提高商品肉猪胴体瘦肉率的技术措施

１选择猪种时，应注意该品种的胴体瘦肉率从遗传学的角度来讲，胴体瘦肉率遗传力很高，所以，选择胴体瘦肉率高的品种作为种猪，可以显著提高商品肉猪的胴体瘦肉率。猪的品种不同，胴体瘦肉率也不同，从整体而言，国外猪种以及我国的培育猪种的胴体瘦肉率明显高于我国地方猪种，所以选择优良的瘦肉型品种，如杜洛克、汉普夏、大白猪、长白猪等作为种用，同时加强种猪胴体瘦肉率的选育，可以明显提高肉猪的胴体瘦肉率。但是，值得我们注意的是，过分追求胴体瘦肉率会带来一定的负效应，主要是肉的品质和猪的繁殖力会明显下降。因此，在实际生…     

提高瘦肉率的途径

猪的瘦肉率是指瘦肉量占其胴体重的比率,通常以百分比表示.在遗传学上有两个性状影响着瘦肉率,即背膘厚和眼肌面积.不同品种的猪的瘦肉率不同,瘦肉型的瘦肉率要比肉脂型猪的瘦肉率高.一只肉脂型猪不可能通过外部因素如饲料等使之达到很高的瘦肉率,不管饲料怎样,瘦肉率的变化仍在其品种的瘦肉率变化范围内.因此要解决瘦肉率,首先要通过遗传育种育成高瘦肉率品种猪.     

选种指数在长白猪,约克夏猪高产系选育中的应用

在家畜多性状的选择过程中，指数选择法的应用最为广泛。它根据个体多个性状的育种值合并成一个数据，以该数据代表个体总的遗传性能，也称为综合育种值。利用综合选种指数对家畜进行选育，在国外从４０年代已开始应用，我国在家畜选种上的应用也有近２０年的历史。尤其是近年来应用的比较广泛和深入，对家畜品质的改良和生产性能的提高，起到了很大促进作用，收到明显效果。长白猪、约克夏猪是我国６０年代从国外引进的优良瘦肉型品种猪，现分布全国各地，虽经多年多次引种和风土驯化，适应性增强，但生长速度和胴体瘦肉率大幅度下降，日增…     

应用PCR—SSCPs,PCR—RFLPs技术检测猪氟烷基因

猪应激综合征（PorcineStressSyndromePSS）是由党染色体上单隐性基因控制的一种遗传疾病。控制诸应激综合征的基因又称为氟烷基因。氟烷基因广泛存在于外来猪种和外来猪种与地方品种杂文而有成的品种品系。氟烷基因纯合于造成肉质下降，产生PSE肉。近年来，各地猪场在努力提高     

一种猪氟烷基因的分子检测方法

<正>猪应激综合征(PSS,又称猪恶性高温综合征)是由常染色体上单隐性基因控制的一种遗传疾病,控制猪应激综合征的基因又称为氟烷基因。氟烷基因广泛存在于外来猪种和外来猪种与地方品种杂交而育成的品种品系。氟烷基因纯合子造成肉质下降,产生PSE肉。近年来,各地猪场在努力提高瘦肉率的同时,发现氟烷基因频率在猪群中有升高的趋势,从而给猪场带来了很大的损失。因此,及早地、准确地对猪群进行氟烷基因的检测,尤其     

松辽黑猪的野外放养技术

松辽黑猪是吉林省农科院畜牧分院培育的我国北方地区第1个瘦肉型黑色母系新品种,它不仅具备外来品种猪生长快、饲料报酬以及瘦肉率高特点;而且还具有地方猪适应性强、繁殖率高、肉质好、无应激等特征特性,是优良的地方培育品种.     

猪应激综合征研究进展

猪应激综合征（Porcine　Stress　Syndrome，PSS）是指一些猪在应激因子的作用下，以异常高的频率发生恶性高温综合征，在运输和宰前囚禁过程中猝死，死亡后肌肉呈PSE和DFD征候。我们拟从PSS产生的遗传基础、环境因素，以及检测方法等几个方面对现有的文献资料作一比较全面、系统的综述。     

猪氟烷基因型的检测及其对生产性能效应的研究

近年来,我国在引入国外猪种进行瘦肉型新品种(系)培育的同时,不断涌现出肉质变劣的问题。肉质变劣的一个主要因素是猪应激综合征(PPS)的发生,PPS易导致猪应激而突然死亡或屠宰后产生白肌肉(PSE)。研究表明,氟烷基因是导致PPS的遗传基础。因此,对猪氟烷基因进行检测以消除有害基因的     

猪应激综合征研究进展

猪应激综合征（Porcine Stress Syndrome,PSS)是指一些猪在应激因子的作用下，以异常高的频率发生恶性高温综合征，在运输和宰前囚禁过程中猝死，死亡后肌肉呈PSE和DFD征候，我们拟从PSS产生的遗传基基础，环境因素，以及检测方法等几个方面对现有的文献资料作一比较全成，系统的综述。     

浅谈规模化养殖荥昌种猪的后备猪基础选育

荣昌猪作为我国三大地方优良猪种之一，其品种形成历史悠久，它具有繁殖性能强、母性好、肉质优良、生长速度较快、瘦肉率较高、性成熟早、配合力好、杂种优势明显、抗逆性强等优良特点，是全国生猪生产上推广利用最多的地方优良品种。荣昌猪在1987年就被农业部列为国家级保护猪种，2000年又被农业部列入了《国家畜禽品种资源保护名录》，     

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.