FACTORS INFLUENCING ACCEPTANCE OF CESAREAN DELIVERED OFFSPRING BY FOSTER MOTHERS

Four or 10 fetuses with the placenta present or absent and delivered by cesarean section at term were fostered to mothers which had been lactating for either 1 or 10 days. Survival of offspring decreased when reared by mothers lactating for 10 days prior to fostering and increasing litter size accentuated the decrease. The presence of the placenta at fostering resulted in a decrease in survival when 10-day lactating animals were used as foster mothers. Growth of the young was less when they were reared by 10-day lactating mothers. Cannibalization of fetuses 24 hr after fostering occurred among 1-day lactating foster mothers but not among 10-day lactating foster mothers. Latency to retrieve consecutive pups decreased more rapidly for 10-day mothers than for 1-day mothers. © 1968.