仔猪的断奶及其饲养管理要点

按照我国传统的养猪方式，仔猪多于60日龄断奶，哺乳期过长，母猪的年产仔数就会较少；发达国家养猪多于20-28日龄或更早断奶，以提高母猪的繁殖率。目前我国各规模猪场尚达不到早期断奶所需的设备和饲料条件，仔猪一般于28-35日龄断奶较为合适，此时仔猪已经基本上适应了饲料和饲养环境条件，育成率较高、发育较为整齐。     

断奶日龄对仔猪生长性能的影响试验

正养猪生产中,仔猪的断奶日龄很大程度上影响着母猪的繁殖效率和仔猪的生长发育。选择合适的断奶日龄是养猪生产的重要环节之一,对提高养猪生产效益具有重大意义。不同猪场仔猪断奶日龄不同,母猪的繁殖率、仔猪发病率、生产成本和经济效益也有较大差异。为探索不同断奶日龄对仔猪的生长发育、健康状况和猪场经济效益的影响,笔者在金华某规模猪场进行仔猪18日龄、21日龄和30日龄的断奶试验,现将试验情况报告如下。     

仔猪断奶日龄对母猪繁殖性能影响的探讨

断奶日龄是影响仔猪和母猪生产性能的重要因素之一,选择合适的断奶时机对养猪生产意义重大。本文介绍了仔猪断奶日龄对母猪繁殖性能的影响,并结合中国生猪生产现状,提出了仔猪断奶日龄选择的策略,旨在为读者提供参考。     

早期断奶仔猪蛋白质及矿物质的营养需要

仔猪断奶是养猪生产中非常重要的环节，是制约养猪生产效益的重要因素。随着养猪生产水平的提高，仔猪断奶日龄日趋缩短(从传统的60Et龄缩短到21～28日龄)，早期断奶不但可以缩短母猪的产仔间隔，提高母猪的利用强度，还可以防止仔猪被压死，切断仔猪最初感染源(母猪)，有利于提高仔猪     

仔猪成功断奶的基本条件

在养猪生产中,合理地仔猪饲养是养猪成功的关键环节之一,它不仅影响本阶段的生长,还严重影响以后的生产性能。而仔猪断奶则是仔猪生产中的关键因素,在传统的养猪生产中,仔猪常在45－60日龄断奶。现代化养猪生产为提高母猪的年生产力,常通过早期断奶技术,将断奶日龄缩短到21－28日龄,以缩短母猪的哺乳期,提高生产性能。     

早期断奶乳猪料的配制原理

仔猪断奶是目前养猪业生产中一个非常重要的环节，是制约养猪生产效益的重要因素，随着养猪生产水平的提高，仔猪断奶日龄逐渐缩短(从传统的60日龄缩短到21～28日龄)，早期断奶不但可以缩短母猪的产仔间隔，提高繁殖母猪的利用强度，还可防止仔猪被压死，切断仔猪最初感染源(母猪)，有利于提高仔猪成活率和生长速度。     

仔猪早期断奶技术要点

仔猪到一定日龄后人为干预停止母猪哺乳,称为断奶.仔猪到多少日龄断奶,直接影响到整个猪群的饲养管理、工艺流程及其猪场建设规划和母猪群的繁殖效率.仔猪早期断奶是提高母猪产产仔数和育成头数的关键性措施.仔猪早期断奶是现代养猪的关键技术之一,在我国的规模化猪场得到广泛重视.仔猪断奶的传统习惯,我国多在60日龄时,国外是在56日龄,现在采取早期断奶,断奶日期大多提早到仔猪出生后35日龄,也有在仔猪出生后28日龄,国外最新技术提倡12~14日龄断奶,早期断奶是一项先进而科学的养猪技术,国外早已推广应用.我国于1985年前后开始推广,现已逐步普及.     

早期断奶仔猪蛋白质营养需要

仔猪断奶是养猪生产中非常重要的环节，是制约养猪生产效益的重要因素。随着养猪生产水平的提高，仔猪断奶日龄日趋缩短(从传统的60日龄缩短到21～28日龄)。早期断奶不但可以缩短母猪的产子间隔、提高母猪的利用强度，还可以防止仔猪被压死，切断仔猪最初感染源(母猪)。有利于提高仔猪成活率和生长速度。但由于仔猪消化系统尚未发育成熟，因此能否配出一个既经济又能减轻“早期断奶综合症”的日粮，使仔猪能顺利完成从母乳到断奶日粮的过度，同时又能维持最大的生长速度，是一个配方师所面临的最大挑战。本文就早期断奶仔猪的消化生理特点、…     

断奶仔猪的营养性应激及其对策

在养猪生产中,合理地仔猪饲养是养猪成功的关键环节之一,它不仅影响本阶段的生长,还严重影响以后的生产性能。而仔猪断奶则是仔猪生产中的关键因素,在传统的养猪生产中,仔猪常在45～60日龄断奶。现代化养猪生产为提高母猪的年生产力,常通过早期断奶技术,将断奶日龄缩短到21～28日龄,以缩短母猪的哺乳期[1];另外,母仔早期分离可防止母猪压死仔猪和减少仔猪感染传染病和寄生虫病的机会,有利于提高仔猪成活率;同时可提高栏舍利用率;但同时也导致仔猪产生应激。应激是指机体对外界或内部的各种非常刺激所产生的非特异性应答反应的总和。仔猪早期…     

仔猪早期断奶腹泻症的防控技术

在集约化、规模化养猪生产中,随着技术水平的不断提高,仔猪断奶日龄已从过去的35日龄以上逐渐提早到21～25日龄,超早期断奶日龄甚至达到10～15日龄.早期断奶的最大特点是仔猪生长迅速,60日龄体重可达到25 kg左右,大大增加了母猪的年产仔数和生猪出栏数,明显提高了养猪生产效益.但是,仔猪早期断奶如果饲养管理不当,断奶后腹泻发生率较高.     

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。     

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。     

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.     

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。     

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.     

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.