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分析了不同累积产蛋期产蛋量的相互关系及产蛋的规律性。在研究了各累积产蛋期产蛋量与全程产蛋量的相关性的基础上 ,利用第 1累积产蛋期产蛋量X1,第 2累积产蛋期产蛋量X2 ,第 3累积产蛋期产蛋量X3等早期产蛋量作为自变量建立了估计全程产蛋量Y的最优回归方程 :Y =17 95 88+1 2 319X1+0 970 1X2 +1 90 4 5X3。由方程预测的全程产蛋量平均为 92 2 5 0 4 9,它与实际全程平均产蛋量 92 2 5仅相差 0 0 0 0 4 9,且最优回归方程的截距和回归系数的T检验都达极显著水平 (P <0 0 0 0 1)。 相似文献
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分析了不同累积产蛋期产蛋量的相互关系及产蛋的规律性。在研究了各累积产蛋期产蛋量与全程产蛋量的相关性的基础上 ,利用第 1累积产蛋期产蛋量 (X1) ,第 2累积产蛋期产蛋量 (X2 ) ,第 3累积产蛋期产蛋量 (X3 )等早期产蛋量作为自变量建立了估计全程产蛋量 (Y)的最优回归方程 :Y =17.95 88+1.2 319X1+0 .970 1X2 +1.90 4 5X3 。由方程预测的全程产蛋量平均为 92 .2 5 0 4 9,它与实际全程平均产蛋量 92 .2 5仅相差 0 .0 0 0 4 9,且最优回归方程的截距和回归系数的T检验都达极显著水平 (P <0 .0 0 0 1)。 相似文献
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北京鸭前期产蛋量与全程产蛋量的相关分析 总被引：2，自引：0，他引：2
测定了中国农业科学院畜牧研究所Z型北京鸭育种场健康、产蛋正常的248只鸭子的产蛋性能指标：组圈后1～3周产蛋量(X1)、4～6周产蛋量(X2)、7～9周产蛋量(X3)以及全程(105d)产蛋量(Y)。以全程产蛋量(Y)为依变量，采用通径系数法计算了各自变量对依变量的通径系数和决定系数。结果表明，三个自变量对全程产蛋量都有较大的影响(通径系数分别为：0．2861，0．2766和0．5595)，显然，通径分析能揭示自变量与依变量之间的真正关系。在此基础上建立了依变量(Y)对自变量(X1)最优回归方程：Y=12.4837 1．2403X1 0．8807X2 2．2459X3。 相似文献
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测定了中国农业科学院畜牧研究所Z型北京鸭育种场健康、产蛋正常的248只鸭子的产蛋性能指标:组圈后1～3周产蛋量(X1)、4～6周产蛋量(X2)、7～9周产蛋量(X3)以及全程(105d)产蛋量(Y)。以全程产蛋量(Y)为依变量,采用通径系数法计算了各自变量对依变量的通径系数和决定系数。结果表明,三个自变量对全程产蛋量都有较大的影响(通径系数分别为:0.2861,0.2766和0.5595),显然,通径分析能揭示自变量与依变量之间的真正关系。在此基础上建立了依变量(Y)对自变量(Xi)最优回归方程:Y=12.4837+1.2403X1+0.8807X2+2.2459X3。 相似文献
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为了提高仙湖鸭早期选种的准确性,利用仙湖鸭B系核心群的系谱资料和产蛋量记录,对245只母鸭不同阶段产蛋量进行相关回归分析。结果表明:仙湖鸭B系母鸭各阶段产蛋量间处于中低程度的相关;第4,5阶段产蛋期产蛋量的相关系数为0.479 2,达到中等的正相关,且相关关系极显著(P0.01);相邻阶段产蛋期产蛋量之间的相关程度要大于非相邻阶段;第4,5阶段产蛋量与全程产蛋量的相关系数较高,分别达到0.615 4和0.625 3。综合预测仙湖鸭全程产蛋量的最优回归方程为:Y=1.397X3+1.601X4+1.627X5+72.690,决定系数(R2)为0.803 3。 相似文献
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从万载康乐黄鸡的产蛋规律探讨地方鸡种产蛋性能的选择 总被引：3，自引：0，他引：3
本文通过对 182只万载康乐黄鸡 2 80日龄产蛋量 (X1 )、30 0日龄产蛋量 (X2 )、2 8～ 4 0周龄产蛋量 (X3)、36～4 0周龄产蛋量 (X4 )、开产体重 (X5)、开产日龄 (X6 )及 5 0 0日龄 (Y)产蛋量等 7项指标进行分析 ,结果发现 :与 5 0 0日龄产蛋量相关程度高低依次为X2 ,X1 ,X3,X4 ,X5,X6 ,皆达极显著水平 (P <0 .0 1)。通过对X2 ,X1 ,X3,X4 ,X5,X6对Y进行逐步回归分析发现 ,引入变量的顺序为X2 ,X1 ,X3,X6 ,X5,X4 ,确定系数分别为 0 .6 80 2 ,0 .6 82 1,0 .6 799,0 .6 76 8,0 .6 77,0 .5 85 2 ,也皆达极显著水平 (P <0 .0 1)。通过对其月产蛋曲线的研究发现 :万载康乐黄鸡产蛋利用期应为 7～ 8个月 ,不宜太长 相似文献
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本研究旨在揭示影响仙湖肉鸭B系全程(64周龄)产蛋量的关键因子。利用相关分析、通径分析和多元回归分析相结合的方法,对仙湖肉鸭B系的开产体质量、开产日龄、平均蛋质量和36周龄、50周龄、64周龄产蛋量进行统计分析。结果表明:36周龄产蛋量、50周龄产蛋量对64周龄产蛋量有着重要的决定作用,其独立效应、通径系数、和相关系数分别为19.954%、0.4467、0.7244和11.202%、0.3347、0.7346;而开产体质量对64周龄产蛋量起着负的直接作用;开产日龄对64周龄产蛋量的间接效应最大(-0.5164),它主要通过与36周龄产蛋量的极显著负相关(-0.6338**)来实现。估测64周龄产蛋量最优回归方程为:^y=33.447-0.0118X1+0.5556X2+0.8417X4+0.5549X5。 相似文献
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对广东地区矮脚黄鸡、新兴黄鸡两个品种280日龄产蛋量(X1)、300日龄产蛋量(X2)、28～40周龄产蛋量(X3)、36～40周龄产蛋量(X4)及400日龄产蛋量(Y)等5项指标进行了分析.试验结果表明:①矮脚黄鸡与新兴黄鸡在主要产蛋性能指标上差异不显著;②400日龄产蛋量与300日龄产蛋量、28～40周龄产蛋量相关性较强;③矮脚黄鸡、新兴黄鸡从开产到达产蛋高峰的时间短,产蛋高峰持续时间长,且下降缓慢;④对400日龄产蛋量进行逐步回归,变量引入依次为X3、X2、X4,其中X4对Y值的影响差异不显著.矮脚黄鸡、新兴黄鸡400日龄产蛋量早期选择最佳指标为300日龄产蛋量和28～40周龄产蛋量,且其产蛋利用期可适当延长至8～9个月. 相似文献
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英国家畜生理及遗传研究所的Petet Sharp博士研究了是否可通过改变商品蛋鸡场常规应用的光照方式而减缓产蛋鸡产蛋高峰后的产蛋下降速度,从而增加总的产蛋量和经济收益。产蛋量随鸡龄增长而下降的原因 Sharp博士说,检查产蛋期头12个月内不同时期中产蛋母鸡卵巢的情况,就可知道产蛋下降的原因。新母鸡产蛋高峰时卵巢中充满蛋黄的黄色滤泡数量多于大龄母鸡。 相似文献
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优质肉鸡矮小型母系品系(S2系)产蛋性状的通径分析 总被引：2，自引：0，他引：2
以4429只优质肉鸡矮小型母系品系(S2系)核心群个体产蛋数据为试验材料,运用通径分析法研究开产日龄(x1)、开产体重(x2)、开产蛋重(X3)、24周产蛋数(X4)、28周产蛋数(X5)5个产蛋性状因子与43周产蛋总数的关系.结果表明:各性状因子的通径系数分别为-0.17576、0.051788、-0.02997、0.259459、0.597501;28周产蛋数是影响43周产蛋数的主要决定因子.各性状(X1)对43产蛋数(Y)的最优回归方程为:Y=56.826-0.292X1+0.006X2-0.030X3+0.770X4>+3.106X5(P<0.01),总相关系数为0.8760,决定系数为0.7674. 相似文献
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C. R. Orton 《British poultry science》1971,12(1):15-24
For many years the Ministry of Agriculture, Fisheries and Food has collected statistics on egg yields of poultry flocks on agricultural holdings in England and Wales, by means of sample surveys. Within a basic framework of stratified random sampling, the surveys have varied over the years, both in sample design and in questions asked. Other bodies, in particular the British Egg Marketing Board and the Poultry Association of Great Britain, have carried out similar surveys of their own, but differences in definition and coverage make comparisons difficult.
The surveys have shown a generally rising level of yields, due partly to the swing to intensive systems of management and partly to an improvement in yields within the systems of management. There has been a large swing towards the battery system, which is losing momentum as the majority of laying fowls are now kept in this system. Each system of management has a recognisable seasonal pattern of yields: the overall pattern has changed with the changing proportions of the systems. 相似文献
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T. C. Carter 《British poultry science》1968,9(3):265-271
One hundred eggs were used, from hens of seven widely differing strains: two commercial brown‐egg hybrids (one British, one American), two commercial white‐egg hybrids (one British, one Canadian), one broiler strain, one highly inbred strain of laboratory White Leghorns and one laboratory strain of Brown Leghorns. The volume occupied by the shell of each egg was estimated from its surface area—itself estimated by means of a three‐parameter model (Carter, 1968)— and its mean thickness, measured with an anvil micrometer. The volume occupied by the egg contents was estimated by subtracting the shell volume from the egg volume, which was also estimated by means of the three‐parameter model. Mean overall shell density (counting as “shell” all mineral matter and spaces between the outer surface of the mineral shell and a surface through the tips of the mammillae) was estimated, by regressing shell weight on shell volume, to be 2.241 ±0.004 g./cm.3; covariance analysis showed that the strains were homogeneous in this respect. Mean incremental shell density (i.e. the density of shell distal to the mammillary region) was estimated, by regressing shell weight per unit surface area on shell thickness, to be 2.386±0.004 g./cm.3; the strains were homogeneous in this respect too. The mean depth of the intermammillary spaces was estimated to be 19.9 μ. All the residual deviation from the common regression line can be attributed to measurement error. The estimated density of incremental shell is lower than that of calcite; the packing fraction of the crystals in the shell aggregate and/or the atoms in the crystals was estimated to be 92.8 per cent. The density of the egg contents (at the temperature of the bird) was estimated by regressing weight of contents on volume of contents; covariance analysis revealed significant differences between strains, one of the brown‐egg hybrids having the highest density of egg contents, 1.045 g/cm.3, and the laboratory Brown Leghorns the lowest, 1.033; both commercial white‐egg hybrid strains gave a value of 1.040 g./cm.3. 相似文献
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1. Data from published trials with laying hens were examined to see whether the concentration of dietary protein needed to achieve maximum egg weight was greater than the amount needed to achieve maximum rate of lay. 2. It is concluded that both rate of lay and egg weight continue to show small responses up to the same level of protein (or limiting amino acid) input. 3. When predicting egg output using asymptotic models, a reasonable assumption is that small increments in dietary protein, close to the optimum, will evoke equal proportional responses in egg size and in rate of lay. 4. When protein supply is severely limiting, the major response is a reduction in rate of lay. Egg weight seldom falls below 0.90 of its maximum value, however inadequate the protein intake may be. 相似文献
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A method is described for the estimation of mean egg weight from data giving the proportions of eggs in different weight grades. Tables are presented in which mean egg weights have been calculated for a range of grading figures, using both the British Egg Marketing Board and the European Economic Community grading systems. 相似文献