共查询到20条相似文献,搜索用时 68 毫秒
1.
现代肉鸡生产有三个方面的需求:饲料和饮水;环境控制;健康保护。这三个方面对肉鸡的生存和生产都是至关重要的,因此不可能把它们的重要性分出先后次序,但是环境控制的可变性最大,也是肉鸡生产者最有可能通过管理来改变的因素,从而提高成活率和生产性能。我们所讲的“环境控制”包括肉鸡舍的建筑结构及使鸡群不受外界不良环境影响的措施。环境控制涉及到重要的管理因素包括温度、空气质量、垫料质量,这些重要的管理因素是相互作用的,通常肉鸡生产者改进了一个因素的同时,也改进了其它因素。例如:当鸡舍内增加新鲜空气量时,排除舍内热空气而改… 相似文献
2.
3.
4.
生产绿色商品肉鸡,必须考虑在充分发挥肉鸡生产性能的前提下,尽可能地提高鸡肉品质。肉鸡养殖的环境控制主要包括鸡舍内外两部分。舍外环境控制主要包括场址布局与鸡舍构造、废弃物处理等;舍内环境控制主要包括雏鸡的选择、通风、光照、饲料、饮水、温度、湿度等环节。 相似文献
5.
生产绿色商品肉鸡,必须考虑在充分发挥肉鸡生产性能的前提下,尽可能地提高鸡肉品质。影响肉鸡生产性能和肉品品质的因素很多,除饲料营养外,还有品种、通风、光照等因素。因此,要降低生产成本,增加养鸡效益,使鸡的生产性能得以充分发挥,生产出高质量的产品,就必须搞好环境控制。肉鸡养殖的环境控制主要包括鸡舍内外两部分。舍外环境控制主要包括场址布局与鸡舍构造、废弃物处理等;舍内环境控制主要包括雏鸡的选择、通风、光照、饲料、饮水、温度、湿度等环节。 相似文献
6.
生产绿色商品肉鸡的环境控制技术 总被引:1,自引:0,他引:1
生产绿色商品肉鸡,必须考虑在充分发挥肉鸡生产性能的前提下,尽可能地提高鸡肉品质。影响肉鸡生产性能和肉品品质的因素很多,除饲料营养外,还有品种、通风、光照等因素。因此,要降低生产成本,增加养鸡效益,使鸡的生产性能得以充分发挥,生产出高质量的产品,就必须搞好环境控制。肉鸡养殖的环境控制主要包括鸡舍内外两部分。舍外环境控制主要包括场址布局与鸡舍构造、废弃物处理等;舍内环境控制主要包括雏鸡的选择、通风、光照、饲料、饮水、温度、湿度等环节。1舍外环境控制1.1场址布局与鸡舍构造鸡场场址以地势高燥、容易排水的平坦或稍有向… 相似文献
7.
(一)什么是舍内小气候舍内小气候是指通过温度、湿度和通风的管理给鸡舍创造一个不受外界影响,适合肉鸡生长的一个良好的小环境,这个小环境就是舍内小气候。舍内小气候控制是指控制好舍内温度、湿度和通风的关系。对于肉鸡饲养管理来说就是做好合适温度控制情况下,再协调好湿度和通风的关系。(二)鸡舍温度的管理方法 相似文献
8.
肉鸡生产的通风与温度控制 总被引:2,自引:0,他引:2
《中国家禽》2016,(19)
环境条件是影响白羽肉鸡生产效果的重要因素,也是当前鸡场建设和日常管理的主要环节。文章分析了鸡舍环境条件与肉鸡疾病之间的关系,系统论述了通风对鸡舍内其他环境因素的影响,并提出了肉鸡舍的温度和通风控制原则与措施。 相似文献
9.
10.
肉鸡腹水症是肉鸡因缺氧而导致循环障碍.继而形成以腹腔积水为特征的一种非传染性疾病。加强饲养管理、控制环境因素是防止鸣腹水症发生的关键。一、鸡舍环境控制腹水症的主要诱发因素是鸡舍内的空气污染。待别是氨气、二氧化碳、硫化氢、一氧化碳等有害气体的浓度超标.从而造成鸡体严重缺氧.引起应激反应.产生心包积液、腹腔积液、呼吸困难等一系列症状.使鸡患腹水症。舍内环境控制主要有以下几个方面。1.加强鸡舍通风换气。保持鸡舍内的空气新鲜是维持鸡健康的重要环节。一些养鸡户往往忽略了这一点.造成舍内有害气体积聚而诱发腹… 相似文献
11.
12.
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
13.
14.
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
15.
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
16.
17.
18.
19.
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
20.
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