Use of trenbolone acetate and estradiol in intact and castrate male cattle: effects on growth, serum hormones, and carcass characteristics.

Abstract

The effects of anabolic implant on growth, carcass characteristics, and serum hormones were examined in 30 young bulls and steers fed a growing diet then a finishing diet. In a 2 X 3 factorial arrangement, steers and bulls received an implant of trenbolone acetate (TBA), TBA and estradiol-17 beta (E2), or no implant. Blood samples were taken serially (every 20 min for 6 h) at intervals during the growing and finishing phases. Percentage of DM, fat, protein, and ash and Warner-Bratzler shear test were measured and taste panel evaluations of the 9-10-11 rib section were obtained. Treatment with TBA and E2 increased weight gain in steers but not in bulls. There were no differences in feed efficiency, serum growth hormone (GH), and cortisol concentrations between bulls and steers or between treated groups and controls in bulls or steers, although during the finishing phase mean GH concentrations in treated steers were twofold higher than in controls and were similar to those in the bull groups. Serum insulin-like growth factor-I (IGF-I) increased twofold during the growing phase, then remained at that level. Steers implanted with TBA and E2, which had the highest gains among the steer groups, had the highest serum GH and IGF-I. Longissimus steaks from bulls treated with TBA alone or TBA and E2 were comparable to steaks from steers in the shear test. Taste panelists found steaks from TBA- and E2-treated bulls to be similar in tenderness and connective tissue to steaks from steers.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of ovariectomy and anabolic steroid implantation on the somatotrophic axis in feedlot heifers

“…= 25.5) observed for serum IGF-1 with LS means of 267.4 (intact implanted), 170.9 (intact control), 434.4 (OVX implanted) South African Journal of Animal Science 2008, 38 (3) © South African Society for Animal Science 213 and 167.0 ng/mL (OVX control) indicating that the greatest response in serum IGF-1 was in the OVX implanted heifers. This agrees with many previous reports indicating that implanting steers increases circulating IGF-1 (Lee & Henricks, 1990;Hunt et al, 1991;Cheatham, 2005). Furthermore, Mader & Kreikemeier (2006) found IGF-1 concentrations to be greater in estradiol+trenbolone acetate implanted heifers compared to controls, but found no differences in IGF-1 between controls and those animals implanted only with estradiol or trenbolone acetate.…”

“…Moreover, serum IGF-1 is generally considered to be a GH dependent peptide (Florini et al, 1991). However, implants do not increase circulating GH (Hunt et al, 1991;Hayden et al, 1992). In fact, Cheatham (2005) reported that, in non-implanted Holstein steers, the GH response to a GH releasing hormone challenge was actually greater than that found in implanted steers.…”

“…Vestergaard et al (1995) found that ovariectomy did not affect circulating insulin like growth factor -1 (IGF-1) in unimplanted Holstein heifers, and Mader & Kreikemeier (2006) found IGF-1 concentrations to be greater in estradiol + trenbolone acetate (TBA) implanted heifers compared with unimplanted heifers, but found no differences in IGF-1 concentrations between controls and those animals implanted only with estradiol or TBA. However, TBA alone or implanted synergistically with an oestrogenic implant had no effect on growth hormone (GH; Hunt et al, 1991). Implanting lambs with estradiol + trenbolone acetate increased hepatic mRNA expression of IGF-1 and implanting steers with estradiol+ TBA increased expression of IGF-1 in the muscle (Johnson et al, 1998).…”

Meta-analysis of the published effects of HGP use on beef palatability in steers as measured by objective and sensory testing

“…There were 47 control steers and 44 treated steers with results given in Table 3. et al (1973) 10.0 8.8 Forrest (1975) 0.8 5.0 Ntunde et al (1977) 1.3 10.8 Nute & Dransfield (1984) -6.4 5.6 Calkins et al (1986 8.8 1.8 Ouali et al (1988) 17.0 3.3 Apple et al (1991) 3.1 1.7 Hunt et al (1991) 0.7 2.6 Thonney et al (1991) 9.3 3.3 Gerken et al (1995) 3.8 2.8 Roeber et al (2000) 7.0 6.3 Barham et al (2003) 1.4 2.0 Platter et al (2003) 9.5 2.8 CRC = DF (2008) 7.1 3.6 CRC = KF (2008) 3.7 3.1 CRC = JF (2008) 3.1 2.5 CRC = DG (2008) 12.7 2.9 CRC = KG (2008) 4.5 2.6 CRC = JG (2008) Negative tenderness (100pt scale) Fig. 3.…”

“…et al (1991) 0.12 0.20 Huck et al (1991) 0.23 0.20 Hunt et al (1991) -0.15 0.39 Gerken et al (1995) 0.40 0.25 Samber et al (1996) 0.24 0.10 Foutz et al (1997) 0.32 0.17 Rumsey et al (1999) 0.95 0.33 Pritchard et al (2000) 0.00 0.20 Roeber et al (2000) 0.37 0.11 Barham et al (2003) 0.37 0.11 Platter et al (2003) 0.63 0.19 Reiling & Johnson (2003) WA-1 trial: Thompson et al (2008a) This trial, utilising three cooking methods, covered a wide range of muscles for heifers and steers. The details are covered in full in Thompson et al (2008a).…”