四种黄羽肉鸡IGF-1多态性与生产性能相关分析

采用PCR-SSCP技术测定了4个黄羽肉鸡品种IGF-1基因2个SNP位点,并分析了它们对不同周龄体重及产蛋性状的遗传效应.结果显示,2个SNP位点分别发生了T→A、G→A的单碱基突变,各有3种基因型,京海黄鸡P1位点偏离Hardy-Weinberg平衡状态(P<0.01).最小二乘方差分析表明,京海黄鸡、江村黄鸡从型个体具有较高的300日龄产蛋量,与AB、BB型间差异显著(P<0.05),江村黄鸡从型具有较高的12周龄和300日龄体重,石岐杂鸡AA型300日龄体重显著高于BB型(P<0.05),表明A为产蛋及体重增效基因;不同黄鸡品种均表现出CC型个体具有较高的300日龄体重和产蛋数(P>0.05).     

鸡胰岛素样生长因子1受体基因G26336A、C111014A多态位点的检测及其与生产性状的相关性

根据GenBank发表的鸡胰岛素样生长因子1受体(insulin-like growth factor 1 receptor,IGF1R)基因序列针对外显子2和3设计2对引物,采用DNA池测序和PCR-SSCP技术,对鸡IGF1R基因的G26336A、C111014A位点进行多态性检测,并与鸡的生产性状进行相关性分析。结果表明,G26336A位点AA基因型个体56日龄体重显著低于BB基因型个体(P<0.05),AA和AB基因型个体在84日龄体重显著低于BB基因型个体(P<0.05)。C111014A位点CC、CD基因型个体初生重显著低于DD基因型(P<0.05),CC基因型个体在300日龄体重显著低于DD基因型(P<0.05)。研究结果初步表明,IGF1R基因可能是影响鸡生长性状的一个主效基因或是与之存在紧密遗传连锁的一个标记。     

贵妃鸡与麒麟鸡微卫星遗传多样性研究

以岭南黄鸡为参照,利用微卫星位点检测贵妃鸡和麒麟鸡的遗传多样性,评估群体遗传资源现状。结果表明:26个微卫星位点在30个贵妃鸡、40个麒麟鸡和30个岭南黄鸡个体中共检测到197个等位基因,每个位点的等位基因范围为3个(MCW0037、MCW0165、MCW0098)~19个(LEI0234),平均7.58;总体平均期望杂合度为0.6816,平均观察杂合度0.5625,平均多态信息含量0.6327;岭南黄鸡的遗传多样性最高,麒麟鸡次之,贵妃鸡最低;3个群体均偏离了哈迪-温伯格平衡;贵妃鸡和麒麟鸡的群体内近交系数高于岭南黄鸡,表明前者的近亲交配事件较频繁;麒麟鸡群体内的遗传分化系数(均值0.2433)和岭南黄鸡(0.2281)大于贵妃鸡(0.0359),表明后者的有效群体较小。在后续的品种选育工作中应当加强亲本亲缘关系的评估,提高选育群体的有效数量,尽量减少近亲交配。     

VIPR-1基因SNP位点与如皋黄鸡产蛋性能和蛋品质的关联分析

本研究旨在分析VIPR-1基因的SNP位点与产蛋性能和蛋品质之间的关联性。实验以如皋黄鸡为素材,采用飞行时间质谱技术对VIPR-1基因内含子2第+1063位碱基(PA位点)的G-T突变和第+3522位碱基(PB位点)的T-C突变进行单位点和多位点组合效应分析。结果表明:PA位点的多态性与产蛋性状中的开产日龄(AFE)和40周龄总产蛋数(EN40)呈显著相关(P<0.05);与蛋品质性状中的蛋壳强度(ESS)、蛋黄比率(YR)和蛋黄蛋白比(YAR)呈显著相关(P<0.05);等位基因T有利于产蛋量和蛋品质的改善。PB位点与本次实验所测的5个产蛋性状相关均不显著(P>0.05),与蛋品质性状中的蛋重(EW)、蛋形指数(ESI)、蛋壳厚度(EST)和蛋比重(ESG)相关显著(P<0.05)。组合效应分析结果表明,对于产蛋性能,GTTT和TTTC组合基因型个体的组合效应显著。     

GH和GHR基因多态性与滩羊生长性状的关联分析

为了解滩羊生长发育的遗传机制,寻找与生长性状相关的分子标记,试验采用PCR-RFLP方法检测宁夏滩羊GH和GHR基因的多态性,分析了多态位点不同基因型及合并基因型与滩羊生长性状的关联性。结果表明:GH基因第2内含子和GHR基因第4外显子分别经PvuⅡ和HpaⅡ酶切各产生BB(0.375 0)、AB(0.625 0)和DD(0.825 0)、CD(0.175 0)2种基因型;GH基因PvuⅡ位点的不同基因型个体初生重和6月龄体重差异显著(P0.05),与断奶重差异极显著(P0.01),AB为优势基因型;GHR基因HpaⅡ位点的CD基因型初生重和6月龄体重显著高于DD基因型(P0.05),而这两种基因型与断奶重差异不显著。对这两个SNPs位点进行基因互作分析发现双杂合基因型个体各生长性状均显著高于其他基因型组合(P0.05),并且多标记位点的组合效应高于单标记位点。说明ABCD是影响滩羊生长性状的最佳基因型组合,可作为滩羊生长性状的遗传标记。     

中国西门塔尔牛CAPN1基因SNPs及其与经济性状关联分析

本研究旨在分析CAPN1基因部分SNPs与中国西门塔尔牛经济性状的关联性.试验选取同龄、同场的135头中国西门塔尔牛为材料,利用PCR-RFLP方法检测CAPN1 316和CAPN1 4751 2个SNPs位点的多态性,并进行方差分析.结果发现,CAPN1 316 SNP位点与大理石花纹显著相关(P＜0.05),杂合子AB基因型个体的大理石纹评分显著高于AA和BB基因型个体(P＜0.05);CAPN1 4751位点与大理石花纹和剪切力显著相关(P＜0.05),大理石花纹性状中杂合子AB基因型个体评分显著高于AA基因型个体,剪切力性状中BB基因型个体显著高于AA基因型个体.结果表明,CAPN1 316和CAPN1 4751位点适合用于中国西门塔尔牛眼肌、肌肉大理石花纹的分子标记选择.     

欣华鸡DRD2基因多态性及其与蛋用性状的关联分析

试验旨在研究多巴胺受体D2(dopamine receptor D2,DRD2)基因多态性及其与欣华鸡蛋用性状的相关性,寻找可用于欣华鸡蛋用性状选育的分子遗传标记。应用Primer Premier 5.0软件设计4对引物,利用PCR-RFLP技术对欣华E系鸡群的473个个体进行基因型鉴定,使用SPSS 19.0软件将欣华鸡的蛋用性状与DRD2基因多态性进行关联分析。群体多态性分析结果表明,存在4个SNPs位点:A-16105G(SNP1)、G-12510T(SNP2)、G+3360A(SNP3)和T+5042C(SNP4),其中SNP1和SNP2位点符合哈代-温伯格平衡(P>0.05),且杂合度较低,但SNP3和SNP4位点显著偏离哈代-温伯格平衡(P<0.05)。关联分析表明,DRD2基因4个SNPs位点与欣华E系鸡群体蛋用性状存在关联,其中与产蛋性状关联结果:SNP1与开产日龄显著关联(P<0.05),SNP2与33周龄产蛋数、300日龄产蛋总数极显著关联(P<0.01),SNP3与开产体重(P<0.05)、300日龄产蛋总数(P<0.01)、平均连产(P<0.01)和最长连产(P<0.05)关联,SNP4与开产日龄极显著关联(P<0.01);与蛋品质关联结果:SNP1与蛋形指数(P<0.01)、蛋黄颜色(P<0.01)和哈氏单位(P<0.05)关联,SNP2与蛋黄重显著关联(P<0.05),SNP3与蛋壳强度极显著关联(P<0.01),SNP4与蛋黄重、蛋清重和哈氏单位显著关联(P<0.05)。单倍型分析发现,DRD2基因4个SNPs位点的不同单倍型组合与欣华鸡的最长连产长度呈极显著相关(P<0.01),与哈氏单位呈显著相关(P<0.05)。组织表达谱分析发现,DRD2基因主要在欣华E系鸡垂体中表达,在58周龄鸡胸肌中有较高表达,在36周龄鸡脑中有少量表达。结果表明,DRD2基因可作为候选基因辅助用于欣华E系鸡群体蛋用性状的遗传改良。     

欣华鸡DRD2基因多态性及其与蛋用性状的关联分析

试验旨在研究多巴胺受体D2(dopamine receptor D2,DRD2)基因多态性及其与欣华鸡蛋用性状的相关性,寻找可用于欣华鸡蛋用性状选育的分子遗传标记。应用Primer Premier 5.0软件设计4对引物,利用PCR-RFLP技术对欣华E系鸡群的473个个体进行基因型鉴定,使用SPSS 19.0软件将欣华鸡的蛋用性状与DRD2基因多态性进行关联分析。群体多态性分析结果表明,存在4个SNPs位点:A-16105G(SNP1)、G-12510T(SNP2)、G+3360A(SNP3)和T+5042C(SNP4),其中SNP1和SNP2位点符合哈代-温伯格平衡(P0.05),且杂合度较低,但SNP3和SNP4位点显著偏离哈代-温伯格平衡(P0.05)。关联分析表明,DRD2基因4个SNPs位点与欣华E系鸡群体蛋用性状存在关联,其中与产蛋性状关联结果:SNP1与开产日龄显著关联(P0.05),SNP2与33周龄产蛋数、300日龄产蛋总数极显著关联(P0.01),SNP3与开产体重(P0.05)、300日龄产蛋总数(P0.01)、平均连产(P0.01)和最长连产(P0.05)关联,SNP4与开产日龄极显著关联(P0.01);与蛋品质关联结果:SNP1与蛋形指数(P0.01)、蛋黄颜色(P0.01)和哈氏单位(P0.05)关联,SNP2与蛋黄重显著关联(P0.05),SNP3与蛋壳强度极显著关联(P0.01),SNP4与蛋黄重、蛋清重和哈氏单位显著关联(P0.05)。单倍型分析发现,DRD2基因4个SNPs位点的不同单倍型组合与欣华鸡的最长连产长度呈极显著相关(P0.01),与哈氏单位呈显著相关(P0.05)。组织表达谱分析发现,DRD2基因主要在欣华E系鸡垂体中表达,在58周龄鸡胸肌中有较高表达,在36周龄鸡脑中有少量表达。结果表明,DRD2基因可作为候选基因辅助用于欣华E系鸡群体蛋用性状的遗传改良。     

STATTAT5b基因多态性及其与京海黄鸡繁殖性状的相关分析

以信号转导和转录激活子5b(STAT5b)基因为候选基因,采用PCR-SSCP和DNA测序技术检测STAT5b基因在京海黄鸡、边鸡、尤溪麻鸡和AA鸡4个群体中的单核苷酸多态性(SNPs),并与京海黄鸡繁殖性状的相关性进行研究。结果表明,就STAT5b基因P1位点而言,在4个鸡群体中检测到6种基因型(DD、DE、DF、EE、EF、FF)。克隆测序发现,与DD基因型相比EE和FF基因型中存在2个突变(A9221G、T9401C)。就P2位点而言,在4个鸡品种中检测到3种基因型(GG、GH和HH),克隆测序发现,与GG基因型比较HH基因型有3个突变(C11159T、T11183C和T11252C)。最小二乘分析结果显示,DF基因型的京海黄鸡300日龄产蛋数显著高于EE基因型的京海黄鸡个体(P0.05),其他性状基因型间无差异(P0.05);GG基因型京海黄鸡300日龄体重显著高于GH基因型的京海黄鸡个体(P0.05),其他性状基因型间无差异(P0.05)。单倍型分析产生8种单倍型,10种单倍型组合。单倍型组合H1H3和H1H8京海黄鸡个体300日龄产蛋数最多;单倍型组合H1H7京海黄鸡个体300日龄蛋重最大;H1H1单倍型组合京海黄鸡个体300日龄体重最高。因此,推测STAT5b基因P1、P2位点对京海黄鸡繁殖性状有一定影响。     

京海黄鸡IGF1R基因Alu Ⅰ、Hin1 Ⅰ多态位点的发现及其与生产性状的相关性

根据GenBank发表的鸡IGF1R基因序列针对外显子2和3设计2对引物,采用池DNA测序和PCR-R FLP技术,对京海黄鸡IGF1R基因的AluⅠ、Hin1Ⅰ位点进行多态性检测,并与京海黄鸡的生产性状进行相关性分析。结果表明:AluⅠ位点AA基因型个体在8周龄体重显著低于BB型个体(P<0.05),AA和AB基因型个体在12周龄体重显著低于BB型个体(P<0.05)。Hin1Ⅰ位点CC、CD基因型个体的初生重显著低于DD基因型(P<0.05),CC基因型个体的300日龄体重显著低于DD基因型(P<0.05)。研究结果初步显示,IGF1R基因可能是影响京海黄鸡生长性状的一个主效基因或是与之存在紧密遗传连锁的一个标记。     

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.