A study was conducted to evaluate the quality characteristics in a comparative manner of grass-fed and grain-fed beef. Thirty two commercially bred beef steers were used. These steers were assigned to one of four treatments; grain-fed, grass/grain-fed, grass-fed and irrigated. These treatments were each reflective of the ration that would be provided to the animal. Individual animal weights were recorded every 28 days throughout the portion of the study. The grain-fed animals realized the highest (P<0.05) average daily gain with the grass-fed and irrigated having the lowest. The steers were harvested when they reached the pre-determined criteria, which was 0.4 inch back fat as measured at the 12th rib via ultrasonography, for the grain-fed or 800 pounds for the grass-fed animals. All animals, once harvested, were graded based upon USDA quality grades with results mirroring those previously mentioned. Carcasses were involved in an aging study in which all left sides of the carcasses were fabricated into primal cuts, vacuumed packaged and aged for 14 days while the right sides were dry aged during the same period. Shear force data were collected to provide for a measure of tenderness. All samples were significantly (P<0.05) more tender following aging with no difference being realized between aging techniques. Percent cutout was also calculated for the two techniques to quantify what difference, if any, existed. No significant difference (P>0.05) was shown between wet and dry aging with regard to percent cutout. Sensory evaluation was also conducted based upon the attributes of juiciness, tenderness and flavor intensity. For all three attributes grain-fed beef was favored (P<0.05). The panelists detected no difference in aging technique for any of the treatments (P>0.05).Carcass soft tissue chemical composition (lipid, protein and moisture) was also evaluated for the treatments. Grain-fed beef was shown to be highest (P<0.05) for overall percent lipid and lowest for percent moisture and protein. The grass-fed carcasses were the opposite, being highest for overall moisture and protein and lowest for lipid (P<0.05).

Biochemical changes in muscle postmortem have been associated with initial beef tenderness early postmortem, and with improvements in tenderness during postmortem storage, defined as meat aging. Differences in the initial contractile state of the sarcomere, the ionic environment of the sarcoplasm including pH, the activity of neutral proteolytic enzymes, and collagen content and solubility have been associated with beef tenderness. In Phase I, steaks from four genetic lines of steers and heifers were used to understand the biochemical differences between tough and tender steaks. The most tender (< 30 N Warner Bratzler shear force (WBS)) and toughest Longissimus steaks (< 30 N WBS) from Angus, Braford, Brangus, and Simbrah heifers and steers were used. For Phase II, samples were obtained from a subset of Santa Cruz yearling heifers selected based of genotypes for tenderness (tough and tender) using a commercial genetic marker. Within genotype for tenderness, each animal was randomly assigned to one of four growth enhancement treatments. The most tender (< 30 N WBS) and toughest Longissimus steaks (< 30 N WBS) were selected for use in this study. In Phase I, tough steaks after 3, 10, and 17d postmortem had higher (P < 0.0005) WBS values than tender steaks. Tender steaks came from carcass with slightly higher (P = 0.008) marbling score and (P = 0.01) Quality grade. Sarcomere length, total and soluble collagen, potassium concentration, and m and µcalpain did not differ (P > 0.05) between tough and tender steaks. Sodium concentration at 10 d was higher (P = 0.03) in tough steaks, but only account for 0.05% of the variation in WBS at 3d. Tender steaks had less (P = 0.04) intact desmin at 24h, but intact desmin was not correlated (P > 0.05) with WBS. In Phase II, tough steaks after 3, 10, and 17d postmortem had higher (P < 0.0001) WBS values than tender steaks. Tender steaks came from carcass with slightly higher (P < 0.03) marbling score and (P = 0.02) Quality grade. Tender teaks were slightly lighter (P = 0.02), with more red (P = 0.02) and yellow (P = 0.007) color, and had slightly lower (P = 0.02) pH, compared with tough steaks. Sarcomere length, total and soluble collagen, sodium and potassium concentration, and m and µcalpain did not differ (P > 0.05) between tough and tender steaks. Tender steaks had less (P < 0.0001) intact desmin at 17d postmortem than tough steaks. Intact desmin at 17d was responsible for 4%, 47%, and 30% of WBS variation after 3, 10, and 17d postmortem, respectively. The slight difference in marbling and quality grade did not account for a significant amount of variation in WBS. However, meat color and pH accounted for variation in shear WBS. Calcium flux may have influenced meat tenderness by activation of calpains and may have altered protein to protein interactions. Results suggested that marbling, µ calpain activity, and desmin degradation, and to a lesser extent pH and meat color contributed to meat tenderness.

A high moisture corn/soybean meal-based finishing ration was used to examine the effects of roughage source (corn silage, alfalfa hay), level of dietary roughage (8, 16, 24%), and ractopamine supplementation (none, Optaflexx) on growth performance, carcass traits, and beef quality for finishing 108 steers and 24 heifers (initial BW = 308 kg). Cattle were allocated by gender to 12 management regimen subclasses. Optaflexx (trade name for ractopamine hydrochloride) was fed over the last 28 d on feed with cattle marketed after common days on feed. Growth performance (ADG, feed intake, and feed efficiency) and carcass traits were assessed on an individual animal basis. A primal rib and semitendinosus (ST) muscle from each animal were processed at the University of Guelph Meat Laboratory for carcass and meat quality evaluations. Tenderness was determined using shear force assessment of product aged 7, 14, and 21 d. Average daily gains were similar (P > 0.27) across main effects while use of corn silage as the roughage source decreased (P < 0.001) dry matter intake and improved (P < 0.001) feed efficiency compared to feeding alfalfa hay. Roughage level and beta agonist supplementation did not affect (P > 0.13) dry matter intake or feed efficiency. When the last 28 days on feed were examined, Optaflexx supplementation increased (P < 0.001) weight change, ADG, and improved feed conversion, while DMI remained unchanged (P > 0.373). Carcass traits including hot carcass weight, grade fat, longissimus muscle area, marbling, and body composition as assessed by rib dissection (% lean, fat, bone) were not affected (P > 0.14) by roughage level, source, or use of Optaflexx. Fat partitioning and liver abscess scores were unaffected (P > 0.09) by source and level of roughage fed, and use of Optaflexx. Source and level of dietary roughage did not affect color (P > 0.21) or shear force (P > 0.20) values for longissimus (LM) and semitendinosus (ST) steaks. Lower DMI and better feed conversion can be achieved using corn silage as the roughage source, while inclusion of up to 24% roughage in finishing diets may not negatively impact gains, carcass characteristics or beef quality. Beef producers may be able to increase amounts of roughage in the diet to lower cost of production without compromising growth performance and carcass and meat quality.

The objectives of this study were to 1) evaluate marker associations for genomic regions of interest and significant ontology terms, 2) evaluate and compare 4 models for their efficacy in predicting genetic merit, 3) evaluate and compare the impact of using breed-of-origin genotypes in a Bayesian prediction model, and 4) evaluate the effects of data partitioning using family structure on predictions. Nellore-Angus F2, F3 and half-sibling calves were used with records for overall temperament at weaning (OTW; a subjective scoring system; n = 769) and Warner-Bratzler shear force (WBSF; a measure of tenderness; n = 389). After filtering, 34,913 markers were available for use. Bayesian methods employed were BayesB (using ̂) and BayesC (using π = 0 and ̂) in GenSel software, where, after estimation, π ̂ = 0.995 or 0.997 for WBSF or OTW, respectively. No regions associated with either trait were found using π ̂, but when π = 0 associated regions were identified (37 and 147 regions for OTW and WBSF, respectively). Comparison of genomic estimated breeding values from these 3 Bayesian models to an animal model showed that BayesC procedures (using ̂) had the highest accuracy for both traits, but that BayesB had the lowest indication of bias in either case. Using a subset of the population (n = 440), genotypes based on the breed in which the alleles originated from (i.e., breed-of-origin genotypes) were assigned to markers mapped to autosomes (n = 34,449), and incorporated into prediction analyses using BayesB (π ̂ = 0.997) with or without nucleotide-based genotypes. In either case, there was an increase in accuracy when breed-of-origin genotypes were incorporated into prediction analyses. Data partitions based on family structure resulted in 13 distinct training and validations groups. Relationship of individuals in the training with validation individuals did have an impact in some cases, but not all. There was poor prediction of genomic estimated breeding values for individuals in the validation population using BayesB methods, but performed better in all cases than breeding values generated using an animal model. Future studies incorporating breed-of-origin genotypes are of interest to determine if accuracy is improved in these groups.

Made available in DSpace on 2014-06-11T19:32:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-02-13Bitstream added on 2014-06-13T19:22:53Z : No. of bitstreams: 1 carvalho_srst_dr_botfmvz.pdf: 515780 bytes, checksum: e44ad97228d55b58523eb7f271bd1d61 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / Foram utilizados 20 bovinos sãos, castrados, da raça Nelore, sendo divididos em cinco abates realizados em épocas diferentes. As colheitas foram divididas em 2 fases, de 10 animais cada, e para cada avaliação foram utilizados 5 animais estimulados (EE) e 5 não estimulados eletricamente (NE). O tempo de maturação foi de 28 dias. Foram avaliados força de cisalhamento, índice de fragmentação miofibrilar e avaliação sensorial no músculo Longissimus dorsi. Quando avaliada a força de cisalhamento, as carcaças estimuladas eletricamente apresentaram carne mais macia que as não estimuladas, com diferenças significativas entre os tratamentos nos períodos de 2 e 7 dias de maturação. As carcaças EE não apresentaram aumento do índice de fragmentação miofibrilar (IFM) em relação ao tempo de maturação, porém nas carcaças NE houve aumento do IFM avaliado aos 21 dias de maturação. Na avaliação sensorial, a estimulação elétrica melhorou os atributos de maciez e mastigabilidade. / Twenty healthy castrated bovines (Bos taurus indicus) were used and divided into 5 slaughters, which were done at different time. The study was divided into two phases with ten animals each, and for each evaluation 5 electrically stimulated animals and 5 non-stimulated animals were used. The ageing time was 28 days. It has been evaluated shear force, myofibril fragmentation index and sensorial evaluation in the Longissimus dorsi muscle. When the shear force was evaluated, the electrically stimulated carcasses showed a meat more tender than the non-stimulated ones, with real differences among treatments in the periods of 2 and 7 days of ageing. The electrically stimulated carcasses did not show an increase in the myofibril fragmentation index toward the ageing time. Nevertheless, in the non-stimulated carcasses there was an increase in the myofibril fragmentation index evaluated after 21 days of ageing. In the sensorial evaluation, the electric stimulation improved the attributes of tenderness and mastication.

Internal and external factors affect the quality of meat, however ageing affects final product. Main objective of this work was to determine the effects of ageing on selected physical factors (pH, colour, water holding capacity and texture shear force) which affect meat quality from consumer and further meat processing perspective. Measuring of those factors was performed in periodical time sequences (one day post-mortem and 14 days of ageing) and factors of raw and heat-modified meat were measured. There were two hundred and fifty-eight samples from Czech pied cattle used in research. Musculus longissimus lumborum et thoracis (sirloin) was analyzed. Statistically high shear force difference (P=0.001) was identified at heat-modified and aged samples (decrease from 22.574 kg to 14.885 kg). Decrease of shear force during ageing of raw meat samples was observed at normal pH (pH < 5.8) beef ? from 6.403 kg to 5.982 kg. Correlations between pH and water holding capacity was found at samples which undergone ageing (r = 0.879 ***) and also at one day post-mortem samples (r = 0.872 ***). Middle correlation was observed between colour and pH at all colour parameters ? L* (r = -0.479 ***), a* (r = -0.478 ***) and b* (r = -0.581 ***). Water holding capacity and pH have influence on shear force of raw beef and also heat-modified beef; this was confirmed by correlation analysis. Lightness (L*) and water holding capacity affect heat-modified samples texture which was confirmed with multi-regression linear analysis (R2 = 0.565). As shown above the influence of meat ageing on quality parameters is high and properly aged meat from young bulls has better texture values. If the aged beef will be sold regularly it could be expected that consumer demand will increase especially due to remove the inconsistency of the quality of beef.

Made available in DSpace on 2014-06-11T19:32:59Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-07-14Bitstream added on 2014-06-13T19:03:46Z : No. of bitstreams: 1 santos_gb_dr_botfmvz.pdf: 656292 bytes, checksum: de36c7b0fca5c7c6ac79ae4fae22735a (MD5) / Universidade Estadual Paulista (UNESP) / O trabalho objetivou identificar por eletroforese as mudanças nas frações das proteínas musculares, separadas no período post-mortem de bovinos de quatro diferentes grupos genéticos (Nelore, TRC-Brahman, Brangus e TRC-Pardo), submetidos ao modelo biológico superprecoce, assim como determinar os valores da força de cisalhamento destas amostras. Foram utilizadas 12 amostras do músculo Longissimus dorsi por grupo genético. De cada uma delas foram retiradas duas fatias, uma foi refrigerada por 24 horas e a outra foi maturada por 7 dias a 2oC. As amostras submetidas a 7 dias de maturação não diferiram quanto à maciez da carne nos grupos genéticos, mas todas apresentaram maciez aceitável, o que pode ser explicado pela baixa idade ao abate destes animais. Na análise das bandas da eletroforese, notou-se degradação da miosina (MHC) e da Troponina-T (TN-T) e o aparecimento do fragmento de 30 kDa para todos os grupos genéticos durante o período de 7 dias de maturação. / This study aimed to identify by means of eletrophoresis the changes in fractions of the muscular proteins, separated within the post-mortem period from cattle from four different genetic groups ( Nelore, TRC- Brahman, Brangus and TRC- Pardo), submitted to the superprecoce biologic model, as well as to determine the values of those samples shear force. Twelve samples of the muscle Longissimus dorsi were used for each genetic group. From each of those there were taken two slices, one of them was kept cold along 24 hours and the other one was aged during 7 days at 2oC. The samples that came through a seven-day-aging process didn't show any changes concerning the meat tenderness in the genetic groups, even though all of them had acceptable tenderness, which can be explained due to the low age of these animals when slaughtered. In the analysis of the eletrophoresis' bands, it was noticed some degradation of the myosin ( MHC) and of the Troponin-T (TN-T) and the presence of the fragment of 30 kDa for all the genetic groups during the seven-day-ageing period.

A maciez é um importante atributo de qualidade para os consumidores de carne. No entanto, não há dados específicos do impacto da maciez da carne ovina de Santa Inês sobre a percepção dos consumidores brasileiros. Portanto, o objetivo foi verificar a avaliação do consumidor de carne ovina apresentando diferentes forças de cisalhamento. Foram utilizados oito cordeiros da raça Santa Inês, que receberam a mesma dieta de terminação. Estes animais tinham 5 a 6 meses de idade e pesavam de 30 a 35 kg quando foram abatidos e suas meias carcaças foram utilizadas para obtenção de 16 amostras de Longissimus dorsi (LD). Estas foram distribuídas aleatoriamente entre quatro diferentes processamentos pós-abate (PA). Os LD usados para a obtenção da Carne Endurecida (CE) foram retirados logo após o abate (0h) e as amostras para os demais tratamentos foram retiradas na desossa às 24h PA. O tratamento para CE consistia em embalar o LD e mergulhá-lo em água a 0° C por duas horas, e logo após congelá-la. Para a obtenção da Carne Fresca (CF), o LD foi retirado na desossa (24h PA), embalado e congelado. E alguns dos bifes obtidos às 24 horas foram embalados a vácuo e maturados a 1°C durante três ou sete dias, que compõem a condição de Carne Maturada (CM) pós-morte, CM3 e CM7, respectivamente. Os principais dados obtidos foram de comprimento do sarcômero (CS), força de cisalhamento (FC), índice de fragmentação miofibrilar (IFM), bem como a aceitação de maciez, suculência e qualidade global por parte de 50 consumidores não treinados, usando escala hedônica de nove pontos. O CS foi de 1,44 &mu;m para CE, significativamente (p<0,05) mais curto que observado para CF, CM3 e CM7, que não diferiram entre si, com valores de 1,84, 1,89, 1,85 &mu;m (SEM=0,09), respectivamente. A CE alcançou FC média de 7,2 kgf, significativamente (P<0,05) mais alta que os três valores similares de 3,3, 3,1, 2,4 (SEM=0,44) observados para CF, CM3 e CM7, respectivamente. Quanto à IFM, os processos pós-abate tiveram diferença entre CE e CM7 (p<0,05), com IFM de 76,2 e 130,5, enquanto a CF e CM3 não diferiram entre os processos com valores de 97,9; 115,6; (SEM= 11,41), respectivamente. As amostras de CE receberam pontuação significativamente mais baixa (P<0,01) para todos os quesitos avaliados na análise sensorial, sendo textura 5,43, suculência 6,51 e qualidade global 5,92, os demais tratamentos tiveram notas acima de 7 para todas as características, mas não diferiram entre si (P<0,01). Os consumidores foram capazes de perceber e avaliaram negativamente a maciez da carne de cordeiro que apresentou alta força de cisalhamento quando comparada com carnes com valores que as caracterizariam como macias. As avaliações de suculência e qualidade global acompanharam a percepção da maciez. Concluiu-se que os consumidores percebem e avaliam negativamente carne de cordeiro com alto valor de força de cisalhamento. No entanto, os dados obtidos não foram capazes de elucidar impacto de diferenças menores na força de cisalhamento entre amostras duras e macias sobre a aceitação do consumidor não treinado. / Tenderness is an important meat quality trait for consumers. However, there is no specific data in the impact of Santa Inês lamb meat tenderness on Brazilian consumers perception. Therefore, objective was to verify the consumer evaluation of lamb meat with different shear force. We used eight Santa Inês lambs that were fed the same diet. These animals of 5 to 6 months of age and weighing 30 to 35 Kg were slaughtered and their half carcasses were used to obtain 16 samples of Longissimus dorsi (LD). These were randomly assigned among four diferent post-slaughter (PS) managements. The LD used for obtaining Toughened Meat (TM) were removed immediately after slaughter (0h ps) and samples for the other managements were obtained from boning at 24h PS. The samples from TM consisted in wrapping excised LD in plastic bag and dipping it into water bath with ice at 0°C for two hours, followed by freezing. Fresh Meat (FM) was obtained from LD removed at boning (24 hours postmortem), followed by wrapping and freezing. And some of steaks obtained at 24 hours were vaccumm packaged and aged at 1 °C for three or seven days, which compose the aging (A) postmortem, A3 and A7, respectively. The sarcomere length (SL), shear force (SF), myofibrillar fragmentation index (MFI), as well as sensory analysis of tenderness, juiciness and overall quality acceptance by 50 not trained consumers using hedonic scale of nine points, were obtained. The SL was 1.44 &mu;m for TM, significantly (P<0.05) shorter than the other treatments. The values of 1.84, 1.89, 1.85 (SEM=0,09) &mu;m for FM, A3 and A7, respectively, didn\'t differ and are values normally reported for post-rigor lamb meat. MT reached an average 7.2 kgf for SF, significantly (P <0.05) higher than 3.3, 3.1, 2.4 (SEM= 0,44) observed for FM, A7 and A3, respectively. As for the MFI, post-slaughter processes had difference between TM and A7 (P<0.05), with IFM 76.2 and 130.5, while FM and A3 did not differ between cases with values 97.9; 115.6; (SEM = 11.41), respectively. Samples from TM received the lowest scores (P<0.01) for all items assessed in sensory analysis, and texture 5.43, juiciness 6.51 and overall quality 5.92, the other treatments were notes above 7 for all traits, but not significantly different (P<0.01). Consumers were able to understand and evaluate negatively the tenderness of lamb that showed high shear force compared to meat with values at low levels, which characterize as tender. It was concluded that consumers will perceive and evaluate negatively lamb meat with high shear force value. However, the results are not conclusive whether smaller differences between tough and tender meat would still have impact on not trained consumer acceptance.

Made available in DSpace on 2014-06-11T19:28:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-25Bitstream added on 2014-06-13T19:16:09Z : No. of bitstreams: 1 pivaro_tm_me_jabo.pdf: 588445 bytes, checksum: 95df0e35e0500ea8feeb836651cb1172 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / No presente trabalho, avaliou-se o efeito do processo de maturação na qualidade da carne do músculo Longissimus de 35 tourinhos da raça Nelore confinados por 96 dias e abatidos com peso de 532,17 ± 30,25kg e 24 meses de idade. Os animais foram alimentados com uma dieta controle sem a adição de óleo e outras quatro dietas contendo diferentes fontes de óleo (soja ou linhaça) protegido ou não da degradação ruminal. Após o abate e 24 horas de resfriamento foram retirados 3 bifes de 2,5cm de espessura entre a 12a e 13a costelas do músculo Longissimus, posteriormente embalados à vácuo e maturados em estufa B.O.D. à temperatura de 2oC durante 7, 14 e 21 dias. Em seguida, foram analisadas as seguintes características: força de cisalhamento, ph, cor, perdas na maturação e composição química da carne assada. Após liofilização, o extrato etéreo foi extraído, metilado e as leituras realizadas por cromatografia gasosa. O delineamento estatístico utilizado foi em blocos casualizados, sendo 5 tratamentos, em 7 blocos e utilizadas 4 medidas repetidas no tempo. As variáveis foram avaliadas por meio de análise de variância e teste t Student à 5% de probabilidade e para as características sensoriais da carne foi utilizado o teste não paramétrico de Kruskal-Wallis. Houve efeito significativo para as variáveis matéria seca, extrato etéreo e matéria mineral. A força de cisalhamento apresentou diferenças entre os grupos de bifes maturados, (5,97; 4,31; 3,25 e 2,96kgf/cm2, para 0, 7, 14 e 21 dias de maturação, respectivamente), sendo que o tempo 14 e 21 foram mais macios que o tempo 7, e este, mais macio que o tempo 0. O ph apresentou diferença entre a carne in natura e os períodos de maturação. Houve efeito significativo para a maturação das variáveis luminosidade, intensidade da cor vermelha e intensidade da cor amarela. As perdas por exsudação na maturação... / In this study, we assess the effect of the ageing process in the meat quality of Longissimus muscles from 35 Nellore bulls young bulls confined for 96 days and slaughtered weighing 532.17 ± 30.25 kg and 24 months of age. The animals were fed with five different diets: the first one was a control diet, without oil and the other four diets containing different oil sources (soy or flaxseed) protected or not from ruminal degradation. After slaughter and 24 hours of cooling, 3 samples with 2.5 cm thickness were removed between the 12th and 13th ribs of Longissimus muscles and subsequently vacuum packaged and aged in an environmental chamber at a temperature of 2o C for 7, 14 and 21 days. We assess the characteristics: shear force, pH, color, ageing losses, chemical composition and fatty acids of meat. The fatty acids were assess by gas chromatography. Variables were evaluated by analysis of variance and Student t test at 5% probability and the sensory characteristics of meat was used nonparametric Kruskal-Wallis test. Shear force differed between the ageing groups, (5.97; 4.31, 3.25 and 2.96 Kgf/cm2 to 0, 7, 14 and 21 days) the period 14 and 21 were softer than the period 7. The pH was different between the fresh beef and the other periods. There was a significant effect on the variable lightness, red color intensity and intensity of yellow color. The losses were larger as the period of ageing increased, and the period of 21 days showed 5.58% of losses. The sensory evaluation showed the difference to variable smoothness for the period of 7 days.. There was a significant effect on concentration of myristic acids (C14: 0), miristoleico \ (C14: 1), pentadecanoic (C15: 0), palmitic (C16: 0), palmitoleic (C16: 1) vacênico (C18: 1 n7) and oleic (C18: 1 n9). In contrast there was an increase in the levels of stearic (C18: 0), linoleic (C18: 2 n6) eicosenoic (C20: 1 n9), eicosadienoico (C20: 2) ... (Complete abstract click electronic access below)

Made available in DSpace on 2014-06-11T19:28:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-23Bitstream added on 2014-06-13T20:28:01Z : No. of bitstreams: 1 vieira_ldc_me_jabo.pdf: 386143 bytes, checksum: ef616fd81495dd161b9f57bba8ca738c (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Avaliou-se o efeito de diferentes períodos de maturação (1, 7, 14 dias) sobre a qualidade da carne de dois músculos (Longíssimus dorsi e Tríceps braquii) de bovinos cruzados, criados em confinamento no sistema “superprecoce”. Foram utilizados 40 bovinos machos não castrados, divididos em quatro cruzamentos, oriundos do acasalamento de fêmeas cruzadas ½ angus + ½ nelore e ½ simental + ½ nelore com touros das raças Angus e Wagyu. Os animais foram confinados em lotes de 4 animais por baia divididos por grupo genético. Após o abate e estabelecimento do rigor-mortis (24 horas) coletou-se amostras dos músculos Longíssimus dorsi e Tríceps braquii, que foram embalados a vácuo e submetidos à maturação (0, 7 e 14 dias). Foram avaliadas características qualitativas (capacidade de retenção de água, cor, pH, perdas de peso por cozimento e força de cisalhamento) e sensoriais (sabor, odor, suculência, fibrosidade, maciez, sabor de gordura e aceitação global). Utilizou-se um delineamento inteiramente casualizado em esquema fatorial 4 x 3 x 2 (4 cruzamentos x 3 períodos de maturação x 2 músculos) com 10 repetições. Os dados foram submetidos à análise de variância e as médias comparadas pelo teste Tukey com 5% de significância. A maturação é eficiente na melhoria da maciez da carne dos animais avaliados. Os animais filhos de touro Wagyu apresentaram carne com sabor de gordura mais acentuado através da avaliação sensorial. O músculo Tríceps brachii foi considerado mais macio e mais suculento tanto na análise sensorial como nas análises físicas, contudo, o músculo Longíssimos dorsi apresentou maior aceitação global / We evaluated the effect of different periods of maturation aged (0, 7 and 14 days) on meat quality of two muscles (Longíssimus dorsi and Triceps braquii) of crossbred beef cattle, reared in confinement in the system “youngbulls”. We used 40 bulls divided into four crossbred from the mating of cows crossbred ½ Angus + ½ Nelore e ½ Simental + ½ Nelore with bulls Angus and Wagyu. The animals were confined in collective stalls 4 animals for pen divided by genetic groups. After slaughter and establishment of rigor mortis (24 hours) samples were collected from muscles Longíssimus dorsi e Triceps braquii, which were vacuum packed and submitted of maturation aged (0, 7 and 14 days). We evaluated quality characteristics (water-holding capacity, color, pH, weight loss for cooking and shear force) and sensory (flavor, scent, juiciness, fibrousness, softness, fat flavor and global acceptance). It was used a 4 x 3 x 2 factorial arrangement (4 crossbred x 3 maturation aged x 2 muscles) with 10 replicates. The dates submitted analysis of variance and the means were compared by Tykey's test (5%). The maturation aged is proved effective improvement the meat in the animals evaluated. The animals crossbred Wagyu bull presented meat-flavored fat sharper through sensory evaluation. The muscle Tríceps brachii was considered more soft and juicy both in sensory evaluation as in physical analysis, however, the muscle Longíssimus dorsi showed higher global acceptance