Genetic Growth Constants in Domestic Fowl

IT HAS been pointed out by Ludwig (1929) that most of the equations purporting to represent growth can be reduced to four types. With k standing for a constant, t for time, w for body weight, At for time at completion of growth and Aw for final weight, these four types can be expressed as follows: 1I.φ=k(At−t), when rate of growth is considered proportional to the time remaining for completion of growth; 2II.φ=k(Aw−w), when rate of growth is proportional to the weight to be gained; 3III.φ=kt,