Effects of Days on Concentrate Feed and Postmortem Aging on Carcass and Palatability Characteristics of Selected Muscles from Cull Beef Cows11This research was funded in part by America’s beef producers through contributions made to the Beef Checkoff

Palatability of Beef Strip Loin Steaks Following Variable Length High-Concentrate Diet Exposure Prior to Pasture-Finishing

Proximate composition, Warner-Bratzler shear force (WBSF), consumer sensory traits, fatty acid composition, and volatile flavor compounds were assessed on steaks from USDA Select strip loins (n = 40; 8/treatment) representing grass-fed beef sourced from New Zealand (NZ) with marbling consistent with USDA Select along with strip loins from four feeding treatments designed to evaluate the effects of early exposure to grain-based diets for 0 d (0D), 40 d (40D), 80 d (80D), or 120 d (120D) prior to pasture-finishing on meat quality and composition. Percent fat, moisture, and protein and WBSF did not differ (P > 0.05), but percent ash was decreased in 120D samples compared to those from NZ, 0D, and 40D (P < 0.05). Consumer scores for all traits differed among samples from the treatments (P < 0.05), with steaks from NZ receiving greater scores for flavor liking than those from 0D, 40D, and 80D (P < 0.05). Consumers also rated NZ and 120D samples greatest for overall liking (P < 0.05). Saturated fatty acids were decreased, and monounsaturated fatty acids were increased in NZ samples compared to samples from all other treatments (P < 0.05), and conjugated linoleic acid was least in samples from NZ (P < 0.05). The ratio of omega-6 to omega-3 fatty acids was greater in 80D and 120D samples than those from all other treatments (P < 0.05). Non-enzymatic browning-derived ketones and 2-pentylfuran were increased in samples from NZ compared to those from all other treatments (P < 0.05), and differences among treatments in lipid-derived compounds were primarily of alcohols and aldehydes. Early exposure to grain-based diets for 120 d prior to pasture-finishing produces beef that is comparable to grass-fed beef from New Zealand in palatability but differs in chemical composition.

Effect of days in feedlot on growth performance, carcass and meat quality attributes of Tanzania shorthorn zebu steers

A study was conducted on 50 steers (183 ± 4 kg initial body weight, 3 years of age) to assess effects of days in feedlot on performance, carcass characteristics and meat quality of Tanzania shorthorn zebu (TSZ) cattle with the aim of determining appropriate finishing period. Periods were 0 day (P0), 25 days (P25), 50 days (P50), 75 days (P75) and 100 days (P100) with 10 animals per period. Steers were housed in individual pens, fed with a concentrate diet and hay on an ad libitum basis except the P0 group which was slaughtered at the beginning of trial. Long stay in feedlot, P100, increased concentrate dry matter intake by 2 kg DM/day over short stay, P25. Final weight and total gain increased (P < 0.05) from P25 (22.6 kg) to P100 steers (95.4 kg). Periods had no influence (P > 0.05) on an average daily gain (ADG) and feed conversion ratio (FCR) but affected carcass characteristics. Empty body weight (EBW) and hot carcass weight (HCW) increased by 61 and 65 %, respectively, from no feedlot, P0 to P100. Dressing percentage was high (P < 0.05) for P100 steers. Carcass measurements, internal fat, fat thickness and carcass total fat were the highest (P < 0.05) on P100 steers and the lowest on P0 steers. Rate of pH decline increased with days in feedlot, while cooking loss and shear force values decreased in advanced ageing time. Feedlot periods of 75 and 100 days resulted into high intake, carcass measurements and tenderness, but 100 days further increased carcass fatness and fat thickness levels, thus, with this particular feeding system and animal's condition, 75 days is the recommended period to finish TSZ cattle in feedlots.

Can calcium chloride injection facilitate the ageing-derived improvement in the quality of meat from culled dairy cows?

This study investigated whether the positive effects of ageing on tenderness of meat from culled dairy cows can be facilitated by CaCl₂. Injections of 250 mM CaCl₂ solution (10% wt/wt) were performed on Longissimus dorsi samples from 32 7-yrs old cows. Samples were vacuum packaged and aged for 0, 1, 3, 5 and 7 days. Ageing alone produced lighter and less red meat with lower shear force, higher myofibrillar fragmentation and tenderness scores but also elevated lipid oxidation. For most traits investigated, CaCl₂-injected meat exhibited similar ageing effects, but drip loss increased with age. The CaCl₂-injected meat had a lower shear force and myofibrillar fragmentation increased more rapidly, but drip loss, off-flavour scores, colour stability and oxidative stability were inferior to untreated meat. Overall, it was found possible to accelerate tenderisation of such meat with CaCl₂, but only at the cost of adverse effects in some other quality traits.

Level and period of realimentation to assess improvement in body condition and carcass quality in cull ewes

Improvement in body condition was assessed in 40 cull ewes (>6 years), equally distributed in two groups and realimented with ad libitum roughage (gram straw) and two levels of concentrate feeding, i.e., 2.5 % (T(1)) of live weight (LW) and ad libitum (T(2)). Five representative animals from an initial 45 were slaughtered at the initiation of the study (0 day) and five animals from each treatment at 44, 67, and 90 days of experiment for carcass attributes. Improvement in body condition score (BCS), nutrient utilization, feed efficiency, and carcass traits were assessed at 44, 67, and 90 days. Metabolism trial of 6-day collection of feed, feces, and urine samples was conducted on five representative ewes from each group after 60 days of feeding. The level of concentrate feeding on LW gain and BCS was significant, and the duration of realimentation showed a linear improvement (P < 0.001). The digestibility and intake of dry matter, organic matter, and crude protein was higher (P < 0.05) in T(2). The N intake, absorption, and balance showed a similar trend. Increase (P < 0.05) in total N, trichloroacetic acid precipitable N, and ammonia N was observed with extension of realimentation period. Blood metabolic profile also showed improvement (P < 0.05) from an undernourished state to normal after alimentation. Animals in T(2) accumulated higher LW with minimal expenditure of metabolizable energy (73.4 vs 79.1 MJ) and higher efficiency of feed conversion during 68 to 90 days of realimentation. Linear improvement (P < 0.01) in carcass traits (preslaughter weight, empty live weight, hot carcass weight, dressing percentage, and amount of subcutaneous and intramuscular fat) and composition of longissimus dorsi muscle was observed. Ad lib concentrate supplementation for a period of 90 days may thus be considered appropriate for achieving desired efficiency of gain and improvement in body condition of cull ewes for quality mutton production.

Effect of sodium citrate plus sodium diacetate or buffered vinegar on quality attributes of enhanced beef top sirloins

As new pathogen intervention products come to market, it is important to ensure that they maintain or improve meat quality. Shelf-life and palatability traits were measured for top sirloins enhanced to 110% with solutions containing 0.5% sodium chloride and 0.4% sodium tripolyphosphate (CNT); CNT with a 1% solution of 80% sodium citrate plus 20% sodium diacetate (SC+D); or CNT with 2% buffered vinegar (VIN) in the final product. Enhancement solution did not influence color over 7days of retail display, except VIN was subjectively more red than CNT and SC+D on d 7 and SC+D had less discoloration than CNT on d 7 (P<0.05). VIN was rated lower (P<0.05) than CNT for trained sensory tenderness and there was no difference in shear force between treatments. SC+D and VIN show promise for use in beef enhancement solutions, however, further sensory studies are warranted.

Comparison of tenderness, palatability, and retail caselife of enhanced cow subprimals with nonenhanced cow and United States Department of Agriculture Select subprimals

The objective of this study was to determine the effects of enhancing cow subprimals on tenderness, palatability, and retail caselife compared with nonenhanced cow and USDA Select subprimals. Strip loin, top sirloin butt, and ribeye subprimals were selected (n = 60 per subprimal; n = 40 cow, n = 20 USDA Select). At 14 d postmortem, one-half of the cow product was randomly selected for enhancement with phosphate, salt, rosemary, potassium lactate, beef stock, ice, and water using a needle injector. All subprimals were fabricated on d 14 postmortem into ten 2.54-cm steaks. Steaks were assigned to analysis for Warner-Bratzler shear force (WBSF), trained sensory panel evaluation, or simulated retail display and assigned randomly to aging periods of 14, 21, or 28 d postmortem. Warner-Bratzler shear force values of ribeye steaks from the nonenhanced cow over all aging groups were significantly greater (P < 0.05) than enhanced cow and USDA Select ribeyes. Furthermore, top sirloin butts from nonenhanced cow had greater (P < 0.05) WBSF values at 14 and 28 d compared with other treatments. Nonenhanced cow strip loin steaks had greater (P < 0.05) WBSF values (4.58 ± 0.15 kg) and greater (P < 0.05) cook loss (20.70 ± 0.68 kg) than enhanced cow (3.90 ± 0.14 kg; 14.32 ± 0.69 kg) and USDA Select steaks (3.09 ± 0.14 kg; 15.01 ± 0.68 kg). Sensory data revealed that enhanced cow steaks from all subprimals were greater (P < 0.05) for initial juiciness for both aging periods, compared with nonenhanced cow and USDA Select. Sensory tenderness ratings for enhanced cow and USDA Select subprimals were greater (P < 0.05) than nonenhanced subprimals. Nonenhanced subprimals received the largest connective tissue amount score by panelists (P < 0.05). Enhanced cow steaks from all 3 subprimals had a greater intensity (P < 0.05) for salty flavor. Panelists detected a more intense (P < 0.05) soapy flavor in enhanced ribeyes. In ribeye and top sirloin butt steaks, grassy/cowy flavor was more intense (P < 0.05) in nonenhanced cow steaks compared with enhanced and Select. Subjective color scores revealed USDA Select ribeye and strip loin steaks aged 14 d were darker red (P < 0.05) when compared with 21- and 28-d aged steaks. Nonenhanced cow steaks from all 3 subprimals had the greatest amount (P < 0.05) of surface discoloration during display. Enhanced cow strip loins had the least (P < 0.05) L* and b* values over all aging periods, while USDA Select strip loins at 28 d had the least (P < 0.05) a* value. The USDA Select top sirloin butt steaks had the greatest (P < 0.05) b* value over all aging periods. Enhanced cow steaks were comparable with or superior to USDA Select steaks for tenderness and juiciness, but additional research is needed to determine consumer acceptability of additional flavors associated with enhancement of cow product and to improve the effects of enhancement on color of cow product.