Implanting trenbolone acetate and estradiol in finishing beef steers
1989
Eversole, D.E. | Fontenot, J.P. | Kirk, D.J.
The effect of implanting trenbolone acetate and estradiol 17 beta on feedlot performance and carcass characteristics of finishing steers was studied. A lactose- or cholesterol-based pellet containing 140 mg trenbolone acetate and 28 mg estradiol was implanted in yearling steers fed a high-roughage diet consisting of corn silage and supplement for 140 d. There was a 20% increase (P< 0.05) in rate of gain from the use of the implant in either base. A second implant with a lactose base given at the mid-point of the feeding period improved daily gain by an additional 7.5%. Dry matter intake was similar among control cattle and those receiving the different implants. Feed efficiency was improved (P < 0.05) by the lactose-base and the cholesterol-based implants. Use of the two lactose-based implants resulted in 23% improvements in feed efficiency, compared to the control cattle. Hot carcass weights were heavier (P < 0.05) for implanted cattle but carcass quality grades were lower (P < 0.05). Ribeye area was increased (P < 0.05) by the cholesterol-base and the two lactose-based pellets. These data indicate that combined androgenic-estrogenic anabolic implants enhanced feedlot performance and tended to increase edible lean and reduce fat in the carcass.
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