无公害肉兔养殖新技术

1 肉兔品种选择 肉兔品种有伊拉兔、布列塔尼亚兔、齐卡兔、新西兰兔、加利福尼亚兔、日本大耳白兔等。在引种的时候，种兔应来自有种兔生产经营许可证的种兔场，生长发育正常，健康无病；引进的种兔应隔离30天，经观察无病后方可人生产群；不要从疫区引兔；肉兔场要逐渐做到自繁自养。     

提高肉兔繁殖力的综合措施

养兔经济效益主要受繁殖力、成活率、饲料报酬、饲料价格、商品兔价格的影响,其中繁殖力和成活率是关键。影响肉兔繁殖力的因素很多,笔者总结这些年来的养兔实践经验,采取以下综合措施,效果好。1严格选育种兔肉兔品种优,个体优。种兔符合肉兔品种特征,健康无病。     

降低养兔成本的有效途径

1选好种兔 应选择耗料少、产肉多和产毛量高的品种作种用。如肉兔可选安阳灰兔、新西兰兔、哈尔滨大白兔：獭兔可选青紫兰兔、加利福尼亚兔;毛兔可选德系安哥拉兔等。在生产过程中,对于生产性能低下的劣质种兔要及时淘汰,不予留作种用。     

提高肉兔繁殖力的综合技术措施

1 加强肉兔的选种选配。肉兔的繁殖力受遗传因素的影响较大，生产中心严格进行选种．尽量选择适应性强、生长发育快、窝产仔数多和遗传品质稳定的肉兔品种．如新西兰兔、加利福尼亚兔、比利时兔、日本大耳白兔和塞北兔等。其次要求种兔健康活泼．性欲旺盛、生殖器官发育良好。实践表明．即使同一品种内个体之间的繁殖力也不尽相同．所以应选择繁殖力高的     

降低养兔成本的有效途径

1 选好种兔 应选择耗料少、产肉多和产毛量高的品种作种用.如肉兔可选安阳灰兔、新西兰兔、哈尔滨大白兔;獭兔可选青紫兰兔、加利福尼亚兔;毛兔可选德系安哥拉兔等.     

如何缩短肉兔的育肥期

1 选养早期生长快的肉兔品种。从目前养殖的肉兔品种来看，主要有：比利时兔、法国公羊兔、德国巨型兔、新西兰白兔、日本大耳白兔；美国加利福尼亚兔、青紫兰兔和丹麦白兔。这些肉兔体重大，能在90日龄前出栏，可以选养。2 充分利用杂交优势培育优良仔兔。仔兔是肉兔养殖的基础。要培育出优良仔兔，就要选好父、母本种兔。因此，父本种兔要求肉质好，早期增重快，饲料转化率高，屠宰率高；母本种兔要求产仔多，母性好，乳力高，哺育能力强，仔兔成活率高且发育整齐。用这样的种兔杂交繁育，产下的仔兔基本上是优良的。3 保持兔舍中适宜的温…     

提高肉种兔繁殖力的综合措施

影响肉兔繁殖力的因素很多,有种兔的品种、年龄、营养水平、配种制度和饲养管理、环境以及种兔的生殖器官疾病等方面.根据家兔生殖生理特点,通过选择优良肉兔品种、加强饲养管理、掌握适宜的配种时间和配种方法,可显著提高肉用种兔的繁殖力.     

提高肉兔繁殖力的综合措施

1加强肉兔的选种选配 肉兔的繁殖力受遗传因素的影响较大.生产中应严格进行选种,尽量选择适应性强、生长发育快、窝产仔数多和遗传品质稳定的肉兔品种,如新西兰兔、加利福尼亚兔、比利时兔、日本大耳白兔和塞北兔等.其次要求种兔健康活泼,性欲旺盛,生殖器官发育良好.实践表明,即使同一品种内个体之间的繁殖力也不尽相同,所以应选择繁殖力高的个体作为种用.公兔要求睾丸对称,阴囊周径较大,精液品质好,无恶癖;母兔要求生产性能高,发情正常,无生殖疾病,乳头在4对以上,窝产仔数多,母性好,泌乳能力强,育成率高等.因此,除了考察个体繁殖性能外,还应考虑祖先生产性能,必要时进行后裔测定.     

如何提高肉兔繁殖力

提高肉兔养殖效益,充分发挥肉兔繁殖潜力,达到多怀、多产、多壮的目的,要从以下几方面做好肉兔繁殖性能的关键技术。1做好选种、选配工作首先要严格选种。要选留遗传品质好、生产性能突出的优良公母兔留种;同时要求种兔健康无病,性欲旺盛,生殖器官发育良好。公兔要求睾丸对称,阴囊周径较大,精液品质优良,无恶癖;母兔选择生长发育良好、发情期明显、母性好、泌乳力强、产仔数多、成活率高的青年种兔。其次要注意选配,避免近亲繁殖,避免     

肉兔的安全引种技术要点

<正>引种工作关系到发展肉兔养殖的成败,特别是对于刚开始养兔的场户,在引进种兔时必须注意下列事项。1引种准备种兔必须从正规的种兔场引进。首先,要了解所引种兔场种兔来源、生产性能以及健康状况,对选购的每只种兔都要进行全面健康检查,确定无病后方可购买。另外,要积极做好种兔运输前的准备工作,路程远的要准备好消过毒的兔笼和青绿饲料等。2引种季节家兔生性怕热,且应激反应严重。所     

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。     

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.     

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.     

Evaluation of serum concentrations of biomarkers of skeletal metabolism and results of radiography as indicators of severity of osteochondrosis in foals

OBJECTIVE: To determine whether serum concentrations of biomarkers of skeletal metabolism can, in conjunction with radiographic evaluation, indicate severity of osteochondrosis in developing horses. ANIMALS: 43 Dutch Warmblood foals with varying severity of osteochondrosis. PROCEDURE: 24 foals were monitored for 5 months and 19 foals were monitored for 11 months. Monthly radiographs of femoropatellar-femorotibial and tibio-tarsal joints were graded for osteochondral abnormalities. Serial blood samples were assayed for 8 cartilage and bone biomarkers. At the end of the monitoring period, foals were examined for macroscopic osteochondrosis lesions. RESULTS: Temporal relationships were evident between certain serum biomarkers and osteochondrosis severity in foals during their first year. Biomarkers of collagen degradation (collagenase-generated neoepitopes of type-II collagen fragments, type-I and -II collagen fragments [COL2-3/4C(short)], and cross-linked telopeptide fragments of type-I collagen) and bone mineralization (osteocalcin) were positive indicators of osteochondrosis severity at 5 months of age. In foals with lesions at 11 months of age, osteochondrosis severity correlated negatively with COL2-3/4C(short) and osteocalcin and positively with C-propeptide of type-II procollagen (CPII), a collagen synthesis marker. Radiographic grading of osteochondrosis lesions significantly correlated with macroscopic osteochondrosis severity score at both ages and was strongest when combined with osteocalcin at 5 months and CPII at 11 months. CONCLUSIONS AND CLINICAL RELEVANCE: The ability of serum biomarkers to indicate osteochondrosis severity appears to depend on stage of disease and is strengthened with radiography. In older foals with more permanent lesions, osteochondrosis severity is significantly related to biomarker concentrations of decreased bone formation and increased cartilage synthesis.