浅谈蛋鸡开产推迟的原因及对策

蛋鸡按时开产和进入产蛋高峰期是衡量蛋鸡产蛋性能的主要途径。如果因饲养管理方面的因素，使蛋鸡不能按时开产和进入高峰期，就会打乱生产计划，造成重大的经济损失。根据邯郸、临漳、磁县、安阳等地６户的蛋鸡推迟开产情况看，一般比标准推迟１～２周，个别户推迟３～４...     

怎样使圈养蛋鸭适时开产

性成熟期是影响蛋鸭产蛋量的生理因素之一,成熟早虽然可以多产蛋,但并不是越早越好,鸭子发育不完全,超过生理条件的早产容易早衰,群体的表现往往是开产不整齐,达不到应有的产蛋高峰,而且产蛋持久性差。如果饲养管理失误,会推迟性成熟期,影响产蛋量。所以要争取圈养蛋鸭的适时开产,必须掌握一定的饲养管理技术。绍鸭群体的开产日龄是140～160天。从入舍到开产,是青年蛋鸭一生中最关键的时期。由于在这期间内,青年鸭生长发育极快,要在7～9周内从不产蛋迅速达到产蛋高峰,因此。这一时期中的饲养管理更要特别注意。1.在装笼入舍时,应轻装轻放,避免损伤蛋鸭的翼和腿,防止笼内拥挤,运辅途中防止受热。2.从放牧到圈养舍饲,对蛋鸭来说是一     

户养蛋鸡新方法

我国北方,传统的户养鸡是夏季孵化、育雏,育成鸡的第一个开产周期在晚秋和冬季。由于冬季寒冷,蛋鸡食入的饲料完全用于抗寒和维持生命的基础代谢需要,产蛋向后推迟,加大饲养成本,降低了饲料报酬。而且造成冬季鲜蛋紧缺。近年来,我们地区冬季在户外北屋窗前砌半地下暖窖饲养蛋鸡的方法基本完善,受益较大。既解决了冬季自家     

采用渐进式饥饿法对蛋鸭实施早期强制换羽

<正>北方蛋鸭养殖受气候限制很大,一般养殖户在2—3月份接雏,6—7月份蛋鸭开产,11—12月份冬季到来后,产蛋率降低直至停产。一个产蛋季为150~180 d,平均产蛋率约为80%。此时的蛋鸭体重小、被毛不整齐,集中上市则价格低、经济效益差,很难实现盈利。笔者利用饥饿法对33周龄商品代蛋鸭进行早期强制换羽,换羽后开产整齐,产蛋率达85%以上且稳定。鸭群经筛选,在冬季进行强制换羽,经3个月左     

影响蛋鸡产蛋性能的原因及对策

要发挥出蛋鸡的最佳性能 ,就必须对目前影响产蛋鸡性能的因素作出全面分析 ,提高科学管理和疾病防制的水平。１产蛋鸡产蛋性能低的表现１ １开产日龄推迟由于多种原因造成鸡群开产日龄推迟。虽然蛋鸡推迟１～２周不常见 ,但肉种鸡推迟１～５周却是常有的事。推迟开产可影响鸡群的单产水平 ,增加开产前期的耗料。１ ２提前开产如果说体成熟与性成熟保持一致 ,那么提前开产１～１０ｄ对整个产蛋期影响并不大 ,若体重偏轻而提前开产 ,也就是性成熟早于体成熟 ,对产蛋影响较大 ,表现为产蛋高峰上不去 ,高峰期短 ,由于体质差使产蛋后期持续期短。…     

开放式鸡舍中遮黑对肉种鸡生产性能的影响

近几年来,延迟开产是肉种鸡饲养管理中普遍存在的问题,短则1～2周,长则推迟3～4周,直接影响生产计划的安排及种鸡场的经济效益.我场从1998年开始采用遮黑技术,使饲养的四批种鸡均达到按时开产,彻底解决了多年来肉种鸡推迟开产的难题,从而进一步提高了种鸡的生产性能.     

蛋鸡产蛋率下降的原因分析与防制措施

正常情况下,蛋鸡开产后5～7周即达到产蛋高峰并维持8个月左右,之后的产蛋率逐渐下降.笔者对江苏省射阳县206户蛋鸡养殖户调查发现,蛋鸡非生理性产蛋率下降现象增多,应开产鸡群开产日龄推迟,产蛋高峰和维持时间延迟或缩短等情况较普遍,产蛋率不稳定.     

冬鸭不停产养鸭赚得多

冬季蛋鸭提前停产是许多养鸭专业户头痛的事,因为冬季蛋鸭停产就意味着当年养鸭收入的降低,因此,抓好冬季蛋鸭管理,让蛋鸭不停产、多产蛋是提高鸭农经济收入的一项重要保证.     

圈养蛋鸭要注意控制体重

圈养的蛋鸭如果活动量小,再加上人为提供过量的优质饲料,很容易造成体重超标.就像饲养蛋鸡一样,蛋鸭过肥,体重超标,将减少产蛋量.如果蛋鸭早期发育过快,则会引起其提前开产,影响产蛋高峰期的持续时间,并且还会直接影响其产蛋率.     

蛋鸡产蛋推迟的原因及防治对策

正我们在蛋鸡饲养过程中,有时会遇到开产时间推迟且没有产蛋高峰期,或者勉强达到高峰又会出现突然产蛋下降的情况。正常情况下,蛋鸡开产一般在120日龄以后,但是有的鸡群产蛋推迟1~2周,个别的推迟3~4周,严重影响蛋鸡生产的经济效益。下面对可能导致蛋鸡产蛋推迟的原因进行分析,并提出相应对策,希望能对蛋鸡养殖起到借鉴作用。     

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。     

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。     

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.