Effects of winter stocker growth rate and finishing system on: II. Ninth-tenth-eleventh-rib composition, muscle color, and palatability

Exploring the effects of ageing on instrumental and sensory characteristics of meat from Lidia breed females: A comparative study of two commercial types

The aim of this study was to assess the influence of ageing on instrumental and sensory qualities in Longissimus thoracis et lumborum (LTL) from heifers (n = 200) and cows (n = 100) of Lidia breed. The animals were slaughtered as heifers (24-48 months) or cull cows (> 48 months). For instrumental analysis, pars Thoracis aged at 7, 14 and 28 days was used; for sensory analysis, pars Lumborum aged at 14 and 28 days was evaluated. Heifers showed redder and yellower meat (P < 0.05) and cows showed slightly higher Water Holding Capacity (WHC): Thawing Loss (TL) = P < 0.05; Drip Loss (DL) = P < 0.01; Pressure Loss (PL) = P < 0.01; Cooking Loss (CL) = P < 0.05. Ageing generated changes in meat colour, with increases in lightness (L*, linear pattern, P < 0.001) and oscillations in a* and b* (quadratic patterns; P < 0.05 and P < 0.001, respectively). Ageing affected TL (increasing, P < 0.001) and PL (decreasing, P < 0.05), and generated a significant improvement in Warner Bratzler Shear Force (WBSF) values (P < 0.001). Commercial type revealed changes in consumer panel ratings for flavour (P < 0.05), juiciness (P < 0.01), tenderness (P < 0.001) and overall acceptability (P < 0.001), with better results in these parameters for cull cows. In contrast to the usual, ageing did not affect the sensory traits. There was no significant interaction between commercial type and ageing time, except for beef flavour, which worsened with ageing (P < 0.05).

Effect of residual feed intake on meat quality in fattening Charolais bulls fed two contrasting diets

The selection of more efficient animals for breeding is of both economic and environmental interest to the industry. The aim of this study was to evaluate the influence of the animals' residual feed intake (RFI) ranking in interaction with the type of diet on the meat quality of Charolais beef cattle. Indeed, several biological mechanisms are associated with RFI, especially when animals are fed high starch-diets. It is therefore possible that quality parameters may show greater changes due to RFI in the context of high starch diets compared to high forage diets. An 84-day feed efficiency trial followed immediately by a second 112-day feed efficiency trial was conducted with a total of 100 animals fed either maize- or grass-diets for 196-days. At the end of the 84-day period, the 32 most divergent RFI animals (16 extreme RFI animals per diet, 8 RFI+ and 8 RFI-) were identified. They were slaughtered after 112-days of finishing. The Longissimus thoracis was characterised in terms of nutritional and sensory quality. RFI had no effect on lab colour, muscle shear force, total fat, fatty acid ratios and most of the total fatty acid content (especially n-3) irrespective of the diet. However, more efficient animals (RFI-) showed higher CLA contents compared to less efficient animals (RFI+) regardless of the diet and also a lower n6/n3 ratio only in animals fed the maize diets. Diet also had a significant effect on lipid and FA content as well as on FA composition.

Evaluation of a Saccharomyces cerevisiae Fermentation Product on the Feedlot Performance and Carcass Merit of Hair Lambs Offered an Annual Ryegrass-Hay-Based Finishing Diet: A Pilot Study

Hair sheep production has increased in recent years, which has resulted in an increased presence in feedlots. Additionally, grass-based finishing systems for ruminant animal production have increased. Data are limited for finishing hair lambs on diets based on cool-season hay. The objective was to evaluate a Saccharomyces cerevisiae fermentation product (SCFP) on the feedlot performance and carcass characteristics of Katahdin lambs offered an annual ryegrass (Lolium multiflorum)-hay-based diet. Twenty-four Katahdin lambs (21.5 ± 2.5 kg BW) were assigned to either the control (CON) or the yeast-supplemented group (SCFP) in a completely randomized design. Lambs were offered a 14% crude protein total mixed ration diet based on annual ryegrass hay. The SCFP group also received the yeast supplement in their diet. Lambs in the SCFP group had a higher final body weight (p < 0.01) and ADG (p = 0.01). Less maximum and total energy were required to cut SCFP lamb meat compared to CON lamb meat (p < 0.03). Results from this study indicated that SCFP supplementation may prove to be beneficial in hair lamb finishing diets. Future research will need to specifically evaluate the use of these products in hair lambs with a larger sample size.

Contribution of intramuscular connective tissue and its structural components on meat tenderness-revisited: a review

The tenderness of meat influences consumers' perceptions of its quality. Meat tenderness is a key quality characteristic that influences consumer satisfaction, repeat purchases, and willingness to pay higher prices for meat. Muscle fibers, connective tissues, and adipocytes are the main structural components of meat that contribute to its tenderness and texture. In the present review, we have focused on the role of connective tissue and its components in meat tenderness, specifically perimysial intramuscular connective tissue (IMCT) and its concept as an immutable "background toughness." The collagen contribution to cooked meat toughness can be altered by animal diet, compensatory growth, slaughter age, aging, and cooking. As well, progressive thickening of the perimysium leads to a progressive increase in shear force values in beef, pork, chicken, and this may occur prior to adipocyte formation as cattle finish in feedlots. Conversely, adipocyte accumulation in the perimysium can decrease cooked meat shear force, suggesting that the contribution of IMCT to meat toughness is complex and driven by both collagen structure and content. This review provides a theoretical foundation of information to modify IMCT components to improve meat tenderness.

Comparing consumer liking of beef from three feeding systems using a combination of traditional and temporal liking sensory methods

Research on the effects of animal diet on consumer liking of beef has yielded conflicting results. Currently it is unknown whether dynamic changes occur in liking during consumption of beef. This study applied a combination of traditional and temporal (free and structured) liking methods to determine consumer liking of beef derived from animals that were fed grain (GF), grass silage plus grain (SG) or grazed grass (GG) during finishing. Three separate panels of beef eating consumers (n = 51; n = 52; n = 50) were recruited from Teagasc Food Research Centre, Dublin, Ireland to assess striploin steaks from animals fed either GF, SG, or GG. Using the free temporal liking (TL) method, results revealed that beef from GF animals was liked significantly less (p ≤ 0.05) in terms of overall liking, tenderness and juiciness, when compared to steaks from the SG and GG animals. These effects were not observed using the structured TL or traditional liking methods. Further analysis showed the evolution of scores over time was significant (p ≤ 0.05) for all attributes using the free TL method. Overall, the free TL method yielded more discriminative data and was perceived as easier to perform by consumers compared to the structured TL method. These results show that the free TL method may provide an opportunity to elicit more in-depth information regarding consumer sensory response to meat.

Characterization of Four Rearing Managements and Their Influence on Carcass and Meat Qualities in Charolais Heifers

The study aim was to identify the effects of the rearing management applied throughout the heifers’ life on the carcass (e.g., conformation, marbling, fat) and meat (color, texture, and sensory profiles) properties. From the individual data of 171 heifers from 25 commercial farms, a typology of four rearing managements was established from 50 rearing factors. The managements had an effect on the conformation, the color (fat and muscle), and the rhomboideus grain meat, for the carcass, and the lightness, the atypical flavor, and the overall acceptability for the longissimus (LM) meat. The carcass traits compared to the meat were more sensitive to a change of rearing management. Our results confirmed that it was possible to target the same carcass or meat quality from different managements. Moreover, according to the aims of the targeted carcass and LM meat quality, management 3 could be an interesting trade-off to jointly manage the quality of both products. For example, the carcasses that were produced had a high conformation, smooth meat grain and the LM meat was more liked. This management was intermediate compared to the other rearing managements and had a long fattening period with a diet mainly based on conserved grass and a high concentrate quantity.

Fatty Acid Composition of Grain- and Grass-Fed Beef and Their Nutritional Value and Health Implication

Beef contains functional fatty acids such as conjugated linoleic acid and long-chain fatty acids. This review summarizes results from studies comparing the fatty acid composition of beef from cattle fed either grass or grain-based feed. Since functional lipid components are contributed through dietary consumption of beef, the fatty acid composition is reported on mg/100 g of meat basis rather than on a percentage of total fat basis. Beef from grass-fed contains lesser total fat than that from grain-fed in all breeds of cattle. Reduced total fat content also influences the fatty acid composition of beef. A 100 g beef meat from grass-fed cattle contained 2,773 mg less total saturated fatty acids (SFA) than that from the same amount of grain-fed. Grass-fed also showed a more favorable SFA lipid profile containing less cholesterol-raising fatty acids (C12:0 to C16:0) but contained a lesser amount of cholesterol-lowering C18:0 than grain-fed beef. In terms of essential fatty acids, grass-fed beef showed greater levels of trans-vaccenic acid and long-chain n-3 polyunsaturated fatty acids (PUFA; EPA, DPA, DHA) than grain-fed beef. Grass-fed beef also contains an increased level of total n-3 PUFA which reduced the n-6 to n-3 ratio thus can offer more health benefits than grain-fed. The findings signify that grass-fed beef could exert protective effects against a number of diseases ranging from cancer to cardiovascular disease (CVD) as evidenced by the increased functional omega-3 PUFA and decreased undesirable SFA. Although grain-fed beef showed lesser EPA, DPA, and DHA, consumers should be aware that greater portions of grain-fed beef could also achieve a similar dietary intake of long-chain omega-3 fatty acids. Noteworthy, grain-fed beef contained higher total monounsaturated fatty acid that have beneficial roles in the amelioration of CVD risks than grass-fed beef. In Hanwoo beef, grain-fed showed higher EPA and DHA than grass-fed beef.

Influence of beef genotypes on animal performance, carcass traits, meat quality, and sensory characteristics in grazing or feedlot-finished steers

A 2-yr study was conducted to evaluate the effects of beef genotypes and feeding systems on performance, carcass traits, meat quality, and sensory attributes. A 2×2 factorial experiment was used to randomly allocate 60 steers in year 1 (YR1) and 44 steers in year 2 (YR2). The two beef genotypes evaluated were Red Angus (RA), and RA x Akaushi (AK) crossbreed. The steers were allotted to two finishing feeding systems: grazing, a multi-species forage mixture (GRASS) and feedlot finishing, conventional total mixed ration (GRAIN). All steers were slaughtered on the same day, at 26 and 18 mo of age (GRASS and GRAIN, respectively), and carcass data were collected 48 h postmortem. Growth and slaughter characteristics were significantly impacted by the finishing system (P < 0.01), with the best results presented by GRAIN. Beef genotype affected dressing percent (P < 0.01), ribeye area (P = 0.04), and marbling score (P = 0.01). The AK steers had a tendency (P = 0.09) for lower total gain; however, carcass quality scores were greater compared to RA. There was a genotype by system interaction for USDA yield grade (P < 0.01), where it was lower in GRASS compared to GRAIN in both genotypes, and no difference was observed between the two genotypes for any GRASS or GRAIN systems. There was no difference in meat quality or sensory attributes (P > 0.10) between the two genotypes, except that steaks from AK tended to be juicier than RA (P = 0.06). Thawing loss and color variables were impacted by the finishing system (P < 0.01). L* (lightness) and hue angle presented greater values while a* (redness), b* (yellowness), and chroma presented lower values in GRAIN compared to GRASS. Sensory attributes were scored better in GRAIN than GRASS beef (P < 0.01). There was a genotype by system interaction for flavor (P = 0.02), where beef from RA had a lower flavor rating in GRASS than in GRAIN, and no difference was observed for AK. Within each system, no difference was observed for flavor between RA and AK. Beef from steers in GRASS had greater (P < 0.01) WBSF than those from GRAIN. These results indicate that steers from GRAIN had superior performance and carcass merit and that AK enhanced these traits to a greater degree compared to RA. Furthermore, the beef finishing system had a marked impact on the steaks’ sensory attributes and consumer acceptability. The favorable results for texture and juiciness in GRAIN, which likely impacted overall acceptability, may be related to high marbling.

Carcass and meat quality of young Angus steers with different growth potential finished exclusively grass-fed or corn supplemented

Beef cattle production has a large variety of systems with different performance and technology levels. This study compared young Angus steers carcass and meat quality traits of high growth potential early-finished animals fed exclusively on pasture with low growth potential late-finished animals. Besides the grazed forage, the low growth potential group received corn grain at 0.8% of their body weight right after the slaughtering of the first group. Following weaning, the 20 steers grazed pastures composed of oat, ryegrass, and clovers. At winter's onset, animals were moved to native pastures improved with fescue and clovers. The supplemented period of late steers began when the first group of ten early-finished animals reached the requirements for slaughter. Supplementation ended when the animals got the slaughter requirements. The high growth potential steers showed a ribeye area (P < 0.0001) and a Longissimus muscle width highly significantly (P < 0.0001) superior to the low growth group. However, corn-supplemented animals showed better dressing percentage (P < 0.0001), subcutaneous fat thickness (P < 0.0001), marbling (P < 0.0001), and muscle (P = 0.0033) scores, but lower shear force (P = 0.0001). The finishing system did impact fat lightness (L*; P = 0.0234) at the slaughter time. Grass-fed animals showed higher red-green color parameter (a*) values than corn supplemented on fat at 24 h (P = 0.0439) but lower hue angle (P = 0.0418). The consumer panel showed better results for tenderness and general acceptability for supplemented animals beef compared to grass-fed. The supplementation resulted in a higher carcass standardization. It also provided higher PUFA: MUFA and n-6: n-3 ratios, and a higher amount of n-3. Supplemental corn grain did not have adverse effects upon the beneficial effects to human health of the grass-fed beef.

Impact of Feeding Cover Crop Forage Containing Brassicas to Steers during Backgrounding on Palatability Attributes of Beef Strip Steaks

Brassica cover crops have been widely used for improving soil health and as a feed resource for grazing cows, but their use in backgrounding diets is unknown. The objective of this study was to determine the impact of feeding a brassica cover crop mixture during backgrounding on beef palatability. Thirty steers were assigned to one of two dietary treatments during backgrounding with (1) ad libitum access to freshly cut brassica cover crop forage (CC) containing radish, turnip, rapeseed, and rye grass, or (2) common Midwestern dry lot backgrounding diet (CON). The steers were transitioned to a common finishing diet after backgrounding. Striploins were collected after harvest, and were analyzed for evaluation of the Warner–Bratzler shear force (WBSF), collagen content, autolysis of calpain-1, proteolysis of desmin, and troponin-T; in addition, the tenderness, juiciness, and flavor evaluated by a trained sensory panel. A treatment x day interaction was observed for WBSF (p = 0.02). Steaks from the CON diet were less tender than CC steaks on days 3 and 7, but did not differ on days 14 and 21. Feeding a brassica mixture cover crop during the backgrounding phase of production did not impact the collagen content, autolysis of calpain-1, or proteolysis of desmin and troponin-T. Thus, additional investigation into the mechanisms responsible for the differences observed in instrumental tenderness is warranted.

Influence of Grain- and Grass-Finishing Systems on Carcass Characteristics, Meat Quality, Nutritional Composition, and Consumer Sensory Attributes of Bison

The objective of this study was to determine the influence of two finishing systems (grain- or grass-finishing) on carcass characteristics, meat quality, nutritional composition, and sensory attributes of bison. Bison heifers were assigned to either a grain- or grass-finishing treatment for 130 days prior to slaughter. Carcass measurements, lean color and fat color were recorded. Striploins (M. longissimus lumborum) were collected for analysis of pH, fatty acid profile, cholesterol, proximate analysis, Warner-Bratzler shear force, cook loss, and consumer sensory evaluation. Grain-finished bison heifers had greater (p < 0.01) hot carcass weights, dressing percentage, ribeye area, backfat, and marbling scores compared to grass-finished heifers. Instrumental color values (L*, a*, b*) of the ribeye and a* value of backfat opposite the ribeye were greater (p < 0.01) for grain-finished heifers. Steaks from grain-finished heifers had increased (p < 0.05) crude protein and fat content and decreased (p < 0.01) moisture compared to grass-finished heifers. The grain-finishing system produced steaks with increased (p < 0.01) cholesterol and total fatty acids (mg/g of wet tissue). The grain-finished system produced more tender (p < 0.05) steaks, but consumer sensory ratings did not differ (p > 0.10) between treatments. These data indicate that finishing systems influence bison carcass characteristics, nutritional composition, and meat quality, but do not translate to differences in consumer preferences.

Effects backgrounding-finishing programs of different age/weight at harvest of feedlot steers

Four ages at harvest (HA: A15, A18, A24 and A30 for 15, 18, 24 and 30 months, respectively) were compared in performance, carcass and meat traits of feedlot finished steers over a 123-day period. Three meat aging periods (postmortem days: 2, 7 and 14) were imposed on a longissimus thoracis muscle (LM) section of each left carcass. Feed efficiency (FE) was greater (P ≤ 0.02) for A15 and A18. Treatment A30 had the lowest FE (P ≤ 0.02). The LM area was largest for A30, but no different (P = 0.15) from A24. Intramuscular fat was lowest (P < 0.01) for A15. No differences were detected (P ≥ 0.11) among the A18, A24 and A30. Treatment A30 had the highest rib fat thickness (P ≤ 0.02) and WBsf values. No differences were detected (P ≥ 0.25) in WBSf between A15, A18 and A24 after any aging period. Results suggested A24 as a threshold for carcass and meat traits.

Meat and sensory eating quality of loin steaks from cattle slaughtered at different ages as a result of short, medium or long finishing systems

Context In the belief that feed costs and use of cereal grains are reduced, production systems based on grazed and conserved forage in which cattle are slaughtered at 30 to 36 months of age are increasingly advocated. Aims As there is a scarcity of information concerning meat quality traits of beef from such extended rearing systems, three finishing systems of different lengths (Short, 14–16 months; Medium, 20–24 months; Long, 31–34 months) were compared in which cattle were slaughtered at similar conformation and fat classification scores. Methods The experiment comprised a three (system) × two (gender) design with 24 Limousin cross-bred cattle (12 steers and 12 heifers) assigned to each system. Characteristics of the rib section (between and inclusive of the 5th and 10th ribs) and sensory properties of M. longissimus thoracis samples were then assessed. Key results Older (Long system) cattle had greater rib section and L. thoracis weights. L. thoracis was tougher in older (Long system) cattle when assessed by a trained sensory panel. Heifers had lower rib section weights than steers but neither rib section composition or meat toughness differed between genders. Gristle (visible connective tissue) in the rib section increased with system length and was associated with an increased perception of gristle on eating. Conclusions Overall meat quality was considered commercially acceptable regardless of system. Implications The likely increased greenhouse gas emissions but reduced utilisation of food resources from the Long system need to be considered in conjunction with the meat quality characteristics of the system.

Longissimus Muscle Composition and Palatability of Grazing Steers Supplemented with Corn Oil or Corn Grain

Twenty-eight Angus (289 ± 3.8 kg) steers were used to evaluate the effect of isocaloric supplementation of 2 different energy sources to steers grazing tall fescue pastures for 197 d on longissimus muscle fatty acid profile, shear force, tenderness and color. Steers were supplemented with either corn grain (PC) or soybean hulls plus corn oil (PO). A negative control, pasture only (PA), and positive control, high-concentrate control diets (CONC) were also included in the study. Total trans-11 vaccenic acid (TVA) and cis-9, trans-11 CLA content per serving were similar with PA, PC and CONC and greatest with PO (P < 0.001). Muscle total fatty acids, myristic and palmitic contents per serving were similar with PC, PO, and PA and greatest with CONC (P < 0.001). Muscle PUFA n-6:n-3 ratio was greater with PC than with PA and lower with PC than with CONC, but it was greatest with PO (P < 0.001). Shear force was lower (P = 0.046) with CONC than with PA and PC; beef from PO did not differ from any of the other treatments. Sensory panel scores for overall tenderness (P < 0.001) were greatest with CONC, greater with PO than with PC, and similar with PA than with PO and PC. Muscle lightness was similar for PO and PC, greater with PO and PC than with PA and lower with PO and PC than with CONC (P < 0.001). Treatment by time postmortem interaction was significant for muscle temperature (P < 0.001), but not for muscle pH (P = 0.79). Temperature decline was fastest with PA and slowest with CONC. Postmortem muscle pH was greater with PA, PC, and PO than with CONC (P = 0.011). Overall, fatty acid profile with PC was closer to the fatty acid profile with PA than that with PO or CONC. Finishing systems altered fat deposition, which impacted chilling rate, muscle color and palatability.

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.

Using 19% of alfalfa hay in beef feedlot finishing diets did not modify meat quality but increased feed intake and ADG1

To evaluate the effects of including extra alfalfa hay (AH) in high-concentrate diets fed to beef heifers on intake, ADG, G:F, and carcass and meat quality, we used 24 Simmental heifers (initial BW 235.6 ± 4.19 kg). Heifers were blocked in four BW blocks and allotted in groups of 3 in a randomized block design with 2 treatments and 12 heifers per treatment. Treatment diets offered as total mixed ration (TMR) were (i) TMR with 10% barley straw (BS), considered the control diet, and (ii) TMR with 19% AH. The experiment was performed over four 28-d experimental periods, and we took measurements in the last week of each period. After this period of performance control, heifers were fed the corresponding diet until each BW block reached the target weight of 400 kg on average. Feed intake and ADG were greater for AH than BS (9.5 vs. 8.4 kg/d, and 1.45 vs. 1.29 kg/d, respectively; P < 0.05), but G:F was unaffected by diet (P > 0.10). Diet did not affect HCW, dressing percentage, backfat color, pH and meat color, or carcass grade. The sixth rib was dissected to determine the proportion of fat, lean, and bone, which were unaffected by diet. Diet did not affect the LM composition in water, protein, collagen, intramuscular fat, and cholesterol. The intramuscular fat proportion of C18:1 n-7 was greater in BS than in AH (P = 0.016), whereas the proportion of C18:3 n-3 tended to be greater in AH than in BS (P = 0.09). When fatty acid concentration was expressed as gram per 100 g of LM, these differences disappeared, and only the content of C15:0 tended to be greater (P = 0.08) in BS than in AH. Meat characteristics evaluated by trained panelists did not differ in toughness, chewiness, juiciness, odor, taste, and overall acceptability, and there were no differences between diets in Warner-Bratzler shear force values after 3 or 10 d of aging (P > 0.10). In summary, heifers fed TMR with AH at 19% of inclusion showed a greater feed intake and ADG than those fed BS at 10% of inclusion, but without affecting G:F ratio. However, this extra AH was not sufficient to cause any relevant change in the carcass and meat quality of the heifers fed this diet.

Performance, carcass and meat quality traits of grazing cattle with different exit velocity

To evaluate the effect of grazing cattle temperament on performance, as well as carcass and meat quality traits, exit velocity (EV) was assessed throughout two production cycles (PC1, n = 38 and PC2, n = 52). Individual EV determinations were assessed throughout each PC and then 100-days period averages were calculated for each animal. Animals were ranked based on their EV (EV-RANK) in the first 100-days period as SLOW, FAST and MEDIUM. The EV decreased from weaning to slaughter in FAST and MEDIUM (P &lt; 0.05); but did not change in SLOW (P &gt; 0.10). Initial liveweight was lowest in FAST and highest in MEDIUM (P = 0.03). DM intake (P = 0.08) and average daily gain (P = 0.94) were not affected by EV-RANK, but carcass subcutaneous fat thickness was lowest in FAST and highest in MEDIUM (P = 0.02). Longissimus muscle colour and shear-force were not affected by EV-RANK (P &gt; 0.05), but muscle glycogen content at slaughter was higher in MEDIUM than in SLOW or FAST (P = 0.047). No EV-RANK effects were observed in the present study on meat colour and shear-force. However, its effects on subcutaneous fat thickness and muscle glycogen could result in low meat quality of temperamental cattle under more stressful handling situations.

Timing of Exposure to High-Concentrates versus High-Quality Forages on Growth and Marbling Deposition in Steers

Forty Angus-cross steers (280 ± 21.4 kg BW, 8 mo.) were used to examine the effects of exposure to 2 diets [high concentrate diets (CONC) versus high quality forages (FOR)] during 2 time periods [early (EARLY; at 30-d post weaning) or late (LATE; just prior to slaughter)] on animal growth, marbling deposition and tenderness. Steers were blocked by weight and randomly assigned to four dietary treatments: 1) CONC-FOR, 2) CONC-CONC, 3) FOR-CONC, or 4) FOR-FOR. Exposure to CONC during the EARLY or LATE period increased (P < 0.05) growth and fat deposition compared to FOR-FOR. Hot carcass weight was greater (P < 0.05) for CONC-CONC and FOR-CONC steers than FOR-FOR and CONC-FOR due to changes in dressing percent. Marbling score was greater (P < 0.05) for CONC-CONC and CONC-FOR compared to FOR-FOR. Exposure to CONC during the EARLY period (CONC-FOR and CONC-CONC) increased (P < 0.05) n-6 polyunsaturated fatty acids (PUFA) deposition in longissimus muscle (LM) and subcutaneous adipose tissue (SQ); whereas, exposure to CONC during the LATE period (CONC-CONC and FOR-CONC) reduced (P < 0.05) n-3 PUFA, trans-11 octadecenoic acid and cis-9 trans-11 isomer of conjugated linoleic acid (CLA). Warner-Bratzler shear force at d 2 and 7 of postmortem aging in ribeye steaks from CONC-CONC and FOR-CONC was greater (P < 0.05) than FOR-FOR and CONC-FOR. Lipogenic gene expression was up-regulated (P < 0.05) and lipolytic gene expression was downregulated (P < 0.06) in SQ from CONC-CONC and FOR-CONC compared to FOR-FOR. Overall, exposure to CONC in both periods increased growth rate and marbling deposition but LATE exposure had the greatest impact on adipose lipogenesis and lipolysis, fatty acid composition, and tenderness.

Ruminant meat flavor influenced by different factors with special reference to fatty acids

Ruminant meat flavor is an important quality and sensory parameter which relays mainly on the organoleptic characteristics of meat. Meat flavor is vital factor for the palatability and acceptability of meat by the consumers. There are various intrinsic and extrinsic factors that influence eating quality of meat. Among these factors, flavor is the major contributor. Fat and low-molecular-weight water-soluble compounds are the most important precursor components in meat, responsible for the meat flavor. The present review focus on the different pre and post-harvest factors that influences the ruminant meat flavor. Raw meat has little flavor but cooking adds value in flavor due to different temperature and cooking methods. The volatile flavoring compounds which are responsible for cooked meat flavor are produced thermally by the Maillard's reaction itself or interaction with lipid oxidation products and vitamin degradation. In nutshell, this review provides perception into previous literature on flavor that affected by various factors particularly the fatty acids and cooking methods.

Honduran and U.S. Consumer Assessment of Beef from Various Production Systems with or Without Marinating

Our objective was to evaluate the effects of different Honduran cattle production systems, enhancement, and country of origin on palatability of the longissimus muscle aged 21 d postmortem as determined by U.S. and Honduran consumers (n = 240/country). U.S.-sourced strip loins (n = 10/treatment) were selected: USDA Select (SE) and Top (upper 2/3) Choice (TC). Honduran-sourced strip loins (n = 10/treatment) included: 1) dual-purpose bulls, raised on native pasture (HDP), 2) F1 crossbred Brahman bulls finished on a corn-based grain diet for 180 d (HCF), and 3) purebred Brahman bulls finished on a sugarcane-based diet for 180 d (HSC). Ten additional strip loins from each Honduran treatment were selected and enhanced (E; 112% ± 3.5%) with water, salt, and tripolyphosphate, resulting in EHDP, EHCF, and EHSC. Steaks were cooked to 77°C prior to consumer evaluation of tenderness, juiciness, and flavor and overall liking, with classification of each trait as acceptable or unacceptable. Consumers indicated if they were willing to pay 0, 3, 6, or 10 USD/0.45 kg. Consumer data were analyzed using the GLIMMIX procedure of SAS as a split plot design, with treatment as the whole plot factor and country and the country × treatment interaction as the subplot factors, including panel as a random effect. The EHCF had greater (P &lt; 0.05) scores for tenderness, juiciness, flavor and overall liking. No differences (P &gt; 0.05) were found between TC and SE when scoring palatability traits, but more (P &lt; 0.05) consumers found TC acceptable for juiciness compared to SE. Honduran consumers ranked all palatability traits greater than U.S consumers and found a greater percentage of samples acceptable for tenderness (P &lt; 0.05). Enhancement of Honduran treatments had a positive effect on palatability traits, as well as the acceptability of those traits. Regardless of the differences in breeds, using high-energy diets and enhancement resulted in greater palatability scores.

Physico-chemical and sensory characteristics of young dairy bull beef derived from two breed types across five production systems employing two first season feeding regimes

BACKGROUND

The present study aimed to assess the physico-chemical and sensory characteristics of Longissimus thoracis muscle from young dairy bulls: Holstein-Friesian (HF) and Jersey × Holstein-Friesian (JEX). Bulls slaughtered at 15 months of age differed with respect to the finishing system, whereas 19-month-old bulls differed in energy consumption during a second grazing season and finishing period. All bulls were offered different diets during the first grazing season.

RESULTS

Insoluble and total collagen contents increased with slaughter age, whereas collagen solubility and hue angle reduced with age. Bulls fed a higher concentrate finishing diet held a longer beef flavour. Intramuscular fat (IMF) content and beef flavour score were enhanced by higher concentrate intake during the second season and finishing period. Beef from a higher forage diet displayed a more intense red colour and higher thawing loss. There was limited effect of silage finishing or first and second grazing season on quality traits. Beef from JEX breed had a higher IMF content, higher flavour, juiciness and texture-related scores while lower moisture content compared to HF beef.

CONCLUSION

The eating quality of beef from young dairy bulls was generally good. Slaughter age and the energy level of diet had obvious effects on quality characteristics. Cross-breeding Jersey with the HF breed can improve the beef quality of young dairy bulls. © 2017 Society of Chemical Industry.

TRIENNIAL GROWTH AND DEVELOPMENT SYMPOSIUM: Dedifferentiated fat cells: Potential and perspectives for their use in clinical and animal science purpose

An increasing body of evidences has demonstrated the ability of the mature adipocyte to dedifferentiate into a population of proliferative-competent cells known as dedifferentiated fat (DFAT) cells. As early as the 1970s, in vitro studies showed that DFAT cells may be obtained by ceiling culture, which takes advantage of the buoyancy property of lipid-filled cells. It was documented that DFAT cells may acquire a phenotype similar to mesenchymal stem cells and yet may differentiate into multiple cell lineages, such as skeletal and smooth muscle cells, cardiomyocytes, osteoblasts, and adipocytes. Additionally, recent studies showed the ability of isolated mature adipocytes to dedifferentiate in vivo and the capacity of the progeny cells to redifferentiate into mature adipocytes, contributing to the increase of body fatness. These findings shed light on the potential for use of DFAT cells, not only for clinical purposes but also within the animal science field, because increasing intramuscular fat without excessive increase in other fat depots is a challenge in livestock production. Knowledge of the mechanisms underlying the dedifferentiation and redifferentiation of DFAT cells will allow the development of strategies for their use for clinical and animal science purposes. In this review, we highlight several aspects of DFAT cells, their potential for clinical purposes, and their contribution to adipose tissue mass in livestock.

A Contribution of Beef to Human Health: A Review of the Role of the Animal Production Systems

Meat and meat products constitute important source of protein, fat, and several functional compounds. Although beef consumption may implicate possible negative impacts on human health, its consumption can also contribute to human health. Quality traits of beef, as well as its nutritional properties, depend on animal genetics, feeding, livestock practices, and post mortem procedures. Available data show that emerging beef production systems are able to improve both, quality and nutritional traits of beef in a sustainable way. In this context, Argentina's actions are aimed at maximising beef beneficial effects and minimising its negative impact on human health, in a way of contributing to global food security.

Supplemental β-carotene I: effect on plasma vitamin A, growth, performance, and carcass characteristics of feedlot cattle

To evaluate the effects of β-carotene (βC) on performance and carcass characteristics, 112 crossbred calves were allotted to 4 treatments consisting of retinyl palmitate (RP) supplemented at 2200IU/kg, and synthetic β-carotene supplemented at 1 (SβC1X), 5 (SβC5X), or 10 (SβC10X) times RP. Compared to RP, SβC1X did not impact performance (P≥0.25) or plasma concentrations of retinoids or carotenoids (P≥0.26). Increasing dietary βC increased (P≤0.04) plasma concentrations of RP and all of the isomers of βC, but did not affect weight, gain, or gain:feed (P≥0.24). Marbling and fat thickness did not differ between RP and SβC1X or because of amount of βC (P≥0.35). Lightness (L*) of LM decreased with increasing concentration of SβC (linear; P=0.01). Yellowness (b*) increased (P=0.04) and redness (a*) tended to increase (P=0.09) in subcutaneous fat as SβC amount increased (quadratic).

Southern Section Interdisciplinary Beef Cattle Symposium: Carryover effects of stocker cattle systems on feedlot performance and carcass characteristics

Stocker cattle production practices may affect subsequent performance of cattle in economically meaningful ways. Literature was reviewed to summarize possible carryover effects of stocker cattle management on finishing performance and carcass traits. The most consistent effects of stocker phase practices on finishing-phase and carcass performance of cattle appear to be explained by changes in placement weight of feeder cattle. Increasing placement weight typically is confounded with age at placement, ADG during stocker period, and duration of the stocker period. It may also be confounded with other factors, such as season of grazing and/or finishing. Data from studies comparing calf-fed to yearling-fed cattle indicate that as age or BW at feedlot entry increased, finishing ADG, DMI, and HCW increased (P<0.01) whereas G:F and days on feed decreased (P<0.01). As age and BW at feedlot entry increased, marbling score decreased (P<0.01) whereas Warner-Bratzler shear force increased (P<0.01). Studies with yearling cattle entering the feedyard after a forage-based backgrounding phase indicate that as backgrounding ADG increased, finishing ADG, DMI, and days on feed decreased (P<0.01) yet HCW and ribeye area increased (P<0.01) with no effect (P=0.45) on marbling. Stocker cattle systems are complex, integrated systems in which producers typically seek to maximize their own economic return with little regard for subsequent performance. If cattle are owned across both stocker and finishing phases of production, then management decisions should focus on maximizing return over the entire ownership period and not just within one segment of ownership. Of the traits of feeder cattle that can be affected by stocker cattle systems, BW is the primary determinate of their value when they are placed into commercial feedyards.

Effects of the forage content of the winter diet on the growth performance and carcass quality of steers finished on mountain pasture with a barley supplement

Eighteen Parda de Montaña steers (366 kg liveweight, 10 months of age) received diets of either forage (F; lucerne hay + straw) or forage and concentrate (FC; lucerne hay + straw + barley) during the winter feeding period, which lasted 118 days. Thereafter, steers continuously grazed in meadows in a dry mountain area until the end of the grazing period in September (160–167 days) and received 4.1 kg DM barley per head for the final 103–110 days of the grazing season. The steers that received the FC winter diet were heavier (491 vs 457 kg, respectively; P < 0.05) and had deposited more fat (7.2 vs 5.8 mm, P < 0.05) and muscle (63 vs 54 mm, P < 0.05) at the end of the winter than the steers that received the F winter diet. During the grazing period, the steers from both groups had similar weight gains (0.728 and 0.756 kg/day for FC and F diet, respectively). At slaughter, the steers from both groups were of similar age (590 vs 599 days, for FC and F diet, respectively) and had similar liveweights (560 vs 539 kg), muscle depths (54 vs 63 mm) and subcutaneous fat thicknesses (7.3 vs 7.2 mm). The serum leptin concentration differed only at the end of the winter period, when steers on the FC diet had higher leptin concentrations than did steers on the F diet (P < 0.05), reflecting differences in fatness. The carotenoid concentration in the plasma during the winter feeding period was higher in steers on the F than on the FC winter diet, but this difference was not seen during the grazing period. Carcasses from steers on the FC winter diet were heavier (324 vs 300 kg; P < 0.05) and had a higher dressing percentage (57.3% vs 56.1%, P < 0.05) than those reared on the F winter diet, but the fatness and conformation scores were similar between the groups. The percentages of fat, muscle and bone in the commercial dissection and 10th rib dissection did not differ between the winter diet groups. In conclusion, the differences resulting from the winter feeding period disappeared after the grazing period, and the carcass quality did not differ between the diets. Therefore, both strategies are equally technically advisable.

Effects of backgrounding and finishing growth rates on P8 fat and intramuscular fat in Bos taurus steers

The present study investigates the effects of backgrounding and finishing growth rates of Bos taurus steers grown out on three post-weaning growth pathways, across 4 years (1995–1998) on fat deposition. Scanned P8 fat at backgrounding exit (SP8exit), scanned P8 fat before slaughter (SP8sla) and carcass intramuscular fat (IMF, %) were evaluated. Four equations to predict SP8sla and four equations to predict carcass IMF across years were developed. Three post-weaning growth pathways (GPs) generated by different nutritional treatments across years were used in the study. Growth pathways were created by backgrounding steers on pasture with no supplementation (GP1), pasture plus supplementary feeding formulated pellets (GP2) or pasture with access to a forage crop (GP3). The steers were then finished in a feedlot or on pasture to slaughter weights of 520 kg (Korean market specification) or 600 kg (Japanese market specification). Cubic smoothing splines were fitted to the liveweight of all animals from the start of backgrounding until slaughter. Backgrounding growth rates were interpolated off the GP curves and the mean average daily gain (ADG, kg/day) at Day 100 (D100, Days 100–91 before relocation to the finishing phase), and Day 150 (D150, Days 150–141 before relocation to the finishing phase) were calculated. Significant (P < 0.01) differences between SP8exit and backgrounding ADG (BADG) were detected in all years except GP2 v. GP3 in 1997. GP1 steers had the lowest BADG across all years, ranging from 0.39 to 0.88 kg/day. At backgrounding exit, the mean SP8exit for the different GPs was ranked, with GP1 < GP3 for all years, with significant (P < 0.01) differences among GP1, GP2 and GP3 in all years except 1996. At the end of finishing, the mean carcass IMF over all years and finish (pasture and feedlot) (P < 0.05) was 4.71% for GP1 v. 5.09% for GP3 for Korean market steers and the mean SP8sla (P < 0.01) was 14.59 mm for GP1 v. 16.04 mm for GP3 and the mean carcass IMF (P < 0.01) was 5.54% for GP1 v. 6.27% for GP3 for Japanese market steers. The residual correlation of the multivariate response variables, namely, D100, D150 and BADG v. SP8exit (n = 1054), SP8sla (n = 1049) and carcass IMF (n = 1002), indicated that the highest correlations, all significant (P < 0.01), were 0.33, 0.20 and 0.12 for BADG v. SP8exit, SP8sla and carcass IMF, respectively. The residual variances (mm2) of the four SP8sla equations were 6.14, 7.44, 8.72 and 10.73 for 1995, 1996, 1997 and 1998, respectively, and the residual variances (%2) for the four carcass IMF equations were 2.51, 2.26, 1.75 and 0.84, for 1995, 1996, 1997 and 1998, respectively.

Effect of feeding treatment during the backgrounding phase of beef production from pasture on: I. Animal performance, carcass and meat quality

This research evaluated effects of feedlot backgrounding on 40, 70 or 100% alfalfa hay diets (40 hay, 70 hay; 100 hay, respectively) or pasture grazing (Pasture) before pasture finishing, on performance and beef characteristics of Angus heifers. Ninety six female calves were allocated to the four feeding strategies. Backgrounding took place during 114 days and subsequent pasture finishing over 132 days. Heifers of each strategy were slaughtered after 114 days (end of the feedlot period) and at end of the study when all remaining animals were finished on pasture. Effects of backgrounding were associated with rate of gain. Backgrounding strategies 40 hay and Pasture resulted in the best performance. Beef attributes were similar. At the end of the feedlot period, 100 hay was smaller and leaner, less tender and less juicy. At the end of the study, Pasture and 40 hay heifers had on average the largest back fat thickness and intramuscular fat measurements. No treatment effects were detected for Warner-Bratzler shear force, muscle pH, muscle color and sensory panel attributes.

Growing rate of gain on subsequent feedlot performance, meat, and carcass quality of beef steers

Eighty Angus and Angus x Simmental steer calves were used in a completely random design to determine the effect of rate of BW gain during the backgrounding period on subsequent feedlot performance, carcass characteristics, Warner-Bratzler shear force (WBSF), and sensory analysis. Animals were stratified by BW and allotted randomly to 1 of 10 pens (5 pens/treatment). Dietary treatments were formulated for an ADG of 0.91 kg/d [low BW gain (LG), 1.06 Mcal of NE(g)/kg] diets and 1.25 kg/d [high BW gain (HG), 1.19 Mcal of NE(g)/kg]. Steers were fed 70 d during the growing period. The LG diet consisted of 52.5% barley silage, 39.0% whole shell corn, and 8.5% supplement, whereas the HG diet contained 43.9% barley silage, 47.4% whole shell corn, and 8.7% supplement (DM basis). Initial BW (226 kg) was not different (P = 0.70) between treatments. Steers fed the HG diet had increased ADG (1.67 vs. 1.40 kg/d; P < 0.001) compared with steers fed LG diet. Dry matter intake was greater (9.49 vs. 8.35 kg/d; P < 0.001) for steers fed the HG vs. LG diet. Total backgrounding cost ($/animal) was less (P < 0.001) for those steers fed LG diet compared with HG diet ($126.00 vs. $140.35, respectively); however, total cost per kilogram of BW gain was not different (P = 0.24; $0.485/kg of BW gain). After the backgrounding period, steers were fed a common finishing diet for 135 d. During the finishing period, LG steers had similar (P = 0.12; 10.73 vs. 10.35 kg/d) DMI compared with those fed HG diets; however, ADG was not different (1.55 kg; P = 0.72) among treatments. Hot carcass weight, marbling score, 12th-rib fat, LM area, and USDA yield grade were not different (P > 0.12) between treatments and averaged 363 kg, Sm(30), 1.33 cm, 83.8 cm(2), and 2.7, respectively. There were no differences (P = 0.77; 3.63 +/- 0.12 kg) in WBSF tenderness of rib-eye steaks. Percent cooking loss was increased in LG diets (P = 0.017). No differences were observed in consumer sensory analysis of tenderness, juiciness, and flavor intensity (P > or = 0.276; 5.43 +/- 0.12, 5.07 +/- 0.13, and 5.17 +/- 0.05, respectively). These data suggest that feeding steers diets that differ in energy concentration and result in ADG of 1.4 and 1.7 kg/d during the growing period results in minimal changes in subsequent finishing performance and does not affect meat quality.

Effects of winter stocker growth rate and finishing system on: III. Tissue proximate, fatty acid, vitamin, and cholesterol content

Angus-cross steers (n = 198; 270 kg of BW; 8 mo) were used in a 3-yr study to assess the effects of winter stocker growth rate and finishing system on LM proximate, fatty acid, cholesterol, vitamin, and mineral composition. During the winter months (December to April), steers were randomly allotted to 3 stocker growth rates: low (0.23 kg/d), medium (0.45 kg/d), or high (0.68 kg/d). At the completion of the stockering phase, steers were allotted randomly within each stocker growth rate to a high concentrate (CONC) or pasture (PAST) finishing system and finished to an equal time endpoint. Winter stocker growth rate did not alter (P > 0.05) proximate, cholesterol, or vitamin content of the LM. All interactions among winter stocker growth rate and finishing system were nonsignificant, indicating that supplementation systems during winter stocker period did not influence beef composition after finishing on PAST or CONC. Finishing steers on CONC decreased (P < 0.001) moisture content of the LM and increased (P < 0.001) lipid content of the LM. Protein, ash, and cholesterol content of the LM did not differ (P > 0.05) between finishing systems. alpha-Tocopherol and beta-carotene content of the LM were 288 and 54% greater, respectively, for PAST-finished cattle than CONC. B-vitamins, thiamine and riboflavin, were also present in greater (P = 0.001) concentrations for PAST than CONC. Calcium, Mg, and K contents of the LM were greater (P < 0.05) for PAST than CONC. Total fatty acid content of the LM was 49% less for PAST than CONC. Myristoleic, palmitoleic, and oleic acid concentrations were all less (P = 0.001) for PAST than CONC. Trans-10 octadecenoic acid percentage in LM was 97% greater (P = 0.001) for CONC than PAST; conversely, trans-11 vaccenic acid percentage in the LM was 90% greater (P = 0.001) for PAST than CONC. Conjugated linoleic acid, cis-9, trans-11 isomer, percentage was greater (P = 0.001) by 117% for PAST than CONC. Linoleic acid (C18:2) concentration did not differ (P > 0.05) among PAST and CONC. Concentrations of all n-3 fatty acids (linolenic acid, eicosapentaenoic, docosapentaenoic, docosahexaenoic) were greater (P = 0.01) for PAST than CONC. Total n-6 PUFA percentages were unchanged (P > 0.05) among finishing systems. The ratio of n-6 to n-3 fatty acids was 4.84 for CONC and 1.65 for PAST. Beef from CONC finished has a greater total, saturated, and monounsaturated fat content; in contrast, beef from PAST finished has less total, saturated, and monounsaturated fat content with greater contents of n-3 fatty acids and a decreased n-6 to n-3 ratio. Beef from PAST finished also has greater contents of B-vitamins and antioxidants (vitamin E and beta-carotene).