Formula-fed and breast-fed baboons: Weight growth from birth to adulthood

The objective of this study was to compare the immediate and long-term effects of type of infant diet (formula-fed vs. breast-fed) on the weight growth of baboons. Longitudinal (serial) weight data were collected from 44 savannah baboons (Papio cynocephalus anubis) for the total preadult period of growth from birth to approximately 8 years of age. Fifty percent of the sample (11 females and 11 males) were fed a standard infant formula by a nursery care technician for the first 18 weeks of postnatal life. The remaining 11 females and 11 males were breast-fed by their mothers for an equivalent period of time. After 18 weeks of age the animals were removed from their infant environments (either nursery or mother-reared) and assigned to one of four age-cohort social groups. Each age-cohort group was balanced for infant treatment and gender. The animals remained in these social groups for the duration of the project and were provided nutritionally identical postweaning diets. No significant weight differences were found between the two rearing conditions for either gender during the initial 15 weeks of growth. Following this period, however, females of breast-fed environments averaged greater weight at all ages than their bottle-fed peers. The intensity of the adolescent growth spurt was also slightly greater among the female breast-fed group. No postinfant average weight-per-age disparity was observed between the male treatment groups.