RELATIVITY OF GROWTH IN LABORATORY AND FARM ANIMALS: II. BIRTH WEIGHT AS A PREDICTOR OF ANIMAL MATURITY
In this article the growth curves of individual animals for various species were examined to determine the 
relationship between birth weight and mature size. For the genotypes studied, the birth weight fraction of maturity (F b ) 
was found to range from approximately 0.6% to approximately 10% of mature size. Generally, for most species in this 
study it was found that F b increased as birth weight became larger and the female of the species generally demonstrated a 
larger fraction of maturity at birth than did the male animals of the same breed. An equation was developed to predict F b 
for each genotype with varying degrees of success. Using the developed equation and the birth weight of an individual 
animal, a physiologically based estimate of the animal’s mature size can be obtained.