提高肉种兔繁殖力的综合措施

影响肉兔繁殖力的因素众多,有种兔的品种、年龄、营养水平、配种制度和饲养管理、环境以及种兔的生殖器官疾病等方面。根据家兔生殖生理特点,通过选择优良肉兔品种、加强饲养管理、适宜的配种时间和配种方法,可显著提高肉用种兔的繁殖力。     

提高肉种兔繁殖力的综合措施

影响肉兔繁殖力的因素众多，有种兔的品种、年龄、营养水平、配种制度和饲养管理、环境以及种兔的生殖器官疾病等方面。根据家兔生殖生理特点，通过选择优良肉兔品种、加强饲养管理、适宜的配种时间和配种方法，可显著提高肉用种兔的繁殖力。     

提高肉种兔繁殖力的综合措施

影响肉兔繁殖力的因素很多,有种兔的品种、年龄、营养水平、配种制度和饲养管理、环境以及种兔的生殖器官疾病等方面.根据家兔生殖生理特点,通过选择优良肉兔品种、加强饲养管理、掌握适宜的配种时间和配种方法,可显著提高肉用种兔的繁殖力.     

提高肉用种兔繁殖力的方法

在饲养肉兔中，种兔繁殖的好坏，直接关系到养殖户的经济效益。影响肉兔繁殖力的因素众多，根据家兔生殖生理特点，通过选择优良肉兔品种、加强饲养管理、适宜的配种时间和配种方法，可显著提高肉用种兔的繁殖力。     

提高肉兔繁殖力的措施

影响肉兔繁殖力的因素众多,如种兔的品种、年龄、营养水平、配种制度和饲养管理、环境以及生殖疾病等。根据家兔生殖生理特点,通过选择优良肉兔品     

生产无公害肉兔的技术要点

1 肉兔品种选择 　　《无公害食品肉兔饲养管理准则》中指出,肉兔是指在经济或体形结构上用于生产兔肉的品种（系）.肉兔从品种上看有伊拉兔、布列塔尼亚兔、齐卡兔、新西兰兔、加里福尼亚兔、大耳白等.生产商品肉兔的种兔应来自有种兔生产经营许可证的种兔场,种兔应生长发育正常,健康无病.引进的种兔应隔离30 d,经观察无病后,方可加入生产群,不要从疫区引兔,肉兔场要逐渐做到自繁自养。     

提高獭兔繁殖率的综合措施

<正>影响獭兔繁殖率的因素有很多,诸如品种、年龄、营养水平、配种制度、饲养管理、环境控制以及疫病防治和种兔的性疾病(如种兔的生殖器官疾病)等等。因此,必须系统地了解獭兔的生殖生理特点,选择优良的獭兔种兔品种,加强饲养管理,掌握适宜的配种时间和配种方法等,认真掌握好獭兔的繁殖技术才能更好地提高獭兔的繁殖效率和兔群质量。     

提高种兔繁殖力的措施

<正>在肉兔场中，种兔的繁殖水平，直接影响养殖场的生产与经济效益。然而种兔的繁殖水平受诸如种兔的质量、初配年龄、配种方式、兔舍环境等多种因素的制约。因此需从种兔选择、初配与繁殖时间、配种方式与时机、繁殖密度等方面着手，科学利用人工授精技术、加强饲养管理、提高种兔健康体魄，以有效提高种兔的繁殖能力、增加养殖收入。但必须以充足的营养条件为前提，保持营养全面均衡，除了供给充足的糖类、脂肪和蛋白质外，还要补充丰富的维生素、微量元素、矿物质等，同时要注意适当补充青绿多汁饲料，维持良好的种用体况。     

肉兔的繁殖技术要点

1科学地确定初配年龄公母兔达到性成熟后,虽然已能配种繁殖,但因身体各器官仍处于发育阶段,未能达到体成熟,此时不能配种,若此时配种(称为过早配种)不仅会影响公母兔的生长发育,而且配种后受胎率低,产仔数少,仔兔初生体重小,成活率低;但也不能过晚配种,过晚配种会影响繁殖数量,并容易引起种兔本身肥胖,生殖机能降低。确定肉兔的初配年龄,主要根据体重和月龄来决定,在正常饲养管理条件下,公母兔体重达到该品种标准体重的70%时,即已达到体成熟,就可开始配种繁殖。一般认为,小型品种初配年龄为4～5月龄,体重2.5～3kg;中型品种为5～6月龄,体重3.…     

提高种兔繁殖能力的方法

在种兔饲养过程中,为了提高种兔繁殖能力,需要了解种兔繁殖情况,帮助种兔适时配种和受孕,同时根据种兔不同生长阶段的发育特点,提供合理的饲养方法,并掌握一些日常管理技巧,促使种兔充分发挥繁殖潜力。     

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。     

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。     

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.     

不同样本商品蜂蜜中硒含量的测定

用硝酸和高氯酸消化蜂蜜,使硒游离出来,在微酸性环境下,硒和2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm,荧光波长518nm处测定其荧光强度。蜂蜜中硒含量范围:0.10～0.82μg/g。表明:蜂蜜应视为天然富硒营养品。     

乳酸杆菌益生作用机制的研究进展

乳酸杆菌作为益生菌广泛用于人和动物。本文综述了乳酸杆菌改善宿主健康的机制。乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道。文章重点讨论了乳酸杆菌表面成分（表面蛋白、脂磷壁酸和肽聚糖）与肠道受体（Ｃ型凝集素受体、Ｔｏｌｌ样受体和 Ｎｏｄ样受体）,阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制。     

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。     

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.