Effects of Dosage Level and Length of Feeding Dienestrol Diacetate on Potentiation of Oxytetracycline

Abstract

VARIOUS methods of antibiotic potentiation have been reported including lowering of the dietary calcium level (Price and Zolli, 1959), addition of terephthalic acid (TPA) to the diet (Peterson 1958) or injecting chicks with estradiol (Harms et al., 1963).More recently Harms et al. (1964) reported that feeding 35 mg. per kg. of diet of the estrogenic hormone, dienestrol diacetate (DD), was not effective in improving antibiotic utilization; however, a significant increase was obtained when 356 mg. were fed.The study reported herein was conducted to determine the effect of feeding various levels of DD for different periods of time upon oxytetracycline blood serum levels. EXPERIMENTAL PROCEDURETwo successive experiments were conducted as a 3×6 factorial arrangement of treatments with levels of 0, 35, 70, 140, 280 and 560 mg. of DD per kg. of diet.Each treatment was given for 5, 10 and 20 day periods. The hormone was furnished…