春季半开放式鸡舍不同位点温湿度变化及蛋鸡生产性能的比较

为探讨春季半开放式鸡舍舍内不同位点温湿度变化及对蛋鸡生产性能的影响,试验选用27周龄海兰灰商品蛋鸡2 520只,按照鸡舍纵向方向分为进风口、中间、出风口3个位点进行分组,每组设12个重复,每个重复70只鸡,按照鸡舍垂直方向分为上层、中层、下层3个位点进行分组,每组设12个重复,每个重复70只鸡.结果表明:平均采食量,中间组与进风口和出风口相比显著降低(P＜0.05),上层和中层、下层相比显著降低(P＜0.01);料蛋比,上层和中层、下层相比极显著降低(P＜0.01),中间组与进风口相比差异显著(P＜0.05),与出风口相比差异极显著(P＜0.01);平均蛋重和产蛋率,进风口、中间、出风口各组之间无显著差异(P＞0.05);平均蛋重和产蛋率,上层和下层相比显著降低(P＜0.05).综合评定春季半开放式鸡舍不同位置温湿度存在梯度变化,中间组和上层笼位温湿度更接近蛋鸡最适温湿度范围,料蛋比和采食量显著降低,生产性能相对提高.     

秋季半开放式鸡舍不同位点温湿度变化及对蛋鸡生产性能的影响

为了研究秋季半开放式鸡舍内不同位点温度、湿度变化及对蛋鸡生产性能的影响,试验选用50周龄海兰灰商品蛋鸡2 520只,在鸡舍纵向方向分为进风口、中间、出风口3个位点,在鸡舍垂直方向分为上层、中层、下层3个位点,测定温度、湿度,同时测定蛋鸡生产性能。结果表明:出风口蛋鸡平均采食量与进风口相比显著增加(P0.05),与中间相比极显著增加(P0.01);进风口蛋鸡平均蛋重与中间相比显著增加(P0.05);中间蛋鸡产蛋率与出风口相比显著降低(P0.05);蛋鸡料蛋比在进风口、中间、出风口间无显著差异(P0.05)。上层、中层、下层蛋鸡的平均采食量、平均蛋重、产蛋率、料蛋比各组均差异不显著(P0.05)。说明秋季半开放式鸡舍不同位置温度、湿度存在梯度变化,受外界环境影响较大,结合环境参数变化综合评定生产性能,中间优于进风口和出风口,中层优于上层和下层。     

侧墙进风小窗位置对蛋鸡舍内环境的影响

为研究蛋鸡舍侧墙进风口不同位置高度对蛋鸡舍内小环境的影响,以及合理改善蛋鸡舍内气流分布的均匀性,以我国北方最常见的侧窗进风、纵向通风蛋鸡舍为研究对象,选择A、B两栋仅安装高度不同侧墙进风小窗的蛋鸡舍,侧墙小窗规格一致(宽0.65 m、高0.23 m),安装高度分别为2.25 m、1.65 m,分别测试两栋舍内温热参数以及舍内空气环境质量。结果显示:A、B两栋蛋鸡舍内平均温、湿度之间均差异不显著(P0.05),但不同走道间温、湿度存在显著差异(P0.05);两栋蛋鸡舍内测点风速、氨气平均浓度差异显著(P0.05);舍内二氧化碳平均浓度差异极显著(P0.01)。结果表明:A栋蛋鸡舍内温湿度波动低于B舍,测点风速普遍大于B栋蛋鸡舍风速,有害气体浓度低于B舍。说明侧墙进风口位置高度不仅影响蛋鸡舍内温、湿度状况,而且影响舍内污染物的分布及排除。     

光照强度对笼养罗曼蛋鸡产蛋性能的影响

选用１７０日龄的罗曼蛋鸡１５００羽,分为３组,分别放在上、中、下３层鸡笼,采用同样的饲养管理制度由于笼位的高低不一,使得３层鸡群同一鸡舍内所接受的光照强度不一,鸡群产蛋性能不一致。通过３０ｄ的试验表明,上层鸡层蛋率为８９．７％,中层鸡群产蛋率为９２．１％,下层以鸡群产蛋率为８８．７％。中层群比上导产蛋率高２．４％,比下层鸡群高３．４％,上层鸡群比下层鸡群产蛋率高１％,从３层笼位鸡群平均蛋重来看,各     

光照强度对笼养蛋鸡生产性能的影响

选用 170日龄的罗曼蛋鸡 15 0 0只 ,随机分为 3组 ,分别放在上、中、下 3层蛋鸡笼。试验结果表明 ,上层鸡群产蛋率为89.7% ,中层鸡群产蛋率为 92 .1% ,下层鸡群产蛋率为 88.7%。中层鸡群比上层鸡群产蛋率高 2 .4% ,比下层鸡群产蛋率高3.4% ,差异显著 (P <0 .0 5 )。上层与中层、下层蛋重差异显著(P <0 .0 5 )。     

湿帘风机降温系统对密闭笼养蛋鸡舍温湿度的影响

为评价南方夏季高温高湿气候条件下湿帘风机降温系统对密闭笼养蛋鸡舍的影响,通过自动温湿度仪采集密闭笼养蛋鸡舍内外、蛋鸡舍内不同高度、不同断面的温湿度数据,评估湿帘风机系统的使用效果。结果表明:蛋鸡舍内外温湿度表现差异显著,温度平均降低约5.4℃(P<0.05),湿度平均增高14.81%(P<0.05);鸡舍内不同高度、不同断面温湿度表现差异显著;舍内不同断面的温湿度差异大(P<0.05),因此,该系统布局有一定的局限性,需要进一步完善和调整。     

封闭式鸡舍冬季温湿度分布规律

蛋鸡舍内最佳温度为13-23℃，下限温度为7-8℃。蛋鸡舍内最适宜的相对湿度为60％-70％。由于长江下游地区空气相对湿度较大，实际生产中为充分发挥环境控制设备的作用，允许舍内相对湿度略高于适宜湿度的上限。受鸡舍结构、风机布局、控制方式等因素影响，冬季封闭式蛋鸡舍温湿度分布并不均匀，需要通过测试试验，掌握舍内温湿度分布状况，有针对性地改进环境控制措施。     

笼养蛋鸭舍环境因子与鸭免疫机能及生产性能的研究

试验检测了春季蛋鸭笼养舍内环境因子分布和蛋鸭生理机能及生产性能变化,为蛋鸭阶梯式笼养模式提出改进建议。结果表明:(1)蛋鸭舍内气载有害菌和粉尘浓度随纵向通风进程持续升高,上层鸭笼大肠杆菌属细菌气溶胶浓度显著低于中层和下层(P<0.05)。平均光照强度自进风口到出风口分布均匀,但上层笼极显著高于下层(P<0.01);(2)上层蛋鸭平均产蛋率(69.37%)显著高于下层蛋鸭(P<0.05);累计死淘率(0.11%)显著低于下层蛋鸭(P<0.05);(3)上层鸭蛋哈氏单位为68.2,极显著高于下层鸭蛋(P<0.01);(4)上层蛋鸭血清过氧化氢酶(CAT)活性、下丘脑GnRH基因表达水平均显著高于下层蛋鸭(P<0.05);下丘脑CRH基因表达水平,脾脏IL-1β、IL-10和TNF-α基因表达水平显著低于下层蛋鸭(P<0.05)。以上结果显示,春季笼养蛋鸭舍内,不同空间位置环境因子分布不均匀,下层蛋鸭长期处于恶劣环境,增加了死亡率,降低了产蛋率和蛋品质。     

光照强度对笼养蛋鸡产蛋性能的影响

选用２６７日龄的产蛋母鸡１５０只，分为三组，分别放在上、中、下三层鸡笼，采用同样的饲养管理制度。由于笼位的高低不一，使得三层鸡群在同一鸡舍内所接受的光照强度不一，导致鸡群产蛋不一致；上层鸡群产蛋率为８４．５０％，中层鸡群产蛋率为８２．００％，下层鸡群产蛋率为７３．６６％。上层鸡群比中层鸡群产蛋率高２．５０％（Ｐ＜０．０５），上层鸡群比下层鸡群产蛋率高１０．８４％（Ｐ＜０．０１），中层鸡群的产蛋率比下层鸡群高８．３４％（Ｐ＜０．０１）。     

环境因子对蛋鸡生产性能的影响

本文研究了春季蛋鸡舍空气环境因素对伊莎蛋鸡生产性能的影响。结果表明，各层笼温差较大，下层比中、上层低1.5～3.0℃；上、中层与下层的产蛋率存在极显著差异(P<0.01)。而中、上层间差异不显著(P>0.05)。1～3层昼夜光照强度差异大；白天光照强烈，且不均匀，南北两列差异极显著(P<0.01)。南列平均值为204.8Lx，北列仅为21.1Lx，是南列出现啄癖多、死淘率高的一个重要原因。相对湿度平均66.7%，在适宜范围之内。舍内平均风速小，仅0.048±0.019m/s；NH     

癸氧喹酯干混悬剂含量测定的改进

采用高效液相色谱法测定癸氧喹酯干混悬剂的含量,在2-250μg/mL范围内,峰面积的常用对数与进样量浓度的常用对数呈良好的线性关系,R^2=1(n=5),平均回收率为99.24%~99.51%,RSD在0.05%~0.28%。此方法分析时间短,样品前处理简便、定量结果准确,重现性好,结果满意,为其质量控制提供了依据。     

商会自治的基石——商会自治规范研究

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。     

猪毛色遗传的研究进展

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。     

中华人民共和国农业部公告 第267号

为贯彻落实《兽药生产质量管理规范》(简称《兽药GMP》),进一步推动兽药GMP实施进程,我部制定了《兽药生产质量管理规范检查验收办法》,现予公告。本公告自2003年6月1日起施行。附件:兽药生产质量管理规范检查验收办法二○○三年四月十日第一章 总则 第一条 为推动《兽药生产质量管理规范》(以下简称兽药GMP)的实施,规范兽药GMP检查验收工作,制定本办法。 第二条 农业部负责全国兽药GMP管理和检查验收工作;负责制修订兽药GMP检查验收管理规定;负责兽药GMP检查员队伍建设和监督管理工作,负责国际兽药贸易中GMP互认工作。 …     

鸡败血支原体垂直传播模式及其阻断方法

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。     

Comparison of 2 methods of centesis of the bursa of the biceps brachii tendon of horses

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.     

不同样本商品蜂蜜中硒含量的测定

用硝酸和高氯酸消化蜂蜜,使硒游离出来,在微酸性环境下,硒和2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm,荧光波长518nm处测定其荧光强度。蜂蜜中硒含量范围:0.10～0.82μg/g。表明:蜂蜜应视为天然富硒营养品。     

乳酸杆菌益生作用机制的研究进展

乳酸杆菌作为益生菌广泛用于人和动物。本文综述了乳酸杆菌改善宿主健康的机制。乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道。文章重点讨论了乳酸杆菌表面成分（表面蛋白、脂磷壁酸和肽聚糖）与肠道受体（Ｃ型凝集素受体、Ｔｏｌｌ样受体和 Ｎｏｄ样受体）,阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制。     

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.