Describing and predicting potential growth in the pig
Describing and predicting potential growth in the pig
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DOI：
10.1017/s1357729800058781
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发表时间：
2004-06-01
期刊：
影响因子：
--
通讯作者：
Kyriazakis, I
中科院分区：
文献类型：
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作者：
Wellock, IJ;Emmans, GC;Kyriazakis, I
大多数动物生长模型包含显式的生长函数。它决定了动物一生中的生长模式，并定义了生长速率（潜力）的上限。对一组或多组数据的“拟合优度”标准经常用于选择合适的增长函数。这里描述了替代标准，可用于在描述潜在增长的形式之间进行选择。在审查的职能中，只有少数符合所有拟议标准。其中，Logistic和Gompertz函数受到青睐，因为它们的参数经济，而且能够将相对增长率描述为规模的简单函数。逻辑斯蒂函数被拒绝的理由是它的数字后果的增长在猪的成熟度范围很广，留下Gompertz函数进行测试，其能力作出明智的预测的潜在增长。出生前的生长数据，假设发生在非限制性条件下，只要母亲没有受到极端不利的营养条件或感染的发病率，被用来估计的两个Gompertz函数参数的值-生长系数和初始条件-给定的估计成熟的大小。这些值与基于出生后生长的文献估计值相当，因此在广泛的成熟度范围内预测生长率是合理的。在这些理由，因为它使用的参数都与生物意义很少，Gompertz函数被提出作为一个合适的描述潜在的增长。
Most animal growth models contain an explicit growth function. It determines the pattern of growth over the lifetime of the animal and defines an upper limit to growth rate ( the potential). The criterion of the 'goodness-of-fit' to one or more sets of data is frequently used to select a suitable growth function. Alternative criteria are described here that can be used to choose between forms that describe potential growth. Of the functions reviewed only a few fulfilled all of the proposed criteria. Of these the Logistic and Gompertz functions were favoured because of an economy of parameters and their ability to describe relative growth rate as a simple function of size. The Logistic function was rejected on the grounds of its numerical consequences for growth in pigs over a wide range of degrees of maturity, leaving the Gompertz function to be tested for its ability to make sensible predictions of potential growth. Pre-natal growth data, assumed to occur under non-limiting conditions as long as the mother is not subjected to extremely adverse nutritional conditions or incidence of infection, were used to estimate the values of the two Gompertz function parameters-the growth coefficient and the initial condition-given an estimate of mature size. The values were comparable with literature estimates based on post-natal growth and predictions of growth rate over a wide range of degree of maturity were thus sensible. On these grounds, and because it uses few parameters all with biological meaning, the Gompertz function is proposed as a suitable descriptor of potential growth.