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Ewes were fed either 150% (High, H) or 50% (Low, L) of theirenergy requirements for maintenance of liveweight during early gestation.Effects of maternal nutrition on fetal ovarian size, histological structureand steroidogenic capacity were studied at Day 47 and on ovarian size andstructure at Day 62 of gestation. At Day 47 of gestation, there weresignificantly higher concentrations of oogonia in the ovaries of L fetusesthan H fetuses (105·9 v. 76·9 germ cellsmm<emph type="7">-2; s.e. 4·94; P <0·001). The capacity of the ovaries to secrete oestradiol(pg/ovary/24 h) at Day 47 was not affected by treatment when they wereincubated either with (H, 773; L, 740; s.e. 179; not signicant, n.s.) orwithout (H, 260; L, 290; s.e. 92·7; n.s.) ovine luteinizing hormone(oLH). At Day 62 of gestation, the process of germ cell degeneration was lessadvanced in L than H fetal ovaries, as indicated by higher oocyteconcentrations in the former (68·4 v. 48·6germ cells mm<emph type="7">-2; s.e. 3·85;P < 0·01). There was a greater percentage ofmeiotic cells in L ovaries (76·5 v. 18·6;s.e. 5·82; P < 0·001). It is concludedthat undernutrition of the ewe from the time of mating signicantly retardsovarian development in fetal ovaries |
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