RESUMO
The aim of this study was to characterize the breast meat of turkeys affected by different degrees of severity (normal [NORM], moderate [MOD], and severe [SEV]) of the white striping (WS) myopathy, as well as to evaluate the influence of this myopathy on meat quality. Twenty-nine samples of the pectoralis major muscles of each treatment were obtained from Nicholas breed male and female turkeys, reared and slaughtered in the center-west region of Brazil. The whole breasts of the turkeys were used for macroscopic classification, weight evaluation, and morphometric measurements. Then, the pectoralis major muscle was separated for histological evaluation and qualitative physicochemical analyses, namely ventral and dorsal color (L∗, a∗, and b∗), pH value, water holding capacity (WHC), cooking loss (CL), shear force (SF) (Meullenet-Owens Razor Shear [MORS] and Warner-Bratzler), sarcomere length, total, soluble, and insoluble collagen contents, proximate composition (protein, lipids, moisture, and ash), cholesterol content, and fatty acid profile. The results showed that muscles affected by myopathy, both MOD and SEV, exhibited larger weights (around 2.8 kg) compared to NORM muscles (1.3 kg) and a significant increase (P < 0.05) in the diameter of the fibers. The increase in the degree of severity of the myopathy increased (P < 0.05) the value of L∗ of the dorsal part and ventral part of the muscle. No differences (P > 0.05) were observed in the pH, CL, and WHC values of the muscles, whereas the MORS and Warner-Bratzler SF of the SEV fillets resulted in significantly lower shear values (P < 0.05) compared to the NORM fillets. In addition, the MOD and SEV fillets presented lower values of protein (P < 0.05) than NORM fillets. No significant differences (P > 0.05) were observed for moisture and lipid and cholesterol contents. Meat with MOD and SEV severity of WS myopathy had higher (P < 0.05) concentrations of total and insoluble collagen. Thus, the presence of WS myopathy in MOD and SEV degrees affected a large part of the histological and quality characteristics evaluated.
Assuntos
Doenças Musculares , Perus , Animais , Brasil , Galinhas , Feminino , Masculino , Carne/análise , Doenças Musculares/etiologia , Doenças Musculares/veterinária , Músculos PeitoraisRESUMO
O objetivo deste trabalho foi avaliar o efeito da temperatura do ambiente de criação e da reutilização da cama sobre o desempenho de frangos de corte, rendimento de carcaça e a qualidade físico-química da carne de peito produzida. Foram utilizados 900 pintinhos Cobb®, sendo 450 aves alojadas em uma câmara climatizada, munida de aquecedores e refrigeradores, e 450 aves em galpão convencional para criação de frangos. Em ambas as instalações as aves foram distribuídas entre a cama nova e reutilizada tratada com cal. Foram avaliados índices de desempenho, rendimento de carcaça e a qualidade físico-química do músculo Pectoralis major aos 42 dias de idade. O delineamento experimental utilizado foi inteiramente casualizado, em arranjo fatorial 2x2 (temperatura: ambiente e termoneutra; cama: nova e reutilizada) com cinco repetições cada. Não houve influência dos tratamentos no desempenho e rendimento de carcaça. Foi observada maior intensidade de vermelho e menor teor oxidação na carne de peito de aves criadas sob temperatura ambiente 2,74 e 0,180 mg TMP/kg, em relação às aves criadas em conforto térmico 2,20 e 0,230 mg TMP/kg, aos 42 dias de idade. Houve redução significativa da força de cisalhamento, que variou de 1,38 kgf/cm² na carne de aves criadas sobre cama nova a 1,86 kgf/cm² na carne de aves criadas sobre cama reutilizada, indicando que a utilização de cama de frango nova favorece a produção de carne mais macia.
The aim of this study was to evaluate the effect of environmental temperature and bed reuse on dressing percentage, breast quality and productive performance of broilers. A total of 900 Cobb® chicks were used, of which 450 were housed in a barn equipped with heaters and coolers while the rest (450 birds) were housed in a traditional shed for broiler production. In both facilities, birds were distributed either to a new or reused bed -the reused bed was previously treated with lime. Performance indices, dressing percentage and physicochemical quality of Pectoralis major muscle at 42 days of age were evaluated. The experimental design consisted in a completely randomized 2x2 factorial arrangement (temperature: thermo neutral or room temperature; bedding: new or reused bed) with five replicates per treatment. No effect of treatment on productive performance or dressing percentage was observed. Birds kept at room temperature had greater intensity of red color and lower breast oxidation (2.74 and 0.180 mg TMP/kg) compared to birds kept in the thermo-neutral environment at 42 days of age (TMP 2.20 and 0.230 mg/kg). Shear force was 1.38 kgf/cm² for the birds kept on new bed compared with 1.86 kgf/cm² for the animals kept on reused bed, indicating that the use of new bed favors meat tenderness.
El objetivo de este trabajo fue evaluar el efecto de la temperatura ambiental y de la reutilización de la cama sobre el desempeño productivo de pollos de engorde, rendimiento de canal y calidad fisicoquímica de la pechuga producida. Fueron utilizados 900 pollitos Cobb®, siendo 450 aves alojadas en un galpón equipado con calentadores y refrigeradores, y 450 aves alojadas en un galpón tradicional para la producción de pollos. En ambas instalaciones las aves fueron distribuidas entre la cama nueva y la cama reutilizada tratada anteriormente con cal. Fueron evaluados índices de desempeño, rendimiento de canal y calidad fisicoquímica del músculo Pectoralis major a los 42 días de edad. El diseño experimental fue completamente al azar con arreglo factorial 2x2 (temperatura: ambiente o termo neutra; camas: nueva o reutilizada) con cinco repeticiones cada uno. No hubo efecto de los tratamientos sobre el desempeño productivo y el rendimiento de canal. Se observó una mayor intensidad del color rojo y menor oxidación de la pechuga de aves mantenidas sobre temperatura ambiente 2,74 y 0,180 mg TMP/kg en relación a las aves mantenidas en ambiente termo neutro 2,20 y 0,230 mg TMP/kg a los 42 días de edad. Hubo una reducción significativa de la fuerza de corte, que vario de 1,38 kgf/cm² en la carne de aves mantenidas sobre cama nueva a 1,86 kgf/cm² en la carne de aves mantenidas sobre cama reutilizada, indicando que el uso de cama nueva favorece a la producción de carne más blanda.