estradiol-benzoate--progesterone-drug-combination and Body-Weight

Beef steer carcasses from three 2 x 2 factorial feeding experiments (Exp. 1, 20 carcasses; Exp. 2 and 3, 19 carcasses each) were evaluated to study the influence of supplementing with roasted soybeans (RSB; 127 degrees C for 10 min) vs soybean meal (SBM) and implanting with the estrogenic growth promoter Synovex-S (SYN, 20 mg estradiol benzoate and 200 mg progesterone) on carcass merit, composition of dissected 9-10-11th rib section, estimated edible carcass composition, and cooking characteristics of strip loin steaks. In all experiments, steers were fed diets consisting of 15% corn silage, 15% orchardgrass silage, and 70% corn-based concentrate. There were no treatment interactions found in this study. Final BW averaged 480.4, 498.5, and 500.7 kg for Exp. 1, 2, and 3, respectively, and hot carcass weights averaged 288.4, 296.4, and 309.1 kg. Across experiments, hot carcass weight was 8.3 kg less (P < .03) for RSB steers than for SBM steers. Fat weight (P < .01) and percentage of fat (P < .01) were less and percentage of bone (P < .04) was greater in the 9-10-11th rib section of RSB steers than of SBM steers. Estimated percentage of fat (P < .02) was less and percentage of bone (P < .04) was greater in edible carcass of RSB steers than in that of SBM steers. Total 9-10-11th rib section weight tended to be less for RSB steers (P < .08) than for SBM steers. Carcass merit measurements were not affected (P > .10) by supplement, but numerically the percentage of kidney, pelvic, and heart fat was 11% greater for RSB steers than for SBM steers in Exp. 2 and 3. Final BW and carcass weight were 38.7 and 22.6 kg greater (P < .01), respectively, for SYN-implanted steers than for steers not implanted. Longissimus muscle area was greater (P < .01), percentage of kidney, pelvic, and heart fat (P < .02) was less, USDA quality grade tended to be less (P < .09), and shear force of strip loin was greater (P < .01) for SYN-implanted steers than for steers not implanted. The 9-10-11th rib section and estimated carcass compositions were not different (P > .10) between SYN-implanted steers and steers not implanted but reflected a somewhat leaner carcass. The authors conclude from this study that in feedlot steers, either implanted or not implanted, there is no benefit from supplementing with RSB in place of SBM, and that the use of RSB in place of SBM in feedlot diets may reduce the amount of edible carcass.

Topics: Adipose Tissue; Animal Feed; Animals; Body Weight; Cattle; Delayed-Action Preparations; Drug Combinations; Estradiol; Glycine max; Meat; Muscle, Skeletal; Organ Size; Progesterone

We conducted this study to determine whether the growth responses of specific skeletal muscles in crossbred beef steers were differentially affected by treatment with recombinant bovine growth hormone (Somavubove, SbV, .1 mg/kg BW, i.m., daily), Synovex-S (200 mg progesterone + 20 mg 17-beta estradiol benzoate, SYN, ear implant), or a combination of the two. Starting body weights of steers averaged 182+/-1.8 kg. Five steers were used at this average BW to obtain data on weight and composition of individual muscles at d 0, and 20 other steers were assigned in equal numbers to control (C, no implant and placebo daily injection), SYN, SbV, and SYN + SbV treatment groups. After 56 d of treatment with placebo or growth promoters, complete rectus femoris (RF), triceps brachii (TB), supraspinatus (SS), psoas major (PM), and semitendinosus (ST) muscles were dissected, weighed, and then ground for determination of moisture, total protein, and fat. To calculate the average daily muscle wet weight, protein, and fat gains, the initial weight, protein content, and fat content of a muscle were subtracted from those obtained at slaughter and the difference divided by 56. Muscle weight was increased over C in TB and SS by SYN (P < .1); in TB by SbV (P < .09); and in RF (P < .05), TB (P < .03), and SS (P < .03) by SYN + SbV. Overall average daily wet tissue gain was increased over C by SbV + SYN (P < .05) in RF, TB, and SS. Average daily protein gain in RF and TB was increased by SYN (P < .1), SbV (P < .06), and SYN + SbV (P < .01) over that calculated for C. For RF, TB, and SS, average daily protein gain was greater (P < . 1) in SbV + SYN than that obtained with SbV or SYN alone. These data suggest that administration of growth promoters, such as somatotropin and Synovex, to cattle differentially affects growth characteristics in certain muscles and can have additive effects on protein gain when used together.

Topics: Adipose Tissue; Animals; Body Weight; Cattle; Drug Combinations; Drug Interactions; Estradiol; Growth Hormone; Male; Muscle Development; Muscle Proteins; Muscle, Skeletal; Organ Size; Progesterone; Random Allocation; Recombinant Proteins

Crossbred steers (n = 140; 353 kg) were implanted as follows: (C) control, no implant; (S) Synovex-S (20 mg estradiol benzoate + 200 mg progesterone); (R) Revalor (20 mg estradiol + 140 mg trenbolone acetate [TBA]; international dosage); (ST) S + finaplix-S (140 mg TBA); (STT) S + finaplix-S with finaplix-S reimplanted on d 58. Steers were harvested after 119 to 126 d on feed. Left sides of 40 carcasses were fabricated into boneless subprimals for two s.c. fat levels: 2.5 and .64 cm. Steers administered an estrogen (estradiol benzoate or estradiol) plus TBA gained more rapidly (P < .05) than C or S steers. Feed efficiency was improved (P < .05) with an estrogen plus TBA. No differences (P > .05) were noted among treatments for carcass s.c. fat thickness, percentage internal fat, or lean color. Carcasses from steers receiving TBA had larger (P < .05) longissimus areas and tended to have lower (P < .10) marbling scores and yield grades than C or S steers. Steers implanted with R had a lower (P < .05) percentage of U. S. Choice carcasses (51.8%) than C, S, and ST steers (82 to 86%). Shear force values for implanted steers tended to be higher (P < .10) than for controls. Implants increased (P < .05) subprimal and total side lean yields (.64 cm) compared to controls; the largest increases of 2.3 and 2.8%, respectively, occurred in steers receiving TBA plus an estrogen. Estrogen plus TBA exhibited favorable effects on gain, efficiency, and composition; however, the single estradiol plus TBA implant (R) decreased quality grade.

Topics: Anabolic Agents; Animals; Body Composition; Body Weight; Cattle; Cooking; Drug Combinations; Drug Implants; Estradiol; Food Technology; Hydrogen-Ion Concentration; Male; Meat; Muscle, Skeletal; Progesterone; Trenbolone Acetate

The influence of Synovex-S (SYN) ear implant (200 mg progesterone and 20 mg estradiol benzoate) and Somavubove (SbV) recombinant bovine growth hormone (.1 mg/kg BW i.m., daily) on live animal performance, tissue growth, and the partitioning of energy gain was determined using a slaughter-balance protocol with 25 young MARC II x (Angus-Hereford crossbred) beef steers (initial BW 182 +/- 1.8 kg). Following 21 d of adjustment to individual pens and to a diet of 80% concentrate and 20% corn-grass (1:1) silages, five groups of five steers per group were assigned to initial slaughter or a 2 x 2 factorial arrangement of treatments of CTL (no implant + daily placebo i.m. injection of bicarbonate-saline), SYN (implant + placebo), SbV, or SYN + SbV and slaughtered at 56 d on treatment. Steers were fed (per kilogram BW.75 daily) 20 g of CP and 252 Kcal of ME and consumed 5.5 +/- .07 kg/d DM across treatments. Empty body and carcass gains were affected (SYN, P < .01; SbV, P < .01) by treatments (CTL, SYN, SbV, and SYN + SbV: 1.26, 1.43, 1.63, 1.78 kg/d, SEM = .05, and .78, .97, .97, 1.08 kg/d, SEM = .04, respectively). Noncarcass gain was .45, .48, .60, and .60 kg/d (SEM = .03; SbV, P < .01). For empty body, both protein and water gains were greater for SYN-implanted steers (P < .05) than for steers not implanted and for SbV-injected steers (P < .01) than for placebo-injected steers. Treatments did not influence the efficiency of energy gain. The proportional amount of energy deposited as protein was greater (P < .01) for SbV-injected steers than for placebo-injected steers. The proportional amount of protein deposited was not influenced by SYN (P > .10); however, means were numerically greater for SYN-implanted steers than for steers not implanted, the largest mean being for the SYN + SbV treatment group. Somavubove increased (P < .01) the efficiency of energy deposited as protein in both the empty body and carcass compared with steers not receiving SbV. Efficiency of energy deposited as protein in the empty body tended to be greater (P < .10) for SYN-implanted steers than for steers not implanted. The efficiency with which total feed energy was deposited as protein in empty body was 10% greater for the SYN group than for the CTL group, 21% greater for the SbV group than for the CTL group, and 37% greater for the combined SYN + SbV treatment than for the CTL group. The data from this study are interpreted to indicate that SYN and SbV act in an additive manner to imp

Topics: Animals; Body Composition; Body Weight; Cattle; Drug Combinations; Estradiol; Growth Hormone; Male; Progesterone; Random Allocation; Recombinant Proteins; Weight Gain

Twelve Charolais-crossbred steers (256 kg) received one of three treatments: nonimplanted controls (C), implanted initially and at 84 days with 36 mg zeranol (Ralgro, R) and implanted initially and at 84 days with 200 mg of progesterone and 20 mg of estradiol benzoate (Synovex-S,S). All steers were fed a corn-based diet (calculated metabolizable energy 2.89 Mcal/kg dry matter) ad libitum. In a parallel comparative slaughter trial, rates of empty body protein accretion were increased 14% in R and 24% in S steers (P less than .01). R and S steers in the present study had heavier pituitary weights (P less than .001), more pituitary growth hormone content (P less than .04) and more pituitary weight/unit live weight (P less than .05) than did C steers. Cattle implanted with R or S exhibited an increased growth hormone (GH) secretory response to a pituitary challenge with thyrotropin releasing hormone (TRH). Plasma insulin profiles were not significantly altered, but tended to be greater for steers given implants. Overall 9-hr GH secretory profiles were not affected by implantation. Plasma urea N at 94 days post-implantation was decreased (P less than .01) by implantation. Plasma glucose was increased (P less than .04) at both 94 and 199 days in R and S vs C steers. Overall mean and total (integrated area) plasma GH, as well as secretory profile components (baseline mean, amplitude of secretory spikes) were negatively correlated with body weight and size on days 94 and 199. Overall mean, baseline and integrated area of plasma insulin on days 94 and 199 were positively related to body weight and size. Thus positive protein anabolic growth responses from implantation (parallel comparative slaughter trial) were coupled with increased pituitary GH content and little change in circulating plasma GH concentrations between implanted and control steers. This may suggest that changes in tissue sensitivity, an increased plasma clearance rate of GH and/or a direct effect on target tissues may be involved in the improved growth performance of cattle implanted with R or S.

Topics: Animals; Body Weight; Cattle; Drug Combinations; Drug Implants; Estradiol; Growth Hormone; Growth Substances; Insulin; Insulin Secretion; Male; Organ Size; Pituitary Gland; Progesterone; Zeranol

The effects of anabolic implants on rate, composition and energetic efficiency of growth were determined in steers fed diets varying in forage and grain content. Santa Gertrudis-cross steers averaging 337 kg were group-fed (n = 72) or individually fed (n = 45) ad libitum one of three diets and either not implanted or implanted (90-d intervals) with Ralgro or Synovex-S implants. Steers were fed to a similar empty body weight (463 kg). Initial empty body composition of individually fed steers was determined via D2O dilution, and final composition of all steers was determined by carcass specific gravity. Rate of empty body gain increased (P less than .05) from 695 g/d for nonimplanted steers to 798 and 844 g/d for Ralgro- and Synovex-implanted steers. Anabolic implants increased (P less than .01) daily empty body protein gain from 91 to 119 and 133 g for Ralgro and Synovex, an increase of 31 and 46%, respectively. The fraction of protein in empty body gain increased (P less than .01) from 13.8% to 15.6 and 15.9%, and the percentage of fat in empty body gain decreased (P less than .01) from 41.7% to 32.9 and 31.3% with Ralgro and Synovex, respectively. Daily rates of protein deposition increased at a decreasing rate, and rates of fat deposition increased at an increasing rate with increasing rate of empty body gain. Implanted steers deposited more protein and less fat at any rate of growth; the magnitude of this shift in nutrient partitioning from fat to protein growth increased with rate of growth.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animal Feed; Animals; Body Composition; Body Weight; Cattle; Drug Combinations; Drug Implants; Energy Metabolism; Estradiol; Male; Progesterone; Resorcinols; Zeranol

The effect of estrogenic anabolic compounds on the kinetic parameters of metabolism of growth hormone (GH) was studied in growing beef steers. Twenty-four beef steers were randomly placed into four groups and assigned to one of the following four treatment groups: zeranol, diethylstilbestrol (DES), Synovex-S and an unimplanted control. GH metabolism was studied from eight steers on day 20 following the implantation of anabolic compounds. The animals were rapidly injected with a solution of bGH (NIH-GH-B18) and the disappearance of injected GH from the plasma was monitored up to 120 min following the injection. The plasma GH disappearance curve displayed an initial rapid phase lasting 5 min and a slow disappearance phase lasting 42 min; the fractional turnover rate from the two compartments were 0.167 and 0.017 min-1, respectively. The average volume of distribution of GH in steers was 6% of the body weight. Mean values of metabolic clearance and secretion rates of GH in steers were 21 liters/h and 252 micrograms/h or 74.5 ml/kg/h and 0.91 microgram/kg/h, respectively. Steers implanted with anabolic compounds gained more rapidly (P less than 0.05) than the controls. Plasma basal GH concentration appeared to be higher in all the implanted than in the control steers. The secretion rate of GH was increased (P less than 0.05) in steers implanted with anabolic compounds when compared to control steers. The secretion rate (microgram/kg/h) was about 96% (P less than 0.05), 107% (P less than 0.05) and 81% (P less than 0.05) higher in steers implanted with DES, zeranol and Synovex-S, respectively, than in the control steers. All the compounds studied were equally effective in increasing the secretion of GH on day 20 following their implantation. Metabolic clearance rate of GH was not affected by anabolic compound implantation in steers. There was, however, a slight reduction in metabolic clearance rate due to DES and a slight elevation due to zeranol and Synovex-S when compared to control steers. There was a positive correlation between growth rate and GH secretion rate (r = 0.78; P less than 0.05). The results indicate that the implantation of estrogenic anabolic compounds increases the secretion rate of GH from the pituitary gland and suggest that their mechanism of action is mediated through increased GH secretion.

Topics: Animals; Body Weight; Cattle; Diethylstilbestrol; Drug Combinations; Drug Implants; Estradiol; Estrogens, Non-Steroidal; Growth Hormone; Half-Life; Kinetics; Male; Metabolic Clearance Rate; Progesterone; Stimulation, Chemical; Time Factors; Zeranol