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我国的白羽肉鸡业经过20多年的发展,通过引进、消化和吸收国外先进的技术取得了巨大的成就,培育形成了稳定的消费市场,已成为我国畜牧业不可或缺的产业之一。根据目前的发展形势和有关部门的预测,2010年我国白羽肉鸡父母代饲养量将达到约3 700万套,年饲养白羽肉鸡约50亿只。但是,我国的肉鸡种源全部依赖进口,这不仅造成了大量外汇支出,同时对肉鸡种质安全带来了极大的威胁。因此,开展白羽肉鸡育种成了国家行政主管和业界学者的热衷话题,同时引起了肉鸡产业中的企业普遍关注,并引发了是否开始我国的白羽肉鸡育种问题的激烈讨论。本文从以下几个方面探讨我国快长型白羽肉鸡育种中的关键问题。 相似文献
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我国肉鸡饲养业现状及对策思考 总被引：4，自引：0，他引：4
1 我国肉鸡饲养业的现状及存在问题 1.1 肉鸡品种 我国肉鸡主要由白羽肉鸡、优质肉鸡两部分组成.白羽肉鸡主要是指快大型肉鸡,从国外引进,是我国肉鸡生产主导品种,先后从7个国家引进了12个肉用祖代鸡品系,主要品种有AA 、罗斯308、科宝和海波罗等,年商品鸡出栏约在32亿只,占整个肉鸡商品生产总量的64%左右. 相似文献
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我国黄羽肉鸡生产现况和发展前景 总被引：1，自引：0，他引：1
肉鸡是由白羽肉鸡、淘汰蛋用老母鸡和优质黄羽肉鸡三部分组成的。所谓快大型白羽肉鸡是指从国外引进的快大型肉鸡,是我国肉鸡生产主导品种,数量最多。所谓蛋用淘汰老母鸡,是指我国产蛋用母鸡,饲养周期到500天左右,就要全部淘汰,全国有几十亿只经过屠宰出售当作肉鸡,也有的被加工成各种各样的烧鸡、烤鸡等 相似文献
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文章针对我国白羽快大型肉鸡祖代鸡完全依赖进口的现状及我国开展白羽快大型肉鸡育种工作的必要性,从国家战略需求、现状与发展趋势、发展思路、战略目标与任务、重点任务安排、相关建议等方面对我国开展白羽快大型肉鸡育种工作进行了探讨。 相似文献
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这里所说的商品肉鸡，是指白羽快大型肉仔鸡AA和艾维茵，是由美国爱拔益加育种公司和艾维茵育种公司引进我国的。自从肉鸡品种引起我国至今，笔者一直在做饲养和服务这两项工作。下面扼要谈谈自已的体会，仅供参考。 相似文献
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本文所说的优质肉鸡是有别于外来的白羽快大肉鸡的有色羽鸡种，它肉质肉味胜过白羽快大鸡，体型较小，生长较慢，在我国大陆和台湾约占肉鸡市场的65％，有广阔的发展前景。但各地市场对优质鸡的质量要求各有不同，大体上有高低档之分。本女就我区优质肉鸡的育种成就与展望试作一次综述，就教于同行们。1成就经十多年的努力，我区育成了快大型、中大型、慢大型、矮脚型、抗病型等五个优质肉鸡种。1．1快大型即良风花鸡，南宁市养鸡厂育成，含有海兰白鸡和本地鸡血统，其特点是体型外貌酷似上鸡，骨骼细，生活力强，父母代66周龄产蛋177枚；商… 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