高温对母猪繁殖性能的影响与防控措施

母猪繁殖性能的高低不仅受遗传因子的影响,而且与环境、营养和饲养管理密切相关,其中环境因素,特别是热应激对母猪繁殖性能的影响不容忽视。在现代集约化高密度的饲养条件下,高温高湿对母猪繁殖性能的影响则更大。     

热应激对大约克母猪繁殖性能的影响分析

热应激是指处于极端高温环境中的动物机体,对热环境刺激所作出的非特异性生理反应的总和。母猪繁殖力的高低不仅受遗传因子的影响,而且与环境、营养和饲养管理密切相关,其中环境因素,特别是热应激对母猪繁殖性能的影响不容忽视。在现代化高密度的饲养环境下,热应激对母猪繁殖性能的负面影响,尤其是在南方地区,夏季炎热的天气使得这一弊端尤为突显。据资料记载,杭州地区属北亚热带季风气候,年平均气温在15~17.7℃,四季温差明显,夏季炎热,冬季寒冷。     

影响母猪繁殖性能的因素分析及防治对策

影响母猪繁殖性能的因素是多方面的,包括遗传,营养,饲养管理,热应激和疾病等。选留优秀后备种猪,加强母猪饲养管理,及时淘汰性能低的母猪,严格控制各类疾病等综合措施可有效提高母猪繁殖性能。     

热应激对母猪繁殖性能的影响及作用原理

热应激会对养猪业带来巨大的负面影响,它能降低群体的生产力并造成不必要的死亡,增加饲养成本,降低养殖效益.本文就热应激的来源、 母猪对热应激敏感性增加的原因、 热应激降低母猪繁殖性能的作用原理等方面作一综述,为实际生产提供指导.     

提高母猪繁殖力的综合措施

影响母猪繁殖性能的因素很多,如遗传、营养、饲养管理、热应激和疫病等因素。选留优秀的后备母猪,加强母猪饲养管理,及时淘汰性能低的母猪,严格控制各类疾病等综合措施可有效提高母猪的繁殖性能。     

哺乳母猪的氨基酸营养

<正>哺乳母猪饲养是养猪生产中最重要的环节之一。哺乳母猪的营养不仅直接影响仔猪的生产性能,而且对母猪的使用年限也会产生很大的影响,尤其是饲料中蛋白质及氨基酸营养,是影响哺乳母猪繁殖性能及     

应激对母猪繁殖性能和母性行为的影响

母猪在饲养过程中面临着各种环境因素和管理相关的应激。应激能够通过干扰母猪下丘脑一垂体一性腺轴的功能从而影响其繁殖性能和母性行为。应激可分为短期应激和长期应激,其中短期应激往往不会影响母猪的繁殖性能和生活习性,相反在一些特定环境下,短期应激能够起到提高母猪繁殖性能的作用。本文综述应激的相关概念及其对母猪繁殖性能和母性行为的影响,期望对养猪生产有参考价值。     

热应激对母猪繁殖性能的影响

热应激对母猪繁殖性能的影响刘学剑（云南省西畴县畜牧站，６６３５００）猪的繁殖力的高低既受遗传因子的影响，又与环境、营养、繁殖技术和管理方式密切相关。环境因素特别是热应激对种猪繁殖性能的影响更不可忽视。本文就热应激对母猪繁殖机能的影响作一简述，供参考。...     

热应激对猪繁殖性能的影响及防止措施

温度对种猪的繁殖性能具有重要的影响,根据相关文献阐述热应激对种母猪发情、受胎率、胚胎成活率、产仔数以及种公猪繁殖性能的影响,提出了控制热应激对种猪繁殖性能影响的具体措施。     

夏季高温对母猪生产性能的影响及对策

<正>由于夏季高温易引起母猪热应激,导致母猪生殖性能受到诸多影响,如受胎率低、泌乳性能下降、产仔数量少、母猪难产率和母猪产后三联综合征(MMA)发病率上升等一系列问题。本文就热应激对母猪生产的影响及规避热应激的营养与饲养管理措施进行阐述,以期对读者有所帮助。1夏季热应激对母猪生产性能的影响1.1高温对重胎及哺乳母猪生产性能的影响母猪遭受热应激时即会做出适应性反应,如增加     

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.