Two experiments were conducted to investigate the effects of feeding kernel processed corn silage to growing calves at 65% inclusion (dry matter [DM] basis; Exp. 1] and finishing beef steers at 20% inclusion (DM basis; Exp. 2). In Exp. 1, steers (n = 184; initial shrunk body weight [BW] = 388 ± 22.3 kg) were used to evaluate the influence that kernel processing of corn silage has on production responses when fed at 65% diet inclusion (DM basis) during a 46-d growing period. Steers were allotted to 1 of 24 pens (12 replicate pens/treatment). Treatments were based upon corn silage that was either kernel processed or not. In Exp. 2, steers (n = 192; initial shrunk BW = 446 ± 28.3 kg) were used in a 112-d finishing experiment. Treatments were grouped in a 2 × 2 factorial arrangement (24 pens total; 8 steers/pen) to evaluate corn silage harvest maturity (1/2 to 2/3 milk line or black layer) and kernel processing (processed or not) at time of corn silage harvest on finishing steer growth performance and carcass traits when corn silage is fed at a dietary DM inclusion of 20%. Both experiments were analyzed as a randomized completed block design with pen as experimental unit. In Exp. 1, final BW tended (P = 0.07) to be increased by 3 kg in kernel processed corn silage. Daily weight gain and DM intake were increased (P ≤ 0.04) by 6% and 2%, respectively, in steers fed kernel processed corn silage compared to controls; however, gain efficiency was not appreciably influenced by treatment (P = 0.15). In Exp. 2, there were no harvest maturity × kernel processing interactions (P ≥ 0.26) for any growth performance measures or any parameters related to efficiency of dietary NE utilization. No harvest maturity × kernel processing interactions (P ≥ 0.08) were observed for any carcass traits except for the distribution of USDA Prime carcasses (P = 0.04). Steers fed 2/3 milk line and unprocessed corn silage had a lower (P = 0.05) proportion of carcasses grade USDA Prime (0.0%) compared to all other treatments (12.0%). Harvest time (P ≥ 0.07) and kernel processing (P ≥ 0.07) of corn silage had no appreciable influence on any other carcass trait measures. These data indicate that kernel processed corn silage fed to growing calves at 65% diet inclusion (DM basis) enhances intake and daily gain, while kernel processed corn silage fed to finishing steers at 20% diet inclusion (DM basis) does not appreciably influence daily gain, efficiency of gain, or carcass parameters.

The objective of this study was to determine if supplementing encapsulated butyric acid and zinc (BZ) in lambs abruptly transitioned to a finishing diet has effects on growth performance, efficiency of dietary net energy utilization, and carcass traits following a 59.5 d finishing period. Polypay wethers (n = 32; initial shrunk BW = 39 kg ± 4.8 kg) were grouped by initial shrunk BW and assigned to dietary treatment (CON: 0 g BZ/kg diet DM; BZ: 2 g BZ/kg diet DM) in a randomized complete block design (RCBD) with pen (n = 16) as experimental unit. Wethers were abruptly transitioned from growing diet (based upon grass hay, dried distillers grains plus solubles, and a soybean meal based pellet; 1.65 Mcal/kg NEm, 0.95 Mcal/kg NEg) to finishing diet (based upon whole corn, soybean hulls, and a soybean meal pellet; 2.02 Mcal/kg NEm, 1.33 Mcal/kg NEg) upon study initiation. Lambs were harvested at the South Dakota State University meat lab and empty body measures and carcass traits were recorded. Growth performance was calculated on a shrunk live basis (BW × 0.96). Data were analyzed as an RCBD with fixed effect of treatment and random effect of block. No differences (P ≥ 0.15) were observed for final shrunk BW, ADG, DMI, feed conversion efficiency, observed-to-expected (O:E) DMI, O:E NEm, O:E NEg, EBW, dressed yield, or HCW. Percentage of boneless closely trimmed retail cuts (BCTRC) and red meat yield (RMY) were decreased (P = 0.03) for BZ vs. CON. Body wall thickness was increased (P = 0.02) for BZ vs. CON. Supplementing wethers BZ during an abrupt transition to a finishing diet had no effects on growth performance, efficiency of dietary net energy, or empty body measures and had minor effects on body wall thickness, percentage BCTRC, and RMY.

Dry corn milling biorefineries have the opportunity to install technology to fractionate corn prior to fermentation which creates a product stream of fibrous bran that can be fed to cattle. The objective of this study was to determine the effects of replacing dietary corn with corn bran and condensed distillers solubles (CBCDS) or wet corn gluten feed (WCGF) on growth performance, efficiency of dietary net energy (NE) utilization, and carcass characteristics in finishing steers. British × Continental steers (n = 240; initial BW = 401 kg ± 43.2 kg) were assigned to the following dietary treatments in a randomized complete block design (RCBD): 1) a Control finishing diet with no corn milling co-products 2) a finishing diet that contained CBCDS at 20% replacement of dietary corn 3) a finishing diet that contained WCGF at 20% replacement of dietary corn. Dietary corn (50:50 of dry rolled corn and high moisture corn) was included at 81.5% for control diet fed steers and 61.5% for steers fed CBCDS and WCGF. Steers were fed for 145.5 d until visually appraised to have 1.27 cm of rib fat (RF) and harvest at a commercial abattoir where carcass data was collected. Data was analyzed as an RCBD with pen as the experimental unit, treatment as a fixed effect and block as a random effect. There were no significant differences (P ≥ 0.28) between treatments for final body weight (BW), average daily gain, dry matter intake, feed conversion efficiency, observed dietary NE for maintenance (NEm) and NE for gain (NEg), or observed-to-expected NEm and NEg. Additionally, no differences (P ≥ 0.16) were noted between treatments for hot carcass weight, ribeye area, RF, marbling score, kidney-pelvic-heart fat, estimated empty body fat (EBF), BW at 28% EBF (AFBW), and distribution of USDA Quality and Yield grades. Control steers tended (P = 0.10) to have the highest calculated yield grade (YG) followed by WCGF and CBCDS. Furthermore, WCGF steers tended (P = 0.08) to have the highest calculated retail yield (RY) followed by CBCDS and Control steers. Replacement NEm and NEg values of corn co-products were determined to be 2.14 and 1.42 for CBCDS and 2.09 and 1.37 for WCGF respectively. Thus, CBCDS can be included in finishing steer diets at 20% replacement of corn without detriment to growth performance or carcass characteristics.

Steers (n = 80; initial BW 271 ± 99) were serially scanned at 42-d intervals during a 378-d feeding period using an Aloka 500 device by a certified Ultrasound Guidelines Council (UGC) technician using real-time ultrasound. This included 10 separate ultrasound scanning sessions following the initial weight and ultrasound data taken on day minus 7 (one week prior to initial start date). Steers were randomly assigned to implant treatment (either implanted with Revalor XS or not) at day -7. Cattle were weighed and scanned for 12th-rib fat thickness (FTU), 12th-rib longissimus muscle area (LMAU), percentage intramuscular fat (%FATU), and rump fat thickness (RFU) to determine the ability of ultrasound to predict carcass grading outcomes at harvest. Scans were processed by CUP Lab technicians. Eight steers were harvested each 42 days. Carcasses were assessed 48h after harvest to determine 12th-rib fat thickness (FTC), 12th-rib longissimus muscle area (LMAC), and marbling score (MARB). Data were analyzed via Pearson correlation and linear regression to determine the relationship of ultrasound measures to carcass outcomes. Positive correlations (P < 0.01) between ultrasound measures taken the day before harvest and carcass measurements indicated strong relationships between FTU and FTC (r = 0.91), LMAU and LMAC (r = 0.93), and moderately strong relationships between %FATU and MARB (r = 0.76). Prediction equations were generated to estimate FTC = .0088 + (1.02585 x FTU), LMAC = 16.29720 + (0.77197 x LMAU) and MARB = 19.87510 + (5.19832 x %FATU). Results suggest real-time ultrasound data provides an effective tool to estimate carcass outcomes pre-harvest.

The objective was to determine if delivery method of organic trace minerals and Saccharomyces cerevisiae yeast culture product influence growth performance, feed efficiency, and hepatic trace mineral measures in newly-weaned steers. Crossbred steers (n = 192; 256 ± 14 kg) were used in a 49-d receiving experiment. Within 36h of weaning, steers were weighed, allotted to 24 pens (n = 8 steers/pen; 8 pens/treatment) and randomly assigned to treatments: traditional receiving diet (Con); traditional receiving diet plus the “stress-pack” directly in the diet (Force); traditional receiving diet plus a low-moisture, cooked molasses block fortified with the “stress-pack” (Tub). “Stress-pack” was offered the first 28 d of the 49-d. Biopsy samples were collected from a subsample of steers (n = 14 steers) on the day of weaning and subsequent samples were collected from the same steer (n = 1 steer/pen) on d 14, 28 and 49 for hepatic trace mineral concentration determination. A treatment × day interaction (P≤0.01) for hepatic Cu concentration was noted. Force had greater hepatic Cu (P≤0.05) compared to Tub and Con for the entire period. Tub had greater hepatic Cu compared to Con on d 14 and 28 (P < 0.05), but was similar to Con on d 49 (P>0.10). Force tended (P=0.08) to have greater DMI compared to Tub from d 1 to 14. From d 15 to 28, steers offered “stress-pack” had greater DMI (P=0.01) and tended (P=0.07) to have greater ADG compared to Con by 12.5%. From d 29 to 49, “stress-pack” steers had greater DMI (P=0.01) and Force consumed 6.9% more DM compared to Tub (P=0.01). Cumulative DMI (P=0.01) and ADG (P=0.05) was greater for Force compared to Tub by 5.4% and 9.4%, respectively. Application of “stress-pack” in diets offered to newly-weaned cattle enhanced production responses, but delivery method influences DMI and daily gain.