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为研究影响贵妃鸡全程(52周龄)产蛋数的关键因子,利用相关分析、通径分析和多元回归分析相结合的方法,对贵妃鸡的开产体重、开产日龄、开产蛋重、40周龄体重、40周龄蛋重、40周龄累计产蛋数和52周龄累计产蛋数进行统计分析。结果表明:开产体重和40周龄累计产蛋数对52周龄累计产蛋数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1.303%、-0.361、-0.4716和56.25%、0.750、0.44325;而40周龄体重对52周龄产蛋数的间接效应最大(-0.37212),它主要通过与40周龄累计产蛋数的间接效应(-0.31937)来实现。估测52周龄累计产蛋数最优回归方程Y=1.184X1+0.361X3+1.121X4-5.157X6-141.151,复相关系数R2=0.7581。 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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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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本文利用宣威火腿原料猪种4个世代鲜肉系和火腿系共465头母猪的繁殖性能数据,对总产仔数(x1)、产活仔数(x2)、初生窝重(x3)、21日龄窝重(x4)、断奶窝重(x5)、育成率(x6)和断奶仔数(y)7个繁殖性状进行最小二乘分析、相关和通径分析,并在此基础上建立了估计断奶仔数的最优回归方程.结果表明,鲜肉系和火腿系繁殖性能在选育中都有所提高.各繁殖性状间在表型值上都存在不同程度的相关性,其中相关程度最高的是21日龄窝重与断奶窝重(鲜肉系r=0.953 5、火腿系r=0.960 6),初生窝重与育成率的相关程度最低(鲜肉系r=0.019 3、火腿系r=-0.011 6).在分析的7个性状中除总产仔数、产活仔数、初生窝重(火腿系)与育成率呈负相关,其他性状间均呈正相关.所建立的多元回归方程为:鲜肉系y=-5.722 9+0.808 4x2+0.016 5x4+0.005 0x5+0.068 9x6,火腿系y=-5.837 8+0.695 5x2+0.017 7x4+0.006 2x5+0.067 3x6. 相似文献
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利用仙湖 3号鸭第 9世代B系核心群 40个家系 2 2 4只母鸭的个体产蛋实测数据 ,统计分析了开产日龄对部分产蛋性状的影响。结果表明 :随开产日龄增加 ,其初生蛋重总的来说呈增加趋势 ;初生蛋重大的 ,其 36周龄、 58周龄的蛋重也大。另一方面 ,母鸭 1 50d产蛋数与开产日龄之间呈曲线相关 ,拟合的回归方程为 :^y =0 1 39x3- 2 891x2 +31 5 535x +1 1 7 82 ,拟合度R2 为 0 867,拟合效果较好。 相似文献
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封闭群五指山小型猪主要繁殖性状的多重回归与通径分析 总被引：1，自引：1，他引：0
试验选取45头普通级封闭群五指山小型猪初产母猪,测定总产仔数(X1)、初生活仔数(X2)、初生窝重(X3)、初生个体重(X4)、21 d活仔数(X5)、21 d窝重(X6)、21 d个体重(X7)、断奶活仔数(X8)、断奶个体重(X9)和断奶窝重(Y)等10个繁殖性状表型值,并对各繁殖性状表型值进行相关、回归及通径分析,以揭示母猪繁殖性状间的真实关系。结果显示,封闭群五指山小型猪的绝大多数繁殖性状的表型值间存在显著正相关,有3对性状间存在较弱负相关。通过多重回归分析建立的估计断奶窝重的多元回归方程为:Y=－4.98690－2.61933X5+1.13628X6－7.55296X7+3.33048X8+6.74545X9,并且形成了三因素水平的性状间因果关系层次。通径分析剖析了相关性状间的直接效应和间接效应,显示X5~X9对断奶窝重有显著性直接影响,表明母猪的泌乳力和营养水平对其繁殖性能有显著影响,先天性繁殖性状对繁殖性能影响较小。 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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非秋眠紫花苜蓿株系优选的性状分析 总被引：1，自引：0，他引：1
以产种期的非秋眠苜蓿Medicago sativa选择优株为材料,对影响株质量的性状进行通径分析。试验数据的总的多元决定系数较大,∑d=0.846 7,表明试验中选择的性状包括了影响生物量的主要性状。通径分析结果表明:结实分枝数、总分枝数、株高、产种量、分枝节数和分枝结实花序数与株质量相关性相对较强,是生物产量的主要决定因素,是非秋眠苜蓿在亚热带地区进行单株选择的主要性状。分析得出的株质量多元回归方程为,y=14.324 9+0.077 2x1（株高）+0.157 3x2（株总分枝数）+0.483 4x3（株结实分枝数）+0.011 2x4（花序长度）+0.068 7x5（分枝结实花序数）+0.032 3x6（主枝结实花序数）+0.000 6x7（茎粗） +0.170 2x8（分枝节数） +0.427 1x9（产种量）。 相似文献
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"邵伯草鸡"母系(S2系)主要产蛋性状的遗传参数估测 总被引：1，自引：1，他引：1
估测了邵伯草鸡母系(S2系)的主要产蛋性状的遗传参数,结果表明开产日龄、开产体重、开产蛋重、43周蛋重、43周产蛋量和66周产蛋量的遗传力分别为0.5240(P＜0.01)、0.5631(P＜0.01)、0.2597(P＜0.05)、0.4759(P＜0.01)、0.2621(P＜0.05)、0.3081(P＜0.01).66周产蛋量与43周产蛋量呈强正遗传相关(0.5126,P＜0.01).43周产蛋量与开产日龄、开产体重、开产蛋重及43周龄蛋重的遗传相关分别为-0.4221、0.0873、-0.5714(P＜0.01)和-0.4311(P＜0.05). 相似文献
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如皋黄鸡产蛋性能与遗传参数分析 总被引：2，自引：0，他引：2
研究以如皋黄鸡第4世代的15个家系351只母鸡为实验素材,测定开产日龄、开产体重、开产蛋重和40周龄产蛋数,统计各周龄群体产蛋率,估算开产性状和40周龄产蛋数的遗传参数。结果表明:如皋黄鸡开产日龄为(153.9±13.13)d,开产体重为(1 366.5±135.51)g,开产蛋重为(32.8±3.17)g,40周龄产蛋数为(101.0±8.94)个;高峰产蛋率为82.1%,70%以上产蛋率维持16周;开产日龄、开产体重、开产蛋重和40周龄产蛋数均为中等遗传力0.177~0.320;开产日龄、开产体重和开产蛋重间两两呈遗传正相关0.736~0.971,40周龄产蛋数与开产日龄、开产体重、开产蛋重间均呈遗传负相关-0.832~-0.639;性状间的表型相关性质和遗传相关一致,且均达到极显著的程度。 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。 相似文献
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本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。 相似文献
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REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air. 相似文献
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Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF
Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo. 相似文献
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以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。 相似文献