Previous research in our laboratory has shown that lactating rats given low protein diets will readily mobilise approximately 20% of body protein to sustain lactational performance. However in such females lactational performance falls markedly around day 6 of lactation and remains at this low level for the remainder of lactation. The objective of this study was therefore to investigate whether this decline in lactational performance coincided with the exhaustion of labile protein reserves, and secondly whether such protein depleted females could reestablish effective lactation in mid lactation when given an increased supply of dietary protein.

Sixty six multiparous Sprague-Dawley rats were mated individually with a proven male breeder, mating being confirmed through the presence of vaginal plugs, then transferred to solid bottomed plastic cages for the remainder of the experiment.