Effect of the energy levels on the body weights (A) and the growth rates (B) of mink. (Energy level as the level of metabolic energy in feed dry matter, growth rate as [(logW2-logW1)/(t2-t1) x2.303x100,where W2 and W1 are the individual weights, in kg, at the beginning and end, respectively, of a period, and t2-t1 is the duration of the period in weeks]).