The effects of finishing diet and postmortem ageing on the eating quality of the M. longissimus thoracis of electrically stimulated Brahman steer carcasses

Regression models from portable NIR spectra for predicting the carcass traits and meat quality of beef cattle

The aims of this study were to predict carcass and meat traits, as well as the chemical composition of the 9th to 11th rib sections of beef cattle from portable NIR spectra. The 9th to 11th rib section was obtained from 60 Nellore bulls and cull cows. NIR spectra were acquired at: P1 -center of Longissimus muscle; and P2 -subcutaneous fat cap. The models accurately estimated (P ≥ 0.083) all carcass and meat quality traits, except those for predicting red (a*) and yellow (b*) intensity from P1, and 12th-rib fat from P2. However, precision was highly variable among the models; those for the prediction of carcass pHu, 12th rib fat, toughness from P1, and those for 12th rib fat, a* and b* from P2 presented high precision (R2 ≥ 0.65 or CCC ≥ 0.63), whereas all other models evaluated presented moderate to low precision (R2 ≤ 0.39). Models built from P1 and P2 accurately estimated (P ≥ 0.066) the chemical composition of the meat plus fat, bones and, meat plus fat plus bones, except those for predicting the ether extract (EE) and crude protein (CP) of bones and the EE of Meat plus bones fraction from P2. However, precision was highly variable among the models (-0.08 ≤ R2 ≤ 0.86) of the 9th and 11th rib section. Those models for the prediction of dry matter (DM) and EE of the bones from P1; of EE from P1; and of EE, mineral matter (MM), CP from P2 of meat plus fat plus bones presented high precision (R2 ≥ 0.76 or CCC ≥ 0.62), whereas all other models evaluated presented moderate to low precision (R2 ≤ 0.45). Thus, models built from portable NIR spectra acquired at different points of the 9th to 11th rib section were recommended for predicting carcass and muscle quality traits as well as for predicting the chemical composition of this section of beef cattle. However, it is noteworthy, that the small sample size was one of the limitations of this study.

Differences in toughness and aging potential of longissimus lumborum muscles between Hanwoo cow, bull and steer

Thirty Hanwoo cattle including bulls, cows, and steers (n = 10 each) were slaughtered and investigated for carcass traits (weight, meat color, fat color, yield index, maturity, marbling score, back-fat thickness, and firmness) and meat quality. The meat quality such as: pH, color, cooking loss, fatty acid, thiobarbituric acid reactive substance, warner-bratzler shear force, tensile tests, and texture profiles were analyzed on longissimus lumborum (LL) muscles of the carcasses at different aging times (3 d and 21 d). The results showed that steers and cows had higher back-fat thickness and marbling score, and a lower firmness (p < 0.001) than bulls. Bulls exhibited a lower meat quality indicating by higher cooking loss, thiobarbituric acid reactive substance content, warner-bratzler shear force and tensile test values (p < 0.01). Regarding the sensory property, the bull meat also had higher hardness, and lower tenderness, juiciness and flavor scores than the cow or steer meat (p < 0.01). Additionally, the bull meat had a higher polyunsaturated fatty acid and a lower monounsaturated fatty acid contents (p < 0.01). With increased aging time, the meat tenderness was improved in all the genders. Taken together, the present study demonstrated that the gender and aging time affected the carcass traits, fatty acid and sensory quality of beef. Postmortem aging could improve the meat tenderness of all genders especially bulls.

- Invited Review - Factors affecting beef quality and nutrigenomics of intramuscular adipose tissue deposition

Beef quality is characterized by marbling (marbling degree and marbling fineness), physiochemical (shear force, meat color, fat color, texture, and maturity), and sensory (tenderness, flavor, juiciness, taste, odor, and appearance) traits. This paper summarizes and addresses beef-quality characteristics and the beef-grading systems in Korea, Japan, the USA, and Australia. This paper summarizes recent research progresses on the genetic and nutritional factors that affect beef quality. Intramuscular (i.m.) adipose tissue deposition or marbling is a major determinant of beef quality. This paper addresses the mechanisms of i.m. adipose tissue deposition focused on adipogenesis and lipogenesis. We also address selected signaling pathways associated with i.m. adipose tissue deposition. Nutrients contribute to the cellular response and phenotypes through gene expression and metabolism. This paper addresses control of gene expression through several nutrients (carbohydrates, fat/fatty acids, vitamins, etc.) for i.m. adipose tissue deposition. Several transcription factors responsible for gene expression via nutrients are addressed. We introduce the concept of genome-based precision feeding in Korean cattle.

Effect of Different Packaging Atmosphere on Microbiological Shelf Life, Physicochemical Attributes, and Sensory Characteristics of Chilled Poultry Fillets

This trial was conducted to evaluate the effect of overwrap, vacuum, and modified atmosphere packaging (MAP) on poultry breast fillets' microbiological, biochemical shelf life and sensory attributes. The fillets were divided into 4 groups, and each of the treatments was replicated 3 times with 60 breast fillets. The first group was a control group with overwrap packaging; the second group was vacuum packed (VP); the third and fourth groups were MAP-1: 0% O2, 40% CO2, 60% N2, and MAP-2: 20% O2, 40% CO2, 40% N2. The microbiological and biochemical analyses were performed for the total viable count, coliform count, Pseudomonas count, Salmonella count, total volatile basic nitrogen (TVB-N), pH, cooking loss, color, lipid oxidation, tenderness, and sensory analysis. The data were analysed through two-way ANOVA by Minitab (Minitab 17.3.1). Meat treated with understudy MAP compositions and vacuum packaging reduced total viable count, Pseudomonas count, and total coliform count than control (p<0.05). TVB-N remained below the recommended limit throughout storage except aerobic packaging (p<0.05). Cooking loss (%) was lowered and showed non-significant results (p>0.05) between vacuum packaging and both MAP concentrations. The meat stored in MAP-2 was characterised by higher (p<0.05) visual scores. Whilst MAP-1 showed higher (p<0.05) L* values and overall acceptability. Sample packaged under aerobic packaging showed significant (p<0.05) results for b* and thiobarbituric acid reactive substances (TBARS). Meat stored in aerobic packaging showed higher (p<0.05) shear force values. The outcome of this trial may help to promote the application of understudy MAP compositions and rapid detection of microbes by biochemical analysis under local conditions.

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.

Meat Substitution with Oat Protein Can Improve Ground Beef Patty Characteristics

The consumer acceptance of alternative plant-focused ingredients within the meat industry is growing globally. Oat protein is insoluble and used to increase product yield and fat retention. Furthermore, inclusion of oat protein can provide manufacturers another option for extending beef supplies. As the consumer diet shifts for improvements in nutritional density, oat protein is an alternative ingredient that lacks information on inclusion in a ground beef formulation. Coarse ground beef was allocated to one of four treatments, mixed with oat protein (0%, 1.5%, 3.5% and 4.5%), water, salt, pepper, textured vegetable protein, soy protein concentrate, and sodium tripolyphosphate. Meat blocks (n = 3 batches) were finely ground and formed into patties (N = 65/treatment). Patties were placed onto an expanded polystyrene tray, overwrapped with polyvinyl chloride film and displayed for 7 days. Instrumental color (L*, a*, and b*) decreased throughout simulated display (p = 0.0001). Increased usage rates of oat protein in patties resulted in greater cook yields (p = 0.0001). Objective measures of Allo-Kramer shear force values increased as oat protein inclusion rates increased (p = 0.0001). Oat protein can be incorporated in ground beef patties with positive effects on cook yield, but inclusion rate may have a deleterious impact on color and instrumental tenderness.

Influence of Plant-Based Proteins on the Fresh and Cooked Characteristics of Ground Beef Patties

Blended meat/plant products are capturing industry market space at the retail counter for value-added beef products. Plant protein ingredients can be added to meat formulations to create appealing and functional products. Ground beef was combined with one of three plant protein inclusion treatments: control, pea, oat, or rice, along with 5% textured vegetable protein (TVP) and 1.5% soy protein concentrate then formed into 226 g patties containing up to 10% plant-based proteins. Patties were analyzed for fresh and cooked characteristics throughout a 5- or 7-day retail display. The inclusion of plant-based proteins negatively affected the instrumental tenderness values which were greater (p < 0.01) in plant-inclusion patties compared to the control patties. The inclusion of plant proteins increased (p = 0.01) the cooking yield of patties compared to the control. Cooking time was longer (p = 0.04) for oat patties compared to the control patties. Cooked color values for vegetable inclusion patties did not affect (p = 0.12) lightness (CIE L*) values; however, redness (CIE a*) was greater (p < 0.01) for rice than all other treatments and yellowness (CIE b*) values were greater (p < 0.01) for all protein treatments compared to the control. Rice improved (p < 0.01) fresh a* values on day 5 of display compared to the control; whereas pea decreased (p = 0.04) values compared to the control. There was a treatment × day interaction (p < 0.01) on lipid oxidation values with a reduction in values on day 3 for all vegetable proteins compared to the control and on day 7 lipid oxidation was reduced (p ≤ 0.03) for oat patties.

Impact of Packaging Film and Beef Trimmings on Ground Beef Shelf Life

Fresh beef storage in the retail setting can be presented in a variety of packaging methods, and identifying an alternative such as vacuum packaging to current traditional methods could potentially increase shelf life and reduce meat waste. The objective of this study was to identify the influence of packaging film and lean trimming sources on fresh ground beef surface color during a simulated retail display period. There were no differences (p > 0.05) in surface color redness (a*), yellowness (b*), chroma, or hue angle regardless of packaging film or lean trimmings. However, thiobarbituric acid reactive substances (TBARS) were greater (p < 0.05) for packages containing a greater percentage of CULL beef trimmings regardless of packaging film. In addition, pH values of ground beef packages did not differ (p > 0.05) among packaging film or lean trimming blends. Visual color did not differ (p > 0.05) throughout the simulated retail display period regardless of beef trimmings or packaging film. Microbial spoilage organisms were greater (p < 0.05) after the simulated display period. These results suggest that ground beef presented in a simulated retail setting using an alternative packaging platform, such as vacuum packaging, is plausible.

Meat Quality, Fatty Acid Content and NMR Metabolic Profile of Dorper Sheep Supplemented with Bypass Fats

The supplementation of rumen bypass fat (RBF) has remained one of the preferred approaches used to decrease undesirable saturated fatty acids (FA) and increase beneficial unsaturated FA in the meat. This study was planned to evaluate the influences of rumen bypass fats on meat quality, fatty acid and metabolic profiles in male Dorper sheep (n = 36) with 24.66 ± 0.76 kg (mean ± standard error) initial body weight. Treatment comprised a basal diet (30:70 rice straw to concentrate) with no added RBF as a control (CON), basal diet with prilled fat (PF), basal diet with prilled fat plus lecithin (PFL) and basal diet with calcium soap of palm fatty acids (CaS). The findings revealed that cooking loss, drip loss and shear force in longissimus dorsi (LD) muscle were not affected by RBF supplementation, while meat pH was significantly higher in the CaS on aging day 1. However, the diet supplemented with prilled fat and lecithin modified the meat's fatty acid profile significantly by increasing unsaturated fatty acids and decreasing saturated fats. The relative quantification of the major differentiating metabolites found in LD muscle of sheep showed that total cholesterol, esterified cholesterol, choline, glycerophosphocholine and glycerophospholipids were significantly lower in CaS and PFL diets, while glycerol and sphingomyelin were significantly higher in CaS and PFL diets. Most of the metabolites in the liver did not show any significant difference. Based on our results, the supplementation of protected fats did not have a negative influence on meat quality and the meat from Dorper sheep fed prilled fat with lecithin contained more healthy fatty acids compared to other diets.

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.

Intramuscular collagen characteristics and expression of related genes in skeletal muscle of cull cows receiving a high-energy diet

We aimed to investigate differences in the synthesis and metabolism of intramuscular collagen in the Longissimus thoracis (LT) muscle between heifers and cull-cows fed high-energy diet. Ten cull-cows, (74.9 ± 3.2 months age, weighing 536 ± 14.55 kg) and ten heifers (18.4 ± 3.2 months age, weighting 310.5 ± 14.5 kg) were fed with high-energy diets for 150 days. The total collagen content did not differ between treatments. Greater collagen solubility was observed in heifers than cull-cows, although no differences in lysyl oxidase activity were observed between treatments. No differences were observed for mRNA expression of CO1A1, MMP2, MMP9 and TIMP2 between treatments. However, cull-cows presented greater mRNA expression of COL3A1, TIMP1 and TIMP3 than heifers. Our data give no indication that feeding a high-energy diet to cull-cows decreases the concentration of intramuscular collagen in the LT muscle or increases its solubility in respect to the collagen solubility in LT muscles from heifers on the same diet.

The effect of gender status on the growth performance, carcass and meat quality traits of young crossbred Holstein-Friesian×Limousin cattle

Objective

The objective of this study was to compare growth performance, carcass traits and meat quality in young bulls, steers and heifers produced by crossing Limousin bulls with Holstein-Friesian cows, fattened semi-intensively and slaughtered at 18 months of age.

Methods

Thirty-one young calves were reared in a conventional production system, and were fed milk replacer, hay and concentrate. At 6 months of age, the animals were divided into groups based on gender, and were fed a total mixed ration composed of grass silage, concentrates I and II in a semi-intensive production system. At the end of the fattening period (18 months), the animals were slaughtered, carcass quality was evaluated, and samples of musculus longissimus thoracis were collected to determine the proximate composition and quality of meat.

Results

Bulls were characterized by the highest percentage share of the most valuable cuts in the carcass, and three-rib sections from bull carcasses had the highest lean meat content with low intramuscular fat content (0.93%). No significant differences in carcass conformation, dressing percentage or the percentage share of round in the right half-carcass were found between bulls vs. steers and heifers. Heifers and steers had higher carcass fat content than bulls, which had a positive influence on the sensory properties of beef. In comparison with the meat of bulls, the meat of steers and heifers was characterized by more desirable physical properties and sensory attributes (water-holding capacity, shear force, color lightness, aroma, juiciness, tenderness, flavor).

Conclusion

Under the semi-intensive production system, heifers and steers had higher carcass fat content than bulls, which had a positive effect on the sensory properties of beef. Bulls are better suited for intensive systems, which contribute to improving the quality of their meat. The results of this study may encourage producers to breed steers and heifers for beef.

Flavor Characterization of Grass- and Grain-Fed Australian Beef Longissimus Lumborum Wet-Aged 45 to 135 Days

The study objective was to evaluate the effects of extended postmortem wet aging of Australian beef, cattle diet, and their interaction on objective and subjective measures of beef flavor of the longissimus lumborum. Beef strip loins were collected from grass- and grain-fed cattle (n = 50 total) at a commercial abattoir near Brisbane, Australia. Beef longissimus lumborum were portioned and assigned randomly to one of 3 postmortem aging periods (45, 70, or 135 d). As each section reached its respective postmortem aging designation, that section was fabricated into 2.5-cm steaks, individually vacuum packaged, and frozen (−21°C). Trained panelists evaluated cooked steaks for numerous flavor attributes, tenderness, and juiciness; volatile compounds were also evaluated. Sensory scores differed (P &lt; 0.05) due to diet, whereby grain-fed samples were rated more intense (P &lt; 0.05) for beef flavor identity, fat-like, liver-like, and sweet but grass-fed samples were more intense (P &lt; 0.05) for green-hay and bitter. Juiciness, tenderness, and 4 flavor attributes (bloody/serumy, metallic, umami, and rancid) were similar (P &gt; 0.05) between diets. Extending postmortem aging from 45 to 135 d resulted in decreased beef and umami flavors (P &lt; 0.05), along with concurrent increased detection of off-flavors, such as liver-like, rancid, bitter, and sour (P &lt; 0.05). Volatile flavor compounds were more influenced by postmortem aging than diet. Increased postmortem aging time increased concentration for both lipid oxidation and Maillard-reaction–derived volatiles, resulting in the concentration of negative flavor volatile compounds rather than the absence of positive flavor compounds. Based on these results, differences existed in the flavor profile of longissimus lumborum from grass- and grain-fed beef, regardless of postmortem aging. However, aging beef strip loins 135 d is not recommended based on reduced beef flavor and increased off-flavor detection compared to samples aged 45 or 70 d postmortem.

Effects of Feeding and Maturation System on Qualitative Characteristics of Buffalo Meat (Bubalus bubalis)

We aimed to evaluate the effects of post dry ageing (PDA) period on meat colour and rheological characteristics in 16 buffalo bulls fed two different diets: with (FRS) or without (CTL) rye grass. Animals were randomly divided into two feeding groups and slaughtered at 540 ± 4.7 and 533 ± 7.0 kg of live body weight, respectively, for the CTL and FRS group. After five days post-mortem ageing (T0), Semitendinosus muscle (ST) and Longissimus muscle (LD) underwent a prolonged maturation process in a controlled meat chamber for 30 days (ST) and until 60 days (LD). After 30 days (T1), significant changes (p < 0.01) in meat colour (ΔE) in both muscles of the FRS group was recorded, while no significant change was observed in CTL group. The FRS diet had a positive effect on textural properties of ST muscle compared to CTL diet, as well as hardness, chewiness and gumminess. All qualitative characteristics improved in the first period of PDA but, whereas LD showed to keep improving, extending the post-ageing period by further 30 days, the ST becomes un-processable at 60 days. In conclusion, a combined used of fresh feeding and PDA period could enhance both tenderness and colour in animal fed FSR.

Meat and sensory quality of major muscles from Angus, Charolais, and Angus crossbred steers with high and low residual feed intake

Effects of residual feed intake (RFI) and genetic group on growth, carcass, and meat quality characteristics of bovine longissimus lumborum (LL), triceps brachii (TB), semimembranosus (SM), and gluteus medius (GM) muscles were investigated using 72 purebred Angus, purebred Charolais, and Angus crossbred steers (n = 24 per genetic group) classified as either high (inefficient) or low (efficient) RFI (n = 12 high and low RFI steers within genetic group). There was no RFI effect (P > 0.05) on growth, carcass, and meat quality measurements except high RFI steers had the highest dry matter intake (P < 0.05), and low RFI TB was rated as having reduced beef flavour intensity and sustained juiciness (P < 0.05). Purebred Angus and Charolais LL and GM had lower shear force values (P < 0.05) than Angus crossbreds and ageing reduced mean shear force values except in TB. For TB, SM, and GM, Angus crossbred steers had the highest mean beef flavour intensity scores, and Charolais SM and TB were less tender than those of Angus crossbred (P < 0.05). Overall, RFI did not influence most meat quality traits; therefore, low RFI animals may contribute to reducing feed costs or environmental impact without compromising meat quality and palatability.

Influence of carcass weight on meat quality of commercial feedlot steers with similar feedlot, slaughter and post-mortem management

The effects of beef carcass weight on muscle pH/temperature profile and selected meat quality attributes were evaluated. Twenty-six carcasses from light (≤260kg, n=15) and heavy (≥290kg, n=11) feedlot steers were randomly allocated and stimulated with low voltage electrical stimulation (LVES) for 30s at 7min post-mortem (pm). Quality evaluations were carried out on samples from the Longissimus et lumborum (LL) muscle from the left side of each carcass. Heavier carcasses showed faster pH decline and slower (P<0.05) temperature decline at 45min, 3, 6, 12 and 24h pm. Heavier carcasses passed through the heat shortening window (i.e. at pH6, temperature was >35°C) but there was no sign of sarcomere shortening in any carcass. Significantly lower (P<0.05) shear force values were recorded in the heavier carcasses at 3days pm but at 14days pm, heavier carcasses had numerically lower but not significantly different shear force. Heavier carcasses produced numerically higher but not significant (P>0.05) drip loss at 3 and 14days pm as well as higher L* (meat lightness) (P<0.05) and C* (chroma) (P<0.05) values early (2days) pm. However, at 14days pm, there were no significant differences between the light and heavy carcasses in terms of L* and C*. No significant difference was observed between heavy and light carcasses in terms of H* at 2 and 14days pm. The study showed that heavier carcasses which favor slaughter house pricing can be produced and processed alongside lighter carcasses without significant detrimental effects on meat quality by using low voltage electrical stimulation (LVES).

Intensive vs. free-range organic beef. A preference study through consumer liking and conjoint analysis

This paper evaluates consumer liking and preferences towards organic beef from two production systems allowed by EU regulation: i) free-range and ii) intensive (fattened in feed-lot with organic feedstuff) as compared with conventionally produced beef. Data were obtained in April-May 2014 with a sample of 150 regular beef consumers who completed two tasks: firstly a sensory test where consumers tasted and rated the meats and secondly a conjoint analysis to study beef purchasing preferences. Willingness-to-pay for the different meats was also calculated from conjoint results. Results show that consumers preferred organic-from-concentrate beef at sensory level while organic beef from animals fed on grass was preferred when process characteristics (i.e. farming system) or attributes perceived at the point of purchase (i.e. colour) were evaluated. It was also found that the price-premium for organic beef is over 40%, with organic-fed-on grass beef preferred slightly over that fed-on-concentrate.

Effects of forage silage species on yearling growth performance, carcass and meat quality, and nutrient composition in a forage based beef production system

Berthiaume, R., Lafrenière, C., Girard, C., Campbell, C. P., Pivotto, L. M. and Mandell, I. B. 2015. Effects of forage silage species on yearling growth performance, carcass and meat quality, and nutrient composition in a forage based beef production system. Can. J. Anim. Sci. 95: 173–187. Forty weaned, crossbred beef calves (predominantly Angus and Simmental) were forage-finished using all-silage diets (red clover–timothy versus tall fescue) to examine forage species’ effects on growth performance, carcass traits, meat quality, and nutrient composition. Weaned calves (257 d of age) were forage-finished using red clover–timothy or tall fescue silage and harvested at approximately 1 yr of age. During carcass processing, one side from each carcass was covered with a polyliner to examine if reducing rates of chilling could compensate for limited fat cover expected from low dietary energy contents fed, and limited time on feed. Longissimus thoracis, semimembranosus, and semitendinosus steaks were aged 10, 14, and 21 d to examine effects on Warner–Bratzler shear force values while fatty acid and vitamin B12 composition were determined on 10-d-aged steaks. Average daily gain, feed efficiency, hot carcass weights, and longissimus muscle area were greater (P<0.03) when cattle were fed red clover–timothy versus tall fescue silage, most likely due to the higher protein content of red clover–timothy silage. Shear force was greater (P<0.002) in steaks from all muscles evaluated from cattle fed tall fescue versus red clover–timothy silage. In comparison to 10-d-aged steaks, 14 d of ageing were needed to reduce (P<0.001) shear force for longissimus steaks, while 21 d of ageing were needed to reduce (P<0.001) shear force for semitendinosus steaks. Use of a polyliner decreased (P=0.0001) the rate of temperature decline at selected carcass sites, but did not reduce shear force values. The percent of n-3 fatty acids and polyunsaturated fatty acid/saturated fatty acid ratio were greater (P<0.04) in longissimus from cattle fed red clover–timothy versus feeding tall fescue silage. Feeding red clover–timothy silage improved growth performance, carcass, shear force, and fatty acid composition traits versus feeding tall fescue silage.

Effects of stress by unfamiliar sounds on carcass and meat traits in bulls from three continental beef cattle breeds at different ageing times

One-hundred-and-twenty-four young bulls of three Continental beef cattle breeds were used to study the effect of pre-slaughter stress by unfamiliar sounds on carcass traits and quality characteristics of beef aged for three different periods. Stress due to unfamiliar noises had a moderately negative effect on carcass and meat quality. Carcasses from group Stressed had higher (P<0.05) values of pH0, pH24, a*, and Warner-Bratzler shear force, and lower (P<0.05) values of L*, b* and pressure losses than from Unstressed animals. There were significant differences (P<0.05) among breeds in L*, a* and pressure losses. The ageing time had a significant effect on chromatic variables, WBSF and pressure losses. The cooking losses were not significantly affected by any of the three factors discussed. These results emphasize the importance of implementing appropriate management practices during pre-slaughter handling of cattle in order to reduce any possible risk factor for stress, as well as the different sensitivity of the breeds to similar stimuli.

Effect of cattle breed on meat quality, muscle fiber characteristics, lipid oxidation and Fatty acids in china

The objective was to compare meat quality, muscle fiber characteristics, lipid oxidation and fatty acids of Limousin (LIM), Simmtental (SIM), Luxi (LX), Qinchuan (QC) and Jinnan (JN) offered the same diet in China. After finishing, eight bulls from each breed were randomly selected for slaughter at 18.5 months old. Longissimus dorsi (ld) muscle was taken from the carcass for meat quality evaluations. Breed had little effect on most of meat and fat color parameters except for Hue and b* in which QC had lower values. LIM showed higher pH (24 h) and better water holding capacity than other breeds. LIM showed the lowest dry matter content but the highest crude protein. LX and LIM had higher percentage and density of red muscle fiber than other breeds. Lipid oxidations were significantly lower in LIM than in QC, with the LX, SIM and JN having the intermediate values. Compared to other four breeds, QC provided the highest values of polyunsaturated fatty acids (PUFA), n-6 fatty acids and n-3 fatty acids. In conclusion, LIM scored better on most of meat quality characteristics; however, local breeds such as LX and QC also had better muscle fiber characteristics and better fatty acids composition.

Eating quality of beef from free-range and confined Podolian young bulls

The purpose of the present study was to assess the effect of grazing on meat quality of young Podolian bulls by using 6 free-ranging (FR) and 6 confined (CON) animals slaughtered at 18 mo of age (Exp. 1). A second experiment (Exp. 2) was performed the subsequent year where the age at slaughter was 15 mo of age (6 animals/group). Quantitative descriptive sensory analysis, water-holding capacity (WHC; thawing, centrifugation, and cooking losses), and shear force (only in Exp. 2) were evaluated on LM, aged 8 d. Both experiments showed that CON animals produced beef with greater overall beef flavor (P < 0.01 and P < 0.05 in Exp. 1 and 2, respectively) and odor intensities (P < 0.10 and P < 0.05 in Exp. and 1 and 2, respectively) and increased malondialdehyde contents (P < 0.01 and P < 0.05 in Exp. 1 and 2, respectively). In Exp. 2 beef from FR bulls showed higher sensory tenderness as compared with CON bulls (P < 0.05) and a lower shear force (P < 0.05). In Exp. 1, beef obtained from FR bulls showed lower centrifugation and greater thawing losses compared with samples from bulls from group CON (P < 0.05) whereas rearing system did not affect any WHC variables in Exp. 2. The results obtained from the 2 experiments were generally consistent. The different results occasionally observed (e.g., sensory tenderness and WHC) is attributed to the different ages at slaughter used in the 2 experiments (18 and 15 mo). In particular, at an earlier age at slaughter (15 mo) the effect of FR on meat quality was beneficial on sensory tenderness and mechanical properties. Therefore, given the additional costs of maintaining the bulls for another 3 mo when slaughtered at 18 mo of age, a reduced age at slaughter of FR bulls may be suggested to avoid the decrement of herbage mass availability inducing the consumption of high amounts of concentrate.

Effect of Acacia karroo Supplementation on Growth, Ultimate pH, Colour and Cooking Losses of Meat from Indigenous Xhosa Lop-eared Goats

The objective of the study was to determine the effect of Acacia karroo supplementation on growth, ultimate pH, colour and cooking losses of meat from indigenous Xhosa lop-eared goats. Eighteen castrated 4-month-old kids were used in the study until slaughter. The kids were subdivided in two treatment groups A. karroo supplemented (AK) and non-supplemented (NS). The supplemented goats were given 200 g per head per d of fresh A. karroo leaves. The kids were slaughtered on d 60 and sample cuttings for meat quality assessment were taken from the Longistimus dorsi muscle. The supplemented kids had higher (p<0.05) growth rates than the non-supplemented ones. The meat from the A. karroo supplemented goats had lower (p<0.05) ultimate pH and cooking loss than the meat from the non-supplemented goats. Acacia karroo supplemented goats produced higher (p<0.05) b* (yellowness) value, but supplementation had no significant effect on L* (lightness) and a* (redness) of the meat. Therefore, A. karroo supplementation improved growth performance and the quality of meat from goats.

Effect of South African beef production systems on post-mortem muscle energy status and meat quality

Post-slaughter muscle energy metabolism meat colour of South African production systems were compared; steers (n=182) of Nguni, Simmental Brahman crossbreds were reared on pasture until A-, AB-, or B-age, in feedlot until A-AB-age. After exsanguination carcasses were electrically stimulated (400 V for 15 s). M. longissimus dorsi muscle energy samples were taken at 1, 2, 4 and 20 h. Post-mortem samples for meat quality studies were taken at 1, 7 and 14 days post-mortem. Production systems affected muscle glycogen, glucose, glucose-6-P, lactic acid, ATP, creatine-P glycolytic potential (P<0.05), with the muscles of feedlot carcasses having a faster glycolysis rate than pasture carcasses. Energy metabolites correlated (0.4<r<0.9) with meat colour (CIE, L*a*b*), (0.3<r>0.5) water holding capacity, drip loss, and Warner Bratzler shear force. Muscle energy only affected muscle contraction of the A-age-pasture system (shortest sarcomere length of 1.66 μm vs 1.75 μm highest WBS of 6 kg vs 5 kg 7 days post-mortem).

Chemical composition, quality and histochemical characteristics of individual dromedary camel (Camelus dromedarius) muscles

This study characterized the chemical composition, quality and histological traits of six muscles from 10 dromedary carcasses. There were significant differences in moisture, fat, protein, mineral, saturated and unsaturated fatty acid contents between muscles. The longissimus thoracis (LT) had the highest cooking loss (33.5%) and triceps brachii (TB) the lowest (29.2%). The shear force value of semitendinosus (ST), semimembranosus (SM) and biceps femoris (BF) were significantly higher than infraspinatus (IS), TB and LT. The LT had significantly higher values for L*, a*, b* than ST. The SM had the lowest MFI (65.3), while IS had the highest value (75.8). The ST significantly had the highest and lowest proportions of Type I and Type IIA muscle fibers, respectively than other muscles. This study indicated that composition, quality, and histochemical parameters varied among camel muscles and the knowledge of this variation allows for better marketing and processing of camel meat.

Current research in meat color

This review surveyed recent literature focused on factors that affect myoglobin chemistry, meat color, pigment redox stability, and methodology used to evaluate these properties. The appearance of meat and meat products is a complex topic involving animal genetics, ante- and postmortem conditions, fundamental muscle chemistry, and many factors related to meat processing, packaging, distribution, storage, display, and final preparation for consumption. These factors vary globally, but the variables that affect basic pigment chemistry are reasonably consistent between countries. Essential for maximizing meat color life is an understanding of the combined effects of two fundamental muscle traits, oxygen consumption and metmyoglobin reduction. In the antemortem sector of research, meat color is being related to genomic quantitative loci, numerous pre-harvest nutritional regimens, and housing and harvest environment. Our knowledge of postmortem chilling and pH effects, atmospheres used for packaging, antimicrobial interventions, and quality and safety of cooked color are now more clearly defined. The etiology of bone discoloration is now available. New color measurement methodology, especially digital imaging techniques, and improved modifications to existing methodology are now available. Nevertheless, unanswered questions regarding meat color remain. Meat scientists should continue to develop novel ways of improving muscle color and color stability while also focusing on the basic principles of myoglobin chemistry.

Meat quality of Nguni steers supplemented with Acacia karroo leaf-meal

The objective of the study was to determine the meat quality of Nguni steers supplemented with Acacia karroo leaf-meal. Thirty 19-month old steers were randomly assigned to A. karroo leaf-meal (AK), sunflower cake (SF) and a control (CN) diets. Steers on the AK and SF diets were given an additional 150 g of protein per day for 60 days. The steers were slaughtered at 21 months and the m.longissimus thoracis et lumborum was sampled for meat quality measurements. Steers that received SF diet had lighter-coloured (L*) (P<0.05) meat than those on AK and CN diets. The highest redness (a*) (17.3+/-0.29) values were recorded in steers supplemented with AK compared to those that received SF and CN diets. Diet had no effect on pH, drip loss, water holding capacity, sarcomere length, muscle bundle areas, myofibrillar fragment length, Warner-Bratzler shear force and cholesterol values. Steers supplemented with AK (22.4+/-0.08%) and SF (22.5+/-0.08%) had higher (P<0.05) meat protein content than those on the CN (20.2+/-0.08%) diet. Highest muscle fibre area (3472.6+/-119.51 microm(2)), fat content (1.2+/-0.11%) and cooking loss (25.2+/-0.73%) of meat aged for 2 days were recorded in steers given the SF diet compared to those on the AK and CN diets. Supplementing Nguni cattle with A. karroo leaf-meal produced beef of comparable quality to natural pasture alone but with a fresher appearance and higher protein content.

A bromochloromethane formulation reduces enteric methanogenesis in cattle fed grain-based diets

Enteric fermentation has been estimated to be responsible for 64.2 Mt CO2-e, or ~16% of Australia’s greenhouse gas emissions (Australian Greenhouse Office 2007). A bromochloromethane (BCM) formulation, previously shown to inhibit methanogenesis, was included in the diet of Brahman (Bos indicus) cross steers, twice daily in three separate experiments, to determine the effect on methane production, daily feed intake, liveweight (LW) gain and accumulation of residues of BCM in edible tissue. In the first experiment, the BCM formulation was fed at rates of 0, 0.15, 0.30, or 0.60 g/100 kg LW, twice daily, for 28 days. Methane production (mean ± s.e.), measured over 11 h after feed was first consumed on day 28, was 0.3 ± 0.13 and 0.1 ± 0.03 L/h for animals treated at a rate of 0.30 and 0.60 g/100 kg LW, respectively. This was significantly less (P < 0.05) than for control animals (4.6 ± 0.46 L/h) and animals treated at a rate of 0.15 g/100 kg LW (2.1 ± 0.28 L/h). The dose rate of 0.30 g/100 kg LW was associated with a decrease in methanogenesis by ~93% compared with the control group and was used in subsequent experiments. The second experiment evaluated the efficacy of the BCM formulation fed at rates of 0 or 0.30 g/100 kg LW, twice daily, for 90 days. Methane production was measured over 24-h periods, on days 30, 60 and 90. For days 30 and 90, methane production was reduced by 60% (P < 0.05) to 4.2 ± 1.82 L/h and by 50% (P < 0.05) to 6.1 ± 0.63 L/h, respectively, for treated animals compared with the control group. The final experiment determined the effect on LW gain and detectable residues in edible tissue, with animals given the BCM formulation at rates of 0 or 0.30 g/100 kg LW, twice daily, for 85 days. Liver, kidney, depot fat and muscle samples collected 1 and 10 days after the last day of treatment had concentrations of BCM that did not exceed 0.015 mg/kg and were less than the temporary maximum residue limit (0.02 mg/kg BCM), which applies to bovine meat, fat and edible offal. There were no significant differences in LW gain (1.4 ± 0.10 v. 1.5 ± 0.07 kg/day), feed conversion ratio (5.7 ± 0.32 v. 5.4 ± 0.09), hot carcass weight (235 ± 5.0 v. 250 ± 6.5 kg) or P8 fat depth (6.4 ± 0.89 v. 8.1 ± 1.15 mm) between control and treated animals. The experiments reported here were completed in 2004 before the Australian Government prohibited the manufacture and use of BCM. It is unlikely that the BCM formulation will be available for commercial use to mitigate livestock methane emissions in Australia. Nevertheless, the study has demonstrated that methane emissions were substantially reduced over a 90-day feedlot finishing period. This indicates that alternative antimethanogens with a similar mechanism of action may have practical commercial relevance.