液氮冷媒介质对速冻饺子冻裂率的影响

研究饺子新型冻结技术,探索液氮速冻工艺对调理食品品质的作用规律。该文以饺子为研究对象,和面水面质量比、皮馅质量比、面粉品质、馅料配比、产品规格、冻结时间、冻结方式、冻结介质等诸多因素对饺子冻裂率都有重要影响。该试验以猪肉、香菇、大豆组织蛋白为饺子馅主要原料,研究了和面时的水面质量比、面团的静置时间、皮馅比、饺子在液氮池中的沉浸时间对饺子冻裂率的影响。结果表明:以上四因素对饺子的冻裂率都有不同程度的影响。和面水面质量比为56∶100、面团静置时间在10 min、皮馅质量比在1∶1.3、液氮池沉浸时间为40 s,制作好的饺子在立即速冻后的冻裂率为37%,感官评定得分为77.6。该研究为液氮沉浸速冻工艺在调理食品的应用提供了一定的理论参考。     

狸獭人工授精的试验研究

对１１只狸獭（Ｍｙｏｃａｓｔｏｒｃｏｙｐｕｓ）用按摩和电刺激相结合的方法人工采精３２只次，成功２７次，成功率８４．４％；射精量为（０．９７±０．１６）ｍＬ，精子密度（７．３４±１．４９）亿／ｍＬ，精子活力０．６５±０．１２，精子畸形率（８．８１±２．５１）％，精液ｐＨ值６．４４±０．１６。对诱排公狸施行输精管结扎术，先后给５只母狸人工输精，每只输精２～３次，在输精后４０～６０ｄ检查，４只受孕，其中有３只顺利产仔，产仔数分别为７只、７只、４只     

小尾寒羊冷冻精液制作保存技术

在制作小尾寒羊冻精颗粒时，对其冷冻稀释液和甘油浓度进行了研究。结果表明，2＃稀释液效果最好（P＜0．05），甘油浓度为6％时的冷冻效果最佳（P＜0．01）；在40－50℃解冻后，其活力可达0．5以上。     

Estimation of Genetic Parameters and Analysis of Season Effects and Age Effects for Semen Traits in Landrace Boars

The purpose of this study was to estimate the genetic parameters of semen traits of Landrace boars in South China and to analyze the influence of the age and season of semen collection on semen traits, so as to provide theoretical basis for formulating reasonable boar breeding program. The Asreml-R was used to analyze the 107 221 semen data of 1 605 Landrace boars from 2 AI stations in Southern China, the single-trait repeatability animal model was used to estimate the variance components, heritability and repeatability of each semen traits, two-trait repeatability animal model was used to estimate genetic correlation and phenotypic correlation of semen volume, semen density, sperm motility and percentage of abnormal sperm. The general linear model of R language program was used to analyze the influence of age and season of semen collection on semen traits. The results showed that the semen volume and percentage of abnormal sperm had medium heritability (0.23 and 0.38), and the variation coefficient of percentage of abnormal sperm was 85.42%, while the other traits had low heritability (0.07-0.19). Semen volume-semen density and sperm motility-percentage of abnormal sperm had extremely significantly negative genetic correlation(-0.77 and -0.90, respectively). Semen density-sperm motility showed extremely significantly positive genetic correlation (0.50). The influence of the age of semen collection on semen traits was significant(P<0.05). After boars reached sexual maturity, semen volume showed a significant increase, semen density and percentage of abnormal sperm showed a general decrease, and total sperm number and functional sperm number were significantly higher in the 13-18-month of age group than those in the other groups (P<0.05). The semen density was the highest in spring, and the total sperm number and functional sperm number were significantly higher in autumn and winter than those in spring and summer (P<0.05). In conclusion, the semen volume and percentage of abnormal sperm of Landrace boars can be selected as candidate traits. In the boar production management, boar whose semen production after 36 months of age decline, will be considered to update. Boar semen quality was significantly higher in autumn and winter than those in spring and summer. It is suggested that cooling work should be done in advance in Southern China in summer.     

火鸡精液液态低温保存

本文研究了3种稀释液在0～5℃下保存火鸡精液的效果及稀释液pH值、稀释比例和卵黄浓度对精子存活力的影响。原精及稀释精液Ⅰ、Ⅱ、Ⅲ不保存时,受精率分别为71.7％,64.03％,63.29％和63.77％(P<0.05);在0～5℃下保存48h后,原精完全丧失受精率(0％),而稀释精液Ⅰ、Ⅱ、Ⅲ的受精率分别为52.40％,45.30％和20.33％(P<0.01)。火鸡精液在0～5℃保存过程中,pH值降低,原精比稀释精液降低程度大。在本研究条件下,pH6.5和1:3稀释最适合于火鸡精子的存活,稀释液中添加5％或10％卵黄可提高火鸡精子的存活力。     

中草药浸提液在牛冻精解冻中的作用

与通用的２．９％柠檬酸钠液相比，经Ｃａｍｅｌｌｉａｓｐ浸提液解冻的牛冻精精子生存时间及活力维持时间延长，精子的生存指数、维持０．３活力的时间及受胎率显著提高。     

Sperm localization in the oviducts of artificially inseminated dairy cattle

Eight animals, 3 heifers and 5 primiparous cows, were artificially inseminated by intrauterine deposition of frozen-thawed semen. The insemination dose comprised 20×10⁶ or 200 × 10⁶ spermatozoa, frozen in French mini straws. Four animals were inseminated at fixed time interval (72 or 84 h) after cloprostenol injection. The remaining 4 animals were inseminated in spontaneous oestrus. Slaughter took place 2 or 12 h after insemination. After fixation the oviducts were cut into segments, which were serial-sectioned and stained. Six sections per segment were examined under the microscope for sperm recovery.The number of spermatozoa recovered from the oviducts varied considerably among animals. Recovery was poor (less than 50 spermatozoa) in 4 animals. Recovery was low when insemination took place in induced oestrus and with the lower sperm number (20×10⁶). In animals in which more than 50 spermatozoa were found the distribution varied both between animals and between oviducts within the same animal. Overall, more spermatozoa were found in the lower (UTJ, isthmus and AIJ) than in the upper (ampulla) parts of the oviducts. In 3 out of 4 animals more spermatozoa were recovered from the left than from the right oviduct. Only in 1 animal were the majority of spermatozoa found in the oviduct ipsilateral to the follicle-bearing ovary.     

Study on the Role of AMPK Activator in Cryopreservation of Sheep Semen

This study aimed to investigate the effects of AMPK activators metformin (Met) and acadesine (AICAR) on sheep semen cryopreservation. Firstly, Met and AICAR with different concentrations (0, 100, 200, 300, 400, 500 μmol·L^-1) were added into the frozen diluent. After freezing and thawing, the optimal concentration (400 μmol·L^-1 Met, 200 μmol·L^-1 AICAR) were selected based on sperm motility, motion performance and membrane integrity; Secondly, the collected semen was froze using different frozen diluents (control group:diluent; Met group:diluent + 400 μmol·L^-1 Met; AICAR group:diluent + 200 μmol·L^-1 AICAR). After thawing, the sperm AMPK protein expression, acrosomal enzyme activity, metabolic index, mitochondrial function and antioxidant enzyme activity were examined. The results showed that the addition of 400 μmol·L^-1 Met and 200 μmol·L^-1 AICAR could significantly improve sperm motility, motion performance and membrane integrity(P<0.05) after thawing. In 400 μmol·L^-1 Met group, the total sperm motility, acrosome integrity rate and plasma membrane integrity rate were 43.20%, 91% and 46%, respectively. Compared with the control group, the level of AMPK phosphorylation in the sperm of the Met and AICAR groups was significantly increased after thawing (P<0.05), the acrosome enzyme activity of sperm was significantly increased(P<0.05); the pyruvate level was significantly decreased (P<0.05), the lactate dehydrogenase activity, lactic acid content, and ATP content were significantly increased(P<0.05). Compared with the control group, the dilution of Met group and AICAR group was more conducive to maintain mitochondrial membrane potential (P<0.05), increase ATPase and antioxidant enzyme activity (P<0.05). The addition of appropriate concentrations of Met and AICAR could improve semen quality of cryopreservation in sheep.     

种公鸡体形外貌及精液品质性状的聚类分析

本研究对种公鸡的体形外貌及精液品质共14个性状，用统计分析软件SPSS(Ver．11．0)进行了聚类分析，结果表明：在SPSS提供的聚类分析方法中，沃特氏(Ward’s method)聚类分析法把这些性状分为5类，能较全面反映性状实际情况。这一结果为种公鸡的体形外貌、精液品质的选育提供了科学依据。     

牛冷冻精液解冻后在不同温度下的存活时间

牛冷冻精液解冻后在3～8℃、室温及37℃条件下保存,分别于2、4、8、12及24小时,观察其活力变化。结果表明:环境温度对精子的存活时间影响很大,活力的下降速度有明显差异。