Abstract

Fifty-six pregnant Romney ewes grazing a ryegrass/white clover pasture were divided into 7 groups of 8 and slaughtered at days 62, 81, 100, 115, 125, 135 and 143 of gestation to remove the conceptus (uterine tissue and membranes, placental fluids and the foetus[es] and determine its total Cu, Zn, Fe, Mn and Se content. The uterus was also removed from 8 ewes just prior to mating. Half the ewes had twin foetuses. The daily rates of deposition of Cu, Zn, Fe, Mn and Se were calculated from the slope of the curves relating the gestational age with the net trace element content of the conceptus. The dietary allowance of Cu, Zn, Fe, Mn and Se for the pregnant ewe was then calculated from the daily deposition rates into the conceptus, determined from this study, and published data on the net requirements for maintenance, coefficients of absorption and DM intakes. The calculated dietary allowances (per kg DM) for single- and twin-bearing ewes, were 7.4 mg Cu, 24 mg Zn, 36 mg Fe, 30 mg Mn and 33

TG, Watson, RL Baker, and TG Harvey

Proceedings of the New Zealand Society of Animal Production, Volume 46, , 23-26, 1986