Influence of trenbolone acetate combined with estradiol-17 beta on growth performance, body characteristics, and chemical composition of goat kids fed milk and slaughtered at different ages.

Abstract

The effects of anabolic agents (5 mg of estradiol-17 beta + 30 mg of trenbolone acetate) on body characteristics and chemical composition of gain were studied in 58 intact male goat kids fed milk replacer. Four kids were slaughtered at 7 d of age to constitute the initial group. The other kids were allotted in a 2 x 3 factorial arrangement with slaughter age (41, 49, and 56 d of age) and treatment (control and implanted at 21 d old) as factors. Energy intake decreased during the first 4 wk after treatment; implanted kids had the same ADG as controls but a better energy efficiency (P < .05). During the last week of the trial, energy intake was the same; treated kids tended (P < .10) to have a higher empty body gain (EBG). Anabolic agents increased carcass (P < .10) and hide proportions (P < .01) in empty BW and in EBG for all groups (except for carcass at 56 d old). Anabolic agents reduced the contribution of adipose tissues (P < .05), empty digestive tract (P < .05), and other organs (P < .01) to EBG. At all slaughter ages, the chemical composition of carcass and hide wet tissues, all dissectible adipose tissues, and EBG were altered by treatment. In these tissues (except for mesenteric fat tissue), water content increased and lipid content decreased (P < .05), but these effects diminished with age. Expressed on a DM basis, the CP content of the treated carcasses was increased in all groups (P < .05). Implanting high doses of steroids altered nutrient partitioning, which reduced fat and increased water and protein in the body.