Modelling growth of chick embryo: correction for egg weight [Modelowanie wzrostu zarodka kurzego z poprawką na masę jaja]

Prediction of embryo weight during incubation is of great interest in research on avian reproduction and choice of optimum hatching regimes. For this purpose the growth curves may be used. In our recent paper [1] it was established that the chick embryo growth model function can be put down as follows:

Wem = at^b exp (-ct) (1)

in which:

Wem is embryo weight at different time of incubation;

t, and a, b and c are constants.

The proposed model reflects mostly adequately the peculiarities of chick growth in the embryonic period. To improve Eqn. 1 to be fit for eggs of different weights the present study was undertaken…

On the basis of the above Eqns. 2-6 the correction for egg weight for every coefficient, a, b and c, was accomplished. The coefficient values were approximated by equations:

a = 0.007656 + 0.000081 W - 0.006771g W (7)

b = W / (9.4307 - 0.34 W + 0.00718 W^2) (8)

c = -0.1 + 9.5734 / W (9)

Coefficient of correlation, r, for Eqns. 7-9 constituted 0.96, 0.985 and 0.92, respectively.

As an example, let us estimate the growth model for a chick embryo of an egg weighed 58 g. After substituting the meaning of W in Eqns. 7-9 and obtaining the appropriate meanings of the coefficients a, b and c, the growth model for the embryo of 58 g egg is:

Wem = 0.00007736 t^3.4247 e^-0.02462 t (10)

The proposed method may be of practical value for non-destructive evaluation of embryonic adaptation under generally accepted, standard conditions of incubation.