如何提高肉用种鸡的均匀度

均匀度是指鸡群生长发育的整齐程度。它包括体重、体型、性成熟等诸多因素。其中以体重的整齐性最为重要。均匀度达７０％（推荐体重或标准体重±１０％范围内）以上为合格种鸡群。均匀度的高低直接影响种鸡产蛋率上升快慢、高峰持续时间长短、全期产蛋数、蛋重一致性及种鸡产蛋期死淘率等。现代向用种鸡生长速度快,易沉积脂肪,体重不易控制,均匀度较低。要提高向用种鸡的均匀度,必须采取综合措施才能取得好的效果。一、制定科学的限饲程序严格控制体重肉用种鸡的限饲方法很多,包括每日限饲,隔日限饲,二、一限饲,四、三限饲,五、二…     

肉种鸡限制饲喂应注意的问题

肉种鸡限制饲喂应注意的问题李华（河北省玉田县畜牧水产局玉田０６４１００）１最迟从第４周开始对肉种鸡实行限饲。２限饲应采取分段式，第４周起实行每日限饲，即每天投喂规定料量；第５周至第１３周实行隔日限饲，两天的标准喂料量在喂料日一次或多次投喂，第二天不喂...     

不同限饲方式对肉用种鸡育成后期均匀度的影响

将 48 0只 15周龄AA父母代肉用种鸡 ,随机分成 4组 ,每组 12 0只 ,设 3个重复 ,每个重复 40只。 4组试验鸡分别按每日限饲、隔日限饲、“五、二”限饲和“四、三”限饲 4种限饲方式进行饲喂 ,以研究不同限饲方式对均匀度的影响。试验期 7周。结果表明 :在育成后期 ,采用每日限饲方式 ,肉用种鸡均匀度最好 ,为71.6 % ,显著高于隔日限饲、“五、二”和“四、三”限饲方式肉用种鸡的均匀度 (P <0 .0 1) ;而采用隔日限饲、“五、二”限饲和“四、三”限饲方式 ,肉用种鸡的均匀度较低 ,分别为 5 5 %、5 6 .7%、6 0 % ,且它们之间差异不显著 (P >0 .0 5 )。因此 ,在育成后期 (15～ 2 2周龄 )、笼养条件下 ,肉用种鸡采用每日限饲的方式效果较好     

AA肉种鸡不同限饲方法对比试验

对ＡＡ肉用种鸡在育雏育成期进行每日限饲和分段限饲对比试验。结果：成活率差异不显著（Ｐ〉０．０５），开产时间均为２４周龄，但分段限饲耗料较少，均匀度优于每日限饲，高峰产蛋率（周）；分段限饲８４．３％，每日限饲６７．６％，差异极显著（Ｐ〈０．０１）。     

肉种鸡育雏育成期饲养管理措施

一体重管理1限饲方法1—6周每日限饲。该阶段是给种鸡的均匀度和体形结构打基础的时期，尤其是前4周种鸡的蛋白积累量，会影响4周后的体重和均匀度，以及开产后蛋的大小、尺寸和产蛋率。7～12周四三限饲。通过严格限制饲喂避免鸡只超重，并维持良好的均匀度。     

肉用种鸡限饲的方法及注意事项

1限饲方法限制饲喂是通过有计划地控制鸡的日粮营养水平、采食量和采食时间,达到控制种鸡的生长发育,使之适时开产的目的。肉用种鸡限饲可以促进种鸡运动,增强骨骼、脏器发育,减少饲料浪费,降低饲养成本,使种鸡在适当时期性成熟与体成熟同步,减少腹脂沉积,降低产蛋期死亡率。1.1限时法此法主要是通过控制鸡的采食时间来控制采食量,以达到控制体重和性成熟的目的。主要方法有:①每日喂给一定量的饲料,或规定饲喂次数和每次采食的时间。这种方法对鸡的应激较小;②隔日限喂,即喂1天,停1天。把2天限喂的饲料量在1天中喂给。此法是较好的限喂方法…     

父母代肉种鸡两种不同限饲方案效果比较

AA父母代肉种鸡两种不同限饲方案比较试验，结果表明：采用分段限饲与每日限饲的鸡群生长发育正常，均按时开产，开产体重符合标准，成活率高。分段限饲鸡群耗料省，体重均匀度高，产蛋高峰期产蛋率和产蛋量均高于每日限饲鸡群。高海拔西宁地区肉种鸡生长发育期采用分段限饲效果较好。     

肉种鸡限饲方案的选择

肉种鸡限饲方案的选择孔繁翠（山东莱芜市种鸡场２７１１１３）开建廷（山东莱芜市种猪场）肉种鸡饲养过程中的限饲是关系到肉种鸡生产性能好坏的最关键的因素，那么生产中如何限饲最为合理呢？一、几种限饲方法的优缺点三．每日限饲，即对鸡每日的饲喂量加以限制，此法饥...     

提高肉种鸡均匀度的方法

均匀度是指鸡群生长发育的整齐程度,它包括体重、体型、性成熟等诸多因素,其中以体重的整齐性最为重要。均匀度达70%(推荐体重或标准体重±10%范围内)以上为合格种鸡群。均匀度的高低直接影响种鸡产蛋率上升快慢、高峰持续时间长短、全期产蛋数、蛋重一致性及种鸡产蛋期死淘率等。现代的肉用种鸡生长速度快,易沉淀脂肪,体重不易控制,均匀度较低。要提高肉用种鸡的均匀度,必须采用综合措施才能取得好的效果。1制定科学的限饲程序,严格控制体重肉用鸡的限饲方法很多,包括每日限饲、隔日限饲、二一限饲、四三限饲、五二限饲、六一限饲等方式。…     

肉种鸡育成期限饲注意事项

限制饲养能提高肉种鸡的生产性能，降低饲料消耗，是养好肉种鸡的关键技术，而母鸡有成期的限饲尤其重要，能否培育出优良的后备种鸡关系着鸡群能否有一个良好的生产成绩。由于限饲技术复杂，有时难以达到预期目标，现以艾维茵父母代种鸡为例，就母鸡在有成期的注意事项谈几点看法。1适时开始限饲管理手册规定第三周龄开始限饲。但是，由于遗传育种的进展，肉鸡增重速度的提高，肉种鸡限饲时间需提前，每日限词已越来越普遍地在7～8日龄开始。根据经验，第二周每日最多采食5～6小时，否则鸡会超重。2限饲方法限饲方法有限质法、限量法和限时…     

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。     

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。     

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。     

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.     

Mechanism of Action of Probiotic Function of Lactobacilli

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.     

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。 …