在动物育种上近交的科学利用

近交具有促使等位基因纯合、降低群体均值的效应,具有固定优良性状、揭露有害基因、保持优良个体的血统、提高群体同质性的作用;在动物育种上,应很好把握近交的应用时机,准确衡量近交的程度,灵活运用近交的方法,严格控制近交的速度和时间,并采取多种措施防止近交衰退的发生,使近交的有利功能充分发挥出来。     

育种微课堂 蜜蜂的近亲交配(一)

正蜜蜂近亲交配(近交)是指血缘或亲缘关系相近的雌雄个体之间的交配。在遗传育种工作中,在选择某一性状表现最优良的个体时,希望使该优良性状的特性稳固遗传下来,往往采用近交的方式,以增加基因的纯合率来实现。但是,近交是把双刃剑,一方面可以使某一优良性状稳定遗传下来;另一方面由于近交,造成性等位基因纯合而产生二倍体雄蜂,二倍体雄蜂在幼虫阶段,往往会被工蜂弃掉,蜂群出现"插花子"现象(图1),     

蜜蜂的近亲交配(一)

蜜蜂近亲交配(近交)是指血缘或亲缘关系相近的雌雄个体之间的交配。在遗传育种工作中,在选择某一性状表现最优良的个体时,希望使该优良性状的特性稳固遗传下来,往往采用近交的方式,以增加基因的纯合率来实现。但是,近交是把双刃剑,一方面可以使某一优良性状稳定遗传下来;另一方面由于近交,造成性等位基因纯合而产生二倍体雄蜂,二倍体雄蜂在幼虫阶段,往往会被工蜂弃掉,蜂群出现“插花子”现象(图1),同时还带来生活力下降和生理机能减弱等不良后果。     

陇东绒山羊近亲交配实地调查

近交作为一种育种措施,必须使用适度,才能收到理想的效果,但在育种群中采用了高度近交后,其效果也满意,并未出现羊只衰退现象。     

近交在动物育种上的应用

随着动物杂交育种的兴起,近交作为一种必要的育种手段得到广泛地应用。然而近交虽能使优良性状迅速得到固定,但也有使群体发生衰退之虞,因此长期以来,对近交存在着两种不同的看法:有人把它看成是育种改良的必要手段而争相采用;也有人把它看成是一种不可容忍的祸害而避而不用。     

蜜蜂的近亲交配(四)——近交遗传效应

正在长期进化过程中,蜜蜂的生殖形成了孤雌生殖和有性生殖两种方式,其中有性生殖交配方式是一雌多雄授精,在空中完成。由此蜂王可以获得丰富的遗传物质,以便适应错综复杂的自然环境。然而,在现代蜜蜂育种中,根据市场对单一蜂产品需求的不断增加,渴望培育出某一性状非常突出的品种,常常采用近交方式进行定向选育。1.蜜蜂近交的益处(1)固定优良性状:近交的基本效应是使基因纯合,用近交的方式来固定优良性状,使其能够比较切实的遗传给后代,     

金华猪品系选育中近交效果的初步分析

长期来人们对近交常具戒心,因为近交会导致生活力、适应性、繁殖力等诸方面的衰退。其实近交与任何事物一样都有其二重性,既有不利一面,也有有利一面。近交的遗传效应能促使基因纯合,从而可以运用近交方法来固定优良性状,促使群体更快地纯化与一致。因此,近交是家畜育种改良的重     

北京花猪Ⅰ系选育中的近交和选择效应

<正> 近交和选择是为配合杂交进行纯种猪群选育的基本手段。在育种猪群中,常因近交程度的增加而导致繁殖力(如每窝的活产仔数和断奶仔猪数)、生长速度和生存率的减退。不过在选择进程中还要求纯种猪群有一定程度的近交。这是因为:一方面近交具有暴露群体内有害隐性基因的作用,通过选择淘汰可改造净化群体的遗传素质;另一方面近交还可在每一群体中分别纯合不同位点的优良基因,通过杂交配合可进一步发挥近交和选择应产生的效应。本文试图应用北京花猪Ⅰ系的育种数据资料,分析研讨育种过程中近交和选择的相互关系。     

从应用BLUP到种猪发展

多性状动物模型BLUP(Best Linear UnbiasedPrediction)法是当今世界上先进的育种值估计方法,能消除各种环境因素的影响,利用各种亲属资料,考虑选择近交及性状间遗传相关等因素,准确地同时估计出种畜各性状育种值以及综合育种值,并能比较场内,场间,地区间甚至国家间种畜优劣,可加速优良种畜的推广利用,提高种畜质量。     

绵羊近交程度对育种效果影响的研究

近亲交配(近交)是育种中经常采用的一种繁殖制度。近交能使有益基因纯合,优良性状得以固定。伊凡诺夫成功地采用了近亲交配的方法,育成了乌克兰草原猪和阿斯卡尼羊。他认为,在畜牧业中,甚至是用最近的近亲交配,无论在品系和品种繁殖过程中作为获得真正纯合子的方法,还是主要作为获得较纯基因型的方法     

Techniques for objective outcome assessment

Companion animal rehabilitation, a collaborative practice of physical therapy and veterinary medicine, can only demonstrate the effectiveness of its theories, techniques, interventions, and modalities through evidence-based practice, utilizing standardized, reliable, and valid outcome measures, correlated with objective diagnostic data. This essay examines existing and potential objective outcome measures utilized in companion animal rehabilitation and physical therapy regarding pain, vital signs, body condition and composition, range of motion, muscle strength, inflammation, functional mobility, and gait. Discussion is included of the traditional disablement model and the evolution of the physical therapy diagnosis, prognosis, and plan of care.     

鸡贫血病毒感染新城疫免疫雏鸡vNDV攻击后免疫病理学变化

本文对鸡贫血病毒感染新城疫免疫雏鸡新城疫强毒攻击后,其血清,泪液,气管液,肠液,胆汁的ＩｇＧ,ＩｇＭ,ＩｇＡ含量和ＨＩ抗本滴度;胸腺,法氏囊,脾脏,哈德尔腺,盲肠扁桃体的Ｔ细胞,ＩｇＧ,ＩｇＭ,ＩｇＡ抗体生成细胞数量以及免疫保护情况进行了检测。     

Topical treatment of canine and feline pyoderma

Abstract This paper is a review of commonly used topical antibacterial medications: benzoyl peroxide, chlorhexidine, povidone iodine, ethyl lactate, triclosan, mupirocin, neomycin, polymyxin B, bacitracin and fusidic acid. Included is a review of the pharmacokinetics, modes of action, adverse effects and clinical uses in veterinary dermatology. General recommendations for topical antibacterial therapy are presented. Résumé— Cet article est une revue des topiques antibactériens les plus couramment utilisés: peroxyde de benzoyle, chlorhexidine, povidone iodée, lactate d'éthyle, triclosan, mupirocine, néomycine, polymyxine B, bacitracine et acide fucidique. Il inclut notamment une revue des pharmacocinétiques, des modes d'action, des effets secondaires et des indications thérapeutiques de ces produits en dermatologie vétérinaire. Les indications générales du traitement topique antibactérien sont présentées. [Guaguere, E. Topical treatment of canine and feline pyoderma. (Traitement topique des pyodermites canines et félines). Veterinary Dermatology 1996; 7 : 145–151.] Resumen Este articulo es una revisión de los productos tópicos antibacterianos más frecuentemente utilizados: peróxido de benzoilo, clorhexidina, povidona yodada, etillactato, triclosan, mupirocina, neomicina, polimixina B, bacitracina y ácido fusidico. Se incluye una revisión de la farmacocinética, mecanismos de acción, efectos colaterales y sus usos clínicos en dermatologia veterinaria. Se presentan recomendaciones generales para la terapia antibacteriana tópica. [Guaguere, E. Topical treatment of canine and feline pyoderma. (Tratamiento topico de la pioderma canina y felina). Veterinary Dermatology 1996; 7 : 145–151.] Zusammenfassung— Diese Veröffentlichung besteht in einer Übersicht von häufig verwendeten topischen antibakteriellen Arzneimitteln: Benzoylperoxid, Chlorhexidin, Povidon-Jod, Ethyllaktat, Triklosan, Mupirocin, Neomycin, Polymyxin B, Bacitracin und Fusidinsäure. Mit eingeschlossen ist eine Übersicht über Pharmakokinetik, Wirkungsweise, Nebenwirkungen und klinische Anwendung in der Veterinärdermatologie. Allgemeine Empfehlungen für die lokale antibakterielle Therapie werden dargestellt. [Guaguere, E. Topical treatment of canine and feline pyoderma (Lokale Behandlung von kaninen und felinen Pyodermien). Veterinary Dermatology 1996; 7 : 145–151.]     

Effect of age on serum chemistry profile, electrophoresis and thyroid hormones in beagle dogs two weeks to one year of age

Chemistry tests were conducted on serum from young Beagle dogs in order to deter mine the effect of age on these parameters. Blood was collected at regular intervals from 25 normal Beagle puppies (13 males and 12 females) at ages ranging from 2 weeks to 12 months. Serum chemistry profiles, protein electrophoresis and radioimmunoassays for thyroxine and triiodothyronine were included. Rapidly changing age related differences were observed in several parameters. Urea nitrogen, cholesterol, triglycerides, lactate dehydrogenase, thyroxine, glucose, gamma glutamyl transpeptidase, and total bilirubin values were elevated early in life, and decreased during the first 6 to 8 weeks, while alanine aminotransferase activity was low initially and increased during this period. Lactate dehydrogenase, thyroxine, gamma glutamyl transpeptidase, total bilirubin and alanine aminotransferase attained stability by 3 months, but the remaining parameters showed slight changes subsequently, gradually approaching adult values. More gradual age related changes were observed in other parameters. These included alkaline phosphatase, inorganic phosphorus and calcium values, which were higher in younger dogs, and creatinine, aspartate aminotransferase and total protein values, which were lower in younger dogs. Creatinine and aspartate aminotransferase values were stable by approximately 6 months; alkaline phosphatase, inorganic phosphorus, calcium and total protein values continued to change gradually up to 1 year.     

Concentrations of macro- and micro-elements in the milk of pasture-fed thoroughbred mares

OBJECTIVE: To determine the changes in Ca, P, Mg, Na, K, S, Cu, Fe and Zn concentrations of milk during the lactation in pasture-fed Thoroughbred mares and then calculate the dietary mineral requirements of the sucking foal and the lactating mare. PROCEDURE: Milk was sampled on days 1, 3, 7, 14, 21, 28 and at various times between 55 to 65, 85 to 95 and 135 to 150 days after parturition from 21 pasture-fed mares. The concentrations of macro- and micro-elements in the milk were determined by inductively coupled plasma emission spectrometry. RESULTS: Concentrations (mg/L) of these elements were highest in colostrum (Mg 302, Na 561, K 955, S 1035, Cu 0.76, Fe 0.79 and Zn 5.5) except for Ca (1245) and P (895), which where highest on day 7. The mean milk mineral element concentrations (mg/L) over days 55 to 150 were Ca 843, P 543, Mg 47, Na 120, K 590, S 219, Cu 0.19, Fe 0.34 and Zn 2.1. The mean plasma element concentrations (mg/L) over the same period were Ca 120, P 77.1, Mg 17.0, Na 3110, K 168, S 983, Cu 1.1, Fe 1.5 and Zn 0.49. Concentration gradients between plasma and milk were observed and, in the case of Ca, P, Mg, K and Zn, their concentrations in milk were greater than those in plasma, while a reverse situation was observed for Na, S, Cu and Fe. CONCLUSION: With the exception of Ca and P, the highest concentrations of mineral elements were observed in the colostrum. The nursing foal should have access to good pasture or creep feed, because the intakes of Ca, P and Cu from milk may be less than optimum to meet the daily mineral element requirements.     

Studies on the Haematology and Trace Element Status of Adult Bactrian Camels (Camelus bactrianus) in China

Reference values were established for some haematological and serum biochemical constituents in Bactrian camels (Camelus bactrianus) in China. The contents of seven trace elements in the blood, hair, liver, kidney, heart, spleen, lung, cerebrum, cerebellum, rib, ovary, pancreas and gluteal muscle of Bactrian camels were also measured. Some of these values are reported for the first time for Bactrian camels in China. Most haematological and serum biochemical values were similar to those of cattle, yaks, sheep and dromedary camels, but the mean serum albumin concentration and the albumim/globulin ratio were significantly higher than those in other ruminants and the mean thyroxine concentration was half that in dromedary camels. The liver contained the highest concentrations of copper, zinc, manganese and iron, and the renal cortex contained the highest concentration of selenium. The concentrations of selenium, cobalt, zinc, manganese and molybdenum in the tissues were within the reference ranges for other ruminants, but the mean iron and copper concentrations in the liver were significantly higher than those in other ruminants.     

中国桑树害虫名录(Ⅺ)

记述了昆虫纲(Insecta)双翅目(Diptera)、缨翅目(Thysanoptera)、等翅目(Isoptera)、膜翅目(Hymenoptera)、革翅目(Dermaptera)、蜚蠊目(Blattaria)的26种桑树害虫,以及蛛形纲(Arachnida)真螨目(Acariformes)、甲壳纲(Crustacea)等足目(Isopoda)、软体动物门(Mollusca)腹足纲(Gastropoda)柄眼目(Stylommatophora)共28种桑树害虫与危害物种,分别介绍了这些害虫及危害物种的中文名称、学名、寄主种类与主要分布区域,为控制桑树各类有害生物的发生与危害提供相关的基础信息。     

MENISCAL OSSICLES IN LARGE NON-DOMESTIC CATS

Radiographs of the stifles of 6 species of 34 large, non-domestic cats were reviewed foremost for the presence of meniscal ossicles and then for the presence of the other potential four sesamoids. The animals in the review included 12 lions, 7 tigers, 7 cougars, 3 leopards, 3 bobcats, and 2 jaguars. Fluoroscopy, arthrography, computed tomography, necropsy, and histology were also used to evaluate the stifles of one tiger after euthanasia. Ossicles were found in the region of the cranial horn of the medial meniscus in most of the lions, tigers, leopards, and jaguars. These ossicles were found in half of the cougars but in none of the bobcats. Among the large, non-domestic cats, meniscal ossicles had been reported previously only in Bengal tigers. The lions, tigers, and leopards having meniscal ossicles appeared to have a lateral but often not a medial fabella of the gastrocnemius muscle, an observation previously unreported. Popliteal sesamoids and patellas were present in all the skeletally mature cats.     

牦牛瘤胃内饲料蛋白质降解率的研究

用瘤胃尼龙袋技术测定了１１种常见饲料在牦牛瘤胃内的降解率。根据饲养水平,瘤胃食糜的外流速度估计为０．０６７／ｈ。测定结果表明,玉米、豌豆秸粉、菜籽饼、豌豆、鱼粉、曲拉、肉骨粉、青稞、甲醛鱼粉、甲醛菜籽饼和麸皮的粗蛋白（ＣＰ）降解率分别为０．６８、０．５６、０．４４、０．８５、０．４９、０．５５、０．８１、０,８３、０．３８、０,４８和０．７９,干物质（ＤＭ）降解率依次为０．６８、０．３０、０．４９、０．７３、０．５０、０,５４、０,５９、０．８２、０．３２、０．４９和０．７４。     

肉仔鸡可消化色氨酸需求参数研究

通过研究日粮中色氨酸水平对肉仔鸡生长性能、氮平衡及血清尿素氮含量的影响，探讨不同生长阶段不同性别肉仔鸡色氨酸的需求参数。试验期８周。结果表明：日粮中色氨酸达到适宜水平时，肉鸡的平均日增重增加（Ｐ＜０．０５）、料肉比降低（Ｐ＜０．０５）、血清尿素氮（ＢＵＮ）含量下降（Ｐ＜０．０５）；色氨酸水平过高则不能继续改善其生产性能，甚至造成负效应。在３～６周龄及６～８周龄阶段，公鸡色氨酸需求参数高于母鸡。日粮色氨酸水平对肉鸡的氮沉积率无显著影响（Ｐ＞０．０５），不同性别肉鸡的氮沉积率无显著差别（Ｐ＞０．０５）。根据各项指标的测定结果，建议在０～３周龄，肉鸡色氨酸需求参数为０．２１％；在３～６周龄，公鸡色氨酸需求参数为０．２０％，母鸡为０．１８％；在６～８周龄阶段，公鸡色氨酸需求参数为０．１８％，母鸡为０．１６％。采用去盲肠成年种公鸡测定基础日粮（玉米—玉米蛋白粉）中色氨酸的消化率，并计算出不同性别肉鸡可消化色氨酸需求参数。