Moisture and fat content, marbling level and color of boneless rib cut from Nellore steers varying in maturity and fatness

Associations between the rumen microbiota and carcass merit and meat quality in beef cattle

The rumen microbiota is important for energy and nutrient acquisition in cattle, and therefore its composition may also affect carcass merit and meat quality attributes. In this study, we examined the associations between archaeal and bacterial taxa in the rumen microbiota of beef cattle and 12 different attributes, including hot carcass weight (HCW), dressing percentage, ribeye area (REA), intramuscular fat content, marbling score, fat thickness, yield grade, moisture content, purge loss, and shear force. There were significant correlations between the relative abundance of certain archaeal and bacterial genera and these attributes. Notably, Selenomonas spp. were positively correlated with live weight and HCW, while also being negatively correlated with purge loss. Members of the Christensenellaceae R-7, Moryella, and Prevotella genera exhibited positive and significant correlations with various attributes, such as dressing percentage and intramuscular fat content. Ruminococcaceae UCG-001 was negatively correlated with live weight, HCW, and dressing percentage, while Acidaminococcus and Succinivibrionaceae UCG-001 were negatively correlated with intramuscular fat content, moisture content, and marbling score. Overall, our findings suggest that specific changes in the rumen microbiota could be a valuable tool to improve beef carcass merit and meat quality attributes. Additional research is required to better understand the relationship between the rumen microbiota and these attributes, with the potential to develop microbiome-targeted strategies for enhancing beef production. KEY POINTS: • Certain rumen bacteria were associated with carcass merit and meat quality • Moryella was positively correlated with intramuscular fat in beef carcasses • Acidaminococcus spp. was negatively correlated with marbling and intramuscular fat.

Performance, Intake, Feed Efficiency, and Carcass Characteristics of Young Nellore Heifers under Different Days on Feed in the Feedlot

Two studies evaluated the productive characteristics of young Nellore heifers receiving different days on feed (DOF) to determine the biological slaughter endpoint. In Experiment 1 (Exp. 1), fifty-one Nellore heifers [324 ± 19.3 kg of body weight (BW); 16 ± 1 months] were split into three DOF lengths (45, 75, or 105 days), while in Experiment 2 (Exp. 2), thirty-six Nellore heifers (362 ± 25.5 kg of BW; 18 ± 1 months of age) were split into three DOF lengths (45, 90, or 135 days). In both studies, all animals were distributed in complete randomized blocks according to initial BW and stratified via carcass ultrasound. The diet was supplied ad libitum, allowing 3% of refusals. The point at which the animals achieved 25% of ether extract of shrunk body weight (EE_SBW) was defined as the biological endpoint. Thus, relationships were made between some characteristics obtained in both studies. Positive linear relationships were found between backfat thickness (BFT) vs. EE_SBW (p < 0.001, r = 0.84) and BFT vs. body weight (p < 0.001, r = 0.77). Our results suggest that the biological slaughter endpoint for young Nellore heifers is 6.97 mm of backfat thickness or 402 kg shrunk body weight, corresponding to around 75 DOF.

Effects of dietary glycerol supplementation on meat quality, palatability, and lipid metabolism gene expression in the longissimus thoracis of Hanwoo steers

This study tested the hypothesis that dietary glycerol supplementation (GS) would affect growth of Hanwoo steers, beef marbling and palatability, and gene expression for lipid uptake and transport and lipogenesis in the longissimus thoracis (LT). Diets with or without 45.2 g daily glycerol supplementation/kg dry matter concentrate were tested in fourteen Hanwoo steers during a 16-week feeding trial. GS did not affect (P ≥ 0.40) the average daily gain or the gain-to-feed ratio. GS increased the LT marbling score (P = 0.01). GS enhanced (P ≤ 0.01) the sensory traits, including the flavor and overall acceptance of the LT. GS tended (0.05 < P ≤ 0.10) to upregulate mRNA levels of fatty acid translocase, lipoprotein lipase, and fatty acid binding protein 4 genes in the LT. These tendencies of upregulated expression of fatty acid uptake and cytosolic transport genes may, in part, contribute to the increased marbling by GS. The increased marbling degree caused by GS may improve palatability including the flavor and overall acceptance of the LT.

Small genetic variation affecting mRNA isoforms associated with marbling and meat color in beef cattle

The aim of this study was to identify mRNA isoforms and small genetic variants that may be affecting marbling and beef color in Nellore cattle. Longissimus thoracis muscle samples from 20 bulls with different phenotypes (out of 80 bulls set) for marbling (moderate (n = 10) and low (n = 10) groups) and beef color (desirable (n = 10) and undesirable (n = 9) group) traits were used to perform transcriptomic analysis using RNA sequencing. Fourteen and 15 mRNA isoforms were detected as differentially expressed (DE) (P-value ≤ 0.001) between divergent groups for marbling and meat color traits, respectively. Some of those DE mRNA isoforms have shown sites of splicing modified by small structural variants as single nucleotide variant (SNV), insertion, and/or deletion. Enrichment analysis identified metabolic pathways, such as O2/CO2 exchange in erythrocytes, tyrosine biosynthesis, and phenylalanine degradation. The results obtained suggest potential key regulatory genes associated with these economically important traits for the beef industry and for the consumer.

Comparison of Nutritional and Meat Quality Characteristics between Two Primal Cuts from Aceh Cattle in Aceh Province, Indonesia

The Aceh cattle are local Indonesian beef cattle that are farmed in Aceh Province. This type of cattle is one of the sources of meat for the Aceh people. This study aims to analyze the quality of two primal cuts (longissimus lumborum and semitendinosus muscle) from Aceh cattle based on the muscle microstructure characteristics and MSTN gene expression. This study used a sample of longissimus lumborum and semitendinosus muscles from 18 adult male Aceh cattle with the age of 2-2.5 years and a BCS of 3.24. Muscle samples were obtained shortly after the cattle were slaughtered in slaughterhouses in Banda Aceh and Aceh Besar districts. Muscle microstructure analysis was performed using the HE, Masson's trichrome, and immunohistochemistry staining methods, while the MSTN gene expression analysis was performed using the qPCR method. The analysis of the physical quality of meat includes pH, meat color, fat color, cooking loss, water holding capacity, and WBSF value. The results showed that the area of LL muscle fibers was smaller than that of ST with relatively the same diameter. Both muscles were dominated by fast fibers with a percentage of 82.37% (LL muscle) and 91.80% (ST muscle). The area and composition of the type of muscle fibers are the main factors that influence the tenderness of Aceh beef. A higher distribution of collagen was found in ST muscles than in LL muscles. MSTN gene expression in both muscle types was relatively the same. Aceh cattle have large muscle fibers and are dominated by fast fibers with a high percentage, resulting in a low level of the tenderness of Aceh beef. However, the level of tenderness of Aceh beef is still in accordance with the cooking preparation of original and favorite cuisine of Aceh people.

Tropical Beef: Is There an Axiomatic Basis to Define the Concept?

Cattle production in tropical regions has been estimated to account for just over half of cattle worldwide, yet it has not been demonstrated that sufficient similarities in the cattle exist to describe tropical cattle and, even less so, to characterize the meat from these animals. The aim of this review is to investigate the quality and nutrient composition of meat from cattle raised in the Tropics to determine if there is an axiomatic basis that would allow the definition of a concept of “tropical beef”. Tropical beef is the meat obtained from cattle raised in tropical environments, the population of which remains largely uncharacterized. Production systems in the Tropics are highly diverse but converge on the use of indigenous and Bos indicus breeds or Bos indicus-influenced crossbreeds under pasture feeding regimes. While some systems allow cattle to be slaughtered at ≤2 years of age, most often animals are ≥3 years. These production systems generally produce lean, low-yielding carcasses and tough (>46 N), lean (≤3.6% intramuscular fat) meat with a macronutrient composition otherwise similar to beef from animals raised elsewhere (72–74% moisture and 20–24% protein). Fatty acid profiles depend on the breed and production systems, while mineral content is influenced by the environment. Although lean and tough, tropical beef is highly acceptable to the consumers it serves, is culturally and traditionally relevant and, in many countries, contributes to food security. Consolidating the findings from animal and meat science studies in the Tropics has allowed the demonstration of an axiomatic basis defining “tropical beef” as a concept.

Are Marbling and the Prediction of Beef Eating Quality Affected by Different Grading Sites?

For the European abattoirs, the preferred carcass grading site is at the fifth rib, and cutting at the tenth rib as in Australia could lead to a lower economic value of the carcass. Therefore, the objective of this study was to compare the grading scores of marbling and the meat and fat color on Musculus longissimus thoracis et lumborum (LTL) at the fifth and the tenth thoracic vertebrae. The consequences on the prediction of beef eating quality using the Meat Standards Australia (MSA) grading scheme were also evaluated for cull cows, which produce the majority of beef consumed in France. Carcasses from 208 French cattle, mainly Limousine cows, were graded according to the Australian Beef Carcase Chiller Assessment System (ABCAS) used for the implementation of the MSA system. The results indicate that there was no significant difference in the marbling score, between the fifth and the tenth ribs and hence in the MSA index and in the Global Quality [meat quality (MQ4)] scores calculated from marbling values from either the fifth rib or the tenth rib. However, the meat color at the tenth rib was significantly darker than that at the fifth rib (p < 0.01), and the fat color at the tenth rib was significantly yellower than that at the fifth rib (p < 0.001). The results of this study suggest that the grading of marbling can be conducted on M. LTL at the fifth thoracic vertebrae for routine use of the MSA system in France and, more generally, in Europe. However, further investigation and adjustment would be needed for other critical MSA scores (such as rib fat thickness) while respecting the European carcass quartering practices.

Sensorial, color, lipid oxidation, and visual acceptability of dry-aged beef from young bulls with different fat thickness

The reduction in slaughter age with minimum fat and dry aging process improves meat tenderness, however, its shelf-life in display has not been studied. It was evaluated the sensorial, and the color, lipid oxidation, and visual acceptance in display of dry-aged beef (0, 14, and 28 days) from young bulls slaughtered with different subcutaneous fat thickness (2.00, 3.00, and 4.00 mm). Meat with 2.00 and 3.00 mm fat had higher acceptability than 4.00 mm (p < .05). Dry aging improved overall acceptability of consumers. Meat with 2.00 and 3.00 mm fat presented higher lightness and lipid oxidation values than 4.00 mm (p < .05) but similar visual acceptance was observed. Dry-aged beef (14 and 28 days) had lower lightness, but higher redness (p < .05) than not dry aged (0 days). Display reduced color over time, for all dry-aged treatments (p < .05). Dry aging process increased lipid oxidation but these values were below 2.00 mg/kg of malonaldehyde only in the first day of display. Dry aged for 14 days had similar visual acceptability to not dry-aged beef until the third day of display (p < .05). Shelf-life of 0, 14, and 28 days of dry aged was 5.41, 2.55, and 0.23 days. Despite of the increase in lipid oxidation and lightness, the sensorial and display acceptability of meat from young bulls was not prejudiced by the reduction in fat thickness. Beef dry-aged for 14 days was visually well accepted and could be displayed for 2.55 days without compromising acceptability.

Application of the principal component analysis, cluster analysis, and partial least square regression on crossbreed Angus-Nellore bulls feedlot finished

Principal component analysis (PCA) and the non-hierarchical clustering analysis (K-means) were used to characterize the most important variables from carcass and meat quality traits of crossbred cattle. Additionally, partial least square (PLS) regression analysis was applied between the carcass measurements and meat quality traits on the classes defined by the cluster analysis. Ninety-seven non-castrated F1 Angus-Nellore bulls feedlot finished were used. After slaughter, hot carcass weight, carcass yield, cold carcass weight, carcass weight losses, pH, and backfat thickness (BFT) were measured. Subsequently, samples of the longissimus thoracis were collected to analyze shear force (SF), cooking loss (CL), meat color (L*, chroma, and hue), intramuscular fat, protein, collagen, moisture, and ashes. Principal component 1 (PC1) was correlated with colorimetric variables, while PC2 was correlated with carcass weights. Afterwards, three clusters (k = 3) were formed and projected in the gradient defined by PC1 and PC2 and allowed distinguishing groups with divergent values for collagen, protein, moisture, CL, SF, and BFT. Animals from high chroma group presented meat with more attractive colors and tenderness (SF = 1.97 to 4.84 kg). Subsequently, the PLS regression on the three chroma groups revealed a good fitness and the coefficients are used to predict the chroma variable from the explanatory variables, which may have practical importance in attempts to predict meat color from carcass and meat quality traits. Thus, PCA, K-means, and PLS regression confirmed the relationship between meat color and tenderness.

Relationships between temperament, meat quality, and carcass traits in Nellore cattle1

The aim of this study was to evaluate the relationship between temperament in Nellore bulls with carcass and meat quality traits. In total, 1,400 bulls were studied, and temperament was assessed using two measurements: movement score (MOV) and flight speed test (FS). Both MOV and FS were measured at two time points, with background (MOVb and FSb) temperament measured at yearling age, ~550 d after birth, and the preslaughter (MOVps and FSps) temperament measured at the end of the feedlot period. The change of temperament resulting in an increase or decrease in reactivity was also used to measure meat quality. The traits used to define carcass and meat quality included carcass bruises (BRU), hot carcass weight (HCW, kg), ribeye area (REA, cm2), backfat thickness (BFT, cm), marbling score (MS), meat pH after thawing (pH), presence or absence of dark cutters, color parameters of luminosity (L*), redness (a*) and yellowness (b*), cooking loss (CL, %), and Warner-Bratzler shear force (WBSF, kg). A principal component (PC) analysis was initially applied to the carcass and meat quality traits, followed by logistic regression models and linear mixed models to evaluate the effects of temperament on carcass and meat quality. The risks of carcass bruises and dark cutters did not differ as a function of any temperament trait (P > 0.05). In turn, animals classified as high MOVb (reactive) had lower PC3 values (P = 0.05), CL (P = 0.02), and tended to have lower MS (P = 0.08). In addition, animals classified as high FSb (faster and reactive cattle) produced carcasses with smaller REA (P < 0.01), higher meat pH (P < 0.01), lower color gradients (L*, P = 0.04; b*, P < 0.01), and lower PC1 and PC4 scores (P < 0.01) when compared with the low FSb class. For preslaughter temperament, high MOVps was related to lower color a* (P = 0.04), whereas high FSps was related to lower HCW, MS, and PC2 (P < 0.01) than the calmer ones (low FSps). The reduction in MOV was related to more tender meat, and the reduction in FS to heavier carcass and brighter meat. We conclude that excitable temperament in Nellore cattle may have negative effects in some of the carcass and meat quality attributes assessed, mainly those related to muscle deposition on carcass and color gradients. Measurement of temperament before the cattle entered the feedlot was a better predictor of carcass and meat quality traits, compared with temperament assessment at the end of the feeding period.

Effects of naturally-produced lovastatin on carcass characteristics, muscle physico-chemical properties and lipid oxidation and cholesterol content in goats

This study investigated the carcass characteristics, physico-chemical properties, storage stability and cholesterol content of meat from goats fed with different levels of naturally-produced lovastatin used to mitigate enteric methane production. Twenty intact Saanen male goats of 5-6 months old with initial live weight of 25.8 ± 4.0 kg were randomly allotted into four dietary treatments containing 0 (Control), 2 (Low), 4 (Medium) and 6 mg (High) per kg live weight (LW) of naturally-produced lovastatin for 12 consecutive weeks. No differences were found in all the parameters measured except for full LW, hot and cold carcass weight, shear force, color and cholesterol content among the treatment groups. Aging had significant effects on all the parameters measured in this study except a* (redness) of meat. Meat samples in the Medium and High treatments were of higher lightness and yellowness, more tender and lower cholesterol levels. We conclude that, in addition to mitigate enteric methane emissions, dietary supplementation of naturally-produced lovastatin at 4 mg/kg LW could be a feasible feeding strategy to produce tender meat containing lower cholesterol.

Effects of breed and different lipid dietary supplements on beef quality

Focus of this study was to evaluate the most suitable breed/crossbred and the appropriate nutritional strategies to increase marbling in beef muscle and to improve its healthy properties, in particular the n-3 fatty acids content. One hundred and seventy-six heifers of three crossbreed commonly reared by Emilia-Romagna farmers: 48 Bleu Belge × Freisian (ITA), 48 Charolais × Aubrac (FRA), and 80 Angus (ANG) were used. Animals of each breed were randomly subdivided in two experimental groups that received two diets, differing for the dietary lipid source. Control group (C) received a basal diet containing protected vegetable fats, whereas treated one (T) received the same basal diet supplemented with 0.9 kg/head/day of extruded flaxseed. After slaughtering, a sample of Longissimus thoracis was collected from each animal for meat quality analysis. Our results demonstrated that, in a shorter fattening period, ANG animals obtained the best dry matter intake, average daily gain and the best fattening scores. ITA and ANG meat presented the highest marbling scores. ANG breed had the highest amount of C18:1, the highest unsaturated/saturated fatty acids ratio and the lowest n-6/n-3 ratio. The T animals, independently from breed, showed the highest amount of α-linolenic acid (ALA). In addition, ANG-T meat presented the highest ALA content.

Correlation of Marbling Characteristics with Meat Quality and Histochemical Characteristics in Longissimus Thoracis Muscle from Hanwoo Steers

The objective of this study was to investigate the correlations of marbling characteristics, including marbling score, intramuscular fat (IMF) content, and fleck traits, with meat quality traits and histochemical characteristics of the longissimus thoracis muscle from Hanwoo steers. Marbling fleck characteristics, especially area, number, and fineness (F) index, measured by computerized image analysis were strongly correlated with marbling score and IMF content (p<0.05). However, coarseness (C) index and F/C ratio were somewhat limited relationships with marbling score. In contrast, the IMF content and the number of smaller white flecks increased with increasing lightness value (p<0.05). Moreover, beef with higher marbling scores showed lower cooking loss and Warner-Bratzler shear force value compared to beef with lower marbling scores (p<0.05). Regarding the muscle bundle traits, as number of bundle increased, number of marbling flecks increased (p<0.05), although most marbling characteristics did not have significant correlation with muscle fiber or bundle characteristics.

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.

An investigation on the relationship among marbling features, physiological age and Warner-Bratzler Shear force of steer longissimus dorsi muscle

Researchers nowadays have paid much attention to the relationships between tenderness and marbling, or physiological age. While the marbling was mainly evaluated qualitatively with scores or grades, and rarely related with physiological age. Present study was carried out to analyze the marbling features of longissimus dorsi muscle between the 12th and 13th ribs from 18, 36, 54 and 72 months old Simmental steers were quantitatively described with area and perimeter using computer vision technique. Relationship between Warner-Bratzler Shear force (WBSF), physiological age and the marbling features were examined performing regression analysis. The results revealed that WBSF positively correlated with physiological age, but negatively with marbling area and perimeter. Regression analysis showed that the relationship between the shear force and the steers' age was more close to the quadratic curve (R² = 0.996) and exponential curve (R² = 0.957). It was observed during study that marbling grew with steers age. Marbling features were in linear correlation with the steers' age, with R² = 0.927 for marbling area and R² = 0.935 for marbling perimeter. The industries in future may speculate beef tenderness and physiological age based on the marbling features (area and perimeter), which can be determined through the online image acquisition system and image processing.

The effects of dry or wet aging on the quality of the longissimus muscle from 4-year-old Hanwoo cows and 28-month-old Hanwoo steers

This study was conducted to discover the differences in physicochemical and sensory qualities of beef from 4-year-old Hanwoo cows and 2-year-old Hanwoo steers after undergoing different meat aging methods. Additionally, the possibility of using 4-year-old cows as value-added aged meat was investigated. Loins from eight cows (average 51 months old) and eight steers (average 28 months old) of quality grade 2 were aged for 28 days using dry and wet aging. Analyses were conducted to evaluate meat quality, including moisture content, pH, cooking loss, shear force, nucleotides, free amino acids (FAA), and sensory evaluation. After 28 days of aging, the moisture and shear force for loins from steers and cows were reduced compared with those of non-aged meat (P < 0.05). Cooking loss was reduced by dry aging. Regardless of aging method and gender, aging decreased inosine-5ʹ-monophosphate content but increased FAA content (P < 0.05). Dry aging increased glutamic acid content in meat, and aging the meat of steer increased the content of aspartic acid and glutamic acid (P < 0.05). Before aging, sensory scores for juiciness, tenderness, flavour, and overall acceptance between cow and steer were significantly different (P < 0.05), but the differences disappeared after aging. Therefore, the quality of lower grade meat from 4-year-old cows is comparable to that of meat from 2-year-old steers after aging, regardless of the aging method used.

Meat quality traits as a function of cow maturity

To investigate the physico-chemical and sensory properties of striploin muscles, 90 Hanwoo carcasses (QG 1+ ) were randomly selected within six maturity levels (4 to 9 according to age in months). Results demonstrated that the protein contents at maturity levels 4 and 5 were significantly higher than 9. No significant difference in fat, moisture and collagen contents were found at different maturity levels (P > 0.05). The quantity of collagen type I and ratio of type I to III were observed at higher maturity levels; collagen type III showed significantly high levels (P > 0.05) at low maturity and decreased with increase in maturity levels. Warner-Bratzler shear force (WBSF) was significantly lower in groups 4 to 6, whereas water holding capacity (WHC) was significantly higher than maturity level 8 and 9 groups (P < 0.05). There were no significant differences in cooking loss among the maturity level groups (P > 0.05). Color properties, L* values of striploin muscle from maturity level 4 were significantly different from level 9 (P < 0.05). Sensory evaluation at level 4-6 groups had significantly higher tenderness and overall likeness scores than level 9 (P < 0.05). The maturity levels were significantly correlated with age, fat, protein content, WHC, WBSF, cooking loss, CIE L* values and sensory properties like tenderness, juiciness, flavor-likeness and overall likeness.

Effect of animal age and trimming practices on the physical composition of Bonsmara beef

Increased economic incentive for producing young and leaner carcasses, as well as demand for lean meat from progressively health conscious consumers, are considered drivers for change in carcass composition over time. Furthermore, many retailers trim visible fat from meat to various degrees and consumers increasingly remove visible fat from meat prior to, or after, cooking. The objective of this study was to determine the composition of South African Bonsmara beef from four age groups from different production systems, as well as to extrapolate the effect of fat trimming on physical composition. Fat content of marketable beef has decreased notably since the 1930s, and beef from the South African Bonsmara breed contains less than 10g lipid per 100g after trimming of subcutaneous fat, irrespective of age. Removal of all visible fat reduces the lipid content to less than 5g per 100g, comparing favourably with other lean animal products.

Evaluation of carcass traits and meat characteristics of Guzerat-crossbred bulls

Our objective was to evaluate carcass and meat characteristics of Guzerat-crossbred bulls finished in feedlot. Carcasses from 18 bulls, randomly selected from a larger group of 36 bulls, consisting of F1 Guzerat×Holstein ("Guzholstein"); F1 Guzerat×Nellore ("Guzonell"); and 1/2 Simmental+1/4 Guzerat+1/4 Nellore (Three-Cross; n=6 each group) were used. Cold carcass weight was greater (P=0.01) for Three-Cross compared with "Guzonell" and "Guzholstein". Three-Cross carcasses had greater (P<0.01) rib-eye-area and 100-kg-adjusted rib-eye-area among groups. Longissimus lumborum length did not differ (P>0.05) among groups, but depth was greater (P<0.01) for Three-Cross compared with other groups. "Guzholtein" had lesser (P=0.05) shear force compared with "Guzonell", with Three-Cross being intermediate. We conclude that "Guzholstein" is an adequate option for producers willing to finish this kind of genetic group, as it is comparable or better than Bos indicus crosses and B. indicus×Bos taurus bulls.

Tenderness and sensory attributes of the longissimus lumborum muscles with different quality grades from Chinese fattened yellow crossbred steers

The objectives were to investigate intramuscular fat (IMF) content,Warner–Bratzler shear force(WBSF) and sensory attributes of Chinese fattened yellow crossbred steer beef with different quality grades, and to determine the relationship between WBSF and Chinese consumers' sensory tender. WBSF of grades A1 to A5 decreased from 50.6 N to 33.1 N with IMF % increased from4.26 to 24.55 (P b 0.05). Consumer panelists showed more likeability grades A4 and A5 with no difference between them. Grades A2 and A3 were slightly preferred (P b 0.05). Grade A1 was undesirable. A regression relationship between WBSF and sensory tender was found, which indicated that consumers disliked beef when WBSF N55.43 N and preferred those with WBSF b41.4 N. The range of 41.4 N to 55.43 N was intermediate. Hence, WBSF N55.43 & b41.4 N allow classification of tough and tender for beef tenderness for Chinese consumers, and grade A4 was recommended as suitable top grade.

Características físico-químicas e composição centesimal de cortes cárneos de borregas confinadas e alimentadas com diferentes proporções volumoso: concentrado

Objetivou-se avaliar as características físico-químicas e a composição centesimal da carne de borregas confinadas recebendo diferentes relações volumoso (V):concentrado (C) (80:20; 60:40; 40:60 e 20:80) e os cortes cárneos destes animais (paleta, lombo e do pernil). Foram utilizadas 24 borregas (mestiças) recém-desmamadas com peso vivo inicial médio de 23,1 ± 2,1kg, confinadas por 120 dias. Após o abate, foram removidos os músculos Triceps brachii (paleta), Longissimus dorsi (lombo) e Semimembranosus (pernil) para representar os respectivos cortes. O aumento nos níveis de C não influenciou a composição centesimal dos cortes cárneos e diminuiu a luminosidade (L*) e aumentou a tonalidade vermelha (a*). O lombo apresentou o menor teor de umidade (U) (699,7g/kg) e maior teor de extrato etéreo (64,5g/kg), enquanto a paleta apresentou maior teor de U (738,7g/kg) e menor teor de PB (214,0g/kg), e o pernil apresentou o maior valor para PB (232,8g/kg) e valores intermediários para U (716,3g/kg) e EE (40,1g/kg). O pernil forneceu a carne menos macia (FC=2,98kgf). Para as características físico-químicas, o lombo e a paleta apresentaram carnes com maior valor de b* e o pernil e a paleta obtiveram maiores valores para a*. As diferentes proporções V:C não alteram a composição centesimal e proporcionam valores diferentes para L* e a*. Os cortes cárneos apresentam diferenças na composição química e nas características físicas.