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猪具有较强的繁殖能力，母猪产仔的多少除了与母猪有关外，还与公猪的品种、饲养管理及适时合理利用好种公猪有密切的关系。在实际生产中，公猪是种猪群的重要组成部分，但经常被生产者忽略。种公猪理想的繁殖性能具有很重要的价值，因为相对较小数量的种公猪要配相当大数量的母猪，俗语：母猪好好一窝，公猪好好一坡。因此，种公猪生产性能的好坏是科学养猪、提高母猪产仔数、降低饲养成本、提高经济效益的一项重要保证。 相似文献
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在实际生产中,公猪是种猪群的重要组成部分,但经常被生产者忽略。种公猪理想的繁殖性能具有很重要的价值,因为相对较小数量的种公猪要配相当大数量的母猪,俗语:母猪好好一窝,公猪好好一坡。因此,种公猪生产性能的好坏是科学养猪、提高母猪产仔数、降低饲养成本、提高经济效益的 相似文献
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张云庆 《养殖与饲料．饲料世界》2003,(9):21-22
猪具有较强的繁殖能力,母猪产仔的多少除了母猪有关的性能外,还与公猪的品种、饲养管理及适时合理利用好种公猪有密切的关系;俗话说:公好好一坡,母好好一窝。因此,种公猪的生产性能是实现科学养猪,提高母猪产仔数,降低饲养成本,提高经济效益的一项重要保证。 相似文献
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猪具有较强的繁殖能力,母猪产仔的多少除了与母猪有关外,还与公猪的品种、饲养管理及适时合理利用好种公猪有着密切的关系。在实际生产中,公猪是种猪群的重要组成部分,但经常被生产者忽略。种公猪理想的繁殖性能具有很重要的价值,因为相对较小数量的种公猪要配相当大数量的母猪,因此种公猪生产性能的好坏是实现科学养猪,提高母猪产仔数,降低饲养成本,提高经济效益的一项重要保证。 相似文献
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种公猪饲养在猪的繁殖育种中，对猪群品质改良起巨大作用，俗话说：母猪好好一窝、公猪好好一坡，但在实际生产中经常被生产者忽略。种公猪理想的繁殖性能具有很重要的价值，因此加强饲养管理对提高种公猪的繁殖力是非常重要的，尤其在采用人工授精的现代化养猪生产中更是占有举足轻重的位置。 相似文献
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在养猪生产中,公猪在养猪场猪群结构中占有非常重要的地位,是猪群的重要组成部分,但是生产者往往忽略了公猪的作用.种公猪理想的繁殖性能具有很重要的价值,因为相对较小数量的种公猪要配种数量很多的母猪.因此,对于采用人工授精进行配种的猪场,对种公猪进行科学的管理利用及对公猪精液进行规范的处理,是提高母猪产仔数、仔猪初生重、降低饲养成本、提高经济效益的重要保障. 相似文献
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<正>在养猪场,猪的繁殖是养猪生产的基础和起点,也是养猪生产的核心环节,一般对种母猪的饲养管理关注较多,对种公猪的重视程度不够。在养猪生产中,产生经济效益的主要因素是饲养母猪进行繁殖产仔,种公猪在养猪生产中非常重要,有句俗话叫"母猪好,好一窝;公猪好,好满坡"。要培育出优质、高产的母猪,还需要饲养品质优良的种公猪。本文就通过公猪的选择与 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
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。 相似文献
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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。 相似文献
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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。 相似文献
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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. 相似文献
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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. 相似文献