大约克新品系生长速度和体尺性状间的典型相关分析

对344头大约克新品系猪的生长速度和体尺性状的11个变量进行了典型相关分析。结果表明:生长速度和体尺性状的第1、2个典型相关系数达极显著水平(P<0.01),第3个典型相关系数达显著水平(P相似文献   

杜洛克和大约克猪体重和体尺性状间典型相关分析

对杜洛克和大约克猪的体重性状和体尺性状进行典型相关分析,结果表明:杜洛克和大约克猪的体重性状和体尺性状间存在较强的相关,其第一典型相关系数达到极显著相关水平(P<0.01),典型相关系数分别为0.891和0.828,分别占总相关的95.90%和92.11%.杜洛克猪体重与体尺性状间的相关主要是由6月龄体重与6月龄体长和胸围引起,而大约克猪体重与体尺性状间的相关主要来自于6月龄体重与6月龄胸围和腹围,其次为6月龄体长.     

杜洛克和大约克猪体重和体尺性状间典型相关分析

对杜洛克和大约克猪的体重性状和体尺性状进行典型相关分析,结果表明:杜洛克和大约克猪的体重性状和体尺性状间存在较强的相关,其第一典型相关系数达到极显著相关水平(P<0.01),典型相关系数分别为0.891和0.828,分别占总相关的95.90%和92.11%。杜洛克猪体重与体尺性状间的相关主要是由6月龄体重与6月龄体长和胸围引起,而大约克猪体重与体尺性状间的相关主要来自于6月龄体重与6月龄胸围和腹围,其次为6月龄体长。     

大约克新品系胴体性状间的相关与方差分析

通过构建固定模型对大约克新品系零至上世代的９９头胴体性状做相关与方差分析。结果表明：胴体性状通过几年持续选育,表型参数都有不同程度提高,相关系数变化范围都在国内外估测范围内,且多数达到显著水平（Ｐ〈０．０５）同时也得出体直长作为瘦肉率选择性状对新品系不适宜;年度效应对胴体重、屠宰率、体直长、眼肌面积、瘦肉率等５个性状有极显著或显著影响,而性别效应对平均背肝厚、眼肌面积、瘦肉率等３个性状有极显著影响     

大约克新品系猪胴体性状的相关与方差分析

通过构建固定模型对大约克新品系零至四世代的９９个个体胴体性状做相关与方差分析。结果表明，胴体性状通过几年持续选育表型参数都有不同程度提高，相关系数变化都在国内外的估测范围内，且多数达到显著水平，同时也得出体直长作为瘦肉率选择性状对新品系不适宜，年度效应对胴体重、屠宰率、体直长、岂面积２、瘦肉率等５个性状有极显著或显著影响，而性别效应对平均背膘厚、眼面积、瘦肉率等３个性状有极显著影响。     

京海黄鸡体重、体尺及屠宰性状间的典型相关分析

对京海黄鸡体重、体尺和屠宰3组性状的23个变量进行了典型相关分析。结果表明:体重和体尺性状间,体重与屠宰性状间以及体尺与屠宰性状间的第1个典型相关系数均达极显著水平,其典型相关系数依次为0.915321、0.996883和0.961838,分别占总相关的98.46%、98.96%和92.82%。在这些性状中,起主要作用的有16周龄重、胫长、胴体重及脚重。本研究结果对京海黄鸡的遗传育种和杂交优势利用有一定的参考意义。     

大约克新品系三元杂交效果研究

采用大（新）长、大（加）长２ 个二元母本,与杜洛克杂交。杜×大（新）长为试验组、杜×大（加）长为对照组。结果表明：肥育性能、饲料利用率、胴体性状和肌肉营养组分,试验组都好于对照组,唯屠宰率试验组稍低于对照组。试验组与对照组相比,日增重增加３３ｇ,提高３．７％ ,饲料利用率提高１．５５％ （ Ｐ＞ ０．０５）,瘦肉率提高２．６％ （ Ｐ＞ ０．０５）。     

杂种猪生长速度与肉质性状间的典型相关分析

对杂种猪的生长速度、胴体品质和肉质3组性状的21个变量进行了典型相关分析。结果表明：生长速度和胴体品质性状间以及胴体品质和肉质性状间的第一、二个典型相关系数达极显著水平，分别占总相关的100％和65．38％；生长速度和肉质性状间第一个典型相关系数达显著水平，占总相关的69．12％。其典型相关系数依次为：0．8890、0．6190、0．8219、0．7049和0．5183。     

萧山鸡体尺性状、产肉性状与血液生化性状的典型相关分析

对萧山鸡体尺、产肉与血液生化3组性状12个变量进行典型相关分析.结果表明:体尺性状与血液生化性状间的第一个典型相关系数达极显著水平,占两组性状间总相关信息的83.98%;体尺性状与产肉性状间和产肉性状与血液生化性状间的第一个典型相关系数达显著水平,分别占两组性状间总相关信息的64.51%和77.67%,其典型相关系数分别为0.948、0.979和0.912.在3组性状中起主要作用的性状有:体斜长、胸肌重、全净膛重、腿肌重、胆固醇含量和碱性磷酸酶活性.     

牛生长性状、肉质性状和胴体性状间典型相关分析

通过对牛生长性状、肉质性状和胴体性状指标的研究,分析3组性状组内及组间的相关性,揭示牛不同类型性状间的相互影响。测量记录327头牛3组性状的表型值,利用简单相关分析和典型相关分析对3组性状相关性进行深入研究。17个性状间共有74对存在极显著简单相关(P0.01),多数相关系数低于0.5。典型相关分析结果表明,3组性状间第一、第二和第三典型相关系数均达到极显著水平(P0.001),其中生长性状与肉质性状间、生长性状与胴体性状间、肉质性状与胴体性状间的第一和第二典型相关系数分别为0.525和0.350、0.993和0.623、0.698和0.394。结果显示,典型相关分析比简单相关能更准确、全面反映3组性状间的相关关系,为肉牛的选育提供科学依据。     

赛加羚羊初生体重与体尺的相关性研究

为了提高测定效率,运用SPSS软件对30只赛加羚羊初生羔的体尺、体重结果进行了相关分析和通径分析,并建立了最优回归方程。结果表明:赛加羚羊初生体重(Y)与体直长(X_1)、体高(X_2)、胸深(X_3)、胸宽(X_4)、胸围(X_5)、尾长(X_6)、耳长(X_7)及管围(X_8)均呈极显著正相关(P0.01),其中体直长(X_1)和胸围(X_5)是体重(Y)的最主要决定变量。初生羔羊体直长(X_1)和胸围(X_5)对体重(Y)的最优回归方程为Y=-1.219+0.052X1+0.072X5。     

波尔山羊生长模型及体尺体重相关分析

用Gompertz、Bertalanffy及Logistic模型拟合4～39月龄的澳洲波尔山羊生长模型.结果表明:Logistic模型拟合效果最好(R2>O.98),公母羊生长模型分别为:w=51.59X(1十6.15×e-1.82)-1和W=52.56×(1+7.15×e2.08)-1.波尔山羊的体重与胸围呈极显著相关(P0.05).利用胸围和体高,估算体重的回归方程为:y=0.279Bug+0.893Bxw-19.28.     

金湖乌凤鸡体重与体尺相关及回归分析

为了分析金湖乌凤鸡体重与体尺的相关性,选取120日龄公母鸡各100羽进行测定和分析,结果表明:公鸡的体重、体斜长、龙骨长、胸宽、胸深、胫长、胫围指标极显著大于母鸡(P＜0.01),公鸡的胸角极显著小于母鸡(P＜0.01).公鸡的体重、胸宽、胸深及母鸡体重、胸宽变异系数均大于10％,体尺其他性状指标均小于10％.公鸡体重...     

12月龄短角牛体重与主要体尺指标的相关性分析

本文旨在探究12月龄短角牛体重与主要体尺指标之间的相关性,构建多元回归方程,研究影响短角牛的主要体尺指标及月龄。选取12月龄公牛163头,母牛261头,共424头短角牛体重、体高、十字部高、体斜长、胸围的体尺数据,使用最小二乘法对已知数据进行最佳线性拟合,构建多元回归方程并分析其相关性。结果显示,12月龄短角公牛的体重与各体尺指标的平均值均高于母牛;且体重与各体尺指标的回归关系达到极显著水平（p﹤0.01）,多元线性回归方程拟合度较高。12月龄短角牛无论公母,其体重与各体尺指标之间均呈现不同程度的相关性, 其中公牛的体高、十字部高、体斜长、胸围与体重的相关性高于母牛。12月龄短角公牛体重与体高、十字部高、体斜长、胸围呈极显著正相关（p﹤0.01）,其中体重与胸围的相关性最大(r=0.902)。12月龄短角母牛的体重与体高、十字部高、体斜长、胸围之间均呈极显著正相关（p﹤0.01）,其中与胸围相关性最大(r=0.823)。12月龄短角牛的体重与体高、十字部高、体斜长、胸围之间均呈极显著正相关（p﹤0.01）,其中与胸围相关性最大(r=0.873)。     

饲料镁和鲈鱼幼鱼的生长及鱼体镁含量相关性研究

为研究饲料中不同镁含量对鲈鱼(Lateolabrax japonicus)的影响,试验在基础饲料中分别添加0、500、1250、3750、5250、8750 mg/kg MgSO4,配制镁含量分别为167、284、491、959、1327、1759 mg/kg的6种试验饲料,饲养初始体重为(12.31±0.02)g的鲈鱼56 d。结果显示:日粮中适当添加镁显著影响鲈鱼的增重率、特定生长率和饲料效率(P <0.05),其中D4组(镁含量959 mg/kg)鲈鱼的增长率和特定生长率均显著大于其他各组(P <0.05)。饲料镁含量显著影响鲈鱼全鱼水分(P <0.05)。随着饲料镁含量增加,肝脏中天冬氨酸转氨酶(GOT)和丙氨酸转氨酶(GPT)呈下降趋势,GOT与GPT比值和肝脏谷氨酸脱氢酶(GDH)也出现显著变化(P <0.05)。通过回归分析增重率得出,本试验中鲈鱼生长的最适饲料镁含量为846 mg/kg。     

鸽载脂蛋白B基因多态性与生长性状相关性分析

利用PCR-SSCP技术和DNA测序方法检测两群体鸽apoB基因编码区序列的单核苷酸多态性,最小二乘分析表明,A57G突变位点导致的3种基因型对石岐肉鸽屠体率及灰色肉鸽屠体重、腹脂率、肝脏重有显著影响(P<0.05);对灰色肉鸽活重、腹脂重、肝脏率及石岐肉鸽活重和全净膛率有一定影响(P<0.2).多重比较显示,石岐肉鸽群体中,BB基因型个体的屠体率高于从基因型个体.灰色肉鸽群体中,BB基因型个体的屠体重、肝脏重、腹脂率均为最大.     

文山高峰牛母牛体重与体尺的相关性分析

[目的]为了探究文山高峰牛母牛的体重与体尺性状的相关性,建立文山高峰牛母牛体重与体尺性状之间的最优回归方程,为文山高峰牛遗传参数的选择提供参考,并为牛品种的选育工作供理论依据。[方法]试验随机选取20头30月龄文山高峰牛母牛,测量体重(Y)、体高(X₁)、十字部高(X₂)、体斜长(X₃)、胸围(X₄)、腹围(X₅)、管围(X₆),然后计算体重和体尺性状的变异程度并进行相关性分析、通径分析及逐步回归分析以建立其体重与体尺性状之间的最优回归方程。[结果]文山高峰牛母牛的体重的变异系数最大(9.42%);体重与6项体尺性状均呈极显著正相关(P<0.01),腹围和体重间的相关系数最大(0.924);通径分析结果显示,腹围对体重的直接作用较大,十字部高、体斜长、胸围对体重的间接作用大。[结论]腹围、十字部高、体斜长是影响体重的最主要性状,通过逐步回归分析构建的文山高峰牛母牛体重与体尺之间的最优回归方程为Y=-648.762+0.639X₅...     

Genetic analysis of absolute growth measurements, relative growth rate and restricted selection indices in red Angus cattle

Performance records on 41,184 Red Angus cattle were analyzed and estimates of parameters calculated for absolute growth rate, relative growth rate and restricted selection indices. Heritability estimates for birth weight, 205-d weight, 365-d weight and postweaning gain were .46 +/- .02, .39 +/- .02, .40 +/- .02 and .36 +/- .02, respectively. Heritability estimates for preweaning, postweaning and postnatal relative growth rates were identical (.33 +/- .02). Heritability estimates for restricted selection indices were .31 +/- .02, .33 +/- .02 and .31 +/- .02 for weaning index, yearling index and postweaning index, respectively. The genetic correlation between preweaning and postweaning absolute growth rate was .15. The genetic correlation between consecutive measurements of relative growth rate (RGR) was -.33. Genetic correlations of birth weight with preweaning RGR and postnatal RGR were -.68 and -.71, respectively. Correlations among measures of relative growth rate using simulated data were similar to correlations of actual data, indicating that these relationships are the result of numerator/denominator relationships and not biological causes. The genetic correlation between weaning and postweaning indices was near zero. Small genetic coefficients of variation for preweaning and postnatal relative growth rates indicate further problems with the expression of growth in this manner. Restricted selection indices exhibited much larger genetic coefficients of variation than measurements of RGR. Genetic standard deviations were 7.8%, 7.2% and 13.7% of the means for weaning, yearling and postweaning indices, respectively.     

Effects of growth rate and compensatory growth on body composition in lambs

Fifty lambs were used in a comparative slaughter experiment to determine the effects of growth rates and compensatory growth on body composition. The study consisted of a growing and a finishing phase. During the growing phase, lambs (20 to 30 kg) were fed three different concentrate levels (30, 50 or 70%) to gain at three different rates (slow, medium and rapid). The finishing phase was evaluated in two periods (early, 30 to 38 kg; late, 38 to 45 kg). All lambs received 70% concentrate diets during the finishing phase. Groups of five lambs were sacrificed at 20, 30, 38 and 45 kg fleece-free weights for whole-body chemical analysis. At 30 kg live weight, lambs on a rapid growth diet were the fattest (P less than .01) and contained the least protein (P less than .05) in their empty bodies. The slower the lambs gained during the growing phase, the greater (P less than .05) was the response in rate of gain and feed efficiency during both periods of the finishing phase. Compensatory growth occurred in two stages; a greater proportion of protein gain was made early while a greater proportion of the fat gain was made during the late period of the finishing phase.     

Factor analysis of body measurements in Arabian horses

Data of 13 body measurements have been analysed from 166 Arabian horses, 123 mares and 43 stallions, ranging from 49 to 298 months of age, belonging to Alzahraa stud, Cairo, Egypt. General linear model was used to study age and gender effects on these measures. Gender was a significant source of variation for most studied traits, but not for neck girth, cannon bone circumference of fore and hind legs, and pastern girth of fore and hind legs. Age significantly affected pastern girths of fore and hind legs and cannon bone circumference of fore legs, while there was no significant effect on the other measurements. Pearson correlations, adjusted for age effect, between measurements were estimated and ranged from 0.02 to 0.84 for mares and from ?0.05 to 0.90 for stallions. Factor analysis with promax rotation for each gender was carried out to derive fewer independent common factors. Three factors were extracted which accounted for 66% and 67% of the total variance in mares and stallions respectively. The first, second and third factors in mares tended to describe body thickness, leg thickness and general size respectively; whereas in stallions they tended to differentiate among general size, leg thickness and body thickness respectively. The three extracted factors for each gender determine the main sources of shared variability that control body conformation in Arabian horses. These factors could be considered in selection programmes to acquire highly coordinated bodies in pure Arabian horses with fewer measurements.