Effect of Diethylbestrol on Tissue Gain and Carcass Merit of Feedlot Beef Steers

Abstract

The effect of diethylstilbestrol (DES) on the composition of tissue gain of Hereford steers was studied in a complete slaughter balance trial. Eight steers were slaughtered initially (IS) and, after 177 days on feed, eight control steers (C) and seven steers that had been fed 20 mg DES daily (DES) were slaughtered. Initial full body weight averaged 224.8 kg, and final full body weight averaged 403.0 kg for the C steers and 433.6 kg for the DES steers. Final empty body weight averaged 346.6 kg for the C steers and 368.0 kg for the DES steers. DES improved live weight gain by 17% and conversion of feed dry matter to live weight by 12%. Recovery of wet weight during slaughter averaged 99.6%. DES steers had larger rib cut weights and greater proportions of separable lean and bone plus connective tissue in the rib cuts than C steers, an ribeye area tended to be larger in DES steers. DES caused a small shift in relative body composition toward more protein, moisture and ash. Tissue gain in DES steers consisted of 28.3% more protein, 26.0% more moisture, 73.2% more ash, 1.5% less fat and 109.1% more residual (dry matter not accounted for by N x 6.25, ether extract and ash) than did tissue gain in C steers. Energy gain per unit of energy intake over the feeding period was not affected by DES treatment, but DES improved protein gain per unit of protein intake and per unit of energy intake by approximately 20% within the total empty body and by about 25% within the carcass fraction. Results confirm indirect estimates in the literature indicating that DES increases skeletal growth and lean tissue deposition in feedlot steers.

Effects of Synovex-S and recombinant bovine growth hormone (Somavubove) on growth responses of steers: I. Performance and composition of gain.

“…Organs, blood, and hide were combined with remaining noncarcass components before grinding and sample collection. Samples of noncarcass, stomach, small intestine, large intestine, and carcass tissues were analyzed for moisture (lyophilization), nitrogen (macro Kjeldahl), lipid (ether extract), ash (muffle furnace at 600°C), and energy (adiabatic bomb calorimetry) as described by Rumsey et al (1981). Analytical dry matter was used to account for any residual moisture due to sample processing.…”

“…Estrogenic growth promoters increase the rate of protein deposition in feedlot steers 22 to 25% (Rumsey et al, 1981;Rumsey, 1982), with variable results between carcass and noncarcass gain. Bovine growth hormone increases gain and protein deposition in feedlot steers, but reports in the literature suggest the greatest effect on steers is in the noncarcass fraction (Early et al, 1990;Moseley et al, 1992;Schwarz et al, 1993).…”

Influence of Frame Size and Zeranol on Growth, Compositional Growth and Plasma Hormone Characteristics

“…Anabolic agents (both estrogenic and androgenic) have been used extensively to improve production of farm animals (Buttery et al, 1978;Heitzman, 1980). The implantation with estrogenic anabolic compounds (zeranol, diethylstilbesterol and estradiol benzoate/progesterone) has been shown to improve growth rate and affect protein metabolism of beef cattle (Sharp and Dyer, 1971;Rumsey et al, 1981).…”

The effects of a combined androgenic-oestrogenic anabolic agent in steers and bulls 1. Growth and carcass composition

“…It was probably at a later stage in the evolution of animal husbandry that the advantage of castration in causing animals to deposit sufficient fat to produce 'finished' carcasses at a relatively early age was appreciated. This may be because most experiments have estimated carcass composition indirectly from, for example, nitrogen balance or sample joint dissection, rather than by measuring it directly by complete carcass analysis (Rumsey, Tyrrell, Dinius, Moe and Cross, 1981;Griffiths, 1982). But the supposedly greater aggressiveness of bulls, and the traditional preference for meat from steers voiced by many in the meat trade, has caused farmers to continue the practice of castration.…”