Symposium on medicated feeds : proceedings of the symposium on medicated feeds sponsored by U. S. Department of Health, Education, and Welfare, Food and Drug Administration, Veterinary Medical Branch, Jan. 23 and 24, 1956 / edited by Henry Welch and Feĺix Martí-Ibánẽz.

  • United States. Food and Drug Administration.
Date:
1956
Catalogue details

Licence: Public Domain Mark

Credit: Symposium on medicated feeds : proceedings of the symposium on medicated feeds sponsored by U. S. Department of Health, Education, and Welfare, Food and Drug Administration, Veterinary Medical Branch, Jan. 23 and 24, 1956 / edited by Henry Welch and Feĺix Martí-Ibánẽz. Source: Wellcome Collection.

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    of this contamination. Contamination, when it occurs, comes to our attention .after the damage has been done to a colony of animals. Consequently, if we can prevent this contamination from occurring by informing all those making laboratory rations of the hazards and insisting upon adequate control procedures, we have accom- plished much more than by initiating legal action after injury has occurred. It seems probable to me that most of the feed mixers or millers are unaware of the injury that may be produced by very small quantities of stilbestrol. Two — parts/billion of stilbestrol in a mouse diet will cause measurable growth in the uterus of an immature mouse and 10 parts/billion will produce continuous estrus. The addition of only 0.9 pound of a steer feed supplement containing 10 mg./Ib. of the drug, when mixed with 1 ton of mouse food, produces a concentration of 10 parts/billion in the mouse diet. Therefore, the industry should be informed of the unusual precautions necessary in cleaning equipment used to prepare stilbestrol supplements before other products can be processed. This is the only way to preserve the integrity of special diets. The information that is available to the Food and Drug Administration relates to the safety of estrogen-containing diets only in steers and chickens. We also have information concerning the injurious capacities of these diets to laboratory rodents. We do not know whether or not it is safe to feed other domestic animals, 1.€., swine or sheep, this drug. We believe that research on these latter animals is now in progress. I should like to propose that an educational program be developed coopera- tively by the Food and Drug Administration and holders of primary new drug applications of stilbestrol supplements to inform various feed mixers and millers of the extent of the damage that might be caused by contamination of laboratory feeds with stilbestrol and to make recommendations as to the extreme care that must be taken to prevent contamination. The value of such a program, when measured in terms of reducing the loss of experimental results and in terms of promoting public good will, will be many times that of the value of the laboratory rations produced.