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Percorrer por autor "Matos, Sofia"

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  • Estimación de la composición de la canal por ultrsonidos y por el modelo comunitario de clasificación de canales ligeras
    Publication . Cadavez, Vasco; Rodrigues, Sandra; Delfa, Rafael; Pereira, Etelvina; Matos, Sofia; Teixeira, Alfredo
    El modelo comunitario de clasificación de canales de corderos definida en el REGLAMENTO (CEE) nº 2 137/92 se basa en la conformación y en la importancia de la capa de grasa subcutánea. No obstante, autoriza que los estados miembros definan otros criterios de clasificación para canales con menos de 13 kilogramos de peso, tales como: peso, color de la carne y capa de grasa subcutánea. Por otro lado, el REGLAMENTO (CEE) n°: 2967/85 establece que el desarrollo de métodos objetivos de clasificación de canales debe basarse en la estimación del porcentaje de carne magra en la canal. debiendo los métodos poseer un coeficiente de determinación (R2) superior a 0,64 y una desviación estándar residual {DER) inferior a 2,5% para que su utilización sea autorizada (Cadavez et al., 2000). El objetivo de este estudio fue evaluar la precisión de modelos de estimación de la composición de la canal utilizando como variables independientes: 1. el peso de la canal caliente (PCC} y medidas de ultrasonidos realizadas in vivo y 2. el PCC y la clase de cobertura grasa (CCG) definida en el modelo comunitario de clasificación de canales de corderos ligeros.
    2001Comunicação em conferência Acesso aberto Ver mais
  • In vivo estimation of lamb carcass composition by real-time ultrasonography
    Publication . Teixeira, Alfredo; Matos, Sofia; Rodrigues, Sandra; Delfa, Rafael; Cadavez, Vasco
    The objective of this study was to evaluate the accuracy of ultrasonography to measure fat thickness in live lambs and predict carcass composition to find a system that can assess carcass composition easily and accurately, without damage to the product and can improve carcass classification. Fat thickness (FTh) between the 12th and 13th ribs and between the 3rd and 4th lumbar vertebrae, was measured in vivo using real-time ultrasound, in 67 Churra Galega Bragançana males (mean weight 36.0 kg, range 21.5–47.0 kg), using an ALOKA SSD-500V equipped with two probes (5 and 7.5 MHz) in order to predict carcass composition. The most satisfactory correlation between carcass and ultrasound measurements was between the 3rd and 4th lumbar vertebrae fat thickness (FTh). The first variable admitted in the models to predict carcass composition (live weight, LW) explained between 63% and 96% of the total variation of the weight of the components of the carcass. In fact, 96% of the variation in total amount of muscle was accounted for by live weight. The inclusion of the ultrasound measures with the 7.5 MHz probe improved, in all prediction equations, the coefficient of determination (R2) with a substantial reduction in the residual standard deviation (RSD). In relation to the subcutaneous fat of the carcass, 85% of the variation was explained by live weight and the FTh 12–13 7.5 measurement. In the prediction model for total carcass fat weight, live weight and ultrasound fat thickness measurement explained 88% of the variation. The results indicate that in vivo ultrasound fat thickness measures in association with live weight can be used to predict carcass composition in Churra Galega Bragançana lambs.
    2006Artigo científico Acesso aberto Ver mais
  • Prediction of carcass composition in vivo by slaughter weight and ultrasound measurements in Churro Galego Bragançano local breed lambs
    Publication . Cadavez, Vasco; Teixeira, Alfredo; Delfa, Rafael; Matos, Sofia
    Forty Churro Galego Bragançano local breed lambs (20 females and 20 males) with an mean live weight of 19.3 kg ( 10 to 28.5 kg) were scanned by ultrasound to M. Longissimus dorsi depth (MLDD), subcutaneous fat thickness (SFT) between the 12th-1 3th dorsal vertebra (D 12), l st-2nd (Ll ) and 3rd-4th (L3) lumbar vertebra and breast bone tissue thickness (BET) at 2nd (S2), 3rd (S3) and 4th sternebra. Lambs were slaughtered after 24-h fast ing. Carcasses were cooled at 4 °C for 24 h. and halved carefully. The left side was divided into eight standardized commercial joints: leg, chump, loin. Ribs, anterior ribs, shoulder, breast and neck. Each joint was then dissected into muscle, subcutaneous fat. intermuscular fat and bone. The in vivo ultrasound measurements plus slaughter weight were fitted to predict carcass tissue composition by stepwise regression analysis. All the developed models were highly significant (P<0.001) and explained 60, 76,64 and 74% of the muscle, subcutaneous fat, intermuscular fat and bone variation, respectively. The models residual standard deviations were lower than 20 g kg-1
    2000Documento de conferência Acesso aberto Ver mais
  • Repetibilidad y reproducibilidad de las medidas de tejidos in vivo efectuadas con ultrasonidos en ovejas adultas y sus correlaciones con la condición corporal
    Publication . Bueno, M.S.; Matos, Sofia; Cadavez, Vasco; Pereira, Etelvina; Rodrigues, Sandra; Batista, Sónia; Delfa, Rafael; Teixeira, Alfredo
    La evaluación de la condición corporal permite conocer el estado de reservas de los animales (Santucci et al., 1991; Delfa el al., 1995; Teixeira et al., 1995), siendo el espesor de los tejidos en la región esternal el punto de elección en caprinos tal como mostró Morand-Fehr et al. (1989). Este conocimiento permite adecuar la alimentación de los animales, no obstante esta metodología es muy susceptible a errores entre operadores (Evans, 1978). Así la substitución de esta técnica por otras más objetivas presenta interés práctico. Las medidas de ultrasonidos que permiten determinar las medidas de espesor de los tejidos, con elevada repetible edad y reproducibilidad, podrán ser una alternativa interesante.
    2003Comunicação em conferência Acesso aberto Ver mais