour city, Egypt, was soaked in Tris-citric acid-fructose diluent for 48 h at 10℃ making a stock solution (70 mg/mL), from this stock solution we obtained concentrations of 0.18 mg/mL, 0.36 mg/mL, 0.54 mg/mL, 0.72 mg/mL, 0.90 mg/mL in addition to the control (0.0 mg/mL) reaching a final volume of 5 mL in each tube. Egg yolk was added to each tube to obtain silymarin enriched semen extender (SEE) with 20% egg yolk, cooled slowly up to 5℃ and equilibrated for 4 h. Semen was packed into 0.25 mL polyvinyl French straws (IMV, France). After equilibration periods, the straws were placed horizontally on a rack and frozen in a vapor 4 cm above liquid nitrogen for 10 min and were then dipped in liquid nitrogen. Extended semen was subjected to evaluation (motility, alive %, abnormality %, intact sperm membrane (HOST)% and conception rate) in both chilled and frozen semen.Results: Table 1 revealed that Sperm motility of the concentrations 2, 3 and 4 after 8 d of chilling were significantly (P<0.02) higher than control. Sperm motility of the concentration 2 (45.00%±2.89%) after 9 d of chilling was higher than control and the other concentrations. Addition of SEE in concentration 1 and 2 gave post thawing sperm motility as high as the control (47.50±2.81 and 45.00±2.58, respectively) while other concentration have lower effects on motility as compared to the control. Addition of silymarin improved post thawing alive% and was significantly higher (P<0.0001) than the control. SEE decreased significantly (P<0.0001) the % of post thawing abnormal sperm in concentration 3 and 4 (11.83±0.65 and 16.00±0.58, respectively). SEE improved significantly (P<0.018) the % of post thawing intact spermatozoa membranes (HOST%) in concentrations 2, 4 and 5 (71.17±0.83, 71.83±0.91 and 75.00±3.42 respectively) (Table 2).Conclusion:It could be concluded that silymarin as a natural additive to semen extenders improved preservability in both chilled and frozen bull semen.

Effect of tris-extender supplemented with various concentrations of strawberry (Fragaria spp.) on bull semen preservability

Objective:To evaluate effect of tris-extender supplemented with various concentrations of strawberry (Fragaria spp.) on bull semen preservability.Methods: Pooled bull semen were extended with tris-citrate-fructose egg yolk diluent (control, 0% strawberry) and various concentrations of tris strawberry (TSB) (1%-6%) to achieve 60 million motile spermatozoa per milliliter. Extended semen were subjected to semen freezing protocol. Semen assessment including motility, alive%, abnormality%, intact sperm membrane (hypo-osmotic swelling test) and conception rate were carried out for both chilled and frozen semen. Results: Results showed that sperm motility after chilling was enhanced in groups treated with various concentrations of TSB from 1% to 5% and exhibited higher significance (P<0.0001) at 6-day post-chilling. In frozen semen, 3%, 4%, 5% and 6% concentrations gave the best significance (P<0.0001) on sperm motility in comparison with the control. Concentration 1% revealed the highest significance (P<0.0001) on alive% as compared to the control. Hypo-osmotic swelling test was maintained as the control. Concentration 3% gave the lowest significance (P<0.0001) considering abnormality%. The conception rate upon using frozen semen in insemination showed higher conception rate in concentrations of 5% and 6% in cattle.Conclusions: It is concluded that 1%-5% concentrations of TSB ameliorate bull semen characteristics after chilling, and 3%-6% concentrations of TSB improve bull semen characteristics after freezing. Higher conception rate exists in 5% and 6% concentration of TSB.

Effect of Butylated Hydroxytoluene on Survival of Frozen-TIhawed Fighting Bull Spermatozoa

The aim of the present study was to evaluate effect of 3 levels of butylated hydroxytoluene （BHT） supplemented in extender for fighting bull semen. Ejaculates were obtained from 10 healthy fighting bulls by artificial vagina. Semen with motility of more than 70% was included in the experiment. Tris-fructose-glycerol-egg yolk extender containing 0, 1, 3 and 7 mM BHT was used to dilute semen to final concentration of 200 × 10^6 cells/ml. Diluted semen was frozen in 0.25 mL straws and frozen semen was thawed in a 37 ℃ water bath for 15 sec before being evaluated at 0 and 1 hour. Sperm motility at 0 and 1 hour after thawing did not differ among groups tested （ranged 47.86-53.57 and 21.79-24.29 respectively）. At 0 hour after thawing, percentage of live sperm of 3 mM BHT （37.39% ± 2.91%） was lower than those of 0 and 1 mM BHT （43.71%± 2.76% and 41.46% ±2.59% respectively, P 〈 0.05） but not different from 7 mM BHT （40.89%± 2.50%）. The effect was more significant at 1 hour after thawing and 3 mM BHT （32.07% ± 2.45%） suppressed live cells more than other concentrations （ranged 35.07%-37.46%, P 〈 0.05）. At 0 hour after thawing, percentage of membrane integrity （hypo-osmotic swelling test） was not affected by BHT concentration （ranged 23.89%-28.54%）. However, at 1 hour after thawing, percentage of membrane integrity of 3 mM BHT （19.75% ± 1.41%） was lower that of 7 mM BHT （23.29% ± 1.88%, P 〈 0.05） but not different from those of 0 and 1 mM BHT （20.32% ±1.81% and 22.07% ± 2.27% respectively）. No significant effect was found on percentage of abnormal sperm. There was no effect of BHT supplementation in extender on most of the Hamilton-thorn motility analyser parameters. It may be concluded that 3 mM BHT can be harmful to fighting bull spermatozoa and lower concentrmion can be used without detrimental effect. Further study may be needed to verify use of BHT in lower range of concentrations.

不同抗氧化剂对牦牛冷冻精液精子活力的影响

为研究维生素C(VC)、维生素E(VE)、维生素B_(12)(VB_(12))及白藜芦醇(Res)抗氧化剂对牦牛冷冻精液精子活力的影响,在卡苏稀释液中分别添加浓度为0、200、400、600、800、1000、1200μg/mL抗氧化剂,确定抗氧化剂的单因素适宜添加量。根据单因素试验结果进行4因素3水平的响应面优化试验,确定冷冻精液中复合抗氧化剂的适宜添加量。结果表明:VC、VE、VB_(12)及Res的单因素适宜添加量分别为200、400、400、400μg/mL,精子活力最大值分别为83.28%、79.72%、78.18%、69.38%。通过响应面优化VC、VE、VB_(12)及Res的添加量分别为228.80、447.00、394.05、400.69μg/mL,精子活力理论值为82.44%。通过3次验证试验,VC、VE、VB_(12)及Res的添加量分别在230.00、450.00、400.00、400.00μg/mL时,牦牛冷冻精液精子活力平均值为83.66%,超过理论值,较好地预测实验结果。

两种氨基酸对公牛精液冷冻效果研究

[目的]试验研究L—半胱氨酸、精氨酸对牛精液冷冻效果。[方法]基础液中分别添加不同浓度的L—半胱氨酸、精氨酸进行试验,再用L_(9)(3^(4))正交表优化最佳配比,获得不同的稀释液配方,然后再进行对比试验,优选出使用效果最好的牛精液冷冻稀释液。[结果]牛精液冷冻稀释液添加0.125%、0.25%、0.375%的半胱氨酸;牛精液冷冻稀释液添加0.5%、0.75%精氨酸,牛冷冻精液解冻活力均得到提高。[结论]结果表明,半胱氨酸、精氨酸可用于牛精液冷冻保存,能改善牛精液冷冻保存效果,对提高牛冷冻精液质量效果明显。

绒山羊细管冻精保存时间对使用效果的影响

为了比较绒山羊细管冻精不同保存时间的品质变化和使用效果,笔者将辽宁绒山羊公羊的细管冻精从2005年分别保存0,5,10,18年,并分别进行抽检,选用成年母羊进行冻精输精,比较了细管冻精解冻后的活力、畸形率、冻精输配受胎率及冻精后代的产羔率、羔羊初生重和120 d断奶重。结果表明:2005年生产的辽宁绒山羊细管冻精经过0,5,10,18年的冷冻保存,解冻后的活力和畸形率没有显著变化(P>0.05),细管冻精的配种受胎效果与后代生产性能也没有显著差异(P>0.05),冻精后代的产羔率、羔羊平均初生重和120 d断奶重都没有显著差异(P>0.05)。说明细管冻精的保存时间在一定期限内对细管冻精的质量和使有效果没有不利影响。

猪精液冻融技术及其影响因素研究进展

养猪业是我国畜牧产业的重要组成部分。国内生猪养殖主要采用自繁自养模式,配种所使用的精液多采用鲜精或常温稀释保存精液,而精液冻融技术可实现猪精液的长期保存,但与牛、小鼠等物种相比较,猪精液冻融技术还有待于进一步优化改善。为进一步改进猪精液冷冻技术并实现在生产上大规模应用,本文主要综述了猪精液冻融技术发展概况、主要技术流程,影响猪精液冻融后精子活力的关键因素,包括精液的采集、冷冻前降温平衡、冷冻保护剂添加和冷冻方法等,以及精子冻融过程中的理化性质变化,包括物理结构损伤、功能性损伤、精子抗冻机制等,最后总结、展望了能够提高猪精液冻融效果的新方法。

“冻精+鲜精”混精对母猪繁殖性能的影响

为探讨“冻精+鲜精”混精使用的实用效果,该试验将长白鲜精与大白冻精设置5种混精比例,每种比例随机与配10头大白母猪,并对6个繁殖性能指标进行了统计分析。结果表明,不同混精比例的母猪受胎率、窝活仔数、窝重、仔猪初生重、妊娠期均无显著影响(P>0.05)。因此,“冻精+鲜精”混精的授精模式不会影响大白母猪的繁殖性能,研究结果对于地方猪保种的授精与非洲猪瘟威胁下中国猪繁育体系模式优化具有重要的指导意义。

牛冷冻精液精子形态活力变化研究与分析

为探讨牛常规冷冻精液解冻后不同时间内精子的形态结构及活力的变化规律,利用河南某种公牛站同一牛号、同一生产批次的300剂常规冷冻精液进行解冻,检测其解冻后不同时间内精子活力、畸形率、顶体完整率及前进运动精子数。结果表明:刚解冻时、解冻后1h精子顶体完整率下降,但差异不显著(P>0.05),解冻后3h、6h、9h的精子顶体完整率显著低于刚解冻时和解冻后1h(P<0.05)。精子畸形率在精液解冻后随着时间延长而逐渐升高,刚解冻时与解冻后1h差异不显著(P>0.05),但显著低于解冻后3h、6h(P<0.05),且解冻后3h的精子畸形率显著低于解冻后6h的畸形率(P<0.05)。精子活力在精液解冻后随着时间延长而逐渐降低,刚解冻时的精子活力最高,与解冻后1h、3h、6h、9h差异显著(P<0.05),解冻后1h精子活力显著高于6h(P<0.05),解冻后9h精子活力低于任何一个阶段的活力,且差异显著(P<0.05)。可见,人工授精时,刚解冻精液与解冻1h内精液的顶体完整率较好、精子畸形率较低,此时输精效果为佳。

柴达木牛精液品质分析

本试验选择10头生长发育良好、年龄在2~2.5岁的柴达木种公牛,按常规方法采集精液,对其品质进行评定分析。结果表明,柴达木牛的精液颜色为乳白色,云雾状,略带腥味,平均射精量为(5.28±1.95)mL,精子活率为(67%±6.45%),精子密度为每毫升(12.21±5.21)×108个,解冻后精子畸形率为≦20%,菌落数为0。通过多重比较分析发现,95号为优秀种公牛,精液量与精液密度呈显著正相关(P<0.05),95、88、91、96、97和98号牛均可开展冻精制作和保存工作。

不同发情阶段冻精配种对辽宁绒山羊受胎率的影响

为了提高绒山羊母羊发情鉴定的准确性、提高细管冻精配种的受胎率,开展了绒山羊不同发情阶段(不同生殖道状态)对冻配受胎率影响试验。试验选择健康经产繁殖母羊146只,在母羊发情的不同时期(4期)使用细管冻精进行子宫颈口输精,观察母羊的受胎状况并统计受胎率。结果表明:受胎率以第3期最高,达77.50%(31/40),其次为第2期,为44.00%(22/50),第1期和第4期分别为8.33%(3/36)和0(0/20)。说明辽宁绒山羊细管冻精的适宜输精期为母羊发情的第3期。

Influence of butylated hydroxytoluene addition to cryodiluents on freezability and DNA integrity of Boer and Zaraibi buck spermatozoa

Objective:To evaluate the cryoprotective effect of butylated hydroxytoluene on buck frozen semen.Methods:Semen was collected from Boer(n=6)and Zaraibi(n=6)bucks by electroejaculator for 5 weeks.Semen aliquots were diluted at 38℃in Tris-buffer with egg yolk 15.0%(vol/vol)(Tris-egg yolk extender)or soya lecithin 2.5%(weight/vol)(Tris-soya lecithin extender)supplemented with butylated hydroxytoluene at 0.0(as the control),0.5,1.0,2.0 and 4.0 mM.Post-thawing motility(at 400×magnification),plasma(hypo-osmotic swelling test),acrosome(Trypan blue/Giemsa dual staining)membranes,DNA(comet assay),and lipid peroxidation(by malondialdehyde concentration)were assessed.Results:Spermatozoa motility was enhanced by butylated hydroxytoluene in Tris-soya lecithin extender at 0.5 mM in the two breeds,and in Tris-egg yolk extender at 1.0 mM in Boer and at 2.0 mM in Zaraibi bucks for up to 3 h post-thawing.Plasma and acrosome membranes and DNA integrity of the two breeds were maximally high with butylated hydroxytoluene at 1.0-2.0 mM in Tris-egg yolk extender and at 0.5-1.0 mM in Tris-soya lecithin extender.Lipid peroxidation was minimal with butylated hydroxytoluene at 1.0-2.0 mM in Tris-egg yolk and soya lecithin extenders in the two breeds.Butylated hydroxytoluene at 4.0 mM deteriorated spermatozoa motility,and plasma and acrosome membranes.Conclusions:The consequence of butylated hydroxytoluene on buck frozen-thawed spermatozoa varies with the levels of supplementation,buck breed,and phospholipid source in the extender.Semen parameters of Boer buck are better in their response to butylated hydroxytoluene than Zaraibi buck.Butylated hydroxytoluene at 1.0 and 2.0 mM in Tris-egg yolk extender,and at 0.5 mM in Tris-soya lecithin extender represents the best concentrations and profitably improves the semen quality of buck semen.

Preservability of bull spermatozoa in Tris-egg yolk extender enriched with different concentrations of butylated hydroxytoluene

Objective:To explore the effect of BHT on cattle spermatozoa during cooling and cryopreservation.Methods: Pooled bull semen were diluted by Tris-Citrate-Fructose egg yolk (TCFY) diluent considered as control (0 BHT) and different concentrations of BHT (1.0, 2.0, 3.0, 4.0, 5.0 and 6.0 mM were prepared in ethanol in prewarmed (37℃) test tubes. The ethanol was allowed to evaporate so that, a thin crystallized layer of BHT was deposited on the inner surface of the tubes. Then extended semen was added into the tubes and incubated at 37℃ for 5 min to allow uptake of BHT by spermatozoa. The tubes were cooled slowly (approximately for 2 h) up to 5℃ and equilibrated for 4 h. After equilibration, semen freezing process was carried out. Extended semen was subjected to evaluation (motility, alive sperm, intact sperm membrane (HOST) % and acrosome integrity) in both cooled and cryopreserved semen. Results:The result revealed that sperm motility of post-cooled spermatozoa improved (P<0.05) by the use of BHT concentrations (1, 2 and 3 mM) in Tris semen extender if compared to the control (85.00±1.09), (83.33± 0.63), (81.67± 0.63) and (78.33± 0.63), respectively. Alive sperm percent was significantly higher in all concentrations of BHT. Sperm abnormalities percent were significantly lower in concentrations of BHT 1 and 2 (11.2±0.2), (11.8±0.2)and (13.4±0.4), respectively. Sperm membrane integrity were significantly higher in BHT concentrations (1, 2, 3, 4 and 5 mM). It is exhibited that improved sperm motility in post-thawed frozen semen in the concentrations of BHT (1, 2, 3 and 4 mM) if compared to the control. The sperm membrane integrity were significantly improved at all concentrations of BHT. Acrosome integrity was significantly higher at BHT concentration 1 mM (81.80±0.57) and (76.00±2.05), respectively.Conclusions: It could be concluded that some concentrations of BHT improved bull semen quality post-cooling and post-freezing.

猪冷冻精液应用研究进展

猪冷冻精液使具有高遗传价值的公猪基因在群体中迅速传播,然而实际生产中的低繁殖率导致其推广应用受限。近20年来使用猪冷冻精液配种的繁殖成绩有了显著提高,配种分娩率达80%以上,产仔数达10头以上。显然这些重大进展不能简单地归功于冷冻保护剂的开发和冷冻程序的优化,而是解冻程序、输精方法、母猪发情排卵调控等一系列操作过程不断改进的结果。本文搜集整理了国内外20世纪80年代至今的27篇猪冷冻精液的生产及应用相关的文献,对其中母猪样本量、输精剂量、精子数量、输精方法时间以及不同处理组等技术因素进行分类,明确冻精繁殖成绩出现显著变化的时间节点,并对提高猪冷冻精液应用效果的技术因素进行分析展望,为进一步提高冷冻精液受精效率提供参考与借鉴。