Masters Theses

Date of Award

3-1972

Degree Type

Thesis

Degree Name

Master of Science

Major

Animal Husbandry

Major Professor

S.L. Hansard

Committee Members

K.M. Barth, C.C. Chamberlain

Abstract

Yearling ewes were closed with a tracer level of radiocopper for blood-balance and subsequent placental-transfer studies, using maternal-fetal copper utilization criteria in comparative studies. Over 92 percent of an oral dose of 64Cu was excreted 120 hours after dosing, while 5.2 percent of an intravenous dose was excreted after 24 hours. Copper levels in total products of conception increased 27 times between trimesters one and two, and after 136 days reached 13.81 mg total copper. Total and radiocopper were highest in liver, and increased in all tissues of the fetus advancing in pregnancy. Higher copper concentration and specific gravity values were observed in the second-trimester (90 day) fetus than third-trimester (136 day) fetus, and concentration was higher in the fetus than in the dam. Ewes retained 0.81 mg copper per day and a first-trimester fetus contained 0.004 mg copper; placenta, 0.47 mg, and placental fluid 0.032 mg. The second—trimester fetus contained 2.84 mg copper; placenta 1.88 mg, and placental fluids, 0.55 mg. The calculated daily amount of copper deposited in the total products of conception of first, second and third-trimester ewes averaged 15 yg, 58 yg, and 101 μg, respectively. During the final trimester, ewes consuming 6.03 mg of copper per day absorbed 13.44 percent and deposited in the total products of conception after 24 hours, 13.81 mg of copper and 6.1 percent of the retained dose. The placenta contained 1.55 mg copper, 3.9 percent 64Cu; fluids, 0.96 mg copper and undetectable amounts of 64Cu. The total fetus accrued 11.34 mg copper and 2.2 percent of 64Cu was retained in the 136 day old fetus.

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