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选用１日龄艾维茵仔鸡４０００只随机分成两组，育雏床上分别采用３５℃和３２℃的初温，以后每周降３℃，比较两组仔鸡在２周龄以内的增重和死亡情况。结果显示一周内肉鸡的增重高温组高于低温组，差异显著（Ｐ＜０．０５）；第二周内增重差异不显著（Ｐ＞０．０５）；二周内鸡的死亡数为高温组低于低温组，差异极显著（Ｐ＜０．０１）。鸡７周龄出栏时料肉比：高温组为１．９４，低温组为２．０１；７周龄出栏平均体重：高温组为２．４９ｋｇ，低温组为２．３０ｋｇ。３５℃初温育雏肉鸡的效果好于３２℃初温。 相似文献
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环境温度对肉用鸡血液生化指标影响的研究 总被引：3，自引：0，他引：3
利用72只32日龄京白904肉仔鸡(公母各半)研究环境温度(简称温度)对血液生化指标的影响。试验采用3×2析因设计。试验鸡在8℃、24℃、30～32℃下处理14d,测定肉用公母鸡在3种温度处理后的第0天、第3天和第14天时的血液生化指标。试验结果表明,温度和性别对血清葡萄糖、尿酸影响不显著(P>0.05)。温度对血清尿素氮影响极显著(P<0.01)。低温组血清尿素氮极显著高于常温组(P<0.01),而常温组及低温组与高温组间差异均不显著(P>0.05)。性别间血清尿素氮差异不显著(P>0.05)。 相似文献
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不同温度育雏与雏鸡白痢发生率关系的试验研究 总被引：2，自引：0，他引：2
选择1日龄新罗曼褐壳商品代蛋雏鸡300只,随机分为3组,即对照组、试验Ⅰ组、试验Ⅱ组。在相同的采食、饮水、饲养管理条件下,采用不同环境温度进行育雏,对照组正常温度育雏;试验Ⅰ组高温育雏(比正常育雏温度高2℃);试验Ⅱ组低温育雏(比正常育雏温度低2℃)。结果表明,高温育雏能明显降低雏鸡白痢发生率,提高雏鸡成活率;低温育雏有使雏鸡白痢发生率增高的趋势。经统计分析,高温育雏组雏鸡白痢发生率与对照组之间存在显著差异(P<0.05)。 相似文献
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用黄芩多糖作为饲料添加剂,研究其对内用仔鸡主要营养物质代谢率以及生长性能的影响。试验选用体重相近的AA肉仔鸡120只,随机分成4个处理,每个处理3个重复,每个重复10只。各组基础日粮相同,试验组分别在基础日粮中按100、200和400 mg/kg饲粮添加黄芩多糖;并分别在第3周龄和第5周龄各进行4 d代谢试验,在7、14、21、35和49日龄以组为单位称重、称余料,计算耗料量、日增重和料重比。分别于21、35和49日龄每组随机取3只体重接近平均体重的鸡进行屠宰,采血,制备血清,进行相关指标检测。试验结果表明,在试验添加量范围内,黄芩多糖对内仔鸡养分代谢率具有降低作用,且对0-3周龄肉仔鸡的影响要大于3-7周龄。在3-7周龄,粗蛋白代谢率最高的是200 mg/kg黄芩多糖添加组,比对照组高24.04%,差异显著(P0.05)。200 mg/kg黄芩多糖添加组对内仔鸡体重、日增重和料肉比影响较显著。 相似文献
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高温条件下湿度对肉用仔鸡干物质和能量采食量及代谢率的影响 总被引：1，自引：0，他引：1
分别用4～5周龄艾维茵肉用仔鸡216只和6～7周龄180只分两阶段进行了试验,第1阶段同在32℃气温下设置30％,60％,90％相对湿度,第2阶段,同在30℃气温下设置30％,60％,90％相对湿度,分别测定对干物质及能量的采食量和表观代谢率.每个处理设6个重复,每阶段试验期为2周.结果表明,高温条件下,相对湿度显著影响4～5周龄肉仔鸡的干物质采食量和能量采食量(P<0．05),而对6～7周龄肉鸡无显著影响;高温条件下6～7周龄高湿组的干物质代谢率和能量代谢率较高(P<0．05),而4～5周龄阶段这一差异不显著 相似文献
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以添加不同水平的牛磺酸日粮饲喂艾维茵商品代肉仔鸡,探讨牛磺酸对肉仔鸡生产性能和消化功能的影响.试验研究表明:日粮中添加牛磺酸可以提高肉仔鸡的生产性能和平均日增质量,降低料肉比,其中以0.1％添加量效果最为显著.对各消化器官指数影响差异不显著,能提高3周龄肉仔鸡胰腺消化酶活性,其中对胰蛋白酶影响差异显著,对6周龄肉仔鸡胰腺消化酶活性影响差异不显著.结果表明:牛磺酸可以提高肉仔鸡生产性能,对消化功能影响不显著. 相似文献
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网上平养育雏舍不同位置环境参数变化和蛋鸡生长性能研究 总被引：1，自引：0，他引：1
试验通过对网上平养育雏鸡舍前端和后端环境指标持续监测,分析不同周龄不同位置的有害气体和粉尘分布规律。环境参数结果显示:网上平养育雏鸡舍后端的温度、氨气和粉尘浓度极显著高于前端(P0.01),前端湿度极显著高于后端(P0.01);后端二氧化碳浓度略高于前端(P0.05);随周龄增加和通风量加大,温度、氨气和二氧化碳浓度逐步降低,最后趋于稳定,湿度逐步升高,2~5周龄鸡舍粉尘浓度逐步升高,5周龄后急剧降低;除了鸡舍室内湿度低于标准要求外,温度、氨气、二氧化碳、粉尘等环境参数均符合养殖场空气质量标准。生产性能结果显示:蛋鸡体重随周龄增加呈线性增加,且鸡舍前后端鸡只体重差异不显著(P0.05);胫长在7周龄前呈线性增加,7周龄之后增加幅度放缓,且前后端差异不显著(P0.05)。 相似文献
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正了解肉用仔鸡的发病特点及规律,掌握肉用仔鸡的疾病防治技术,才能更好地进行饲养管理。肉用仔鸡生长发育特点1.生长速度快、饲养周期短、饲料报酬高一般肉用仔鸡孵出时体重为40g左右,育雏期(0～3周龄)体重可达0.6kg左右;快速生长期(4周龄以上至出栏体重)可达2.0kg左右。目前肉用仔鸡的料肉比一般为1.95∶1～1.70∶1的水平。2.各组织器官和肌肉的生长发育不均衡肉用仔鸡的生长发育过程中,肌肉的生长速度远快于内脏的生长发育。心肺不能满足肌肉快速生长对血氧的需要,而常导致代偿性疾病的发生,特别是腿骨和胸骨表面长期受压,因此很容易出现腿部和胸部疾病。 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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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
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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