02347naa a2200289 a 450000100080000000500110000800800410001902400330006010000190009324501040011226000090021652015560022565000140178165000210179565000240181665000230184065000100186365000100187365000170188365300110190065300160191165300150192770000170194270000130195970000180197277300670199020758112017-09-19       1958    bl uuuu     u00u1 u    #d7 a10.2527/jas1958.171157x2DOI1 aANDREWS, F. N.  aThe effects of diethylstilbestrol, testosterone and reserpine on growth and carcass grade of lambs.  c1958  aTwo experiments involving a total of 372 ewe and wether lambs were conducted. Rate of gain was significantly increased by the implantation of 3 or 6 mg. pellets of diethylstilbestrol alone or in combination with an implantation of 20 mg. of testosterone propionate. The estrogen-androgen combination produced the most rapid gains, but the improvement was not statistically significant in comparison with diethylstilbestrol. The feeding of DES at a level of 1 mg. per pound of ration improved rate of gain but not as much as when DES was implanted. The oral administration of reserpine at a level of 0.25 mg. per pound of ration increased gain slightly but decreased growth when fed at a level of 0.50 mg. per pound and significantly reduced growth when fed at the 0.50 mg. level in combination with chlortetracycline. There was an apparent improvement in gross feed efficiency in all groups of lambs that received DES in the feed, by implantation or in combination with testosterone propionate. The maximum feed saving occurred in the lambs which were implanted with 6 mg. of DES and 20 mg. of TP. Carcass grades were consistently reduced by any form of DES administration, and the reduction appeared to be related to the amount of hormone used. The lambs receiving testosterone propionate alone had carcasses equal to the controls. It is regarded as an interesting observation that the combination of reserpine and chlortetracycline produced carcasses equal or superior to the controls although rate of gain was reduced at the higher reserpine level.  aAndrogens  aAnimal nutrition  aCarcass composition  adiethylstilbestrol  aLambs  aSheep  aTestosterone  aGrowth  aGrowth rate  aOestrogens1 aPERRY, T. W.1 aSTOB, M.1 aBEESON, W. M.  tJournal of Animal Sciencegv. 17, n. 1, p. 157-163, Feb. 1958.