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The effects of antibiotics on bovine luteinizing hormone (bLH)-stimulated output of androstenedione were examined in intact small white follicles (SWF, n = six hens), aliquots of 100,000 F1 and F2 theca cells (n = six hens), and aliquots of 10,000 F1 and F2 granulosa cells (n = eight hens). Cells and SWF were isolated from ovaries of Leghorn hens killed 20 h prior to ovulation and were incubated for 3 h in 1 mL of Medium 199 (Sigma Chemical Co., St. Louis, MO) at 37 C. Cells and follicles were incubated with 10 ng bLH and Penicillin-streptomycin (Pen-Strep; 20, 100, and 200 micrograms), gentamicin sulfate (gentamicin; 10, 50, and 100 micrograms), and fungizone (.5, 2.5, and 5.0 micrograms). Two control treatments consisted of tissues incubated alone (no bLH, no antibiotic) and tissues incubated with 10 ng bLH (no antibiotic). Androstenedione output by SWF and F1 and F2 theca cells and progesterone output by F1 and F2 granulosa cells were determined by radioimmunoassay of incubation media. The steroid contents of the incubation media were significantly increased in SWF and theca and granulosa cells with the addition of bLH. Neither Pen-Strep nor gentamicin significantly affected steroid output. Progesterone output by F1 and F2 granulosa cells was significantly reduced by the inclusion of fungizone. The inhibition of steroid output with the use of fungizone should be considered when using this antibiotic in studies of steroidogenesis in preparations of ovarian cells.

. 1989. The influence of egg weight loss during and immediately tbllowing incubation, and dietary intake of energy and protein on giowth and feed efficiency in broiler chickens. Can J. Anim. Sci. 69 1049-1057. One thousan

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