产蛋鸡抗高温添加剂的研究

产蛋鸡抗高温添加剂的研究邯郸农业高等专科学校杨俊琦，唐国云，杨英华炎夏酷暑，过高的环境温度往往会引起蛋鸡新陈代谢和生理机能的改变，进而影响到蛋鸡的产蛋量和饲料利用率，使舍内鸡群出现热性喘息、采食减少、产蛋率下降、蛋重减轻、壳质薄脆，死淘率上升等严重热...     

产蛋鸡热应激的综合防制

随着全球气候变暖 ,高温对产蛋鸡造成的严重热应激日益成为制约我国南方夏季产蛋鸡生产性能的因素。因此 ,了解热应激对产蛋鸡的影响 ,并采取相应切实可行的防制措施 ,才能最大限度地缓解热应激。1　热应激对产蛋鸡的危害　 1.1　对产蛋鸡产蛋量、蛋品质的影响　实验表明 ,产蛋鸡在 2 9～ 38℃ ,产蛋量蛋重下降 ,蛋壳变薄、变脆 ,表面粗糙 ,失去正常颜色。鸡的等热区为 18～ 2 3℃ ,当温度超过 2 3℃ ,温度每升高 1℃ ,采食量就下降 1.5% ;当鸡舍温度在 2 5～32℃之间 ,每上升 1℃ ,产蛋率下降 1.5% ,蛋重减轻0 .3g/个。超过此温度 ,产蛋率…     

高温对产蛋种鸡的影响及防制措施

种鸡的生产性能受多种因素的影响 ,环境温度对产蛋鸡的生产性能影响最大 ,一到高温季节 ,产蛋鸡就会出现明显的热应激。1　高温对产蛋鸡的危害　产蛋鸡最适宜的环境温度为 1 3～ 2 3℃ ,当环境温度超过 2 8℃时 ,鸡群就会出现热应激 ,表现为食欲减退 ,饮欲增加 ,排泄稀便 ;伸舌发喘 ,呼吸加快 ;产蛋率下降 ,蛋壳变薄 ,蛋重变轻 ,破蛋增多 ,种蛋受精率下降 ;随着舍温的升高 ,死亡率明显增加 ,尤其是下午 2 :0 0～ 5 :0 0时。2　高温的应对措施　由于高温对产蛋鸡的危害 ,必须及时采取措施 ,降低环境温度 :鸡舍墙壁、房顶可涂成白色或屋顶铺上…     

夏季蛋鸡饲养管理技术要点

夏季高温环境对产蛋鸡造成的热应激影响极为显著。蛋鸡由于饮水量增加、采食量下降而导致产蛋率、蛋重、蛋品质下降。高温、高湿的环境造成鸡舍有害气体含量过高，有利于病原微生物的孳尘或存活，长期热应激引起机体免疫力下降，诱发疾病，严重影响蛋鸡的生产效益。为了避免上述现象的发生，夏季蛋鸡饲养管理应该抓好以下技术要点。     

笼养蛋鸡饲养环境的管理及各季节的注意要点

1饲养环境的管理 1.1温度 温度对产蛋鸡的开产日龄、产蛋率、蛋重、蛋壳质量及饲料消耗均有影响。成年母鸡适宜的温度是5～27℃,产蛋的最佳温度为12.8～18.0℃。当温度上升到22℃时,蛋重开始减轻,蛋壳变薄,温度越高,产蛋率越低。环境温度越高,鸡的体温越高,呼吸次数越多,产蛋率就随之下降。当温度下降到-9℃,时,鸡的活动迟缓,产蛋率明显下降,鸡冠开始受冻。在我国北方地区,冬季舍温必须维持在12.8℃以上,方能发挥出笼养鸡的最高生产效益。     

浅谈蛋鸡饲养环境的控制

影响鸡体健康的因素很多,其中环境因素特别是饲养环境与鸡的生理、生态、疾病、生产性能之间存在着直接关系。1蛋鸡舍的环境控制因素1.1空气温度在正常条件下,产蛋鸡的适宜温度为13~23℃,能保持生产性能的稳定。蛋鸡在27℃产蛋率不会明显下降,若室温在30℃以上则产蛋率下降明显,室温超过35℃就有部分蛋鸡中暑死亡。高温能使商品蛋鸡的蛋壳厚度变薄,蛋品质下降。轻型蛋鸡较耐热,重型蛋鸡较耐寒。当环境温度过低时蛋鸡的活动迟钝,耗料增加明显,生产性能下降,所以在一般情况下冬季舍温最好不要低于7℃。1.2空气湿度常用相对湿度表示。空气湿度…     

高温对产蛋鸡的影响与缓解对策分析

1 热应激对产蛋鸡的影响 　　1.1 对产蛋性能的影响 　　高温环境下,家禽首先表现出采食量下降而饮水量增加.试验表明:当舍温在21～25 ℃区间内,温度每升高1℃,鸡采食量相应降低1.5%,产蛋率下降0.5%;在25～32 ℃区间内,温度每升高1℃,鸡采食量相应降低2.5%,产蛋率下降1.5%;而在32～38 ℃区间,每升高1℃,采食量相应降低4.6%,产蛋率下降3%～5%.采食量的下降,引起营养物质摄入不足,导致蛋重减轻,蛋品质下降.……     

缓解家禽热应激药物的研究进展

高温引起鸡的热应激,导致鸡的新陈代谢和生理机能的变化和紊乱,从而使肉鸡的增重,蛋鸡的产蛋率和种蛋的受精率下降,蛋重减轻,蛋壳变薄,破蛋率上升,饲料利用率下降,严重时因热衰竭而死亡.在日粮或饮水中添加维生素、电解质、抗生素、有机酸及中草药等抗热应激药物,其目的在于调整机体的生理机能,提高鸡的抗热应激能力.     

浅谈产蛋鸡的四季管理技术要点

温度是导致产蛋鸡出现热应激,影响鸡群健康和性能发挥的首要环境因素,而在我国北方地区,一年四季中每个季节的温度以及空气质量都不相同,鸡舍内的环境也会随着四季的变化而变化,这就要求饲养者在不同季节时对产蛋鸡应该采取不同办法进行饲养管理,方能发挥出笼养鸡的最高生产效益。成年母鸡适宜的环境温度是5~27℃,产蛋的最佳环境温度为12.8~18.0℃。当环境温度上升到22℃时,蛋重开始减轻,蛋壳变薄,环境温度越高,鸡的体温越高,呼吸次数越多,产蛋率就随之下降。     

蛋鸡热应激及其综合防制措施

1热应激对蛋鸡的影响1．1蛋鸡采食量减少．产蛋率降低当舍内环境温度上升到一定程度时,采食中枢的兴奋受到部分抑制．表现出采食量下降,同时以增加饮水量来减轻热负荷。采食量的下降将导致营养摄人的不足,使产蛋率下降,蛋重减轻,蛋品质变差,体重持续下降。饮水量增加,导致肠道内消化酶浓度降低,加剧肠道蠕动,饲料在肠道停留时间缩短,饲料消化利用率降低,鸡体营养不良进一步加剧。蛋重降低和蛋壳变薄是热应激时最早发生的现象。另外,热应激还可使蛋鸡排卵数减少,产蛋率下降。     

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.