Abstract
Summary
Increasing the litter size of rats from 0 to 2, 6, or 12 pups progressively decreased (p<0.05) pituitary growth hormone (GH) content, whereas mammary development (DNA) and metabolic activity (RNA and litter weight gain) progressively increased (p<0.01). Nursing intensity did not significantly alter (p > 0.05) LH content of the pituitary, although LH tended to decrease in the lactating rats with increasing nursing intensity. All non-nursed and one-half of the 2-pup nursing intensity group began their estrous cycles before day 16 of lactation, but rats nursing 6 or 12 pups did not.
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