Pubertal weight gain in female rhesus macaques.

In order to describe the timing and extent of accelerated pubertal weight gain in female rhesus, we examined a large colony data base consisting of over 10,000 weight records for animals between 1.5 and 3.0 years of age (menarche occurs at about 2.6 years). Average colony weights were determined by week of age from information on age at weighing. Cross-sectional analyses with linear regression demonstrated an acceleration in weight increase from 196 to 231 weeks (28-33 months) when colony weights increased 381 g/12 weeks as opposed to an average of 193 and 203 g, respectively, during the preceding and succeeding age intervals of the same length. Longitudinal analyses (n = 428) indicated that maximum individual growth velocity averaged 499 +/- 18 g/12 weeks and occurred at 119 +/- 5.6 weeks (29.7 +/- 0.2 months) of age. Nonlinear modeling with the Gompertz function indicated that decelerating growth rates seen at earlier ages were not characteristic of the period of accelerated pubertal growth.