A differential effect of protein and calorie deficiency on ovarian follicular growth in the sow.

Either protein or calorie deficiency alters the pre-antral growth of ovarian follicles in the sow. Protein deficiency depressed the rates of oocyte, oocyte nuclear and oocyte nucleolar growth in follicles composed of one or more layers of granulosa cells. Calorie deficiency depressed the growth of the follicle envelope but only in multilaminar follicles. It is concluded that the effect of protein deficiency on ovarian follicular growth differs significantly from that of calorie deficiency in this species. Neither treatment altered the maximum dimensions of the oocyte at the completion of the intra-ovarian growth phase (phase A).