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Virginia Polytechnic Institute and State University, Blacksburg 24061 and U.S. Department of Agriculture, Front Royal, Virginia 22630
Abstract
USE of pesticides is an essential part of efficient agricultural production, including that of feed crops. But some pesticide residues, notably those of the chlorinated hydrocarbon compounds, are not fully decomposed when the crop is fed to livestock. Bovard et at. (1961) found over 80 ppm DDT in the omental fat of beef heifers fed contaminated apple pomace. Other chlorinated hydrocarbons are also persistent.
Heptachlor is a persistent chlorinated hydrocarbon used until 1964 to control the alfalfa weevil (Hypera postica). Engel et al. (1965) found 0.02, 0.05, 0.18 and 0.42 ppm heptachlor in alfalfa harvested in 1964 from land to which heptachlor was applied in the fall of 1961, 1962, 1963 and the spring of 1964, respectively. In 1965, many farmers had grown and stored hay crops like alfalfa known to contain heptachlor. But little was known about heptachlor contamination in cattle.
The present experiment was begun to study the rate and level of accumulation of heptachlor and heptachlor epoxide, hereafter cited as HHE, in cattle fed a fattening ration for 6 months.
1 Department of Animal Science, Virginia Polytechnic Institute and State University, Front Royal.
2 Department of Animal Science, Virginia Polytechnic Institute and State University, Blacksburg.
3 Beef Cattle Research Station, A.R.S., Front Royal.
4 The authors gratefully acknowledge assistance of T. S. Rumsey, A.R.S., U.S.D.A., Beltsville, Md., with HHE analyses of duplicate samples; of Ruel L. Wilson of Biometrical Services, A.R.S., U.S.D.A., Beltsville, Maryland, with statistical analyses; and of D. F. Watson, Veterinary Science Department, Virginia Polytechnic Institute and State University, Blacksburg, with perianal biopsies.
5 Appreciation is expressed to Agri-Tech, Inc., Kansas City, Missouri, for supplying the thyroprotein ("Protamone").
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