| Popis: |
ORAL administration of estrogens for fattening poultry has produced good responses, but optimum conditions have not yet been described. Extensive feeding trials for this purpose have been reported with only two of the available synthetic compounds with estrogenic activity—diethylstilbestrol and its derivative dianisylhexene. From a practical standpoint these compounds both present disadvantages. Diethylstilbestrol has a relatively low oral estrogenic potency for chickens (Jaap, 1945; Munro and Kosin, 1946) and large doses are required to produce fattening. Thayer, Jaap and Penquite (1944, 1945) observed a slight improvement in finish of 8-week-old Barred Plymouth Rock cockerels fed diethylstilbestrol for 3 and 4 weeks. During these periods each bird consumed about 75 and 100 mg. of the estrogen respectively; birds that were fed for 2 weeks only and consumed about 50 mg. showed no improvement in grade. Feeding 6- and 11-week-old Single Comb White Leghorn cockerels for 4 weeks produced only a . . . |
