Effect of free range rearing on growth and meat quality of three different local chicken's phenotypes

The present study was undertaken in order to evaluate the growth performances and meat quality of three indigenous chickens phenotypes reared under extensive conditions in the region of Chlef in Algeria. A week after hatching, 3 random groups of 35 chicks from each phenotype; normal plumage free-range chicken (NPFRC), crested free-range chicken (CFRC) and naked neck free-range chicken (NNFRC) were chosen and reared in free-range conditions for 18 weeks. The highest growth performance was shown by the crested free-range chicken (CFRC). In terms of meat quality, the analysis of variance (ANOVA) showed that crested phenotype (CFRC) showed the best nutritional qualities especially proteins and moisture. The discriminant analysis revealed that CFRC and NNFRC were better in terms of tenderness and overall acceptability. As consequence of these very interesting qualities, these local breeds should be considered for extensive production in order to provide a good quality meat, while assuring their preservation.(AU)

Performance and meat quality of Label Rouge chickens at different slaughter ages / Parâmetros de produção e qualidade da carne de frangos Label Rouge em diferentes idades de abate

This study evaluated the performance parameters, carcass characteristics, and meat quality of Label Rouge chickens raised under an alternative system as a function of age at slaughter. The design was completely randomized with a 5×2 factorial arrangement, with slaughtering at five ages (70, 90, 120, 150, and 180 days) and two sexes. A total of 240 birds (Pescoço Pelado strain) were used, including 120 females and 120 males. Performance, carcass, physicochemical, proximate composition, and muscle fiber traits were evaluated. Rearing time and sex had significant effects on performance-related traits, with better results for males. The interaction between slaughter age and sex had a significant effect on the carcass and physicochemical parameters, which cause different responses in males and females with increasing slaughter age. For the proximate composition and muscle fiber analysis, the interaction between the parameters studied only had a significant effect on ether extract in the breast. The increase in age resulted in chickens with higher live and carcass weight at slaughter but lower performance indices. Females had lower carcass yield and greater deposition of abdominal fat. Females had lower tenderness in the drumstick and males in the breast with increasing slaughter age, and both cuts had more intense color and redness and reduced lightness starting at the slaughter age of 90 days.

O objetivo deste estudo foi avaliar os parâmetros de desempenho e as características de carcaça e qualidade da carne de frangos Label Rouge criados em sistema alternativo em função do aumento da idade de abate. O delineamento foi inteiramente casualizado (DIC) disposto em esquema fatorial (2x5), sendo dois sexos (macho e fêmea) e cinco idades de abate (70, 90, 120, 150 e 180 dias). Foram utilizadas 240 aves (Pescoço Pelado), sendo 120 fêmeas e 120 machos, sendo avaliados os parâmetros de desempenho, carcaça, físico-químicos, composição centesimal e fibra muscular. Com o aumento no tempo de produção houve efeitos dos períodos de produção e sexo em relação a variáveis de desempenho, com melhores resultados para os machos. Para os parâmetros de carcaça e físico-químicos, houve interação entre sexo e idade de abate, revelando comportamento diferenciado para machos e fêmeas com aumento da idade de abate. Para a composição centesimal e análise das fibras musculares, somente para extrato etéreo no peito foi verificado interação entre os fatores estudados. O aumento da idade proporcionou a obtenção de frangos com maiores pesos vivos e de carcaça ao abate com consequente redução dos índices de desempenho, além de menor rendimento de carcaça e maior deposição de gordura abdominal nas fêmeas. As fêmeas apresentam menor maciez na coxa e os machos no peito com aumento da idade de abate e, em ambos os cortes, ocorreu maior intensificação da cor, índice de vermelho e redução do brilho a partir de 90 dias ou em maiores idades de abate.

Performance and meat quality of Label Rouge chickens at different slaughter ages / Parâmetros de produção e qualidade da carne de frangos Label Rouge em diferentes idades de abate

ABSTRACT: This study evaluated the performance parameters, carcass characteristics, and meat quality of Label Rouge chickens raised under an alternative system as a function of age at slaughter. The design was completely randomized with a 5×2 factorial arrangement, with slaughtering at five ages (70, 90, 120, 150, and 180 days) and two sexes. A total of 240 birds (Pescoço Pelado strain) were used, including 120 females and 120 males. Performance, carcass, physicochemical, proximate composition, and muscle fiber traits were evaluated. Rearing time and sex had significant effects on performance-related traits, with better results for males. The interaction between slaughter age and sex had a significant effect on the carcass and physicochemical parameters, which cause different responses in males and females with increasing slaughter age. For the proximate composition and muscle fiber analysis, the interaction between the parameters studied only had a significant effect on ether extract in the breast. The increase in age resulted in chickens with higher live and carcass weight at slaughter but lower performance indices. Females had lower carcass yield and greater deposition of abdominal fat. Females had lower tenderness in the drumstick and males in the breast with increasing slaughter age, and both cuts had more intense color and redness and reduced lightness starting at the slaughter age of 90 days.

RESUMO: O objetivo deste estudo foi avaliar os parâmetros de desempenho e as características de carcaça e qualidade da carne de frangos Label Rouge criados em sistema alternativo em função do aumento da idade de abate. O delineamento foi inteiramente casualizado (DIC) disposto em esquema fatorial (2x5), sendo dois sexos (macho e fêmea) e cinco idades de abate (70, 90, 120, 150 e 180 dias). Foram utilizadas 240 aves (Pescoço Pelado), sendo 120 fêmeas e 120 machos, sendo avaliados os parâmetros de desempenho, carcaça, físico-químicos, composição centesimal e fibra muscular. Com o aumento no tempo de produção houve efeitos dos períodos de produção e sexo em relação a variáveis de desempenho, com melhores resultados para os machos. Para os parâmetros de carcaça e físico-químicos, houve interação entre sexo e idade de abate, revelando comportamento diferenciado para machos e fêmeas com aumento da idade de abate. Para a composição centesimal e análise das fibras musculares, somente para extrato etéreo no peito foi verificado interação entre os fatores estudados. O aumento da idade proporcionou a obtenção de frangos com maiores pesos vivos e de carcaça ao abate com consequente redução dos índices de desempenho, além de menor rendimento de carcaça e maior deposição de gordura abdominal nas fêmeas. As fêmeas apresentam menor maciez na coxa e os machos no peito com aumento da idade de abate e, em ambos os cortes, ocorreu maior intensificação da cor, índice de vermelho e redução do brilho a partir de 90 dias ou em maiores idades de abate.

Comparative analysis of various sources of selenium on the growth performance and antioxidant status in broilers under heat stress

Abstract The supplementation of Selenium-enriched probiotics is effective in reducing oxidative stress and maintaining meat quality stability in broiler chicken especially under heat stress. An experimental study was conducted to perform Comparative analysis of Selenium yeast with inorganic Se in broilers under heat stress. A total of 120 broilers chicks of one day were assigned to 4 groups each consisting 30 chicks fed on same basal diet but different selenium sources. The basal diet of group D1 was not supplemented with Se source (Negative control), group D2 basal diet was supplemented with inorganic selenium (Sodium selenite 0.22mg/Kg starter phase and 0.15mg/Kg finisher phase), group D3 basal diet was supplemented with commercially available organic selenium (Seleno-methionine 0.22mg/Kg starter phase and 0.15mg/Kg finisher phase) and group D4 basal diet was supplemented with self-developed organic selenium (Se-enriched yeast 0.22mg/Kg starter phase and 0.15mg/Kg finisher phase). The performance parameters i.e. feed intake (FI), live body weight (BW) and FCR were not significantly (p>0.05) effected by selenium supplementation in the starter phase but were significantly (p 0.05) effected in the finisher phase. Selenium supplementation significantly (p 0.05) effected serum Se level in different supplemented groups. Higher serum Se value (58.20±0.06) was recorded in D4 group. Similarly significantly lower selenium value was recorded for D4 and higher was recorded for D1 (11.36±0.08). However lower serum Paraoxonase (PON) value was recorded for D4 (13.24±0.01) and higher for D1 (13.33±0.03). Comparatively self-developed Se enriched yeast increased the Se accumulation and improved antioxidant system. Glutathione peroxidase (GPx) was found higher in D4 (12.333±0.03) followed by D3, D2 and D1 respectively. Whereas superoxide dismutase (SOD) was significantly lower (p 0.05) in D4 (0.1437±0.003) followed by D3 (0.1457±0.002). Selenium supplementation increased the birds survival rate. Birds fed on Se enriched yeast showed higher Se deposition and better antioxidant capacity as compared to other sources of selenium. Se-enriched yeast displayed an improved result on Se deposition in tissues, and oxidative capacity, meat tenderness and immune response level as compared to other sources of selenium.

Resumo A suplementação de probióticos enriquecidos com selênio é eficaz na redução do estresse oxidativo e na manutenção da estabilidade da qualidade da carne em frangos de corte, especialmente sob estresse por calor. Um estudo experimental foi conduzido para realizar uma análise comparativa da levedura selênio com o Se inorgânico em frangos de corte sob estresse térmico. Um total de 120 pintos de um dia foi dividido em 4 grupos, cada um consistindo de 30 pintos alimentados com a mesma dieta basal, mas com diferentes fontes de selênio. A dieta basal do grupo D1 não foi suplementada com fonte de Se (controle negativo), a dieta basal do grupo D2 foi suplementada com selênio inorgânico (selenito de sódio 0,22 mg / kg fase inicial e 0,15 mg / kg fase finalizadora), a dieta basal do grupo D3 foi suplementada com selênio orgânico disponível comercialmente (fase inicial de seleno-metionina 0,22 mg / kg e fase finalizadora de 0,15 mg / kg) e a dieta basal do grupo D4 foi suplementada com selênio orgânico autodesenvolvido (fermento enriquecido com Se 0,22 mg / kg fase inicial e 0,15 mg / kg fase finalizadora). Os parâmetros de desempenho, ou seja, consumo de ração (FI), peso corporal vivo (PC) e FCR não foram significativamente (p > 0,05) afetados pela suplementação de selênio na fase inicial, mas foram significativamente (p 0,05) afetados na fase final. A suplementação de selênio afetou significativamente (p 0,05) o nível de Se sérico em diferentes grupos suplementados. O maior valor de Se sérico (58,20 ± 0,06) foi registrado no grupo D4. Da mesma forma, valor de selênio significativamente menor foi registrado para D4 e maior foi registrado para D1 (11,36 ± 0,08). No entanto, um valor mais baixo de Paraoxonase (PON) sérica foi registrado para D4 (13,24 ± 0,01) e mais alto para D1 (13,33 ± 0,03). A levedura enriquecida com Se comparativamente autodesenvolvida aumentou o acúmulo de Se e melhorou o sistema antioxidante. A glutationa peroxidase (GPx) foi encontrada maior em D4 (12,333 ± 0,03) seguido por D3, D2 e D1 respectivamente. Enquanto a superóxido dismutase (SOD) foi significativamente menor (p 0,05) em D4 (0,1437 ± 0,003) seguido por D3 (0,1457 ± 0,002). A suplementação de selênio aumentou a taxa de sobrevivência da ave. Aves alimentadas com levedura enriquecida com Se apresentaram maior deposição de Se e melhor capacidade antioxidante em comparação com outras fontes de selênio. A levedura enriquecida com Se apresentou um resultado melhorado na deposição de Se nos tecidos, capacidade oxidativa, maciez da carne e nível de resposta imune em comparação com outras fontes de selênio.

Comparative analysis of various sources of selenium on the growth performance and antioxidant status in broilers under heat stress / Análise comparativa de várias fontes de selênio no desempenho de crescimento e status antioxidante em frangos de corte sob estresse térmico

Abstract The supplementation of Selenium-enriched probiotics is effective in reducing oxidative stress and maintaining meat quality stability in broiler chicken especially under heat stress. An experimental study was conducted to perform Comparative analysis of Selenium yeast with inorganic Se in broilers under heat stress. A total of 120 broilers chicks of one day were assigned to 4 groups each consisting 30 chicks fed on same basal diet but different selenium sources. The basal diet of group D1 was not supplemented with Se source (Negative control), group D2 basal diet was supplemented with inorganic selenium (Sodium selenite 0.22mg/Kg starter phase and 0.15mg/Kg finisher phase), group D3 basal diet was supplemented with commercially available organic selenium (Seleno-methionine 0.22mg/Kg starter phase and 0.15mg/Kg finisher phase) and group D4 basal diet was supplemented with self-developed organic selenium (Se-enriched yeast 0.22mg/Kg starter phase and 0.15mg/Kg finisher phase). The performance parameters i.e. feed intake (FI), live body weight (BW) and FCR were not significantly (p>0.05) effected by selenium supplementation in the starter phase but were significantly (p<0.05) effected in the finisher phase. Selenium supplementation significantly (p<0.05) effected serum Se level in different supplemented groups. Higher serum Se value (58.20±0.06) was recorded in D4 group. Similarly significantly lower selenium value was recorded for D4 and higher was recorded for D1 (11.36±0.08). However lower serum Paraoxonase (PON) value was recorded for D4 (13.24±0.01) and higher for D1 (13.33±0.03). Comparatively self-developed Se enriched yeast increased the Se accumulation and improved antioxidant system. Glutathione peroxidase (GPx) was found higher in D4 (12.333±0.03) followed by D3, D2 and D1 respectively. Whereas superoxide dismutase (SOD) was significantly lower (p<0.05) in D4 (0.1437±0.003) followed by D3 (0.1457±0.002). Selenium supplementation increased the bird's survival rate. Birds fed on Se enriched yeast showed higher Se deposition and better antioxidant capacity as compared to other sources of selenium. Se-enriched yeast displayed an improved result on Se deposition in tissues, and oxidative capacity, meat tenderness and immune response level as compared to other sources of selenium.

Resumo A suplementação de probióticos enriquecidos com selênio é eficaz na redução do estresse oxidativo e na manutenção da estabilidade da qualidade da carne em frangos de corte, especialmente sob estresse por calor. Um estudo experimental foi conduzido para realizar uma análise comparativa da levedura selênio com o Se inorgânico em frangos de corte sob estresse térmico. Um total de 120 pintos de um dia foi dividido em 4 grupos, cada um consistindo de 30 pintos alimentados com a mesma dieta basal, mas com diferentes fontes de selênio. A dieta basal do grupo D1 não foi suplementada com fonte de Se (controle negativo), a dieta basal do grupo D2 foi suplementada com selênio inorgânico (selenito de sódio 0,22 mg / kg fase inicial e 0,15 mg / kg fase finalizadora), a dieta basal do grupo D3 foi suplementada com selênio orgânico disponível comercialmente (fase inicial de seleno-metionina 0,22 mg / kg e fase finalizadora de 0,15 mg / kg) e a dieta basal do grupo D4 foi suplementada com selênio orgânico autodesenvolvido (fermento enriquecido com Se 0,22 mg / kg fase inicial e 0,15 mg / kg fase finalizadora). Os parâmetros de desempenho, ou seja, consumo de ração (FI), peso corporal vivo (PC) e FCR não foram significativamente (p > 0,05) afetados pela suplementação de selênio na fase inicial, mas foram significativamente (p < 0,05) afetados na fase final. A suplementação de selênio afetou significativamente (p < 0,05) o nível de Se sérico em diferentes grupos suplementados. O maior valor de Se sérico (58,20 ± 0,06) foi registrado no grupo D4. Da mesma forma, valor de selênio significativamente menor foi registrado para D4 e maior foi registrado para D1 (11,36 ± 0,08). No entanto, um valor mais baixo de Paraoxonase (PON) sérica foi registrado para D4 (13,24 ± 0,01) e mais alto para D1 (13,33 ± 0,03). A levedura enriquecida com Se comparativamente autodesenvolvida aumentou o acúmulo de Se e melhorou o sistema antioxidante. A glutationa peroxidase (GPx) foi encontrada maior em D4 (12,333 ± 0,03) seguido por D3, D2 e ​​D1 respectivamente. Enquanto a superóxido dismutase (SOD) foi significativamente menor (p < 0,05) em D4 (0,1437 ± 0,003) seguido por D3 (0,1457 ± 0,002). A suplementação de selênio aumentou a taxa de sobrevivência da ave. Aves alimentadas com levedura enriquecida com Se apresentaram maior deposição de Se e melhor capacidade antioxidante em comparação com outras fontes de selênio. A levedura enriquecida com Se apresentou um resultado melhorado na deposição de Se nos tecidos, capacidade oxidativa, maciez da carne e nível de resposta imune em comparação com outras fontes de selênio.

Extruded urea could replace true protein source in supplements for lambs finished in tropical pastures / A ureia extrusada pode substituir a fonte de proteína verdadeira em suplementos para cordeiros terminados em pastagens tropicais

The aim of this study was to evaluate the effects of replacing 50% of the true protein from soybean meal with extruded urea on the performance and carcass characteristics of lambs finished on pasture. Twenty lambs with initial weight of 29.9±6.2kg and 5 months of age, distributed in two treatments in blocks at random, were kept in pastures of Urochloa spp. Supplemented with 2% of body weight (BW). The treatments consisted of supplements containing soybean meal as the only true protein source (control), or extruded urea replacing 50% of soybean meal (NPN treatment). There was no effect of treatment on total supplement intake. There were differences in average daily gain (242.1 vs. 264.6g/day), slaughter weight (41.9 vs. 45.0kg) and carcass weight (18.9 vs. 20.1kg). There was no effect of the treatment on the final body condition score, hot carcass yield, carcass length, breast depth, subcutaneous fat thickness or rib eye area. The group of animals that received extruded urea showed superior carcass finishing characteristics (99.0% vs. 66.0%), maturity (22.0% vs. 0.0%), marbling (55.0% vs. 33.0%), meat texture (44.0% vs. 33.0%) and fat (66.0% vs. 22.0%). There were no significant effects on tenderness (7.5kg/f) or flesh color (L* = 33.2; a* = 16.2; b* = 8.3). There were no significant changes in the biochemical profile of the animals' blood during the experiment for both treatments. The replacement of 50% of protein from soybean meal by the extruded urea as NPN source in the supplement for lambs finished in Urochloa spp pastures provides better animal performance and qualitative characteristics of meat, without altering quantitative carcass characteristics.

Objetivou-se avaliar os efeitos da substituição de 50% da proteína verdadeira do farelo de soja por ureia extrusada sobre o desempenho e as características de carcaça de cordeiros terminados em pasto. Vinte cordeiros de 29,9+6,2kg de peso inicial e com cinco meses de idade, distribuídos em dois tratamentos em blocos ao acaso, foram mantidos em pastagens de Urochloa spp. suplementado com 2% do peso vivo (PV). Os tratamentos consistiram em suplementos contendo farelo de soja como única fonte de proteína verdadeira (controle), ou ureia extrusada em substituição a 50% do farelo de soja (tratamento NPN). Não houve efeito do tratamento na ingestão total de suplemento. Houve diferenças no ganho médio diário (242,1 vs. 264,6 g/dia), no peso ao abate (41,9 vs. 45,0kg) e no peso da carcaça (18,9 vs. 20,1kg). Não houve efeito do tratamento sobre escore de condição corporal final, rendimento de carcaça quente, comprimento de carcaça, profundidade do peito, espessura de gordura subcutânea ou área de olho de lombo. O grupo de animais que recebeu ureia extrusada apresentou características superiores de acabamento de carcaça (99,0% vs. 66,0%), maturidade (22,0% vs. 0,0%), marmoreio (55,0% vs. 33,0%), textura da carne (44,0% vs. 33,0%) e gordura (66,0% vs. 22,0%). Não houve efeitos significativos na maciez (7,5 kg/f) nem na cor da carne (L*= 33,2; a*= 16,2; b * = 8,3). Não houve mudanças significativas no perfil bioquímico do sangue dos animais durante o experimento para ambos os tratamentos. A substituição de 50% da proteína do farelo de soja pela ureia extrusada como fonte de NPN no suplemento para cordeiros terminados em pastagem de Urochloa spp. proporciona melhor desempenho animal e características qualitativas da carne, sem alterar as características quantitativas da carcaça.

Fatty acid profile and beef quality of Nellore and Angus bulls fed whole shelled corn

ABSTRACT: This study aimed to evaluate the quality traits and fatty acid profile of beef from Nellore and Angus bulls fed whole shelled corn (WSC) and ground corn plus maize silage (GC) diets. Eighteen Nellore and 18 Angus young bulls [381 ± 12 kg initial body weight (BW) and an average age of 20 ± 1.9 months] were used in a completely randomized design using a 2 × 2 factorial arrangement and were slaughtered at a final BW of 451.5 kg and 545.5 kg, respectively. Twentyfour hours after slaughter, samples of longissimus thoracis muscle were collected for the analysis of lipid oxidation, color, fatty acid profile, shear force, and cooking loss. There was no effect of diet × breed interaction on meat color, lipid oxidation, shear force, and cooking loss. Angus beef had lower shear force (p 0.05) than Nellore beef and had a greater concentration of linoleic acid and polyunsaturated fatty acids (PUFA) (p 0.01). Beef of bulls fed WSC tended to have greater concentration of CLA C18:2c9t11 (p = 0.09), greater concentration of CLA C18:2t10c12 (p = 0.01), and PUFA (p = 0.05), and consequently, higher oxidation levels. Angus bulls produced beef with greater tenderness and PUFA concentration. The results of fatty acid show a possible change in biohydrogenation when animals are fed the WSC diet, reducing lipogenesis, as this diet increases the C18:2t10c12 content.

Chitosan Edible Coating as Decontaminant During Water Thawing of Frozen Broiler Carcasses

The present study was designed to evaluate the effects of chitosan edible coating applications on the sensory, physicochemical, and bacterial load on chicken during thawing. Edible coatings prepared with 0.5 &1% chitosan in acetic acid (0.5%), was used as thawing solution. The frozen chicken was submerged for 2 hrs in tap water as control, 0.5 &1% chitosan treatments. Chitosan 1% coating improves tenderness and in turn overall acceptability scores. The result of shear force analysis emphasized the tenderness sensory scores of cooked broilers. Application of chitosan coat reduces pH value, APC, Psychrotrophic count, with significant (p<0.05) reduction in thawed broilers with 1% chitosan coat. Therefore, commercial chitosan can be applied in water thawing of frozen broiler to improve the quality characteristics economically. The results demonstrate that the application of chitosan can be an effective method for reducing contamination in chicken meat during thawing.(AU)

Gender, lineage, and age on muscle morphometry traits and meat tenderness of free-range chickens / Associação de fatores de produção e de morfometria muscular sobre a maciez da carne de frangos caipiras

This study assessed whether the meat tenderness of broilers raised in a free-range system varies by sex, lineage, and age at the time of slaughter. Physicochemical parameters were measured to adequately assess breast and thigh muscle morphometry, including shear force (SF), muscle fibre diameter (MD), histological connective tissue (HCT) content, and total and soluble collagen contents (TCC and SCC, respectively). The experiment was conducted with a completely randomized design using two lineages (Pescoço Pelado and Paraíso Pedrês), with specimens of both sexes raised in a free-range system. Randomly selected broilers were slaughtered at 65, 75, 85, and 95 days old. A total of 192 birds were analysed. SF values correlated positively with age. The highest SF values were measured in thighs of the Pescoço Pelado lineage. Age also showed a positive correlation with MD and HCT content of the breast regardless of lineage. Gender did not have any significant correlation with physical parameters; although, higher values were measured in thighs of the Paraíso Pedrês than in those of the Pescoço Pelado lineage. There were no significant differences among treatments regarding the SCC and TCC of thighs and breasts. Principal component analysis (PCA) revealed relationships between SF and the rest of the measured attributes. PCA showed that age was positively correlated with the SF, MD, and HCT content of thighs and breasts. In contrast, SCC and TCC had negative correlations. The greatest breast and thigh MD values were associated with the least tender meat. Thus, age at the time of slaughter proved to be the most significant parameter impacting the physical characteristics of muscle morphometry and meat tenderness of breasts and thighs of broilers raised in a free-range system.

Objetivou-se com este estudo avaliar os fatores relacionados a maciez da carne de frangos criados em sistema alternativo. Para o experimento foi avaliado a força de cisalhamento, diâmetro das fibras musculares do peito e da coxa, conteúdo de tecido conjuntivo através de histologia e teor de colágeno solúvel e total. O experimento foi executado em delineamento inteiramente casualizado (DIC) com uso de duas linhagens (Pescoço Pelado e Paraíso Pedrês) de ambos os sexos (macho e fêmea) e abatidos em quatro idades (65, 75, 85 e 95 dias), criados em sistema alternativo, sendo utilizado um total de 192 aves. Para força de cisalhamento (FC), ocorreu aumento nos valores em ambos os cortes em função da idade de abate e houve interação entre linhagem e sexo, com as maiores médias para os machos da linhagem Pescoço Pelado e diferença entre sexo para Paraíso Pedrês. A idade de abate influenciou o diâmetro das fibras musculares e o conteúdo de tecido conjuntivo do peito e da coxa, havendo aumento linear destes parâmetros em função da idade ao abate. O sexo não afetou o diâmetro das fibras musculares da coxa, enquanto na linhagem Paraíso Pedrês foram verificadas maiores médias em relação à Pescoço Pelado. A análise de componentes principais demonstrou a relação entre a força de cisalhamento e as demais variáveis analisadas. Assim, o aumento do diâmetro das fibras musculares do peito e da coxa também está relacionado à redução da maciez da carne de frangos caipiras, conjuntamente com o aumento da quantidade de tecido conjuntivo, teor de colágeno total e redução de sua solubilidade.

Expression of calpain system transcripts responds inversely to beef tenderization after vitamin D3 supplementation in Nellore cattle / Expressão de transcritos do sistema calpaína responde de forma inversa ao amaciamento após suplementação com vitamina D3 em bovinos Nelore

Uma vez que o sistema calpaína é central para o amaciamento da carne e dada a importância da atividade de calpastatina na determinação da maciez de bifes de bovinos Bos taurus indicus, o objetivo do presente estudo foi determinar se a expressão do gene de µ-calpaína (CAPN1), calpastatina total (CAST T), e suas variantes (CAST I e II) foi induzido pela inclusão de vitamina D3 na dieta. Os animais receberam nenhuma ou 2 × 106 UI dose de vitamina D3 por 2 ou 8 dias antes do abate, e foram submetidos a diferentes condições durante o confinamento: exposição solar ou sombreamento artificial. Bifes do Longissimus lumborum foram fabricados e submetidos a maturação por 1, 7, e 21 dias post-mortem e posteriormente usados para determinação da força de cisalhamento e do índice de fragmentação miofibrilar. Vitamina D3 não influenciou a abundância de RNAm, exceto para maior abundância de transcritos de CAST II em animais que foram suplementados por 8 dias antes do abate. Foi encontrada associação negativa entre a abundância de CAST II e a força de cisalhamento. Essa contradição revela uma importante modulação da expressão do sistema calpaína resultado da suplementação com vitamina D que pode ser importante na determinação de estratégias para melhorar a maciez da carne.(AU)

The calpain system is the central player for meat tenderization and the calpastatin activity plays an important role in beef tenderness of Bos taurus indicus cattle. This study investigated whether dietary vitamin D3 induced gene expression of µ-calpain (CAPN1), total calpastatin (CAST T), and their variants (CAST I and II). Animals received none or 2 × 106 IU of vitamin D3 for either 2 or 8 days before slaughter and were submitted to different conditions during feedlot: sun exposure or artificial shade. Steaks from Longissimus lumborum were fabricated, aged for 1, 7, and 21 days post-mortem, and later used for the analyses of shear force and the myofibrillar fragmentation index. Vitamin D3 did not influence mRNA abundance; however, it induced a greater CAST II transcript in animals supplemented 8 days before slaughter. There was a negative association between CAST II abundance and the shear force, which revealed an important modulation of the calpain system expression due to vitamin D supplementation. This result is an important tool for strategies to improve beef tenderness.(AU)

Meat quality of (Bos indicus) cattle finished on different concentrate feeds

The study investigated meat quality of bulls fed concentrate feeds and hay. The treatments were hay ad libitum + dried cafeteria leftover 4 kg DM d-1(D1); hay ad libitum+ wheat bran 4 kg DM d-1(D2); hay ad libitum+ 4 maize grain 4 kg DM d-1(D3); hay ad libitum+ mix 4 kg DM d-1(1:1, wheat bran to maize grain, respectively (D4)); hay ad libitum+ scrambled whole groundnut 4 kg DM d-1(D5); and hay ad libitum+ mix of each ingredient 4 kg DM d-1(D6)). Samples from longissimus lumborum muscle were taken in triplicate. Beef from bulls fed D5 had highest (p < 0.05) protein and fat than those fed other treatments. However, bulls finished in D3 had similar fat to those fed with whole ground nut. Highest meat tenderness (p < 0.05) recorded at 24thfollowed by 16thd than those aged on other periods. Beef from D6 produced lean meat, which is acceptable to consumer and market demand than D3, produced carcass with highest fat coverage This study confirmed that meat from D6 had an acceptable quality attribute suggesting the breed could serve as a potential source in red meat industry.(AU)

Meat quality of the Berrichon du Cher lambs and its cross-breeds with a native breed / Qualidade da carne dos cordeiros Berrichon du Cher e seus cruzamentos com raça nativa

This study evaluated the meat of lambs from crossbreeding of Polish lowland sheep, heather and rams of the Berrichone du Cher breed (B). The lambs were kept in a medium-intensive feeding system. During fattening, they received haylage and grass hay with the addition of clover, and a mixture of cereal grains with the addition of minerals and vitamins. During the fattening period, all feeds were given at will. The slaughter and cutting of the carcasses were performed in accordance with the technology applicable in the meat industry. In the longissimus lumborum muscle, the content of dry matter, total protein, total fat and ash was determined. In addition, the pH value of 45 minutes and 24 hours after slaughter, as well as the parameters of colour and tenderness of the meat were measured. The content of collagen protein, cholesterol and selected fatty acids was also determined. As a result of the conducted analyzes, the influence of the Berrichone du Cher breed on the improvement of quantitative parameters related to the slaughter value and some parameters related to the physicochemical composition of the hybrid meat was reported.

O objetivo deste estudo foi avaliar como o cruzamento da raça Berrichon du Cher com raças nativas de ovelhas polonesas de baixa altitude e ovelhas de charneca polonesa afeta os parâmetros qualitativos da carne .O maior teor de proteína (19,86 ± 0,36%, P <0,05) em cordeiros foi encontrado no grupo Berrichon du Cher e no grupo de cordeiros ovinos (19,23 ± 0,67%, P <0,05). Por outro lado, o maior teor de colágeno total (1,10 ± 0,21%) e a maior sensibilidade do tecido muscular (10,69 ± 0,74 N cm-2), que também apresentaram o menor diâmetro das fibras musculares (24,01 ± 4,62 µm, P < 0,01) foi encontrado nos cordeiros mestiços Berrichon du Cher e Polish Heath Sheep. Tanto a raça quanto o gênero afetaram significativamente o teor de colesterol na carne de cordeiro e o maior teor de colesterol foi encontrado na carne dos cordeiros Berrichon du Cher. Seu menor teor foi demonstrado na carne de Ovinos da Baixada Polonesa com a diferença de 9,1 mg 100g-1 de tecido muscular. Um dos níveis mais baixos do isômero CLA (C 18: 2 cis-9 trans-11) também foi encontrado no grupo dos cordeiros Berrichon du Cher. Este isômero evita a formação de colesterol. Dependência semelhante em relação ao gênero também foi observada. Os resultados obtidos indicam que as raças nativas são utilizadas em cruzamentos com a raça Berrichon du Cher destinada à engorda, principalmente para melhorar parâmetros quantitativos relacionados ao valor de abate e parâmetros selecionados de propriedades físicas e químicas da carne ovina.

Fatty acid profile and beef quality of Nellore and Angus bulls fed whole shelled corn

This study aimed to evaluate the quality traits and fatty acid profile of beef from Nellore and Angus bulls fed whole shelled corn (WSC) and ground corn plus maize silage (GC) diets. Eighteen Nellore and 18 Angus young bulls [381 ± 12 kg initial body weight (BW) and an average age of 20 ± 1.9 months] were used in a completely randomized design using a 2 × 2 factorial arrangement and were slaughtered at a final BW of 451.5 kg and 545.5 kg, respectively. Twenty–four hours after slaughter, samples of longissimus thoracis muscle were collected for the analysis of lipid oxidation, color, fatty acid profile, shear force, and cooking loss. There was no effect of diet × breed interaction on meat color, lipid oxidation, shear force, and cooking loss. Angus beef had lower shear force (p < 0.05) than Nellore beef and had a greater concentration of linoleic acid and polyunsaturated fatty acids (PUFA) (p < 0.01). Beef of bulls fed WSC tended to have greater concentration of CLA C18:2c9t11 (p = 0.09), greater concentration of CLA C18:2t10c12 (p = 0.01), and PUFA (p = 0.05), and consequently, higher oxidation levels. Angus bulls produced beef with greater tenderness and PUFA concentration. The results of fatty acid show a possible change in biohydrogenation when animals are fed the WSC diet, reducing lipogenesis, as this diet increases the C18:2t10c12 content.

Fatty acid profile and beef quality of Nellore and Angus bulls fed whole shelled corn

This study aimed to evaluate the quality traits and fatty acid profile of beef from Nellore and Angus bulls fed whole shelled corn (WSC) and ground corn plus maize silage (GC) diets. Eighteen Nellore and 18 Angus young bulls [381 ± 12 kg initial body weight (BW) and an average age of 20 ± 1.9 months] were used in a completely randomized design using a 2 × 2 factorial arrangement and were slaughtered at a final BW of 451.5 kg and 545.5 kg, respectively. Twenty­four hours after slaughter, samples of longissimus thoracis muscle were collected for the analysis of lipid oxidation, color, fatty acid profile, shear force, and cooking loss. There was no effect of diet × breed interaction on meat color, lipid oxidation, shear force, and cooking loss. Angus beef had lower shear force (p < 0.05) than Nellore beef and had a greater concentration of linoleic acid and polyunsaturated fatty acids (PUFA) (p < 0.01). Beef of bulls fed WSC tended to have greater concentration of CLA C18:2c9t11 (p = 0.09), greater concentration of CLA C18:2t10c12 (p = 0.01), and PUFA (p = 0.05), and consequently, higher oxidation levels. Angus bulls produced beef with greater tenderness and PUFA concentration. The results of fatty acid show a possible change in biohydrogenation when animals are fed the WSC diet, reducing lipogenesis, as this diet increases the C18:2t10c12 content.

Spray chilling on carcass weight loss, and physicochemical and microbiological quality of beef cuts during storage / Efeitos da aspersão de carcaças na perda de peso e na qualidade físico-química e microbiológica de cortes cárneos bovinos durante estocagem

Different chilling treatments are used before meat storage. The effect of spray chilling (SC) on meat quality appears to vary. Here, we investigated the effects of SC on beef carcass weight loss and meat quality during subsequent storage. The 2-h SC program tested involved 180-s initial spraying, followed by 60-s spray cycles at 540-s intervals. Deboned chuck tender (IMPS 116B) beef cuts were vacuum-packaged and stored for up to 60 d. Purge and cooking losses, Warner-Bratzler shear force, meat colour [CIE L*, a*, b*], and microbiological quality were evaluated. SC reduced carcass weight loss (P<0.001) compared with conventional chilling. However, storage time affected the purge and cooking losses, and Warner-Bratzler shear force. CIE a* and b* values increased (P<0.05) after 30-d aging in both chilling treatments. Pronounced psychrotrophic growth was observed during storage after both treatments. In conclusion, SC can be used to reduce the economic losses associated with meat chilling, without affecting meat quality attributes.

Diferentes tratamentos de resfriamento são utilizados antes da estocagem das carnes. O efeito da aspersão de carcaças (SC) na qualidade da carne parece variar. Neste estudo, investigou-se os efeitos da aspersão de carcaças bovinas na perda de peso e na qualidade da carne durante subsequente estocagem. O programa de aspersão testado foi de um tempo total de 2 h, com uma aspersão inicial de 180 s, seguida por ciclos de aspersão de 60 s em intervalos de 540 s. Os cortes comerciais desossados "Peixinho" (IMPS 116B) foram embalados a vácuo e estocados por até 60 dias. Foram avaliadas as perdas por exsudação e cozimento, força de cisalhamento por Warner-Bratzler, cor da carne (CIE L*, a*, b*) e qualidade microbiológica. SC reduziu a perda de peso da carcaça (P < 0,001) em comparação com o resfriamento convencional. No entanto, o tempo de estocagem influenciou a perda por exsudação, por cozimento e força de cisalhamento. Os valores de CIE a* e b* aumentaram (P < 0,05) após 30 dias de maturação em ambos os tratamentos de resfriamento. O crescimento pronunciado de psicrotróficos foi observado durante a estocagem em ambos os tratamentos. Em conclusão, o SC pode ser usado para reduzir as perdas econômicas associadas ao resfriamento da carne, sem afetar os atributos de qualidade da carne.

Immunocastration on performance and meat quality of Bos indicus (Nellore) cattle under different nutritional systems

The present study aimed to evaluate the effects of immunocastration on the animal growth, carcass traits, and meat quality of Nellore cattle receiving or not Ionophore supplementation at pasture or pasture with concentrate (semi-feedlot). The first experiment (Pasture) was carried out during the rainy season, while the second (supplemented = Semi-feedlot) was conducted during the dry season. In each assessment, 60 males were allocated into three treatments, in a completely randomized design: non-castrated, immunocastrated (anti-gonadotropin-releasing hormone vaccine), and immunocastrated animals receiving ionophore. The highly energetic supplemented diet was prepared using 85 % corn and 10 % soybean meal at 1 % body weight, while the ionophore was provided with salt containing 1,650 mg kg−1 of lasalocid. After slaughter, the carcasses were graded, and Longissimus thoracis et lumborum samples were collected for meat quality analysis. The non-castrated animals exhibited a more significant final body weight and hot carcass weight than those immunocastrated regardless of ionophore supplementation (p < 0.05). The carcasses of non-castrated animals had less fat cover and marbling than castrated animals. A high incidence of dark cutting beef was verified in non-castrated animals. The immunocastrated cattle produced tenderer beef, mainly at pasture rearing. In conclusion, regardless of production system or ionophore supplementation, immunocastration was an adequate choice to generate high-quality meat, since it increased marbling and improved beef tenderness. However, limitations regarding animal growth should be estimated.

Immunocastration on performance and meat quality of Bos indicus (Nellore) cattle under different nutritional systems

The present study aimed to evaluate the effects of immunocastration on the animal growth, carcass traits, and meat quality of Nellore cattle receiving or not Ionophore supplementation at pasture or pasture with concentrate (semi-feedlot). The first experiment (Pasture) was carried out during the rainy season, while the second (supplemented = Semi-feedlot) was conducted during the dry season. In each assessment, 60 males were allocated into three treatments, in a completely randomized design: non-castrated, immunocastrated (anti-gonadotropin-releasing hormone vaccine), and immunocastrated animals receiving ionophore. The highly energetic supplemented diet was prepared using 85 % corn and 10 % soybean meal at 1 % body weight, while the ionophore was provided with salt containing 1,650 mg kg−1 of lasalocid. After slaughter, the carcasses were graded, and Longissimus thoracis et lumborum samples were collected for meat quality analysis. The non-castrated animals exhibited a more significant final body weight and hot carcass weight than those immunocastrated regardless of ionophore supplementation (p < 0.05). The carcasses of non-castrated animals had less fat cover and marbling than castrated animals. A high incidence of dark cutting beef was verified in non-castrated animals. The immunocastrated cattle produced tenderer beef, mainly at pasture rearing. In conclusion, regardless of production system or ionophore supplementation, immunocastration was an adequate choice to generate high-quality meat, since it increased marbling and improved beef tenderness. However, limitations regarding animal growth should be estimated.(AU)

Impact of frozen temperature and thawing methods on the Brazilian sensory profile of Nellore beef

We evaluated the effect of frozen storage temperature and thawing methods on acceptance and sensory profile of steaks of Nellore beef strip loin under 30 days of frozen storage. Fresh strip loin (n = 13), collected two days after slaughter, were aged (2 °C) for 14 days and cut into seven steaks subjected to one of the treatments: control (unfrozen), combination of two freezing temperatures (-10 and -20 °C), and three thawing methods (microwave, ambient temperature, and refrigeration thawing). Steaks in the frozen/thawing treatment were frozen using an ultra-fast freezer until the desirable temperature was reached and were stored for 30 days. After cooking, steaks were analyzed by 11 panelists for the Quantitative Descriptive Analysis (QDA®) and by 120 beef consumers for acceptance. Storage temperature and thawing methods showed little or no changes in the sensory quality of strip loin steaks, detected by either panelists or consumers. In the QDA®, apparent juiciness was lower in samples thawed in microwave, while the rancid flavor was lower for samples frozen at -20 °C and thawed in refrigeration ( p < 0.05). The consumer test showed that samples stored at -10 °C and microwave thawing was most accepted in terms of tenderness, juiciness, and overall impression. Fresh steaks (unfrozen) had low acceptance for overall impression in relation to frozen meat. This indicates that consumers could use a household freezer (-10 °C) and quicker thawing methods (microwave or room temperature) without compromising the sensory perception of steaks frozen up to one month.(AU)

Impact of frozen temperature and thawing methods on the Brazilian sensory profile of Nellore beef

We evaluated the effect of frozen storage temperature and thawing methods on acceptance and sensory profile of steaks of Nellore beef strip loin under 30 days of frozen storage. Fresh strip loin (n = 13), collected two days after slaughter, were aged (2 °C) for 14 days and cut into seven steaks subjected to one of the treatments: control (unfrozen), combination of two freezing temperatures (-10 and -20 °C), and three thawing methods (microwave, ambient temperature, and refrigeration thawing). Steaks in the frozen/thawing treatment were frozen using an ultra-fast freezer until the desirable temperature was reached and were stored for 30 days. After cooking, steaks were analyzed by 11 panelists for the Quantitative Descriptive Analysis (QDA®) and by 120 beef consumers for acceptance. Storage temperature and thawing methods showed little or no changes in the sensory quality of strip loin steaks, detected by either panelists or consumers. In the QDA®, apparent juiciness was lower in samples thawed in microwave, while the rancid flavor was lower for samples frozen at -20 °C and thawed in refrigeration ( p < 0.05). The consumer test showed that samples stored at -10 °C and microwave thawing was most accepted in terms of tenderness, juiciness, and overall impression. Fresh steaks (unfrozen) had low acceptance for overall impression in relation to frozen meat. This indicates that consumers could use a household freezer (-10 °C) and quicker thawing methods (microwave or room temperature) without compromising the sensory perception of steaks frozen up to one month.

Meat quality of cattle subjected to period of aging process: a cross-heifer study / Qualidade da carne de bovinos submetida ao processo de maturação: estudo com novilhas cruzadas

The aim of this study was to evaluate the effects of aging on meat quality of crossbred heifers. Qualitative and quantitative evaluations of carcasses and meat of 148 crossbred heifers with an average age of 13 months and 407.5 ± 29.22 kg body weight at slaughter were performed. After cooling for 24 h, the carcasses were evaluated for hot carcass weight, pH, conformation, physiological maturity, finishing, fat distribution, and length. Characteristics, such as pH, color, marbling, exudation, as well as cooking losses, percentage of ether extract, and shear force were evaluated in meat at time zero and after seven days of aging. The carcasses displayed satisfactory results for parameters such as pH at 24 h of cooling (pH24), finishing, distribution of fat, and subcutaneous fat thickness (5.58, 3.27, 2.40, and 6.62 mm, respectively). The meat had a low marbling score (5.08) and percentage of ether extract (1.71), indicating that the meat was relatively lean. Exudation and cooking losses showed similar results at zero and seven days of aging. The meat subjected to seven days of aging showed higher lightness and hue (40.98 and 0.77, respectively) and tenderness of 5.25 kg. These results indicated that aging affected meat color and shear force parameters; the meat of cross-heifers was softer but less red after maturation.(AU)

O objetivo deste estudo foi avaliar os efeitos da maturação na qualidade da carne de novilhas mestiças. Foram realizadas avalações quali-quantitativas de carcaças e carne de 148 novilhas mestiças com idade média de 13 meses e 407,5 ± 29,22 kg de peso corporal ao abate. Após resfriamento por 24 horas, as carcaças foram avaliadas quanto ao peso da carcaça quente, pH, conformação, maturidade fisiológica, acabamento, distribuição de gordura e comprimento. Características como pH, cor, marmoreio, perdas por exsudação, assim como perdas por cocção, porcentagem de extrato etéreo e força de cisalhamento foram avaliadas na carne no tempo zero e após sete dias de maturação. As carcaças apresentaram resultados satisfatórios para parâmetros com pH em 24 horas de resfriamento (pH24), acabamento, distribuição de gordura e espessura de gordura subcutânea (5,58, 3,27, 2,40 e 6,62 mm, respectivamente). A carne apresentou baixo índice de marmoreio (5,08) e porcentagem de extrato etéreo (1,71), indicando que a carne era relativamente magra. As perdas por exsudação e cozimento apresentaram resultados semelhantes aos zero e sete dias de maturação. A carne submetida a sete dias de maturação apresentou maior luminosidade e hue (40,98 e 0,77, respectivamente) e maciez de 5,25 kg. Esses resultados indicaram que a maturação afetou os parâmetros de cor da carne e a força de cisalhamento; a carne das novilhas cruzadas ficou mais macia, mas menos vermelha após a maturação.(AU)