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用1日龄樱桃谷肉鸭900只，要用二因素三水平的完全随机设计研究光照制度对肉鸭生产性能和脂肪沉积的影响。结果表明，光照制度和公母的分群方式分别对肉鸭的日增重有显著影响（P＜0．05）和极显著影响（P＜0．01）；对肉鸭的死亡率和饲料转化率均无显著影响（P＞0．05）；对肉鸭的腹脂率和脂率均有极显著的影响（P＜0．01）。以间隙光照制制和公母分群饲养的效果最好。 相似文献
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用1日龄樱桃谷肉鸭900只,采用二因素三水平的完全随机设计研究光照制度对肉鸭生产性能和脂肪沉积的影响.结果表明,光照制度和公母的分群方式分别对肉鸭的日增重有显著影响(P＜0.05)和极显著影响(P＜0.01);对肉鸭的死亡率和饲料转化率均无显著影响(P＞0.05);对肉鸭的腹脂率和皮脂率均有极显著的影响(P＜0.01).以间隙光照制和公母分群饲养的效果最好. 相似文献
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本试验选用1日龄樱桃谷肉鸭20只，随机分为2个组，每组2个重复，每个重复50只肉仔鸭，试验采用单因素试验设计，以探讨间歇光照制度对肉鸭生产性能和经济效益的影响。结果表明：间歇光照制度对肉鸭的增重，死亡率和饲料转化率均无显影响（P＞0．05）。对采食量有显影响（P＜0．05）；对经济效益有显影响（P＜0．05）。 相似文献
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本试验选用１日龄樱桃谷肉鸭９００只，随机人灵９个组，每组２个重复，每个重复５０只肉仔鸭。试验组采用二因素、每个因素三个水平的完全随机设计，以研究光照制度对肉鸭生产性能和脂肪沉积的影响。结果表明：（１）日增重：光照制度和公母的分解方式对日增重分别有显著影响（Ｐ〈０．０５）和极显著影响（Ｐ〈０．０１），间歇光照组显著优于渐增光照组（Ｐ〈０．０５），连续光照组与间歇光照组，渐增光照组差异不显著（Ｐ〉０．０５），连续光照组与歇光照组、渐增光照组差异不显著（Ｐ〉０．０５）；公鸭组的日增重极显著高于母鸭组和公母混群组（Ｐ〈０．０１），母鸭组与公母混群组差异显著（Ｐ〈０．０５）。（２）死亡率，光照制度及公母的分群方式对肉鸭的死亡率均无显著影响（Ｐ〉０．０５）。（３）饲料转化率；光照制度及公母的分群方式对肉鸭的饲料转化率均无显 相似文献
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光照是蛋鸡生产的必要环境条件之一,不同的光照时间、强度、颜色、波长以及光照刺激的起始时间,光照和黑暗交替的持续时间,都会在家禽生长发育过程中激起一定的特异性反应,从而对蛋鸡的行为、健康状况和生产性能具有重大的影响。一般认为禽类有两个光感 相似文献
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光照作为主要的环境因素之一,影响动物的方方面面,随着畜牧业的不断发展如何提高生产效率成为关注的重点。其中光照与动物生活环境密切相关,一方面可以影响畜禽的生长,如降低料重比,提高肉品质和多种畜禽水产的成活率等。另一方面光照通过不同的光周期影响禽类产蛋率、哺乳动物发情等方面,提高畜禽繁殖性能。该文简要概述了不同光照来源、光照强度、光照时长、光波长等条件下的光照对畜牧生产的影响,简单介绍光照的作用机理,哺乳动物和禽类的感光系统,以及光照在生产管理方面的作用,旨在为畜牧生产中合理使用光照提供依据,提高畜禽的生产效率,并为后续的研究建立基础。 相似文献
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试验选用 1日龄樱桃谷肉鸭 90 0只 ,随机分 9个组 ,每组 2个重复 ,每个重复 5 0只肉仔鸭。试验组采用二因素、每个因素三个水平的完全随机设计 ,以研究光照制度对肉鸭生产性能和脂肪沉积的影响。结果表明 :光照制度和公母的分群方式分别对肉鸭的日增重有显著影响 (P <0 .0 5 )和极显著影响 (P <0 .0 1) ;对肉鸭的死亡率和饲料转化率均无显著影响 (P >0 .0 5 ) ;对肉鸭的腹脂率和皮脂率均有极显著的影响 (P <0 .0 1)。以间歇光照制和公母分群饲养的效果最好 相似文献
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光照不仅对动物繁殖性能有显著影响,对动物的生长发育等也有一定作用。长期以来,光照控制一直是禽类生产中的一项重要措施,但至今也还没有确定适合不同品种、生理阶段和生长需要的光照制度。在牛的生产中,尽管光照控制显得不像鸡那么重要,但在冬季舍饲和集约化生产的条件下,光照对牛生产性能(如体增重和产奶量)的影响日益受 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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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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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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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