Copyright (c) 2013 All rights reserved. http://works.bepress.com/rdelmore Recent documents in Robert J. Delmore, Jr. en-us Mon, 28 Jan 2013 14:15:30 PST 3600 http://works.bepress.com/rdelmore/12 http://works.bepress.com/rdelmore/12 Wed, 27 Apr 2011 11:37:06 PDT The objective of this research was to evaluate changes in the muscle conformation of subprimal top-loins (M. longissimus lumborum) from calf-fed Holstein steers fed zilpaterol hydrochloride (ZH). Top-loins (n =100) were transversely cut into 2.54 cm-thick steaks, weighed, and objectively evaluated via image analysis software for muscle area, width, and length traits. Top-loin steaks from steers fed ZH were heavier (P < 0.01; 367 vs. 337 g) and average muscle area per steak was greater (P < 0.05; 80.9 vs. 77.2 cm²) as compared to steaks from control steers. Muscle width (medial–lateral) was not different (P = 0.23) between control steers and those fed ZH. However, steaks from steers fed ZH had greater (P < 0.05) depth (dorsal–ventral) than steaks from control steers throughout the top-loin. The increased muscle depth of top-loins from calf-fed Holstein steers fed ZH may improve the center-of-the-plate salability of a cut that has traditionally suffered from poor muscling.

]]> T. E. Lawrence et al. Articles http://works.bepress.com/rdelmore/11 http://works.bepress.com/rdelmore/11 Tue, 23 Nov 2010 17:14:50 PST Zilpaterol hydrochloride (ZH) is a β-adrenergic agonist approved to be fed at a rate of 8.3 mg/kg (100% DM basis) during the final 20 to 40 d of the finishing period in beef cattle followed by a minimum 3-d withdrawal period antemortem. The Federal Drug Administration (FDA) approved label claims of increased rate of BW gain, improved feed efficiency, and increased carcass leanness. Before the release of ZH for commercial use in 2007, approximately 10 independent research trials at various universities and commercial feedlots were initiated. Articles in recent issues of the Journal of Animal Science are a result of the large comprehensive body of research designed to increase the understanding of the effect of ZH on beef cattle growth, carcass traits, and beef quality. The feeding of ZH for 20 to 40 d with a 3-d withdrawal resulted in significantly increased ADG. The increases equate to an average of 9 kg heavier BW in ZH-fed steers. Hot carcass weight has been shown to increase to a larger degree compared with BW, with an average improvement of 15 kg. Dressing percent is increased by 1.5 to 2.0% with the feeding of ZH. Increases in carcass leanness were reported for cattle fed ZH mainly through a reduction in yield grades. The LM area was increased, along with yield of subprimal cuts from the round, flank, and loin. Warner-Bratzler shear force studies have shown LM steaks from ZH-treated cattle to have increased shear force values of 1.1 to 1.7 kg for 7-d-aged steaks, 0.4 to 1.3 kg for 14-d-aged steaks, and 0.27 to 1.4 kg for 21-d-aged steaks compared with controls. Recent research has suggested that the aging response is normal in ZH steaks. Consumers were able to identify tenderness differences in 14-d-aged Choice steaks from cattle fed ZH for 20 d compared with 14-d-aged steaks from control cattle; this difference was mitigated with 21 d of postmortem aging. Zilpaterol hydrochloride has been shown to increase cattle growth and efficiency as well as lean tissue deposition in the carcass, with some impact on carcass traits such as Warner-Bratzler shear force.

]]> R. J. Delmore et al. Articles http://works.bepress.com/rdelmore/10 http://works.bepress.com/rdelmore/10 Thu, 16 Sep 2010 14:03:08 PDT No Abstract.

]]> James Ahern et al. Articles http://works.bepress.com/rdelmore/8 http://works.bepress.com/rdelmore/8 Thu, 26 Aug 2010 18:02:45 PDT Two experiments were conducted to evaluate the effectiveness of zilpaterol hydrochloride (ZH) to enhance growth performance and carcass characteristics in calf-fed Holstein steers. In Exp. 1, Holstein steers (n = 2,311) were fed in a large-pen trial in 2 phases at a commercial feed yard in the desert Southwest. In Exp. 2, a total of 359 steers were fed in a small-pen university study. In Exp. 1 and 2, cattle were implanted with a combination trenbolone acetate-estradiol implant approximately 120 d before slaughter. Cattle were fed ZH for 0, 20, 30, or 40 d before slaughter at a rate of 8.3 mg/kg (DM basis). A 3-d withdrawal was maintained immediately before slaughter. Cattle within an experiment were fed to a common number of days on feed. During the last 120 d before slaughter, ADG was not enhanced by feeding ZH for 20 d (P = 0.33 in Exp. 1, and P = 0.79 in Exp. 2). Gain-to-feed conversion was increased by feeding ZH for all durations in Exp. 1 (P < 0.05). Feeding ZH increased HCW by 9.3 (Exp. 2) to 11.6 (Exp. 1) kg at 20 d compared with the control groups. Across both experiments, dressing percent was increased for all durations of feeding ZH (P < 0.05). Although skeletal maturity score, liver integrity, lean color, fat thickness, and KPH were not affected by feeding ZH for 20 d in either experiment (P ≥ 0.6), LM area was increased for all durations of feeding ZH (P < 0.05). The percentage of carcasses identified as USDA Choice was reduced (P < 0.01) for all durations of feeding ZH in Exp. 1. This effect was not observed in Exp. 2. Holstein steers clearly respond to the β-agonist ZH, and 20 d of feeding ZH with a 3-d withdrawal significantly increased carcass weights, muscling, and carcass leanness.

]]> J. L. Beckett et al. Articles http://works.bepress.com/rdelmore/9 http://works.bepress.com/rdelmore/9 Thu, 26 Aug 2010 18:02:45 PDT Beef from retail and foodservice establishments in 11 US cities was evaluated using Warner–Bratzler shear (WBS) and consumer evaluation panels. Postmortem aging times ranged from3 to83d for retail and7 to 136d for foodservice with mean aging times of 22.6d and 30.1 d, respectively. For retail, the three cuts from the round – top round, bottom round, and eye of round – had the highest (P < 0.05) WBS values compared to cuts from the chuck, rib, and loin. Top loin steaks had the lowest(P < 0.05) WBS value compared to ribeye and top sirloin foodservice steaks. Retail bone-in top loin, top loin, ribeye, T-bone, and porterhouse received the highest (P < 0.05) ratings by consumers for overall like and like tenderness. Quality grade had little or no effect on foodservice sensory evaluations. Improvements in round tenderness are needed to increase consumer acceptability.

]]> K. L. Voges et al. Articles http://works.bepress.com/rdelmore/6 http://works.bepress.com/rdelmore/6 Thu, 26 Aug 2010 18:02:44 PDT To evaluate the impact of zilpaterol hydrochloride (ZH) on carcass cutability and tenderness of calf-fed Holstein steers, calf-fed Holstein carcasses (n = 102) were selected from a pool of 2,300 steers that were fed 0 or 8.3 mg/kg (DM basis) of ZH. Zilpaterol hydrochloride was supplemented the last 20 d of the finishing period and withdrawn for 3 d before slaughter. Carcasses were selected based on carcass weight as well as predetermined USDA Yield grade categories. For tenderness evaluation, steaks from the strip loin, bottom round, and top round (n = 54 per subprimal) were aged for 14 or 21 d postmortem. Carcasses from ZH-fed steers had more (P < 0.01) saleable yield than carcasses from control-fed steers. Additionally, ZH-fed steers had greater (P ≤ 0.01) subprimal yield from the shoulder clod, strip loin, peeled tenderloin, top sirloin butt, bottom sirloin tri-tip, peeled knuckle, inside round, bottom round flat, eye of round, heel, and shank. Furthermore, ZH decreased (P < 0.01) the total amount and percentage of bone and fat trim from the carcass. Moisture loss was not affected by ZH in LM or inside round steaks (P > 0.05); however, ZH increased thawing loss (P = 0.05) but reduced cooking loss (P = 0.05) in bottom round steaks. Shear force values of LM and inside round steaks increased with ZH inclusion (P < 0.01), but there was no difference in bottom round steaks (P > 0.05). Steaks aged for 21 d had smaller (P < 0.01) Warner-Bratzler shear force (WBS) values than 14-d steaks from all 3 subprimals. Trained sensory panelists did not detect any differences (P > 0.05) in sensory juiciness, tenderness, or flavor variables of LM or inside round steaks, except ZH steaks from the LM received smaller scores for sustained juiciness (P = 0.01) and overall tenderness (P = 0.04) than control steaks. Although LM steaks from ZH cattle were tougher than control steaks, the ZH-treated steaks had an average WBS value of 4.10 kg, which would be classified as intermediate in tenderness, with trained panelists rating ZH steaks slightly to moderately tender. Feeding ZH improved carcass cutability of calf-fed Holstein steers; however, tenderness was reduced in LM and inside round steaks. The interaction of postmortem tenderization techniques should be investigated to evaluate their impact on palatability in cattle supplemented with β-agonists to allow the beef industry to take full advantage of the enhancement in performance and carcass yield.

]]> A. J. Garmyn et al. Articles http://works.bepress.com/rdelmore/7 http://works.bepress.com/rdelmore/7 Thu, 26 Aug 2010 18:02:44 PDT ABSTRACT: Two studies using beef and calf-fed Holstein cattle were conducted to determine the effect of zilpaterol hydrochloride (ZH) supplementation on the color of strip loin steaks packaged in traditional and modified-atmosphere packaging. Select (USDA) strip loins were obtained from the carcasses of beef (n = 118) or calf-fed Holstein (n = 132) cattle fed ZH (6.8 g/ton on a 90% DM basis) for the last 0, 20, 30, or 40 d of feeding. One portion of the strip loin was moisture enhanced, cut into steaks, and packaged in an atmosphere containing 80% oxygen and 20% carbon dioxide. The remaining portion of the strip loin was vacuum-packaged until further processing. At 14 d postmortem, the vacuum-packaged loins were portioned and packaged in traditional retail packaging. Traditionally packaged and modified-atmosphere-packaged steaks were then placed in retail cases at −1 to 3°C for 5 d and evaluated by both trained and consumer panelists. Instrumental color values and purge loss were also recorded. Zilpaterol hydrochloride duration had no effect on the color and purchase intention scores of consumer panelists for beef and calf-fed Holstein strip loin steaks. Zilpaterol hydrochloride feeding duration had no effect on the color or discoloration scores of trained panelists for enhanced, modified-atmosphere-packaged beef strip steaks. Traditionally packaged beef steaks from cattle treated with ZH for 20 d had more desirable (P < 0.05) lean color scores than steaks from cattle not treated with ZH on d 2, 3, and 4 of display and had similar discoloration scores on d 1, 2, and 3 of display. The color scores of trained panelists for enhanced calf-fed Holstein steaks were more desirable (P < 0.05) for steaks from cattle not treated with ZH than for steaks from cattle treated with ZH for 20 d on d 1, 2, 3, and 4 of display. However, the discoloration scores of trained panelists for enhanced and modified-atmosphere-packaged calf-fed Holstein steaks were similar for steaks from cattle treated with ZH for 0 and 20 d on d 1, 2, and 3 of display. The scores of trained panelists indicated that traditionally packaged steaks from calf-fed Holsteins treated with ZH for 0 d had a darker lean color (P < 0.05) than steaks from ZH-treated cattle on d 1 of display, whereas the lean color scores for ZH treatments of all durations were similar on d 4 of display. The scores of trained panelists indicated that ZH treatment had no effect on the discoloration of traditionally packaged, nonenhanced strip steaks from calf-fed Holsteins. Therefore, feeding ZH to beef or calf-fed Holstein steers had no detrimental effect on the lean color or color stability of strip loin steaks subjected to enhancement, packaged in modified-atmosphere or traditional packaging, and displayed under simulated retail conditions.

]]> H. R. Rogers et al. Articles http://works.bepress.com/rdelmore/4 http://works.bepress.com/rdelmore/4 Thu, 26 Aug 2010 18:02:43 PDT A market basket survey for beef retail cut composition at the retail level (four stores each from two chains in each city) was conducted in 11 US cities from January to March 2006. Beef cuts (n = 17,495) were measured for external fat thickness with cuts from the chuck (0.05 cm), round (0.05 cm), and miscellaneous (0.04 cm) having less (P < 0.05) fat than cuts from the loin (0.11 cm) and rib (0.11 cm). Beef cuts (n = 1327) were separated physically into separable components with round cuts having more (P < 0.05) separable lean (96.63%) than chuck cuts (86.81%) and miscellaneous cuts (86.18%), which had more (P < 0.05) separable lean than loin cuts (84.53%) with rib cuts (69.34%) having the lowest (P < 0.05) separable lean. Chemical fat from the separable lean differed (P < 0.05) between each cut category: round cuts (3.71%), miscellaneous cuts (4.99%), loin cuts (5.60%), chuck cuts (6.90%), and rib cuts (8.61%). Ground beef samples (n = 235), with declared lean/fat percentages ranging from 73/27 to 96/4, had overall chemical fat values of 13.41% and moisture values of 67.42%. This survey documents the current beef retail cut and ground beef composition, which is helpful to those who need this information for various dietary and marketing purposes.

]]> C. L. Mason et al. Articles http://works.bepress.com/rdelmore/5 http://works.bepress.com/rdelmore/5 Thu, 26 Aug 2010 18:02:43 PDT Zilpaterol hydrochloride (ZH) is designed to increase carcass leanness, chilled side weight (CSW), and percent saleable yield. The objective of this study was to evaluate the effect of a single dose of ZH on cutability and subprimal yield of calf-fed Holstein steers when fed for increasing durations. Two hundred forty steers were fed 8.3 mg/kg of ZH on a DM basis for 0, 20, 30, or 40 d, with a 3-d withdrawal before slaughter. After slaughter, steers were fabricated into 4 pieces (round, loin/flank, rib/plate, and chuck), packaged in combos, shipped to 2 locations, and further fabricated into subprimal pieces and trim. Trim was collected from each primal and separated into groups based on composition of 90, 80, and 50% lean. Zilpaterol hydrochloride increased (P = 0.01) CSW by 6.22 kg and saleable yield by 6.4 kg when included in the diet for 20 d. Furthermore, saleable yield as a percentage of CSW was increased (P = 0.03) 1.18 percentage units when included in the diet for 20 d. Steers fed ZH for 20 d had heavier strip loins (4.47 vs. 4.12 kg, P = 0.02), tenderloins (2.75 vs. 2.49 kg, P = 0.02), and ribeye rolls (5.74 vs. 5.30 kg, P = 0.01) than steers not fed ZH. These advantages are further demonstrated as a percentage of CSW. Strip loins (P = 0.06), tenderloins (P = 0.04), and ribeye rolls (P = 0.04) of ZH-fed steers had a greater percentage of CSW than controls. Zilpaterol hydrochloride also increased the percentage of CSW of the 3 primary components of the round when fed for 20 d. The knuckle was 0.10 percentage units heavier (P = 0.11), the top round was 0.24 percentage units heavier (P = 0.04), and the bottom round was 0.22 percentage units heavier (P = 0.03) in ZH-fed steers when compared with steers not fed ZH. Based on these data, it can be concluded that ZH significantly increased sub-primal cutting weights, yields, and percentage saleable yield of calf-fed Holstein steers when fed for at least 20 d before slaughter. Zilpaterol hydrochloride increased percentage of CSW of subprimal cuts from Holstein steers in the round and to a lesser degree in the loin.

]]> D. D. Boler et al. Articles http://works.bepress.com/rdelmore/3 http://works.bepress.com/rdelmore/3 Thu, 26 Aug 2010 18:02:42 PDT The objective of these studies was to evaluate the effects of zilpaterol hydrochloride (ZH), fed for 0, 20, or 30 d, on meat quality attributes of calf-fed Holstein steers. Steers were slaughtered at a commercial facility, and carcasses were selected by HCW to represent the pen mean. Further carcass selection was based on quality grade (Choice and Select) and yield grade. Proximate composition, measures of water holding capacity, and tenderness using Warner-Bratzler shear force after 7, 14, or 21 d postmortem were evaluated on the shoulder clod (triceps brachii), top butt (gluteus medius), and strip loin (longissimus lumborum). Percentage of purge for the 3 subprimals was not different (P > 0.05) among ZH treatments. Steers fed ZH for 20 d or 30 d had decreased (P < 0.05) percentages of fat in the triceps brachii, compared with 0-d ZH. Percentage of fat was less (P < 0.05) in the gluteus medius and longissimus lumborum when steers were fed ZH for 30 d compared with those steers fed ZH for 0 d. Percentage of fat was greater in Choice triceps brachii (P < 0.05) and longissimus lumborum (P < 0.10) compared with Select. Thaw loss was not different (P > 0.05) for any muscle due to ZH treatment. Only longissimus had a greater (P < 0.05) cooking loss with ZH treatment. Cooking loss was not different (P > 0.05) for the gluteus medius or longissimus lumborum due to quality grade or aging day. At each aging day, the 20- and 30-d ZH longissimus lumborum had greater (P < 0.05) shear force values than 0 d; however, 20- and 30-d ZH had a greater absolute change in shear force from 7 to 21 d than that of 0 d ZH. Triceps brachii steaks were less tender (P < 0.05) after ZH treatment, but gluteus medius steaks were not different (P > 0.05). There was no difference (P > 0.05) in shear force due to quality grade. Results illustrate the use of ZH in calf-fed Holstein steers will have minimal effects on purge, thaw, or cooking loss. Percentage of intramuscular fat will decrease, especially when fed for longer durations. Steaks from ZH treated steers were tougher than steaks from control animals at all aging times, but ZH steaks became more tender with postmortem aging.

]]> S. F. Holmer et al. Articles http://works.bepress.com/rdelmore/2 http://works.bepress.com/rdelmore/2 Thu, 26 Aug 2010 18:02:42 PDT This study evaluated the efficacy of marination for increasing consumer acceptability of beef. Top-sirloin steaks from 28 USDA select steers were randomly assigned to one of six marination treatments: control (CT), 150 mM calcium chloride (CA), 10% solution of beef-flavoring/seasoning mixture (FL), CA and FL (CF), 2.5% sodium phosphate and FL (PF), and tap water (TW). Steaks were marinated in vacuum pouches, aged for 7 days, cooked to 70°C and evaluated by a trained sensory panel. Marination with CA did not affect tenderness ratings, but increased (P<0.05) bitter and metallic flavors compared to CT or TW treatments. Use of FL, alone or in conjunction with CA or sodium phosphate, increased (P<0.05) tenderness and juiciness ratings and reduced (P<0.05) bitterness and metallic flavors compared to CT, CA and TW marinades. Marination of beef, in vacuum pouches, is an effective method for increasing consumer acceptability and value beef.

]]> J. A. Scanga et al. Articles http://works.bepress.com/rdelmore/1 http://works.bepress.com/rdelmore/1 Thu, 26 Aug 2010 18:02:41 PDT Precooked longissimus chops and semimembranosus/adductor roasts from pigs (n = 30) given no supplemental vitamin E (CON) or supplemented with 100 mg vitamin E/kg diet (VITE) were evaluated for lipid oxidation, microbial growth, sensory characteristics, cooking/storage losses and reheating losses. Chops and roasts were vacuum packaged, precooked to 60°C and stored at 2°C for 0, 7, 14, 28, or 56 days. Lipid oxidation was lower in VITE chops and roasts than in CON chops and roasts. Off-flavor intensity scores were more acceptable and storage/ cooking losses were lower for VITE roasts than for CON roasts. Supplementation of vitamin E in a swine diet provided added protection against lipid oxidation and precooking pork under vacuum provided a palatable product with a shelf-life of 56 days.

]]> J. E. Cannon et al. Articles