牛场奶牛乳房炎的发病因素探究及其判别分析方程的建立

利用2011年1月至2014年12月山东地区某牛场的奶牛生产性能测定(DHI)数据库及其乳房炎发病记录为数据集,通过sas统计分析软件,对胎次、泌乳天数、采样季节、采样年份、体细胞数、产奶量、乳脂率、乳蛋白率与乳房炎发病记录做逐步判别(Stepdisc)和glm相关性方差分析。结果显示:胎次、泌乳天数、采样季节、采样年份和体细胞数与乳房炎的发生显著相关。因此,综合与奶牛乳房炎发病密切相关的胎次、泌乳天数、采样季节、采样年份和体细胞评分建立了直观、相对准确的判定奶牛乳房炎发生的判别分析方程Y_0(未患乳房炎)和Y_1(患乳房炎),通过比较Y_0和Y_1的大小对未知个体牛是否患有乳房炎做出初步判断。此判断虽然不能对乳房炎的发生做出确诊,但能够帮助奶牛场管理者对奶牛群体进行宏观监测,从奶牛群体中筛选出发生乳房炎概率较大的作为重点监测对象。由此奶牛场能够尽早发现乳房炎,节约乳房炎检测成本,为乳房炎的及时控制与治疗提供科学理论依据,对DHI的推广和DHI报告的充分利用也具有重要意义。     

金华猪生长激素基因多态性分析及生长曲线比较

采用PCR-RFLP法测定了金华猪生长激素基因Apa -Ⅰ及Msp Ⅰ酶切多态性.并分析了各基因型与生长速度的相关性,进而对金华猪的生长曲线进行了拟合.结果表明,金华猪生长激素基因经Apa Ⅰ酶切后未出现多态,经Msp Ⅰ酶切后出现了AB(274、238、137 bp)和BB(238、137 bp)2种基因型,且不同基因型间的个体初生体质量、1月龄体质量、2月龄体质量、3月龄体质量、5月龄体质量、6月龄体质量及0～6月龄间平均日增体质量的差异不显著(P>0.05),而BB基因型4月龄体质量差异高于AB基因型(P<0.05).生长曲线拟合结果表明,Bertalanffy模型效果最佳.AB与BB基因型2种生长曲线进行比较,显示出BB基因型具有早期生长速度较快、生长拐点早、拐点体质量小的特点.     

A generalized framework for AMOVA with multiple hierarchies and ploidies

The analysis of molecular variance (AMOVA) is a widely used statistical method in population genetics and molecular ecology. The classic framework of AMOVA only supports haploid and diploid data, in which the number of hierarchies ranges from two to four. In practice, natural populations can be classified into more hierarchies, and polyploidy is frequently observed in extant species. The ploidy level may even vary within the same species, and/or within the same individual. We generalized the framework of AMOVA such that it can be used for any number of hierarchies and any level of ploidy. Based on this framework, we present four methods to account for data that are multilocus genotypic and allelic phenotypic (with unknown allele dosage). We use simulated datasets and an empirical dataset to evaluate the performance of our framework. We make freely available our methods in a new software package, polygene , which is freely available at https://github.com/huangkang1987/polygene .     

Use of structured antedependence models for the genetic analysis of growth curves

Growth curve analysis is an important issue for many agricultural and laboratory species, for both phenotypic and genetic studies. The aim of this paper is to present the use of a novel statistical approach, namely the structured antedependence (SAD) models, to deal with this issue. The basic idea of these models is that an observation at time t can be explained by the previous observations. These models are especially appropriate to deal with cumulative traits such as growth, as BW at age t clearly depends on BW measures at ages (t -1), (t -2), etc. These models were applied on an INRA experimental Charolais herd data set. The data comprised BW records for 560 cows born over an 11-yr period (from 1988 to 1998) from 60 sires and 369 dams. The proposed SAD models were compared with the well-known random regression (RR) models that are already widely used in various areas of longitudinal data analysis. It was found that the SAD models fit the growth process better with far fewer parameters than the RR models (9 instead of 16 covariance parameters for the phenotypic analysis, and 14 instead of 21 for the genetic analysis). Despite this smaller number of covariance parameters, the likelihood value was found to be much higher with the SAD vs. the RR models, with a difference of 262.9 for the phenotypic analysis with a quartic polynomial for the RR and 751.5 for the genetic analysis with a cubic polynomial for both the genetic and environmental parts of the RR model. The SAD models also proved to be better able to interpolate missing values. Heritability, genetic, and environmental correlation coefficients were estimated for weights from birth to adulthood. The structured antedependence models proved, in this study, to be very appropriate to model growth data in a parsimonious and flexible way.     

应用统计软件SPSS拟合生长曲线方程

介绍了应用统计软件SPSS中非线性回归子程序进行生长曲线拟合的步骤,运用实例分析表明,应用SPSS软件拟合生长曲线具有交互性好,易学易用、方便快截的特点。     

A chemically defined medium for the growth of Cowdria ruminantium

Chemically defined media, termed SFMC-23 and SFMC-36, were devised for the in vitro culture of Cowdria ruminantium, the causative agent of heartwater in domestic ruminants. Both media were based on Dulbecco's modified Eagle's medium nutrient mixture Ham F-12 (DME/F-12) containing various supplements. Medium SFMC-23 and SFMC-36 supported the long-term growth of the Welgevonden stock of C. ruminantium for a total of 55 and 28 passages, respectively, with regular passage intervals of 3 days. Using SFMC-23, split ratios varied from 5-10, depending on which host cell line was used. Other stocks of C. ruminantium (Sankat, Blaauwkrantz, Senegal) were successfully propagated for a test period of ten passages.     

Quantitative analysis of long-bone growth in the horse

Long-bone growth at the distal ends of the radial bones, the distal ends of the 3rd metacarpal bones, the distal ends of the 3rd metatarsal bones, and the proximal ends of the proximal phalangeal bones (of thoracic and pelvic limbs) was quantitatively analyzed in 9 Thoroughbred-Quarter Horse foals from birth to 2 years of age. Metal growth markers were surgically implanted in the bones of the animals at 2 to 4 days of age. Radiographs of the bones were made on the day of surgical manipulation, the next day, and then once a week for 8 months, and once a month thereafter for an additional 18 months. On each radiograph, the intervals between the growth markers were measured and plotted, and these accumulated growth data were subjected to statistical analyses. Growth curves, cumulative growth, and relative growth rates were determined. The ages of radiographic growth plate closure also were determined. Total bone growth observed in these foals was proportionately greater than that observed in a similar study of Shetland-Welsh ponies, probably indicating a breed difference. The most rapid growth rate at the 5 anatomic sites in the foals occurred from birth to 10 weeks of age; however, in the distal part of the radius, there was a continuous, though declining growth rate until 60 weeks of age, whereas in the distal ends of the 3rd metacarpal and metatarsal bones and the proximal end of the proximal phalanges growth ceased abruptly and nearly plateaued after 10 weeks of age.(ABSTRACT TRUNCATED AT 250 WORDS)     

A prediction equation for enteric methane emission from dairy cows for use in NorFor

Abstract

A data-set with 47 treatment means (N = 211) was compiled from research institutions in Denmark, Norway, and Sweden in order to develop a prediction equation for enteric methane (CH₄) emissions from dairy cows. The aim was to implement the equation in the Nordic feed evaluation system NorFor. The equation should therefore be based on input variables available in NorFor. The best equation to predict CH₄ (MJ/d) was based on dry matter intake (DMI, kg/d), and content of (g/kg DM) fatty acids (FA), crude protein (CP), and neutral detergent fiber (NDF). The equation was CH₄ = 1.36 (±0.10) × DMI – 0.125 (±0.039) × FA – 0.02 (±0.012) × CP + 0.017 (±0.005) × NDF (RMSE = 3.00 MJ CH₄/d; CV = 13.8%; R² = 0.77), where RMSE is the root mean square error and CV is the coefficient of variation. However, CP was on the borderline of being significant and did not quantitatively explain much variation in CH₄ emission. Based on the present research, we concluded, therefore, that the equation CH₄ = 1.23 (±0.08) × DMI – 0.145 (±0.039) × FA + 0.012 (±0.005) × NDF (RMSE = 3.10 MJ CH₄/d; CV = 14.3%; R² = 0.75) is most suited for being implemented in NorFor. However, the ability of the proposed equation to predict enteric methane emissions is uncertain until evaluated on an independent data-set.     

一种蓝莓不良症状的诊断方法

本文介绍了一种分析蓝莓生长不正常时原因的方法,通过4个步骤的原因分析,从而帮助蓝莓种植者作出正确地判断并解决问题。     

浅析仔犬的生长发育规律

通过近4年对某犬场所繁育的德国牧羊犬与罗威纳犬两个品种共760头2月龄内仔犬的累计生长、绝对生长、相对生长的分析。研究发现仔犬在15～25日龄、35日龄和55日龄左右出现了生长发育低谷;罗威纳仔犬的生长发育要比德国牧羊犬仔犬推迟5～10天左右。在此研究的基础上,结合日常饲养管理分析,归纳出仔犬的生长发育规律。     

A generalized staphylococcal scalded skin-like disease in lambs

An idiopathic disease involving skin and kidneys was seen in two Merino lambs from the same herd. A generalized skin exfoliation in association with acute renal failure were the most prominent clinical features. The condition resembled staphylococcal scalded-skin syndrome of man, and pure cultures of Staphylococcus aureus were isolated from the lesion. Acute renal failure was diagnosed by clinical, biochemical and histological criteria, and necropsy.     

应用灰色关联度综合评价26个青贮玉米的生产性能

采用灰色关联度分析法对26个参试青贮玉米（Zea mays）品种的7个性状进行综合评价。结果表明,在赤峰地区表现较好的青贮玉米品种有中农大青贮67、金岭18、雅玉青贮79491、金岭17、金岭21、青贮772、雅玉青贮29、东陵白、金岭37、中北青贮410,而YA473182、英国红（小）、东陵白（小）的生产性能较差。各项指标的权重大小顺序为株高＞穗位叶叶面积＞生物产量＞单株鲜质量＞单株干质量＞果穗鲜质量∶单株鲜质量＞果穗鲜质量,本研究结果可为赤峰地区乃至内蒙古农牧交错带青贮玉米引种及推广提供科学依据。     

应用绵羊粪便的近红外光谱方程评定其日粮的粗蛋白

利用近红外光谱法(NIRS)对绵羊粪便的扫描值和日粮粗蛋白的化学测定值来建立定标方程式.试验以绵羊为试验动物,日粮主要由各种牧草、作物秸秆和棉花籽壳组成,试验动物日粮设计了78个蛋白水平.在2002年和2003年分别用15只和20只成熟母羊(体重为55±2.4 kg)进行了为期7周的试验.用凯式定氮法测定日粮的粗蛋白(CP)水平是从4.3 %到23.5 %,日粮粗蛋白的定标方程式决定系数R2=0.95,定标标准误差(SEC)=1.08.用12只饲喂美国北部大平原饲草的成年母羊的粪便光谱扫描值和与粪便对应的日粮粗蛋白的化学分析数据来校验粗蛋白预测方程式的有效性,结果显示,决定系数(R2)=0.81,预测标准误差(SEP)=1.51,斜率=0.89,表明利用近红外光谱法(NIRS)发展的粪便近红外光谱方程可以有效预测绵羊日粮的粗蛋白含量.     

Thymocyte growth factor: A progression growth factor for cycling immature cortical thymocytes

A growth factor for cultured guinea pig thymocytes was isolated from an extract of calf thymus. This thymocyte growth factor (TGF) was purified to apparent homogeneity employing reverse phase high performance liquid chromatography as the final step. TGF was characterized as an N-terminal blocked hydrophilic peptide with an apparent M_r of 1600. The amino acid composition revealed a high content of acidic amino acids but no apparent relationship with previously defined growth factors and thymic differentiation hormones. TGF was active in nanomolar concentration and stimulated the DNA synthesis and mitotic activity specifically in a subpopulation of thymocytes with immature cortical phenotype. The responsive thymocytes were recruited from G₁ into S phase within 2 h after addition of TGF. In the absence of the growth factor, the target cells were blocked at a putative restriction point in G₁, prior to the onset of the S phase. It is proposed that TGF is a progression growth factor participating in the regulation of the intense proliferation of immature thymocytes in the thymus cortex in vivo.     

A case of post-operative generalized staphylococcal infection in a bitch

A case of post-operative generalized infection in a 9-year-old, cross-bred terrier bitch is described. A coagulase-positive strain of Staphylococcus aureus was isolated from an acute inflammatory lesion in the foreleg (the site of intravenous injection), the viscera and the major limb joints. The animal showed lesions of endocarditis, myocarditis, hepatitis, nephritis, splenic infarcts and polyarthritis. It is suggested that the entry of the organism and its preliminary multiplication occurred at the site of the intravenous injection of the anaesthetic used for inducing a general anaesthesia. Résumé. Observation d'une septicémie post-opératoire chez une chienne terrier métissée de 9 ans. On a isolé une souche de staphylocoques dorés coagulase-positive à partir d'un foyer inflammatoire aigu de la patte antérieure (siège d'une injection intraveineuse), des viscères et des grandes articulations des membres. L'animal présentait des lésions d'endocardite, de myocardite, d'hépatite, de néphrite, d'infarctus de la rate et de polyarthrite. On suppose que le germe Pathogène a pénétré dans l'organisme et s'est multiplié tout d'abord au lieu de l'injection intraveineuse de l'anesthésique utilisé pour provoquer une anesthésie générale. Zusammenfassung. Ein Fall von postoperativer generalisierter Infektion bei einer 9 Jahre alten Terrier-Hündin aus einer Kreuzung wird beschrieben. Aus einer akuten entzündlichen Läsion am Vorderbein (der Stelle einer intravenösen Injektion), den Eingeweiden und den grossen Gliedmassengelenken wurde ein koagulasepositiver Stamm von Staphylococcus aureus isoliert. Das Tier zeigte Läsionen von Endocarditis, Myocarditis, Hepatitis, Nephritis, Milzinfarkten und Polyarthritis. Es wird angenommen, dass der Eintritt des Organismus und die anfängliche Vermehrung an der Stelle der intravenösen Injektion des für eine Vollnarkose gegebenen Narkotikums erfolgte.     

A growth medium for the production of a bacterin for immunization against infectious coryza.

A serum-free modified Casman broth medium was developed to grow Haemophilus gallinarum to titers of 10-8 organisms per ml. Formalin-inactivated bacterins prepared form the broth culture were used to immunize chickens. A single dose of bacterin containing adjuvant protected 6 of 7 chickens against a homologous challenge 4 weeks postvaccination. A second dose given 3 weeks after the first offered no better protection than a single dose.     

Genetic analysis of growth curve parameters for male and female chickens resulting from selection on shape of growth curve

The objectives of this research were to evaluate gender differences and selection on body weight as they affect growth curves of chickens. Marginal posterior densities of growth curve parameters were studied by Gibbs sampling on 10,671 male and female chickens originating from five lines. Line X-+ was selected on low body weight at 8 wk (BW8) and high body weight at 36 wk (BW36), line X+- on high BW8 and low BW36, X++ on high BW8 and BW36, X-- on low BW8, and BW36, and X00 was an unselected control line. Growth was modeled by a Gompertz function. Heritabilities and genetic correlations among parameters of the Gompertz curve were estimated. Marginal posterior densities were drawn for parameters of the growth curve and for sexual dimorphism at ages ranging from hatching to 1 yr. Lines selected for a higher BW8 had higher initial specific growth rates (L), higher maturation rates (K), and lower ages at inflection (T(I)). Lines selected for a higher BW36 had higher asymptotic body weights (A). Estimates of A, L, and T(I) were higher in males and K was higher in females. Difference between sexes for A was greater in the line selected for a lower BW8 and a higher BW36. Dimorphism for L and K was the lowest in lines X++ and X--, respectively. The greatest difference in T(I) was observed in the line selected for lower BW8 and BW36. Sexual dimorphism of body weight was lower at most ages in the lightest line. Before 15 wk, sexual dimorphism in X++ line was lower than in the line selected for higher BW8 and lower BW36. The increase in sexual dimorphism with body weight could be reduced by selecting animals on body weight at two ages instead of one, as is usually done in commercial lines.     

Bayesian conjugate analysis using a generalized inverted Wishart distribution accounts for differential uncertainty among the genetic parameters--an application to the maternal animal model

Consider the estimation of genetic (co)variance components from a maternal animal model (MAM) using a conjugated Bayesian approach. Usually, more uncertainty is expected a priori on the value of the maternal additive variance than on the value of the direct additive variance. However, it is not possible to model such differential uncertainty when assuming an inverted Wishart (IW) distribution for the genetic covariance matrix. Instead, consider the use of a generalized inverted Wishart (GIW) distribution. The GIW is essentially an extension of the IW distribution with a larger set of distinct parameters. In this study, the GIW distribution in its full generality is introduced and theoretical results regarding its use as the prior distribution for the genetic covariance matrix of the MAM are derived. In particular, we prove that the conditional conjugacy property holds so that parameter estimation can be accomplished via the Gibbs sampler. A sampling algorithm is also sketched. Furthermore, we describe how to specify the hyperparameters to account for differential prior opinion on the (co)variance components. A recursive strategy to elicit these parameters is then presented and tested using field records and simulated data. The procedure returned accurate estimates and reduced standard errors when compared with non-informative prior settings while improving the convergence rates. In general, faster convergence was always observed when a stronger weight was placed on the prior distributions. However, analyses based on the IW distribution have also produced biased estimates when the prior means were set to over-dispersed values.