Heritability of parameters of the allometric-autoregressive model and its correlation with common growth and efficiency traits

Author: M.M. Scholtz, C.Z. Roux, D.S. de Bruin and S.J. Schoeman
Year: 1990
Issue: 2
Volume: 20
Page: 52 - 56

The heritabilities of the parameters slope (b) and intercept (In a) of the allometric function: y = In a + bx [where y = In (body mass) and x = In (cumulative feed intake)] and for p, which is the slope of the autoregressive relationship (t against t – 1), were investigated using the rat as model. The heritability estimates for In a (0,34), b (0,31) and p (0,12) agree with those of a previous study. Since In a and b are both directly proportional to growth efficiency, it may be possible to use the model to change the entire efficiency curve of growing animals. The correlations (phenotypic, genetic, ordinary) between these parameters and common growth (growth rate, feed intake, body mass) and efficiency (three types) traits were also investigated. There are positive correlations between band the efficiency traits (0,71; 0,82; 0,37), and growth rate (0,31). There is, however, a negative correlation between b and feed intake      (- 0,38). If this is true, it may be possible to increase growth rate via b without an increase in feed intake.



Keywords: Allometric-autoregressive model, correlation, heritability
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