Differential maternal retrieval of jaundiced versus non-jaundiced Gunn rat pups.

Gunn rat dams were tested for differential retrieval of their jaundiced versus non-jaundiced offspring in 2 experiments. In Experiment 1, in which testing took place every day from Day 1 to Day 8 postpartum, non-jaundiced pups were retrieved significantly faster than jaundiced pups. In Experiment 2, in which testing took place every other day from Day 1 to Day 15 and the pups were weighed each test day, the order of retrieval of the 4 gender/genotype (jaundiced vs non-jaundiced) classifications as found in the 1st experiment was replicated and the non-jaundiced pups tended to be retrieved faster. Heavier pups were retrieved significantly faster than lighter pups, indicating that weight or size may be a cue to differential retrieval.