共查询到20条相似文献,搜索用时 62 毫秒
1.
制成颗粒是最普通的饲料加工方法,将近一半的猪、家禽和牛饲料以颗粒形式出售。颗粒饲料除了可以避免饲喂过程中的畜禽挑食,还可增强某些营养成分的利用效率,提高动物生产性能,减少粉尘和简化饲料操作方法。由于水产颗粒饲料必须具有良好的耐水性,因而使用挤压机可以提高水产颗粒饲料质量。挤压加工使饲料中的蛋白质和淀粉粘结变形,从而提高了颗粒饲料的耐水性。非挤压加工方法主要生产沉水颗粒料。挤压能使蛋白质的组织结构致密。因此,挤压成形的颗粒饲料其耐水性能更佳,并且具 相似文献
2.
影响颗粒饲料耐久性指数的因素及其控制 总被引:1,自引:1,他引:0
<正>颗粒饲料耐久性指数(PDI,Pellet durability index)是反映颗粒饲料质量最主要的指标之一,它是用来衡量颗粒饲料成品在输送和搬运过程中饲料颗粒抗破碎的相对能力。其含义是把冷却、筛分后的颗粒饲料样品放在一个特制的回转箱中翻转一定时间,模拟饲料的输送和搬运过程,在样品翻转后通过筛分,最后 相似文献
3.
影响饲料制粒工艺效果的因素 总被引:3,自引:0,他引:3
颗粒饲料是一种由全价混合粉料或单一原料(如牧草、饼粕等)经挤压作用而制成的粒状饲料.颗粒饲料虽然制造成本较高,但是经过大量的畜禽饲养试验,证明它的饲养效果好,经济效益明显.近年来,随着饲料工业的飞速发展,颗粒饲料已逐渐被广大养殖户所接受,用量有继续增长的趋势.颗粒饲料的质量受多种因素影响.早在1992年Reimer就曾报道了影响颗粒饲料质量的因素之间存在一定的比例关系,其中饲料配方占40%、粉碎粒度占20%、调质占20%、环模规格占15%、冷却干燥占5%.可见饲料原料的选择对颗粒饲料的质量影响最为重要. 相似文献
4.
挤压膨化水产饲料的要点 总被引:3,自引:0,他引:3
近几年来,我国水产养殖发展比较快,而水产养殖的关键是提供能满足水产动物营养摄食习惯的各种形态的饲料,这种饲料应制成浮性(上层鱼类、蛙类)、慢沉性(中下层鱼类)、沉性(河蟹、虾类)三类,并且在水中能够完整地保持一定时间,以便动物有足够的摄食时间。要制出各种沉降速度的饲料,只有利用挤压膨化技术,这是其他制造技术难以实现的。为满足水产养殖者需求,盐城市浓缩蛋白饲料厂在1996年从美国Wenger公司引进全套膨化饲料生产线,陆续开发生产了河蟹、虾类、蛙类、经济鱼类等沉浮颗粒饲料,其典型颗粒直径范围是1… 相似文献
5.
<正>颗粒饲料使动物(包括肉鸡、猪、牛、蛋鸡等)的生产表现总体提高5%~10%。颗粒饲料加工成本在美国是5~20美元/t,因饲料种类、加工设备及生产管理而异。鱼类颗粒饲料,特别是虾饲料,加工成本更高,但它带来的效益也更高,不论是水产养殖本身还是环境 相似文献
6.
利用挤压技术生产的水产膨化饲料具有普通颗粒饲料无法比拟的优势。本文从技术角度对挤压生产中的原料、设备、工艺、操作等进行了理论阐述。 相似文献
7.
8.
9.
近年来,水产养殖规模不断扩大,养殖技术不断更新,养殖品种不断增加,尤其是网箱养鱼、流水养鱼、特种水产养殖的迅速崛起,传统的养殖技术已越来越不适应现代经济发展的需要.传统的粉状配合饲料和颗粒配合饲料由于存在着水中稳定性差,沉降速度快,易造成饲料散失浪费和水质污染等弊端,也正面临着严峻的挑战,而膨化饲料能较好地克服粉状和硬颗粒饲料的弊端,是现代水产养殖业的理想饲料品种,已显示出较好的市场前景,水产膨化饲料将是未来水产饲料发展的必然趋势. 相似文献
10.
制粒和膨化加工技术在水产饲料生产上的应用分析 总被引:3,自引:0,他引:3
我国是世界第一水产大国,水产养殖年增10%以上,由于水产养殖业的持续发展和颗粒饲料在水产养殖业中的应用,促进了水产养殖业向高密度、集约化方向发展。为了提高饲料的转化率、改善水体的环境,水产养殖业一直在通过优化饲料配方及选择最佳的机械设备去提高颗粒饲料的质量。实际上,根据鱼类有肠道短、饲料在肠道内的停留时间短的生理特点,只要采用适当的加工方法,同样可达到改善水质、减少鱼病、增强养殖业的可持续性、提高产量和产品质量、提高饲料转化率和经济效益的效果。本文就是从通过分析比较生产水产饲料的两种加工方法——… 相似文献
11.
12.
13.
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
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