兔体外受精的研究

为完善家兔体外生产胚胎技术，采用FSH＋HCG法处理48只母兔，获得卵母细胞.采用获能的精子与卵母细胞进行体外受精，使用TCM199为基础液进行受精卵的体外培养.结果显示：平均每只供体兔可获得30.69枚可用卵母细胞.屠宰法获得的精子获能以后与卵母细胞进行体外受精，卵裂率达65.51%，囊胚发育率18.04%.自然射出法获得的精子获能以后，与卵母细胞进行体外受精，卵裂率达66.33%，囊胚发育率17.83%.屠宰法与自然射出法获得的精子获能以后卵裂率和囊胚发育率差异不显著.     

半胱胺对牛卵母细胞早期胚胎发育能力的影响

半胱胺（Cysteamine）是一种重要的巯基物,在体外培养体系中添加半胱胺能够增强谷胱甘肽（GSH）的合成和胚胎发育能力。本研究旨在探讨不同浓度半胱胺处理对牛卵母细胞体外成熟和早期胚胎发育能力的影响。结果表明,在牛卵母细胞体外成熟液中添加100μM的半胱胺,其囊胚率与对照组有显著差异;但是,与同时在成熟液和发育液中都添加100μM的半胱胺组差异不显著。研究结果也表明,在牛卵母细胞体外成熟培养液中添加半胱胺会提高牛卵母细胞的囊胚发育率,而且随着浓度的增加这种作用将达到饱和,其最佳作用浓度为100μM。     

不同培养时间对家猫卵母细胞核成熟的影响

为了研究不同培养时间对家猫卵母细胞核成熟的影响,以M 199为基础培养液,并添加FSH、LH,分别培养24、28、32、36和43 h后,观察第一极体排出,然后用地衣红染色,将排出第一极体和染色体处于MⅡ期作为卵母细胞成熟的参考判断标志。结果表明,家猫卵母细胞随着培养时间的延长其成熟率也随之增加。成熟培养43 h,极体排出率极显著高于其他各组（P<0.01）,达到66.89%;而24 h组极体排出率为31.51%,极显著低于其他各组（P<0.01）;28、32、36 h各组间差异不显著（P>0.05）。经地衣红染色后,到达MⅡ期的卵母细胞比例与极体排出率趋势相同。43 h组退化率极显著高于其他各组（P<0.01）,达到22.30%。因此,综合考虑成熟率和退化率两项指标,28～36 h为家猫卵母细胞体外核成熟的最佳培养时间。     

PMSG和hCG对猪卵母细胞体外成熟的影响

对猪卵母细胞不同发育阶段的激素需要进行了初步探讨。结果表明 :猪卵母细胞体外培养 48h ,前 2 4h在培养液中加入激素 ,后 2 4h不加激素 ,卵母细胞的A级成熟率 (51 73% )和总成熟率 (83 2 5 % )最高 ,极显著高于前 2 4h不加激素 ,后 2 4h添加激素培养的成熟率 (P <0 0 1 ) ;也显著高于不含激素的培养液连续培养 48h的成熟率 (P <0 0 5) ;但与添加激素连续培养 48h组成熟率差异不显著 (P >0 0 5)。     

Developmental competence of cat oocytes from ovaries stored at various temperature for 24 h

We conducted two experiments to investigate the effects of storage temperature and period for cat ovaries on the meiotic and developmental competence of oocytes collected from the ovaries. In Experiment 1, ovaries were stored in physiological saline for 24 h at 4 C, 23-25 C, or 38 C (cold, room, and incubator temperature groups, respectively), and then oocytes were collected from the ovaries in each group. Morphologically intact oocytes were then selected and cultured in maturation medium for 24 h. Significantly more oocytes reached metaphase II (MII) in the cold temperature group (53.4%) than in the room and incubator temperature groups (20.0 and 2.4%, respectively). In Experiment 2, ovaries were stored in physiological saline at room temperature for 0, 6, 12 or 18 h, and then they were stored at 4 C (cold storage) until reaching a total storage period of 24 h. After storage of the ovaries, morphologically intact oocytes were matured, fertilized with frozen-thawed spermatozoa, and cultured in vitro. The rates of morphologically intact oocytes obtained from the ovaries stored at room temperature for 0, 6, 12 or 18 h were 35.3, 30.0, 26.4 and 14.7%, respectively, and the rates of intact oocytes that reached MII were 63.2, 36.4, 26.5 and 11.9%, respectively. The results suggested that the numbers of morphologically intact oocytes and intact oocytes that reached MII after in vitro maturation decrease gradually as the period of storage at room temperature before cold storage increases. Only oocytes from ovaries stored for 6 h developed to the blastocyst stage after in vitro maturation and fertilization when ovaries were stored at room temperature before cold storage. These results indicate that 24 h storage of ovaries at high temperatures (>23 C) decreases the meiotic competence of oocytes. The quality and developmental competence of oocytes are influenced by the length of storage at room temperature before cold storage.     

Effects of Plasma Urea Nitrogen Levels on the Bovine Oocyte Ability to Develop After In vitro Fertilization

The overall aim of the present study was to evaluate in vitro development ability of oocytes recovered from 56 Holstein Frisian heifers with low [group 1 (G1): <13 mg /dl], moderate [group 2 (G2): 13–16 mg /dl] and high [group 3 (G3): >16 mg /dl] plasma urea nitrogen (PUN) concentrations, to determine whether PUN concentrations affect the competence of oocytes to progress to blastocysts after in vitro fertilization. In vitro oocyte and embryo development was assessed by blastocyst rates, embryo total cell numbers and apoptosis. Blood samples for the determination of PUN were collected 24 h prior to collection of the ovaries at the slaughter. A total of 112 ovaries were collected at a local abattoir and oocytes (n = 697) were aspirated, in vitro matured and fertilized. On day 8, blastocysts were assigned to the terminal dUTP nick end labelling assay. Cleavage rates were significantly higher (p < 0.001) for groups 1 and 2 than for group 3 (i.e. 72.5% and 72.2% vs 61.7%, respectively). The proportion of fertilized oocytes that developed into blastocysts was higher (p < 0.05) for group 1 than for group 3 (34.0% vs 23.0%, respectively). Day 8 blastocysts showed higher total cell counts (p < 0.05) for group 1 than for group 3 (123.7 vs 76.3), and a higher (p < 0.05) total apoptotic cell rate was found in group 3 (25.9 and 19.0 vs 43.2 for G1, G2 and G3, respectively). In conclusion, the ability of oocytes from heifers with increased levels of PUN to develop to the blastocyst stage was significantly reduced when standard routines for in vitro maturation, fertilization and culture were followed. These detrimental effects can be mediated in part through direct effect of urea and/or by the metabolic products on the process of follicle-enclosed oocyte nuclear and cytoplasmic development.     

Effects of iron and copper in culture medium on bovine oocyte maturation, preimplantation embryo development, and apoptosis of blastocysts in vitro

The aim of this study was to investigate the effects of iron and copper on bovine oocyte maturation, preimplantation embryo development and apoptosis of blastocysts. The concentrations of iron in the culture media were 0 (control), 0.45, 0.81, 1.96 and 3.26 mg/l, and the concentrations of copper were 0 (control), 0.093, 0.27, 0.46 and 0.68 mg/l. The changes in the iron (1.96 mg/l) and copper concentrations (0.46 mg/l) in the culture media were measured after oocyte maturation for 22 h and after zygote culture for 48, 96, 144 and 192 h. The results showed that there were no significant differences in oocyte maturation and cleavage between media containing iron and the control, but the media containing iron had higher (P>0.05) rates of 8-cell embryos, morulae, and blastocysts than the control, and addition of 1.96 mg/l of iron increased the blastocyst rate (P>0.05). The effects of copper on oocyte maturation and cleavage were similar to iron, and addition of 0.46 and 0.68 mg/l of copper increased the rates of morulae and blastocysts (P>0.05). Addition of iron or copper significantly decreased the number of apoptotic blastomeres compared with the control (P>0.05). After oocyte maturation for 22 h and zygote culture for 48 h, the iron concentrations decreased by 3.6 and 9.2%, respectively, and the copper concentrations decreased by 6.5 and 10.9%, respectively. After zygote culture for 96, 144 and 192 h, the iron concentrations decreased by 21.4, 25.5 and 27.0%, respectively, the copper concentrations decreased by 23.9, 28.3 and 30.4%, respectively. In conclusion, iron and copper played an important role in the success of culture of 8-cell embryos, morulae, and blastocysts, and long-term lack of iron or copper increased the number of apoptotic blastomeres. Furthermore, transition of primary demand for trace amounts of iron or copper from the cytoplast to culture medium for utilization by zygotes may occur after in vitro zygote culture for 48 h.     

Effect of Preserving Condition of Porcine Ovaries on the Development of In Vitro Matured Oocytes

The effect of preservation condition of ovaries on the in vitro maturation of the porcine oocytes was studied. Cumulus‐oocyte complexes (COCs) were obtained from the ovaries preserved in Dulbecco’s phosphate buffered saline (PBS) solution at various temperatures for different time intervals, and cultured in M199 maturation medium. Matured oocytes were obtained from the ovaries preserved in PBS for 8 h and electrically activated. The activated oocytes were then cultured in NCSU23 embryo culture medium for 16 h to observe activation or 144 h to observe embryo development. It was found that the preservation temperature affected the maturation of porcine oocytes greatly. The effect was described as a compromise of the suppressions of autolysis at physiological temperature and frostbite because of low temperature. A preservation temperature of approximately 25°C showed the maximum maturation rate for a preservation time of 8 h. Preservation temperature also affected the activation and embryo development of porcine oocytes greatly, following a trend similar to the effect of preservation temperature on the maturation. Based on maturation rate, activation rate and cleavage rate, a preservation temperature of approximately 25°C would be optimum for a preservation time of 8 h.     

Sperm Pre-Incubation Prior to Insemination Affects the Sex Ratio of Bovine Embryos Produced in vitro

The objective of the present study was to determine whether sperm incubation prior to oocyte insemination in vitro affects the sex ratio of resulting blastocyst. Cumulus–oocyte‐complexes (COCs) collected from slaughterhouse ovaries were matured in vitro and inseminated with frozen‐thawed semen of three proven artificial insemination (AI) bulls pre‐incubated in vitro in Sperm‐Talp for 6 and 24 h. On day‐9 blastocysts were collected and processed for sex determination. More than 80% of blastocyst were successfully sexed. There were no significant differences in cleavage and blastocyst rates using sperm pre‐incubated for 6 h as compared with the 0‐h pre‐incubation control group. The cleavage and blastocyst rates were significantly lower in the 24‐h pre‐incubation group. The male to female ratio, when compared with the theoretical 1 : 1, differed significantly in favour of females among hatched (viable) blastocysts derived from sperm pre‐incubated for 24 h prior to insemination as well as among all blastocytsts in the 6‐h group. Moreover, when the sperm treatment was considered, the sex ratio was affected only among hatched blastocysts in 24‐h pre‐incubation group. It was concluded that prolonged sperm pre‐incubation influences the rate of development and the sex ratio among hatched blastocysts.     

Effect of modification of ovary preservation solution by adding glucose on the maturation and development of pig oocytes after prolonged storage

Oocytes lose their developmental competence during prolonged storage of the ovary. In the present study, we supplemented the preservation solution for pig ovaries (phosphate buffered saline, PBS) with glucose and preserved the ovaries for 6 h at 25 C. Subsequently, we examined the glucose concentration of the follicular fluid (FF), pH of the FF, survival rate of the granulosa cells, and maturation and developmental competence of oocytes after storage. During storage, the glucose concentration of the FF (2.1 mM), pH of the FF (7.4), and survival rate of the granulosa cells (69.5%) rapidly decreased (glucose concentration: under 1.1 mM; pH: 6.8; and survival rate: 43%). On the other hand, when the preservation solution was supplemented with glucose (15 mM), the glucose concentration of the FF increased and the survival rate of the granulosa cells improved, although the pH of the FF decreased further (from 6.8 to 6.6). In addition, supplementation with glucose significantly improved the rates of oocytes at metaphase II (0 h: 65.0%; 6 h without glucose: 23.8%; and 6 h with glucose: 43.8%) and attenuated the decline in the rates of fertilization and development that resulted from prolonged storage, although there were no significant differences. In conclusion, modification of the preservation solution by the addition of glucose increased the glucose concentration of the FF and improved the rate of maturation of pig oocytes.     

生物频谱对牛胚胎体外生产效率的影响

本试验利用可调式周林生物频谱发生器对牛卵母细胞体外成熟、体外受精和体外培养过程实施辐射 ,以提高牛胚胎体外生产效率。频谱发生器与培养材料的距离为 5cm ,辐射强度根据辐射温度加以调节。实验结果表明 ,辐射温度控制在 39℃时 ,入孵卵母细胞的卵裂率 ( 63% )与对照组 ( 61 % )无显著差异(P >0 0 5) ,而囊胚发育率 ( 39% )显著高于对照组 ( 1 9% ) (P <0 0 5) ;当辐射温度达到 4 0℃时 ,实验组的卵裂率仅为 1 4 % ,囊胚率为 0。体外受精生产的囊胚用EFS4 0液进行玻璃化冷冻保存 ,解冻后发现 ,整个生产过程经生物频谱辐射胚胎的体外发育率 ( 86% )显著高于对照组 ( 65% )。     

猪小腔卵泡卵母细胞体外成熟研究

本实验通过与2～6mm猪卵泡卵母细胞相对比，研究了猪2mm以下卵泡卵母细胞的体外成熟。结果如下(1)由2mm以下卵泡获得的小(直径100.29±7.9μm)、中(109.36±3.71μm)和大(118.90±2.46μm)3类卵母细胞培养48h的成熟率分别为0、22.31％和45.45％。(2)2mm以下卵泡卵母细胞的成熟率(52.63％)显著低于2～6mm卵泡卵母细胞的成熟率(80.39％)。(3)以含PFF的培养液培养2mm以下卵泡卵母细胞其成熟率(53.54％)显著高于不含PFF的对照组(22.77％)。(4)在培养的前24h加入PMSG、后24h去除PMSG，其成熟率(41.86％)与含PMSG的培养液连续培养48h的成熟率(50.0％)无显著差异，而显著高于前24h不加PMSG，后24h加入PMSG培养的成熟率(5.41％)；也显著高于以下不含PMSG的培养液连续培养48h的成熟率(3.3％)。     

Effects of Gonadotropins on In Vitro Maturation and of Electrical Stimulation on Parthenogenesis of Canine Oocytes

The objective of this study was to determine the effects of gonadotropins on in vitro maturation (IVM) and electrical stimulation on the parthenogenesis of canine oocytes. In experiment I, cumulus oocyte complexes were collected from ovaries at a random phase of the oestrus cycle and cultured on maturation medium treated with hCG or eCG for 48 or 72 h. There were no significant differences in the effects on the metaphase II (MII) rate between the hCG and eCG treatment groups over 48 h (5.4% vs 5.5%). The MII rate in the co-treatment group of hCG and eCG for 48 h was higher than in each hormone treated group (15.5%, p < 0.05). In experiment 2, the parthenogenetic effect on oocyte development, at various electrical field strengths (1.0, 1.5, 2.0 kV/cm DC) for 60 or 80 μs with a single DC pulse after IVM on the co-treatment of hCG and eCG, was examined. The rate of pronuclear formation (37.1%) in electrical activation at 1.5 kV/60 μs without cytochalasin B (CB) was higher than that of oocytes activated in the other groups (p < 0.05). However, we did not observe the cleavage stages. Also, CB did not influence parthenogenesis of canine oocytes. The results showed that the pronucleus formation rate, indicative of the parthenogenesis start point, could be increased by electrical stimulation. Therefore, these results can provide important data for the parthenogenesis of canine oocytes and suggest the probability of parthenogenesis in canines.     

Effect of exposure duration of ovaries and oocytes at ambient temperature on parthenogenetic development of porcine follicular oocytes

This study was conducted to evaluate the effects of exposing porcine ovaries to 30-33 C during transportation for 4 h and subsequently room temperature (25 C) for 6 h of storage on in vitro maturation (IVM) and subsequent parthenogenetic development of oocytes collected from the ovaries. After IVM, oocytes having a tight oopalsm membrane and no signs of degeneration were exposed to Dulbecco's phosphate-buffered saline (DPBS) with 7% ethanol (v/v) for 7 min to induce parthenogenetic activation. Moreover, we also determined whether exposure of the collected oocytes to room temperature for 1, 2 and 4 h in DPBS or porcine follicular fluid (pFF) affected parthenogenetic development. When porcine ovaries were stored after transportation, oocytes collected from the stored ovaries showed a significantly higher rate of degeneration after 65 h of IVM (58.4%) and a significantly lower rate of cleavage after parthenogenetic activation (40.1%) than oocytes collected from ovaries immediately after transportation (38.9% and 47.4%, respectively). However, there was no significant difference in developmental rates to the morula and blastocyst stages between these two groups (14.4% and 14.3%, respectively). The duration of preservation, 1, 2, and 4 h, of oocytes in DPBS did not affect parthenogenetic development. In contrast, when preserved for 4 h in pFF, the developmental rates of the oocytes were significantly decreased. This suggested that some factor(s) in follicular fluid affects the developmental rate of oocytes with the passage of time in ambient conditions. These results suggest that even after 6 h storage of ovaries, oocytes having normal morphology after IVM have the same rate of parthenogenetic development as oocytes collected from ovaries just after 4 h of transportation, except for a lower cleavage rate, and that exposure of oocytes to room temperature for 4 h in DPBS does not affect their parthenogenetic developmental competence.     

Bovine Oocyte Quality in Relation to Ultrastructural Characteristics of Zona Pellucida,Polyspermic Penetration and Developmental Competence

In the present study, the effect of bovine oocyte quality related to ultrastructural characteristics of zona pellucida (ZP), polyspermic penetration and embryo developmental competence was evaluated. Cumulus–oocyte complexes were punctioned from 453 ovaries, classified as 1, 2, 3 and 4 according to their morphological aspect, matured for 24 h and then divided into two groups. In group A, oocytes were fixed in 2.5% glutaraldehyde and 0.1 m sodium cacodylate and examined under a scanning electron microscope. Photomicrographs were taken and ZP’s pores were evaluated in squares of 6.4‐μm width. In group B, oocytes were fertilized in vitro. After 48 h, non‐cleaved oocytes were fixed for polyspermy evaluation. On days 7, 9 and 10, embryos were classified as developed (blastocysts and hatched blastocysts). Results showed that quality 1 oocytes revealed a ZP pore diameter of 0.50 ± 0.07 μm, which was smaller than the observed on oocytes of quality 2 (0.83 ± 0.10 μm), quality 3 (1.02 ± 0.22 μm) and quality 4 (1.38 ± 0.59 μm) (p ≤ 0.05). For In Vitro Fertilization (IVF), results showed that embryos originating from oocytes classed as 3 and 4 had lower cleavage rate (68.4% and 43.8%) than those belonging to class 1 and 2 (79.5% and 69.3%) (p ≤ 0.05). None oocyte classified as 3 and 4 developed to hatch blastocysts, while for oocytes belonging to quality 1 and 2, these values were, respectively, 15.2% and 12.5%. Concerning polyspermy, oocytes class 1 and 2 had lower polyspermic penetration than those belonging to class 3 and 4 (respectively 4.1%, 4.5%, 11.1% and 9.8%, for class 1, 2, 3 and 4). In conclusion, the present study demonstrated that oocytes with low qualities result in lower developmental competence and with high percentage of polyspermy after IVF, which can be the result of the ZP structure such as the number and the pore’s diameter.     

水牛卵母细胞孤雌激活及孤雌胚与体外受精胚发育比较

对MII期水牛卵母细胞进行人工诱导激活可以帮助人们间接判断体外成熟卵母细胞质量的优劣。并且，卵母细胞的充分激活也是提高核移植效率的关键因素之一。试验比较了水牛卵母细胞体外成熟时间对孤雌激活胚发育能力的影响以及不同化学激活方法对水牛卵母细胞孤雌激活效果的影响，并在相同条件下，对孤雌激活胚与体外受精胚的发育能力进行了比较。结果表明，水牛卵母细胞体外成熟27小时或30小时的囊胚发育率（19．0％或17．7％）明显高于体外成熟21小时或24小时的囊胚发育率（12．3％或13．8％）；Ion联合6-DMAP激活水牛卵母细胞的效果优于其他几组激活方法；在相同条件下，孤雌激活胚与体外受精胚的发育能力存在着差异，其中卵裂率差异不显著，但孤雌激活胚的囊胚发育率显著高于体外受精胚（13．0％vs21．7％）。     

Effect of Meiotic Stages During <Emphasis Type="Italic">In Vitro</Emphasis> Maturation on the Survival of Vitrified-Warmed Buffalo Oocytes

The present study was conducted to investigate the effect of meiotic stages during in vitro maturation (IVM) on the survival of vitrified-warmed buffalo oocytes, vitrified at different stages of IVM. Cumulus oocyte complexes obtained from slaughterhouse ovaries were randomly divided into 6 groups: control (non-vitrified, matured for 24 h at 38 ± 1^°C, 5% CO₂ in humidified air), and those matured for 0 h (vitrified before IVM) or 6, 12, 18 and 24 h before vitrification. Cumulus oocyte complexes were vitrified in solution consisting of 40% w/v propylene glycol and 0.25 mol/L trehalose in phosphate-buffered saline supplemented with 4% w/v bovine serum albumin. Vitrified cumulus oocyte complexes were stored at −196^∘C (liquid nitrogen) for at least 7 days and then thawed at 37^°C; cryoprotectant was removed with 1 mol/L sucrose solution. Cumulus oocyte complexes in the 0, 6, 12, 18 and 24 h groups were then matured for an additional 24, 18, 12, 6 and 0 h, respectively, to complete 24 h of IVM. Among the five vitrification groups, 89–92% of cumulus oocyte complexes were recovered, after warming, of which 84–91% were morphologically normal. Overall survivability of vitrified cumulus oocyte complexes was lower (p < 0.05) than that of non-vitrified cumulus oocyte complexes (94.5%). Survival rates of cumulus oocyte complexes matured 24 h prior to vitrification (61.3%) were higher (p < 0.05) than those matured for 12 h (46.7%), 6 h (40.6%) and 0 h (37.6%). Nuclear status following 24 h IVM was assessed. A higher proportion of non-vitrified (control) oocytes (72.7%) reached metaphase II (M-II) stage in control than oocytes vitrified for 24 h (60.0%), 18 h (54.4), 12 h (42.3%), 6 h (33.3%) and 0 h (31.6%) (p < 0.05). The results suggest that length of time in maturation medium prior to vitrification influences post-thaw survivability of buffalo oocytes; longer intervals resulted in higher survival rates.     

绵羊体外受精技术条件优化的研究

探讨了卵泡液、受精时间和季节对绵羊卵母细胞体外培养效果的影响。从屠宰场采集羊卵巢,抽取卵巢表面2mm-6mm的卵泡卵母细胞,进行体外成熟培养;卵母细胞成熟后,与处理后的精子共同培养进行受精。结果表明,在卵母细胞成熟培养液中添加绵羊卵泡液（SFF）组的卵裂率和囊胚发育率均优于添加同等浓度的牛卵泡液（BFF）组;受精22、18、12h组的卵裂率分别为64.85%、54.39%、48.72%,受精22h和18h组间差异显著（P〈0.05）,受精22h组和12h组间差异极显著（P〈0.01）。秋季绵羊体外受精的卵裂率和囊胚率均高于夏季,差异显著（P〈0.05）,但秋季与春季相比差异不显著（P〉0.05）。因此,进行绵羊卵母细胞体外成熟培养时,培养液中添加SFF;受精时,精卵共培养时间为22h的效果较好。在绵羊的繁殖季节秋季进行体外受精较春季和夏季的结果好。     

体外成熟对牛卵母细胞孤雌激活后发育潜力的影响

本试验在卵母细胞体外成熟的研究基础上,研究了培养用水、卵泡液和成熟时间对卵母细胞体外成熟及孤雌激活后发育潜力的影响.结果表明(1)将卵母细胞分别于蒸馏水和Milli-Q超纯水配制的成熟培养液中培养22～24 h, 孤雌激活后, 卵裂率无显著差异(P>0.05); 但孤雌卵在超纯水配制的胚胎培养液中培养,囊胚发育率为22.3%, 明显高于在蒸馏水配制的培养液中的囊胚发育率14.1%(P<0.05).(2)在成熟培养液中添加10%、20%卵泡液,成熟卵母细胞孤雌激活后的囊胚发育率(32.3%, 30.9%)明显高于添加5%和0%卵泡液组的囊胚发育率(21.8%, 22.7%,P<0.05).卵母细胞在添加20%卵泡液的培养液中成熟培养,孤雌激活后囊胚孵化率明显低于添加0、5%、10%卵泡液组的囊胚孵化率(P<0.05).(3)成熟28 h或30 h的卵母细胞孤雌激活后,其囊胚发育率(30.5%或29.4%)明显高于成熟24 h或26 h组的囊胚发育率(20.5%或22.1%,P<0.05).     

鸡精液稀释配方对低温保存精子活力和输精效果的影响

为了完善中国南方地区鸡场公鸡精液的保存技术、提高精液的利用率，本试验研究了在低温（4 ℃）保存的条件下，不同的保存时间（0、4、8、24 h）、不同的稀释液配方（原精液、配方Ⅰ和配方Ⅱ）对精液的精子活力变化以及人工输精繁殖效果的影响。选用33周龄黄鸡母鸡192只、公鸡42只，192只母鸡依笼号分为12组（3种处理精液×4个保存时间），每组16只母鸡，公鸡不分组。统一采精后用两种不同稀释液稀释、低温（4 ℃）保存至0、4、8、24 h后观察精子活力，并对母鸡输精，分组收集鸡蛋，对各组受精率、出雏率、健雏率进行比较分析，以原精液低温保存作为对照。结果显示，两种稀释液组的精子低温（4 ℃）保存4、8、24 h，其精子活力极显著高于原精液组（P<0.01），配方Ⅱ组精子的活力高于配方Ⅰ组（P>0.05）；两种配方稀释液组的精液低温（4 ℃）保存4 h，输精受精率高于原精液组（P<0.05）；两种配方稀释液组的精液在低温（4 ℃）保存8 h，输精受精率极显著高于原精液组（P<0.01）。表明这两种精液稀释液更有利于精液保存，经稀释后的精液可以显著提高受精率，可为中国南方鸡场种公鸡精液保存技术的完善提供有力的数据支撑。