低温高能日粮对肉鸡肺动脉和腹水症的影响

本试验用高能日粮饲养１日龄ＡＡ父母代公雏，２１日龄开始用低温估为发病模型诱发肉鸡腹水症，取不同日龄的肉鸡肺脏和肺动脉固定，光镜和电镜观察肺脏组织学变化，用图像分析仪进行肺动脉测定，结果如下：低温组３５日龄时直径５０～１００rm、１００～２００um肺动脉中膜肥大，管腔面积，差异极显著（Ｐ〈０．０１）。外膜下弹力纤维、胶原纤维增多。低温下２８日龄超微结构观察表明肺动脉内皮细胞肿胀、细胞突起消失。随着低温时     

低温及L—精氨酸对肉用鸡腹水综合征的影响

用高能日粮饲养400只1日龄AA肉用鸡，14日龄时保优淘弱，随机分为3组，其中100只为常温（20℃）对照组；150只为低温（11℃）试验组；100只为低温（11℃）及日粮添加10g/kgL-精氨酸试验组，用单因子低温诱发肉用鸡腹水综合征，并不于同时间用红细胞压积、腹水心脏指数和腹水阳性率作为常规指标来判定肉用鸡腹水综合征，结果表明，低温组复制出肉鸡腹水综合征动模型，其发病率为9．33％，对照组为3．00％，与低温组比较差异极显著（P＜0．01）；L－精氨酸组腹水综合征发病率为3．00％。与低温组比较差异极显著（P＜0．01）。     

两种组胺受体拮抗剂对肺动脉高压肉鸡右心功能的影响

探讨组胺H,受体拮抗剂扑尔敏和H。受体拮抗剂西咪替丁对低温诱发肺动脉高压肉鸡右心功能的影响,由此反证内源性组胺在低温诱发肉鸡肺动脉高压形成过程中的作用。采用160只17日龄AA肉鸡随机分为4组,每组40只。（1）常温组：在常温条件下饲养（22～23℃）,每天注射生理盐水2次;（2）低温组：低温环境中饲养（9～11℃）,每天注射生理盐水2次;（3）扑尔敏组：与低温组相同饲养,每天注射扑尔敏2次;（4）西眯替丁组：与低温组相同饲养,每天注射西眯替丁2次。分别于低温处理后1周（24日龄）、2周（31日龄）、3周（38日龄）、4周（45日龄）从每组中各随机抽取7只,利用右心导管法测定右心室内压和右心室压最大变化速率,计算腹水心脏指数（AHI）和右心衰竭率。剖杀后用常规阿尔新蓝法对心脏中肥大细胞（MC）染色,免疫组化方法显示组胺。结果：（1）低温处理后使肉鸡肥大细胞和组胺阳性细胞数量显著降低,但2种组胺受体拮抗剂对肥大细胞数量及组胺阳性细胞数无明显影响;（2）扑尔敏组肉鸡右心内压相对稳定,45日龄时右心室舒张压显著低于低温组（P〈0．05）。西咪替丁组肉鸡右心收缩压和舒张压处于较低水平,且在31和38日龄时显著低于低温组（P〈0．05）;（3）扑尔敏组右心内压最大变化速率相对稳定,31日龄时显著低于低温组（P〈0．05）,而45日龄时显著高于低温组（P〈0．05）。西咪替丁组右心内压最大变化速率处于较低水平;（4）45日龄时,扑尔敏组AHI显著低于低温组（P〈0．05）;（5）扑尔敏组显著（P〈0．05）降低了右心肥大指数和右心衰竭发生率,西咪替丁组仅显著（P〈0．05）降低了右心衰竭率。以上结果表明,内源性组胺可能通过H3受体介导肉鸡右心肥大和衰竭,从而促进肺动脉高压综合征的发生发展。     

右心功能在肉鸡腹水综合征发病过程中的动态变化

20 0只艾维茵商品代肉鸡常规育雏 ,15日龄时随机分为两组 ,10 0只在常规温度下饲养 ( 2 2～ 2 3℃ ) ,为常温组 ;10 0只在低温环境中饲养 ( 9～ 11℃ ) ,为低温组。分别于处理后 0、7、14、2 1d每组随机抽取 10只 ,利用右心导管法测定右心室内压最大变化速率 (±dp/dtmax) (RV) ,并测定腹水心脏指数 (AHI) ,统计至 50日龄出栏时各组腹水发生率。结果为 :( 1)低温处理 1周后 ( 2 2日龄 ) |±dp/dtmax|显著高于 15日龄 (P <0 0 5) ,处理 2周后 ( 2 9日龄 )降至 15日龄水平 ,处理 3周后 ( 36日龄 ) |±dp/dtmax|极显著降低 (P <0 0 1) ,腹水鸡 |±dp/dtmax|较 15日龄极显著下降 (P <0 .0 1) ;常温组 |±dp/dtmax|亦有相近变化趋势。 ( 2 ) 2 9日龄之前AHI变化不显著 ,2 9日龄之后AHI较 15日龄极显著升高 (P <0 .0 1) ,36日龄AHI进一步增加 ,发生腹水鸡AHI达 39 97%± 6 3% ,显著高于15日龄 (P <0 0 1)。常温组AHI变化幅度比低温组小。 ( 3)低温组腹水发生率显著高于常温组 (P<0 .0 5)。结果表明 :反映右心室舒缩功能的±dp/dtmax(RV)出现先升后降变化 ,反映右心肥大程度的AHI逐渐增加 ,证明在肉鸡腹水综合征发生发展过程中右心的功能和结构出现代偿、失代偿直至右心衰竭的动态变化过程。     

热应激对12周龄麒麟鸡屠宰性能和肉品质的影响

为研究麒麟鸡（卷羽鸡）的肉用开发价值。本试验分别测定并比较了在常温（26±2．0℃）和高温（33±2．0℃）环境饲养12周龄的麒麟鸡屠宰性能及肉品质特性。结果表明：①屠宰性能：在常温和高温环境饲养12周龄的麒麟鸡（公母平均）体重分别达到1581．16g和1540．74g,差异不显著（P〉0．05）;麒麟鸡在高温处理后,其全净膛重显著低于常温组（P〈0．05）;高温处理下的麒麟鸡的腹脂重、腹脂率和肌间脂肪宽显著高于常温组（P〈0．05）;其余各指标差异不显著（P〉0．05）;②肉品质：在腿肌方面,12周龄的高温组麒麟公鸡剪切力显著高于常温组（P〈0．05）,高温组麒麟母鸡的肉色（a值）显著低于常温组（P〈0．05）,高温组麒麟鸡（公母平均）肉色（a值）显著低于常温组（P〈0．05）;在胸肌方面,12周龄高温组麒麟公鸡剪切力显著低于常温组（P〈0．05）,高温组麒麟母鸡的肉色（a值）显著低于常温组（P〈0．05）,高温组麒麟鸡（公母平均）的剪切力显著低于常温组（P〈0．05）：其余各指标差异不显著（P〉0．05）。麒麟鸡的耐热性、较高的屠宰率及肉质鲜美等特点．有望成为一种适合热带高温地区饲养的优质肉鸡。     

两种育雏温度培育肉仔鸡的效果

选用１日龄艾维茵仔鸡４０００只随机分成两组，育雏床上分别采用３５℃和３２℃的初温，以后每周降３℃，比较两组仔鸡在２周龄以内的增重和死亡情况。结果显示一周内肉鸡的增重高温组高于低温组，差异显著（Ｐ＜０．０５）；第二周内增重差异不显著（Ｐ＞０．０５）；二周内鸡的死亡数为高温组低于低温组，差异极显著（Ｐ＜０．０１）。鸡７周龄出栏时料肉比：高温组为１．９４，低温组为２．０１；７周龄出栏平均体重：高温组为２．４９ｋｇ，低温组为２．３０ｋｇ。３５℃初温育雏肉鸡的效果好于３２℃初温。     

猪瘟兔化弱毒疫苗不同免疫方法的免疫效果试验

将猪瘟兔化弱毒疫苗按后海穴和常规肌肉免疫注射，对免疫效果进行比较试验。选６０日龄健康三元杂交猪１００头，分为４组。Ａ组：后海穴全量注射疫苗２ｍＬ／头，３０头；Ｂ组：后海穴半量注射疫苗１ｍＬ／头，３０头；Ｃ组；肌肉全量注射疫苗２ｍＬ／头，３０头；Ｄ组：不注射疫苗健康对照，１０头。免疫后３０ｄ测定血凝（ＨＡ）效价，结果显示，Ａ组与Ｃ组相比，差异极显著（Ｐ〈０．０１）；组与Ｃ组相比，差异显著（Ｐ〈０．０     

复方中草药饲料添加剂对江汉土鸡生产性能的影响

采用３２０只江汉土鸡,对Ａ（混合型基础日粮＋中草药添加剂）、Ｂ（混合型基础日粮＋抗生素添加剂）、Ｃ（玉米型基础日粮＋中草药添加剂）、Ｄ（玉米型基础日粮＋抗生素添加剂）四种饲料进行了饲养试验。结果表明：Ａ组平均日增重比Ｂ、Ｃ、Ｄ组分别提高２１．５１％、１９．４３％、４８．２３％,与Ｂ、Ｃ组之间差异显著（Ｐ〈０．０５）,与Ｄ组之间差异极显著（Ｐ〈０．０１）;经济效益Ａ组比Ｂ、Ｃ、Ｄ各组分别提高２６．３     

2种组胺受体拮抗剂对低温诱发的肉鸡肺动脉高压的影响

为探讨组胺H1受体拮抗剂扑尔敏和H2受体拮抗剂西咪替丁对低温诱发的肉鸡肺动脉高压的影响,并由此推测组胺在低温诱发的肉鸡肺动脉高压形成过程中的作用。140只17日龄AA肉鸡随机分为4组。(1)常温组:40只在常温条件下饲养(22～23℃),每日注射生理盐水2次;(2)低温组:40只在低温环境中饲养(9～11℃),每日注射生理盐水2次;(3)扑尔敏组:40只在低温环境中饲养(9～11℃),每日注射扑尔敏2次;(4)西咪替丁组:20只在低温环境中饲养(9～11℃),于24日龄至38日龄期间每日注射西咪替丁2次。分别于低温处理后1周(24日龄)、2周(31日龄)、3周(38日龄)、4周(45日龄)从常温组,低温组,扑尔敏组中各随机抽取10只,西咪替丁组在低温处理后2周(31日龄)、3周(38日龄)各随机抽取10只,称取体重,然后利用右心导管法测定肺动脉压(PAP),并测定红细胞压积(PCV),腹水心脏指数(AHI)。结果发现:(1)24日龄、31日龄、38日龄时,低温组肺动脉收缩压,舒张压显著高于(P<0105)或极显著高于(P<0101)同日龄常温组。24日龄时扑尔敏组肺动脉收缩压显著低于(P<0105)同日龄低温组。38日龄时西咪替丁组肺动脉收缩压,舒张压极显著低于(P<0101)同日龄低温组。(2)24日龄、31日龄、38日龄、45日龄时,低温组PCV极显著高于(P<0101)同日龄常温组。24日龄时扑尔敏组     

饲粮 ｎ-６／ｎ-３多不饱和脂肪酸比例对鹅肌肉脂肪酸组成的影响

本文旨在探讨饲粮 ｎ-６／ｎ-３多不饱和脂肪酸（ＰＵＦＡ）比例对扬州鹅肌肉脂肪酸组成的影响。试验选取 １６０只健康、体重接近的 ２１日龄扬州鹅,随机分成 ４组,分别饲喂 ｎ-６／ｎ-３ＰＵＦＡ比例为 １２∶１、９∶１、６∶１及 ３∶１的饲粮,于 ７０日龄时取胸肌和腿肌,进行脂肪酸组成的测定。结果表明：１）在胸肌中,亚油酸的含量 ９∶１组显著高于 ３∶１组（Ｐ＜０．０５）,而与其他各组之间无显著差异（Ｐ＞０．０５）;α－亚麻酸的含量 ３∶１组显著高于 ６∶１和 ９∶１组（Ｐ＜０．０５）,极显著高于１２∶１组（Ｐ＜０．０１）。２）在腿肌中,亚油酸的含量 １２∶１和 ６∶１组均显著高于 ３∶１组（Ｐ＜０．０５）,而与９∶１组无显著差异（Ｐ＞０．０５）;α－亚麻酸的含量 ３∶１组显著高于 ６∶１组（Ｐ＜０．０５）,极显著高于１２∶１和 ９∶１组（Ｐ＜０．０１）。综上所述,鹅肌肉中 ｎ-６／ｎ-３ＰＵＦＡ比例随饲粮中该比例的下降而下降,并以 ３∶１组最低,但除 １２∶１组的腿肌 ｎ-６／ｎ-３ＰＵＦＡ比例较高外,其他各组比例均在世界卫生组织推荐的适于人体健康的（６∶１）～（１０∶１）的比例范围内。     

白术、微米白术和白术多糖对断奶仔猪生长性能和肠道形态及微生态区系的影响

试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。     

Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia

Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.     

Y‐chromosomal variation of local goat breeds of Turkey close to the domestication centre

Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.     

A brief history of the prevention of infectious diseases by immunisations

Infectious diseases have always been a terrible scourge for humans. The appearance of these plagues, as they were called without distinction, was generally connected to various conditions: asters, climatic changes or religious reasons. The concept of contagious, and then infectious, diseases came slowly. Variolation, i.e. transmission of ‘virulent’ matter to induce a natural disease and the immunity against it, was brought from Constantinople to England by Lady Montague, in 1721. This ‘variolation’ technique was also often performed in veterinary medicine against diseases like sheep-pox or pleuropneumonia. As ‘vaccination’ is the term generally accepted for ‘immunisation’, variolation can be the word designating such a technique. The second period of the history of immunisation began, in 1880, with the studies of Pasteur and his collaborators. A great number of bacterial vaccines were developed: dead, live but attenuated or only parts of pathogens. The viruses were produced in animals, then in eggs and at last, in tissue cultures. Second generation vaccines appeared with genetic engineering: recombinant vaccines, vector vaccines, nucleic acids vaccines, and markers vaccines, among others. These novel technologies can permit the development of new ones and improve the quality of the vaccines already existing.     

Micronutrient Content of Certain Tropical Conventional and Unconventional Feed Resources of Southern India

The ash, silica and certain important micronutrients were estimated in conventional and unconventional feed and fodder resources available in Southern India. Commonly used dry roughages, such as paddy straw, ragi straw, maize kadbi/stalk, jowar kadbi/stalk, bajra stalk and wheat straw, were high in ash (9.9% +/- 0.77%) and silica (6.4% +/- 0.65%) and low in most of the other micronutrients, except iron, with paddy straw containing most silica (>9%). Cultivated non-leguminous (maize, jowar) and improved green crops (hybrid napier, guinea, green panic, NB-21, CO-1) were also high in ash (10.5% +/- 0.60% and 12.5% +/- 0.51%) but were moderate sources of P, Mg and Cu and good sources of Zn (98 +/- 13.8 ppm and 55 +/- 6.7 ppm). Leguminous green fodders (stylosanthus, lucerne, cow pea, soyabean) were excellent sources of Ca (1.9% +/- 0.16%), Mg (0.40% +/- 0.05%), Cu (30 +/- 5.2 ppm), Zn (121 +/- 14.7 ppm) and Fe (1234 +/- 166 ppm) and moderate sources of P. Mixed local grasses and weeds were high in silica (6.9% +/- 1.00%) but were good sources of Cu, Zn and Fe. Cereal grains (maize, wheat, rice, ragi) were low in ash (2.9% +/- 0.33%) and were relatively poor sources of Ca (0.22% +/- 0.03%), Mg (0.19% +/- 0.03%) and Cu (13 +/- 3.1 ppm). Pulses were low to medium sources of most minerals and good sources of Fe (1230 +/- 293 ppm). Oil seed cake/extractions (groundnut cake, cotton seed cake, soyabean meal, sunflower cake, safflower cake) and cereal by-products (rice polish, rice bran, wheat bran) were excellent sources of P (1.1% +/- 0.47% and 2.3% +/- 0.19%) and good sources of Zn (65 +/- 3.9 ppm and 66 +/- 10.7 ppm) and Fe (938 +/- 130 ppm and 662 +/- 126 ppm). Among the unconventional feeds screened, orange peel, sunflower heads, meat meal, rubber seed cake, spirulina algae and sea weeds contained plentiful Ca, Zn and Fe: tree leaves/top feeds (mulberry, erythrina, glyricidia, banana, subabul, groundnut haulms) were excellent sources of Ca (1.5% +/- 0.13%), Zn (120 +/- 22.9 ppm) and Fe (1033 +/- 133 ppm) but relatively poor sources of P. Soyabean husk, cocoa seed husk, rubber seed cake and meat meal were moderate to good sources of P (1.0% and 0.33%). The high Zn and Fe values of most feeds/fodders were probably due to soil contamination. This account of the micronutrient content of feed/fodder resources should help in strategic supplementation intended to alleviate local deficiencies.     

Bovine Mastitis in Selected Areas of Southern Ethiopia

A study on bovine mastitis, designed to determine the causal agents, prevalence of infection and impact of risk factors in three cattle breeds, was conducted in selected areas of southern Ethiopia. A total of 307 lactating and non-lactating cows, of which 162 were indigenous Zebu, 85 Jersey and 60 Holstein-Friesian, were examined by clinical examination and the California mastitis (CMT) test. Of these, 40.4% were positive by CMT and bacteriology for clinical or subclinical mastitis, with prevalence rates of 37.1% and 62.9%, respectively. Out of 1133 quarters examined, 212 (18.7%) were found to be infected, 83 (39.2%) clinically and 129 (60.8%) subclinically. The prevalence of mastitis was significantly higher in Holstein-Friesian than in indigenous Zebu, in non-lactating cows than in lactating cows, in the early lactation stage than in the mid-lactation stage, in cows with lesions and/or tick infestation on skin of udder and/or teats than in cows without this factor, and in the wet season than in the dry season. Mastitis increased with parity number (R = 0.9). Of 248 CMT and clinically positive udder quarter samples analysed microbiologically, 212 were culturally positive for known mastitis pathogens and 36 were negative. Of the 199 positive samples, Staphylococcus accounted for 39.2%, Streptococcus for 23.6%, coliforms for 14.1%, Micrococcus and Bacillus species for 8.0% each and Actinomyces or Arcanobacterium (Corynebacterium) for 7.0%. It was concluded that there was a high prevalence of clinical and subclinical mastitis, mainly caused by Staphylococcus aureus, Streptococcus agalactiae and Escherichia coli, in this study area.     

不同日粮氮水平对山羊氮代谢和微生物蛋白质合成的影响

本试验旨在探讨不同日粮氮水平对内蒙古白绒山羊氮代谢和微生物蛋白质合成(MCP)的影响,以达到提高氮利用率,减少环境污染和饲料资源的浪费。试验选用9只体况良好、体重为(43.83±2.95)kg,装有瘤胃瘘管的内蒙古白绒山羊,按体重随机分为3组,每组3只。日粮分为低氮7.5%、中氮10.5%、高氮13.5%3个氮水平。试验使用常规试验方法分析测定粪尿血液等生化指标,通过全收尿法和尿嘌呤衍生物法估测MCP。结果表明:随着氮水平增加,氨氮(NH3-N)浓度、氮摄入量、尿氮排出、尿中尿素氮(UUN)和MCP显著增加(P0.05),干物质采食量(DMI)显著降低(P0.01);沉积氮占总摄入氮的比例在中氮组最高,MCP在高氮组最高。综上所述,适当降低日粮氮水平可减少粪尿氮排放,提高反刍动物氮利用率。     

Microsporidial keratopathy in two dogs

A microsporidial keratopathy is described in two dogs. Both dogs presented with a unilateral stromal keratopathy characterized by multifocal coalescing opacities, and the diagnosis was made on histopathologic examination of keratectomy specimens. Transmission electron microscopy (TEM) on formalin‐fixed, paraffin‐embedded corneal tissue was performed in one dog, and the morphologic features were consistent with Nosema species infection. Both dogs were initially diagnosed and treated by superficial keratectomy. One dog received additional antifungal medication and underwent a penetrating keratoplasty following local recurrence two years later. No other systemic lesions attributable to the microsporidial infection were identified clinically. The clinical and diagnostic pathology findings, treatment, and follow‐up are discussed.     

优质肉鸡S3系体重与体尺性状指标的主成分分析

为研究地方优质肉鸡S3系体重和体尺性状之间的内在相关性,12周龄时选取同一饲养条件下的150只鸡(公母各半)进行体重和体尺性状等7个指标的测定。结果表明:S3系公鸡的体重、体斜长、龙骨长、胸角均显著高于母鸡(P0.05);公母鸡体重、体斜长、胸宽、胫围这4项指标变异系数较大,有较大选育空间;体重与体斜长、龙骨长、胸宽、胸角、胫围呈极显著正相关(P0.01),相关系数分别为0.57、0.52、0.51、0.49和0.47,与胸深、胫长呈显著相关(P0.05),相关系数分别为0.44和0.39;其他各体尺指标间也存在不同程度的正负相关性(P0.05或P0.01);体重和7个体尺性能指标综合成5个复合指标,累计贡献率达92.6355%,其中第l、2、3、4、5主成分分别解释总变异的36.5353%、22.8642%、13.3115%、10.4535%和8.4710%;各主成分的特征根分布较广,经统计计算入选的5个主成分所包含信息的侧重点各有相同,分别都在一定程度上反映了S3鸡的体型特征和生长发育规律,为今后选育出更加符合市场需求的屠宰加工优质型肉鸡指明了的方向。     

Efficacy of tropicamide,homatropine, cyclopentolate,atropine and hyoscine as mydriatics in Angora goats

Abstract

AIM: To document the efficacy of five commercially available mydriatics for their potential for diagnostic and therapeutic use in Angora goats.

METHODS: Over 8 weeks, the mydriatic effects of 1% tropicamide, 2% homatropine, 1% cyclopentolate, 1% atropine and 0.25% hyoscine were evaluated. Given as block treatments, drugs were applied randomly to one eye of 10 Angora goats, and the contralateral eye served as a control. Vertical and horizontal pupil diameters were measured to document onset ofeffect, time to reach a difference of 5 mm in the vertical/horizontal pupil diameter between eyes, time to maximum pupillary dilation, and duration of mydriatic action.

RESULTS: Onset of mydriasis for all drugs occurred within 15 minutes. Time to reach a difference of 5 mm in the vertical pupil diameter between eyes was shortest for 1% tropicamide and 0.25% hyoscine (0.5 h), then 2% homatropine and 1% atropine (0.75 h), and longest for 1% cyclopentolate (1.5 h). The maximum vertical pupillary dilation occurred earliest with 1% tropicamide and 1% atropine (2 h), followed by 0.25% hyoscine (3 h), 2% homatropine (4 h), and latest with 1% cyclopentolate (8 h). The duration of vertical dilation of the pupil was shortest with 1% tropicamide (6 h), then 2% homatropine (12 h), 1% cyclopentolate (12 h), 1% atropine (24 h), and longest for 0.25% hyoscine (96 h).

The time to reach maximum horizontal dilation of the pupil in treated eyes was shortest with 1% cyclopentolate (1 h), followed by 1% tropicamide (1.5 h), 0.25% hyoscine (3 h), 2% homatropine (3.5 h), and 1% atropine (4 h). The duration of horizontal pupil dilation was shortest with 1% tropicamide (4.5 h), and longest with 0.25% hyoscine (48 h).

CONCLUSION: All five mydriatics induced clinical dilation. Tropicamide (1%) had the shortest duration of effect, but gave incomplete dilation. Good dilation was achieved with 1% cyclopentolate and 2% homatropine, but took too long to reach maximum dilation for routine mydriasis. The largest vertical dilation of the pupil was achieved with 1% atropine and 0.25% hyoscine, but pupils remained dilated for more than 24 h.

CLINICAL RELEVANCE: For routine mydriasis in goats, it is recommended that 1% tropicamide be used, though there may be incomplete dilation. For a longer duration of mydriasis, such as in the treatment of anterior uveitis, 1% atropine or 0.25% hyoscine would be the drugs of choice.