Comparison of the effects of long-acting Synovex One with Revalor-XS and Synovex Plus on growth performance and carcass quality in steers

Journal of Animal Science

Thompson

Hutcheson

et al. 2018

Crossbred beef steers (n = 240; 12 pens/treatment; initial BW = 305 ± 17.7 kg) were used in a randomized block design feedlot study to evaluate the influence of coated trenbolone acetate (TBA) and estradiol-17β (E2) implants (Merck Animal Health, Madison, NJ) on gain performance, carcass traits, and sera metabolites. The five treatments were no implant (NI), Revalor-XR on d 0 [200 mg TBA + 20 mg E2 (coated); XR], Revalor-XS on d 0 [200 mg TBA + 40 mg E2 (total): 80 mg TBA + 16 mg E2 (noncoated) and 120 mg TBA + 24 mg E2 (coated); XS], Revalor-200 on d 0 [200 mg TBA + 20 mg E2 (noncoated); E200], or Revalor-200 on d 70 (D200). Interim BW and blood were collected on d 0, 14, 35, 70, 105, 140, and 175 prior to feeding and on d 213 prior to shipping. Following a 24 h clot at 4 °C, sera was harvested to quantify circulating E2, IGF-I, NEFA, serum urea-N (SUN), and 17β-trenbolone (17β-TbOH). Implanted steers had greater (P ≤ 0.05) ADG, G:F, and final BW than NI controls. Implants increased (P < 0.05) HCW by 8%, 366 vs. 391, 414, 380, and 396 ± 6.4 kg, for NI vs. XR, XS, E200, and D200, respectively. The greatest (P ≤ 0.05) dressing percentage, yield grade, and calculated empty body fat occurred in XS, which had greater (P < 0.05) rib fat than NI, XR, and D200. Marbling scores in NI were greater (P < 0.05) than E200 and D200; steers in XR and XS were intermediate (P > 0.10), not differing from NI, E200, or D200. An implant × day interaction (P ≤ 0.01) was noted for circulating E2, IGF-I, SUN, and 17β-TbOH. Implanted steers had elevated (P ≤ 0.05) sera E2, IGF-I, and 17β-TbOH, and decreased (P < 0.05) SUN following implantation compared to NI controls. Serum NEFA differed (P < 0.01) over time, but did not differ (P > 0.10) due to implant treatment. These data indicated that the polymer coating applied to the XR implant delayed release of steroidal hormones congruently to D200, with no negative impact on marbling. The greatest dose of E2, contained in XS, provided improvements in gain and carcass weight without detriment to marbling scores compared to NI.

Section: Discussionmentioning

confidence: 98%

Section: Discussionmentioning

confidence: 98%

Evaluation of coated steroidal implants containing trenbolone acetate and estradiol-17β on live performance, carcass traits, and sera metabolites in finishing steers

Journal of Animal Science

Thompson

Hutcheson

et al. 2018

“…McLaughlin et al 2013reported that steers receiving a long-acting implant (sustained release coated implant: 200 mg TBA + 28 mg estradiol benzoate) had lower ADG and G:F when compared to steers given a conventional implant (non-coated implant: 200 mg TBA + 28 mg estradiol benzoate) during the initial 75 d post-implantation. While steers administered a Revalor-XS (initial and delayed release implant) were intermediate and did not differ from either implant group (McLaughlin et al 2013). According to the FOIA (2017b), 70 d post-implantation steers receiving a Revalor-XR implant do not differ from negative controls for ADG or G:F. However, from 71 to 200 d post-implantation cattle implanted with Revalor-XR have improved ADG and G:F over negative controls (FOIA 2017b).…”

Section: Live Animal Performancementioning

confidence: 91%

“…It is well documented that the use of implants, regardless of coating, total dose, or timing of administration increases final live BW measures relative to non-implanted (NI) steers (Reinhardt 2007;Parr et al 2011a;Parr et al 2011b;McLaughlin et al 2013). The altered payout characteristics associated with coated implants have been shown to improve final live BW measures over administration of a single TBA + E 2 implant (Parr et al 2011a;Parr et al 2011b).…”

Section: Live Animal Performancementioning

confidence: 99%

“…According to the FOIA (2017b), 70 d post-implantation steers receiving a Revalor-XR implant do not differ from negative controls for ADG or G:F. However, from 71 to 200 d post-implantation cattle implanted with Revalor-XR have improved ADG and G:F over negative controls (FOIA 2017b). McLaughlin et al (2013) indicated that steers receiving a coated implant have a marked improvement for interim period ADG from d 75 to 140 over steers administered a noncoated implant.…”

Section: Live Animal Performancementioning

confidence: 99%

See 1 more Smart Citation

Mechanisms of steroidal implants to improve beef cattle growth: a review

Journal of Applied Animal Research

Johnson

2020

For more than 60 y, beef cattle producers have safely used various types of growth-enhancing technology (GET) such as steroidal implants with anabolic activity and orally active beta-adrenergic agonists to increase skeletal muscle growth rate, improve carcass leanness, increase average daily gain (ADG), and alter dry matter intake (DMI) compared to non-treated cattle. Generally, the use of a GET increases ADG and only moderately affects DMI relative to non-treated cattle; subsequently, this enhances the rate of live weight gain relative to the amount of feed needed to achieve that gain, this is referred to as feed efficiency (G:F). When a producer chooses to utilize a GET, improvements in treated cattle over non-treated cattle are typically in the range of 8% to 28% for ADG and 5% to 20% for G:F. This review of the literature is intended to provide up to date insight into the mechanisms of how steroidal implants with anabolic activity enhance cattle growth and how these technologies have evolved since their introduction to U.S. beef producers nearly 60 y ago.

Feedlot performance and biological responses to coated and non-coated steroidal implants containing trenbolone acetate and estradiol benzoate in finishing beef steers123

Journal of Animal Science

Kim

Johnson

2019

Predominately Angus steers (n = 24; initial BW = 435 ± 28.3 kg) were used to evaluate non-coated (NC) and coated implants (CI) containing equal amounts of trenbolone acetate (TBA; 200 mg) and estradiol benzoate (EB; 28 mg) in finishing steers on sera metabolite responses, gene expression, and immunohistochemical analyses of the Longissimus muscle (LM). Performance data were analyzed as a randomized complete block design, and all other data were analyzed as repeated measures for a completely randomized design. Treatments were no implant (NI), NC (Synovex-PLUS; Zoetis, Parsippany, NJ), and CI (Synovex-One Feedlot) implant. There were 2 pen replicates per treatment (n = 4 steers/pen). LM biopsies, blood, and BW were collected before feeding on days 0, 14, 28, 56, 84, 112, and 133, with final BW being captured on day 140. Genes of interest were determined by RT-qPCR using two housekeeping genes. Sera was analyzed for estradiol-17β (E2),17β-trenbolone (TbOH), insulin-like growth factor 1 (IGF-I), NEFA, and urea-N (SUN). An α of 0.10 determined significance for performance and sera data; α of 0.05 was used for gene and histology data. No performance differences (P ≥ 0.10) were detected. An implant × day interaction (P ≤ 0.10) for E2, IGF-I, and SUN was detected; implants elevated (P ≤ 0.10) E2, 17β-TbOH, and IGF-I; and decreased SUN across day of the study, meaning sera metabolites are not altered with time on feed. An implant × day interaction was detected for myogenic factor 5 (MYF-5) positive cells and proportions of MHCIIX. In LM, CI had greater (P < 0.10) IGF-I in LM over NI. CI increased (P < 0.05) G protein-coupled estrogen receptor 1 (GPER1) expression, as well as, GPER1 semi-quantitative scores over NI and NC. An implant × day interaction (P ≤ 0.05) for estrogen and androgen receptor-positive nuclei was detected; implants had increased (P ≤ 0.05) estrogen and androgen receptor-positive nuclei compared to NI. CIs increase genes associated with muscle tissue growth.