Maternal regulation of milk composition, milk production, and pouch young development during lactation in the tammar wallaby (Macropus eugenii)

Abstract

Specific changes in milk composition during lactation in the tammar wallaby (Macropus eugenii) were correlated with the ages of the developing pouch young (PY). The present experiment was designed to test the hypothesis that the sucking pattern of the PY determines the course of mammary development in the tammar wallaby. To test this hypothesis, groups of 60-day-old PY were fostered repeatedly onto one group of host mothers so that a constant sucking stimulus on the mammary gland was maintained for 56 days to allow the lactational stage to progress 42 days ahead of the age of the young. Analysis of the milk in fostered and control groups showed the timing of changes in the concentration of p..