Olfactory bulbectomy and nursing behavior in rat pups (Wistar DAB).

To determine whether bilateral olfactory bulbectomy led to a change in nursing behavior, and thus death, we bilaterally bulbectomized (BX) pups from 14 litters at 2, 7, and 11 days of age. Litters treated on Days 2 and 7 consisted of 3 BX pups, 2 surgical control (SC) pups, and 2 handling control (HC) pups. Litters treated on Day 11 consisted of 1 or 2 BX, 1 or 2 incompletely bulbectomized pups (IBX), 2 SC pups, and 2 HC pups. These litters and 3 additional nontreated litters were observed on Days 4,7,10,13, and 16. A smaller number of BX pups survived through Day 10 than SC, HC, IBX, and nontreated pups. Differential treatment of the BX pups by females or littermates was not found. The females' mammary glands were functional but the BX pup stomachs had little or no milk. The BX pups spent less time nursing and more time away from the female and their littermates than did the other pups.