不同季节对种公牛精液品质的影响

种公牛优良的精液对牛群的遗传改良起着极其重要的作用,为了提高种公牛精液品质与冷冻精液的质量,通过对不同季节种公牛精液的原精活力、鲜精密度、射精量及冻后活力的变化进行总结分析,研究不同季节对种公牛精液的品质的影响。结果表明:春季种公牛鲜精活力、密度、冻后活力最佳;夏季鲜精活力与冻后活力最差;秋季射精量最高但密度最低,鲜精活力与冻后活力仅高于夏季;冬季射精量最低,但鲜精活力、密度及冻后活力仅次于春季。因此,充分利用适宜生产的季节,合理安排采精,可提高种公牛的鲜精品质,进而提高冻精产量,使优秀种公牛的遗传潜力得到最大的发挥。     

季节变化对德州驴精液品质的影响

为探究季节变化对成年德州种公驴精液品质的影响,本研究对东阿国家黑毛驴繁育中心9头种公驴2016—2019年的采精状况进行统计分析,并按气温分为春季(3—5月)、夏季(6—8月)、秋季(9—11月)、冬季(12—次年2月)。结果表明:春、夏季公驴射精量最多,平均精液量均超过56 mL,显著高于秋、冬季节;秋季种公驴的原精密度最大,显著高于其他季节,与原精密度最低的春季相比,升高幅度超过25%;种公驴在秋季原精活力最高,达到0.88,且显著高于其他季节,而夏季的原精活力最低,仅为0.81,但与春、冬季无统计学差异;经过冷冻再解冻后,春、秋两季生产的冻精其冻后活力显著高于夏季和冬季,冬季生产的冻精其冻后活力最低,较春季降低约22%;种公驴精子冷冻复苏率在夏季时最低,显著低于其他季节,春季和秋季的复苏率相对较高,但二者并无显著差异。综上,季节变化对种公驴精液质量产生明显影响,春季和秋季是优质精液生产的最有利季节。     

采精频率对德州驴精液品质的影响

为探究采精频率对成年种公驴精液品质的影响,对东阿国家黑毛驴繁育中心34头种公驴的采精状况及生产数据进行跟踪与统计分析,并将数据分为4组,A组(每3天采精1次)、B组(每4天采精1次)、C组(每5天采精1次)和D组(每10天采精1次)。结果表明:D组的总精液量显著低于其他各组(P0.05),C组的总精液量显著低于A组(P0.05)和B组(P0.05);C组精液的精子密度与D组间无显著性差异(P0.05),但显著高于A组(P0.05)和B组(P0.05);D组精液的原精活力和冻后活力均显著低于其他各组(P0.05),但A、B、C三组间差异并不显著(P0.05);D组精子的复苏率显著低于其他各组(P0.05),B组与C组间差异不显著(P0.05),但均显著低于A组(P0.05);采精频率与冻后活力、复苏率之间均呈显著负相关(P0.05)。结论:种公驴采精频率为每3天采精1次时,可以获得稳定的精液品质。     

采精年龄对德州驴精液品质的影响

以德州驴为试验动物,探究采精年龄对其精液品质的影响,旨在确定种公驴精液采集的最适年龄范围,从而最大限度地发挥优良种公驴的生产性能。对东阿国家黑毛驴繁育中心42头种公驴的采精状况进行整理,并将数据按年龄分为4组:4岁组(n=10)、5岁组(n=12)、6岁组(n=10)及7岁组(n=10)。结果表明:①采精年龄为6岁组时,其总精液量显著高于4岁组(P<0.05)和5岁组(P<0.05),但与7岁组间无显著差异(P>0.05);②采精年龄为4岁组时,其精液的精子密度与5岁组不存在显著差异(P>0.05),但均显著高于6岁组(P<0.05)和7岁组(P<0.05);③随着采精年龄的增大,各组精液的原精活力并无显著差异(P>0.05),但6岁组和7岁组的冻后活力却显著高于4岁组(P<0.05)和5岁组(P<0.05);④采精年龄为6岁组时,其精子的复苏率与7岁组不存在显著差异(P>0.05),但均显著高于其他各组(P<0.05);⑤采精年龄与总精液量、冻后活力、复苏率之间均呈极显著的正相关(P<0.01),与精子密度呈显著的负相关性(P<0.05)。结论:种公驴采精年龄为6～7岁时,可以获得较好的精液品质。     

季节和品种对种公牛鲜精液品质的影响

研究按季节和品种对种公牛采精记录进行方差分析,分别比较了季节对夏洛来、西门塔尔、利木赞、红安格斯、荷斯坦种公牛和弗莱维赫6个品种鲜精液品质的影响以及相同季节下的6个品种精液品质间的差异。分析了在季节和品种的双重条件下,精液品质间的相关性。结果表明:(1)西门塔尔、夏洛来和荷斯坦种公牛的单次射精量随季节变化排序均依次是:夏季秋季春季冬季。(2)西门塔尔、夏洛来、利木赞和红安格斯的鲜精子密度随季节变化排序依次是:春季夏季冬季秋季,且这四个品种鲜精子密度在四季的排序均为:西门塔尔夏洛来利木赞红安格斯。(3)各品种种公牛四季鲜精子活力排序均依次是:冬季春季秋季夏季;各品种种公牛鲜精子活力在四季的排序均为:利木赞夏洛来弗莱维赫、西门塔尔荷斯坦红安格斯;各品种夏季鲜精子活力均极显著低于其它三个季节(P0.01)。(4)荷斯坦种公牛鲜精子活力夏季占春季活力比率最高为(0.54/0.59),利木赞次之(0.5/0.63),弗莱维赫第三(0.47/0.6),安格斯最低(0.34/0.49)。(5)红安格斯的单次射精量、精子密度和精子活力在相同季节下都低于其它5个品种。(6)在不同季节不同品种下,种公牛的射精量与鲜精子密度和鲜精子活力的相关系数分别是0.006和~0.019,鲜精子密度和鲜精子活力的相关系数是0.253。     

牛细管冷冻精液对提高解冻后精子活力及增强优秀公牛利用率的探讨

当前评定公牛精液品质的主要依据是采精量、原精活力、精子密度、精子的冻后复活率(冻后活力/原精活力)等项指标。而公牛由于个体间的差异使以上各项评定指标,尤其使冻后解冻活力出现较大差异。精液冷冻主要目的是为充分利用优良种公牛的精液,以先进的手段--深冷技术,制成冻精剂型加以保存,然后解冻(40℃水浴)复     

德州驴体尺、性行为与精液品质的相关性研究

公牛的体型外貌性状与繁殖性状间有一定的关联性,可通过外貌标记选择种公牛,但公驴的体型外貌性状是否与繁殖性状相关,国内外一直未见报道。本文收集种公驴体重、体尺和生产过程中的性行为数据,结合公驴射精量、密度、活力、冻精活力等精液品质数据,进行统计分析。结果显示:(1)单次射精量与体高(r=0.423,P=0.044)、阴茎周径(r=0.495,P=0.043)呈正相关关系,单次射精总精子数与体重(r=0.444,P=0.036)、阴囊周径(r=0.520,P=0.039)呈正相关关系。(2)射精量与爬跨次数(r=-0.159,P=0.035)、勃起所需时间(r=-0.181,P=0.023)呈负相关关系,精液密度与交配时间(r=-0.211,P=0.004)呈负相关关系,总精子数与勃起所需时间(r=-0.159,P=0.047)呈负相关关系。结果表明精液品质与种公驴体尺、体重、性行为有一定的相关关系。     

季节对不同品种种公牛精液品质的影响

为探讨季节对不同品种种公牛精液品质的影响,实验采集了中国荷斯坦牛、西门达尔牛和日本和牛的种公牛精液周年生产数据,进行分析比较。结果表明:荷斯坦牛春、冬季原精活力达标率显著高于夏季(P0.05),冬季极显著高于夏季(P0.01);冬、秋季冻精活力达标率显著高于夏季(P0.05),秋季极显著高于春、夏(P0.01),春、冬季射精量显著高于秋季(P0.05),春季极显著高于秋季(P0.01);春、秋、冬季精液密度显著高于夏季(P0.05);西门达尔牛在春季原精活力达标率呈现最高,显著高于夏、秋季(P0.05);日本和牛冬季原精活力和冻精活力均最高,射精量四季之间无显著差异(P0.05),夏季精液密度显著高于春季(P0.05),极显著高于秋、冬季(P0.01)。春、冬季种公牛原精和冻精的达标率最佳;肉牛品种精液品质优于奶牛品种,肉牛品种中的西门达尔种公牛的精液品质优于和牛。     

饲料中添加Penergetic-T对种公牛精液品质的影响

试验旨在研究 Penergetic-T 对种公牛精液品质的影响,选择 120 头健康无疾病的西门塔尔种公牛随机分为试验组和对照组,每组 60头,每头牛为 1个重复。对照组饲喂基础日粮,试验组在基础日粮中添加 0.25 g(/ d 头)Penergetic-T,共饲喂 90 d,检测射精量、精子密度、冻精产量及精子活力、精子畸形率。结果表明:饲料中添加 Penergetic-T 种公牛鲜精的射精量、精子密度、冻后产量、精子活力及畸形率均优于对照组,且差异显著。说明,饲料中添加 Penergetic-T 可显著提高种公牛的精液品质与冻精产量,给种公牛站带来更多的经济价值。     

南德温种公牛原精、冻精品质初步分析

本文通过统计 1 999年～ 2 0 0 2年 4年中南德温种公牛采精记录 ,对采精量、原精密度、原精活力以及冻后活力进行初步的总结 ,并就这 4项内容的数据进行各季节及各年的相互比较分析。通过数据分析 ,初步总结出了南德温这一引进的新品种鲜精和冻精的品质特性。不同的年份和季节对南德温牛精液无明显影响     

癸氧喹酯干混悬剂含量测定的改进

采用高效液相色谱法测定癸氧喹酯干混悬剂的含量,在2-250μg/mL范围内,峰面积的常用对数与进样量浓度的常用对数呈良好的线性关系,R^2=1(n=5),平均回收率为99.24%~99.51%,RSD在0.05%~0.28%。此方法分析时间短,样品前处理简便、定量结果准确,重现性好,结果满意,为其质量控制提供了依据。     

猪毛色遗传的研究进展

本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。     

商会自治的基石——商会自治规范研究

在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。     

獭兔睾丸的组织学观察

家兔作为一种实验动物 ,推动了繁殖技术的发展。本试验通过对不同年龄公獭兔的睾丸进行组织学观察、测定 ,研究精子的发生规律 ,为系统地进行繁殖生理工作提供依据。1　材料与方法选 60日龄、75日龄、90日龄 3个年龄公獭兔各5只 ,用外科手术法摘取两侧睾丸 ,放入 Bouin氏液中固定 ,二甲苯透明 ,石蜡包埋 ,切成 5～ 8μm切片 ,H.E.染色。在显微镜下观察 ,并进行定量组织学指标测定及差异性比较。2　结果和讨论2 .1　睾丸定量组织学指标的测定结果　见表 1。表 1　獭兔睾丸定量组织学指标　　　μm,个 /精细管60日龄 75日龄 90日龄曲细精管…     

中华人民共和国农业部公告 第267号

为贯彻落实《兽药生产质量管理规范》(简称《兽药GMP》),进一步推动兽药GMP实施进程,我部制定了《兽药生产质量管理规范检查验收办法》,现予公告。本公告自2003年6月1日起施行。附件:兽药生产质量管理规范检查验收办法二○○三年四月十日第一章 总则 第一条 为推动《兽药生产质量管理规范》(以下简称兽药GMP)的实施,规范兽药GMP检查验收工作,制定本办法。 第二条 农业部负责全国兽药GMP管理和检查验收工作;负责制修订兽药GMP检查验收管理规定;负责兽药GMP检查员队伍建设和监督管理工作,负责国际兽药贸易中GMP互认工作。 …     

鸡败血支原体垂直传播模式及其阻断方法

以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。     

Observations of fracture of the anconeal process of the ulna of swine

Fractures of the anconeal process of 5 pigs ranging in age from 4 to 8 months were studied radiographically and histologically. Clinically, animals with a fracture of the anconeal process had a "tight," restricted gait. In pigs at 4.5 months of age, a radiolucent line through the base of the anconeal process was composed of fibrocartilage, fibrous connective tissue, and hyaline cartilage. Subperiosteal proliferation of woven bone was located along the cranial surface of the olecranon, adjacent to the base of the anconeal process. In older animals, the radiolucent line through the anconeal process contained variable amounts of fibrous connective tissue and fibrocartilage. The proliferation of subperiosteal bone at the base of the anconeal process formed a "buttress callus" which retained a radiolucent area between the callus and the proximal surface of the anconeal process. The latter region of radiolucency was continuous with the transversely oriented line that traversed the base of the anconeal process.     

Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF

Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo.     

Comparison of 2 methods of centesis of the bursa of the biceps brachii tendon of horses

REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air.