肝素或钙离子载体诱导牛、羊冻精体外获能的研究

本文采用肝素或钙离子载体(I-A)诱导牛、羊冻精体外获能,根据对去透明带仓鼠卵的穿透情况评定获能效果,并用台盼蓝·姬姆萨(TG)染色观察了精子的死活及顶体状态.结果发现,牛、羊冻精经肝素或I-A处理后与卵子一起培养,2 h穿透仓鼠卵,4 h开始形成雄原核,6 h形成发育良好的雄原核.牛冻精用50μg/mL肝素及0.1μmol/L I-A处理效果最好,穿透率分别为72.8％和92.3％;羊则以20μg/mL肝素及0.3μmol/L I-A为宜,穿透率分别为73.1％和68.O％.咖啡因与I-A或肝素并用均有协同作用,能提高精子的穿透能力,并能促进卵内原核的发育.肝素和I-A均能在体外诱导牛、羊冻精的顶体反应,有顶体反应活精子百分率与穿透率呈强正相关,羊冻精比较脆弱,获能处理后活力较低.     

精粗比条件下新疆芦苇在断奶初期奶公犊瘤胃内动态降解的研究

选用3头三月龄左右装有瘤胃瘘管的荷斯坦公犊,按3×3完全拉丁方试验设计,喂给三种日粮,日粮组成按精粗比分别表示为:Ⅰ:70∶30;Ⅱ:60∶40;Ⅲ:50∶50,研究不同日粮组成下新疆芦苇的DM、CP以及NDF在断奶初期奶公犊瘤胃内动态降解。结果表明:精粗比为60∶40日粮时,其CP的消失率和降解参数显著低于精粗比为70∶30和50∶50的日粮(P<0.05);其DM和NDF的消失率和降解参数显著高于精粗比为70∶30和50∶50的日粮(P<0.05)。     

中国荷斯坦牛凝血因子XI缺陷症遗传分析

凝血因子XI缺陷症（FactorXIdenciency）是荷斯坦牛的一种常染色体单基因控制的隐性遗传缺陷。该病的遗传基础是由位于牛第27号染色体的凝血因子XI基因外显子12上发生的一段76bp序列插入。本研究采用PCR方法对我国13个主要公牛站的571头荷斯坦公牛的凝血因子XI基因进行了全面检测,未发现隐性有害基因携带者和纯合个体。     

牛精液冷冻保护剂研究进展

牛的人工授精技术是目前应用最为广泛的动物繁殖技术之一,对牛的遗传改良做出了巨大贡献。但是,在冷冻一解冻过程中仍然有大约40％～50％的精子失去活性,限制良种公牛种用性能的发挥。论文在分析精子冷冻保存原理的基础上,阐述了渗透性、非渗透性冷冻保护剂以及低密度脂蛋白对牛精子的冷冻保护作用,以期为开发新型冷冻保护剂的研究提供一定参考,进一步提升牛冷冻精液的质量。     

Sperm subpopulations influence the pregnancy rates in cattle

This study aimed to study the characteristics and subpopulations of spermatozoa from bulls with low and high reproductive performance based on pregnancy rates. Based on historical records of pregnancy rate from four farms, 24 bulls were selected. Two groups were established, with low pregnancy rates (n = 12; LOW), including bulls that presented pregnancy rates <52.27% (33.33% to 51.81%); and a group with high pregnancy rates (n = 12; HIGH), with pregnancy rates >52.27% (52.27% to 69.64%), after fixed-time artificial insemination (FTAI). The thawed sperm straws were analysed to sperm kinetics, morphology, plasma membrane integrity and sperm subpopulations. The LOW group exhibited a higher proportion of static cells (p < .05). In contrast, the HIGH group showed greater percentages for membrane integrity and total and progressive motility, and cells with fast and medium velocity (p < .05). In the cluster procedures, four sperm subpopulations were established. The low-fertility bulls presented the highest percentage of subpopulation 2 (41.46%), characterized by slow and progressive spermatozoa. The high-fertility bulls exhibited the highest percentage of subpopulation 3 (37.17%), characterized by fast and nonlinear spermatozoa. Results from this study indicated that bulls with greater percentages of fast and nonlinear spermatozoa seem to have greater fertilization capacity and the subpopulations analysis can be considered a tool to identify ejaculates with high fertility.     

Increased Inflammatory Mediators in Horses Naturally Infected with Trypanosoma vivax. A Preliminary Study

The aim of this study was to measure the levels of inflammatory mediators in serum from horses naturally infected with Trypanosoma vivax. Banked serum samples collected during a previously reported T. vivax natural infection were used to analyze proinflammatory cytokines such as interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), interleukin 1 (IL-1), interleukin 6 (IL-6), and nitrite/nitrate (NO_x) levels. We evaluated 12 serum samples from horses from a farm in southern Brazil, four of which had parasitological and molecular diagnoses for T. vivax and presented with clinical signs of disease. Cytokines were assessed by quantitative sandwich enzyme-linked immunosorbent assay, and NO_x was measured using the modified Griess method. Levels of IFN-γ, TNF-α, IL-1, IL-6, and NO_x were increased in serum of infected animals compared to that in noninfected animals. Therefore, infection with T. vivax caused an increase in proinflammatory cytokines and nitric oxide content.     

季节变化对不同品种种公牛精液品质的影响研究

 选择3~4.5岁的四个品种种公牛25头,观察季节变化对其次均采精量、平均密度、平均活力、精子畸形率、精液利用率及制冻数量的影响并进行比较。结果显示：在四季变化中,除次均采精量要显著低于国外引进品种外,鲁西牛种公牛精液的平均密度、平均活力、精子畸形率、精液利用率及次均制冻数量均表现出一定的优势。因此,鲁西牛作为地方品种受季节变化影响最小,繁殖性能更为稳定。     

The influence of crossbreeding on collagen solubility and tenderness of Infraspinatus and Semimembranosus muscles of semi‐intensively reared young bulls

The aim of the present study was to investigate the effects of crossbreeding on collagen content and solubility, shear force (WBSF) and the eating quality of Infraspinatus (INF) and Semimembranosus (SM) muscles of young bulls and the relationships between collagen content and solubility, shear force and the eating quality of beef. The experimental material comprised muscles of crossbred young bulls (about 600 days old) of Polish Holstein‐Friesian (PHF) × Limousine (LM) (n = 10), PHF × Charolaise (CH) (n = 9), PHF × Hereford (HER) (n = 9) breeds. The crossbreeding influenced WBSF, aroma and taste, total, water‐soluble, acid‐soluble, total soluble and insoluble collagen content, as well as the acid‐soluble, total soluble and insoluble collagen proportions. WBSF was significantly negatively correlated with sensorial tenderness and water‐soluble collagen content. The eating quality of beef obtained from different crossbreds was similar; however, the meat from PHF × LM and PHF × HER bulls had lower WBSF values than PHF × CH bulls. © 2016 Japanese Society of Animal Science     

番茄红素对秦川牛精液冷冻保存及鲜精品质影响

旨在探究番茄红素对秦川牛精液冷冻保存和新鲜精液品质的影响,为番茄红素作为新型精液稀释液添加剂和种公畜日粮添加剂提供依据。本研究采集3头年龄3~5岁健康状况良好秦川种公牛的新鲜精液混合,用0、1、2、3、4 μmol·L^-1浓度的番茄红素稀释液冷冻保存;利用计算机辅助分析仪、低渗肿胀检测法、花生凝集素荧光标记检测法、罗丹明荧光检测法等检测精子的运动性能、顶体完整率、质膜完整性、线粒体活性和抗氧化性能;在秦川种公牛日粮中添加15 mg·kg^-1 BW番茄红素,检测饲喂前后秦川种公牛的新鲜精液品质和血清抗氧化指标。结果表明,在秦川牛精液冷冻保存过程中添加番茄红素可以显著提高冷冻-解冻后精子的活力、顶体完整率、质膜完整性和线粒体活性以及抗氧化酶CAT和GSH-Px酶活性,显著降低精子中MDA含量,且番茄红素的最适添加浓度为2 μmol·L^-1(P<0.05);饲喂15 mg·kg^-1 BW番茄红素后,与饲喂之前相比,秦川种公牛的精子活力显著提高(P<0.05),精子畸形率显著降低(P<0.05),血清中抗氧化酶SOD、CAT、GSH-Px酶活性显著增加(P<0.05),MDA含量显著降低(P<0.05)。综上所述,一定浓度的番茄红素对精子在冷冻过程中造成的精子损伤和秦川牛机体应激造成的繁殖性能降低具有良好的保护作用,这可能与番茄红素通过抗氧化作用减少精子在冷冻-解冻过程中的氧化损伤和提高动物机体的抗氧化能力有关。     

Effects of glutathione treatments during sperm washing and in vitro fertilization on the in vitro early development of embryos of Japanese Black cattle

This study was conducted to examine the effects of adding glutathione (1 mM) to media used for sperm washing and in vitro fertilization (IVF) on the improvement of early development of embryos produced using cryopreserved spermatozoa of the less IVF-competent bull (the one considered unqualified as spermatozoa supplier for the production of bovine blastocysts using IVF). The cryopreserved spermatozoa of this bull were characterized by normal motility and lower ATP content and blastocyst productivity than those of IVF-competent bulls. The addition of glutathione to the sperm washing medium was more effective in improving the productivity of blastocysts and ATP content than the addition of glutathione to the IVF medium or no glutathione addition at all (control). These results suggest that this simple method may be used to improve the potential of cryopreserved spermatozoa of less IVF-competent bulls to fertilize oocytes in vitro and to induce normal embryonic development after fertilization.