Meat quality of rabbits reared with two different feeding strategies : with or without fresh alfalfa ad libitum

The aim of this study was to evaluate production performance, carcass characteristics and nutritive value of meat of rabbits reared under the 2 prevailing feeding strategies in Uruguay. One week after weaning, 96 purebred V line rabbits were randomly distributed between 2 treatments: (T1) commercial pelleted food ad libitum and (T2) commercial pelleted food ad libitum plus fresh alfalfa ad libitum. Each treatment included 12 cages containing 4 individuals each (2 males and 2 females). Growth performance characteristics (live weight evolution, commercial food consumption and food/gain ratio) were evaluated. The consumption of alfalfa was not measured. Rabbits were slaughtered at a live weight of 2500 g and carcass characteristics were evaluated. Samples of meat and dissectible fat were analysed to determine intramuscular fat content at muscle L. dorsi, dissectible fat and intramuscular fat composition, minerals (Zn, Fe, Mg and Na), vitamin E and purines. Sensory evaluations were conducted to assess the effect of treatments on the consumer’s perception of differences and the existence of attributes determining preferences. Differences between treatments were significant for total commercial food intake (23356 vs. 20930 g/cage; P<0.001) and feed conversion ratio (3.82 vs. 3.41; P<0.01) for T1 and T2 respectively. No significant differences were found in average daily gain, age at slaughter and carcass characteristics. There were no significant differences in the intramuscular fat content. The fatty acid composition of dissectible and intramuscular fat was affected by the inclusion of alfalfa in the diet increasing the linolenic acid content (1.82 vs. 3.28% and 2.29 vs. 5.15% for T1 and T2 at intramuscular and dissectible fat, respectively; P<0.001), and improving the n-6/n-3 relationship (8.60 vs. 5.82 and 11.58 vs. 5.64 for T1 and T2 at intramuscular and dissectible fat, respectively; P<0.001). There were no significant differences in vitamin E, Fe or Zn content between treatments, but differences were significant in Mg (22.5 vs. 24.4 mg/100 g for T1 and T2; P<0.05) and Na (44.1 vs. 48.2 mg/100 g; P<0.05). In the sensory evaluation, panellists significantly perceived differences between treatments with 95% confidence

Efecto de la dieta de cerdos en crecimiento sobre el valor nutritivo y la aptitud tecnológica de la carne y grasa

Se sometieron cerdos con peso medio inicial de 53 kg a tres tratamientos: T1) dieta testigo conteniendo suplementos proteicos de origen vegetal y animal, T2) dieta basada exclusivamente en suplementos proteicos de origen vegetal y T3) dieta testigo restringida al 90 % de la cantidad ofrecida al T1 más libre acceso a pasturas. Se determinaron parámetros de comportamiento productivo y características de la canal en planta de faena. Se determinaron contenido de grasa intramuscular del Longissimus dorsi, perfil lipídico de la grasa subcutánea e intramuscular, contenido de hierro, zinc, magnesio, sodio y vitamina E. Se determinó también el punto de fusión de la grasa dorsal como indicador de aptitud tecnológica para la elaboración de productos fermentados. Con grasa procedente de cada tratamiento se elaboraron salames que fueron evaluados sensorialmente. En los parámetros de calidad de canal evaluados no hubo diferencias estadísticamente significativas. El acceso a pasturas determinó un incremento en el contenido de ácido linolénico y una mejora de la relación n6/n3 en la grasa subcutánea. No hubo diferencias significativas en el punto de fusión de la grasa. Las muestras de salame resultaron ser distintas, con un nivel de confianza del 95 % para los atributos textura e intención de compra

Efecto de la dieta de cerdos en crecimiento sobre el valor nutritivo y la aptitud tecnológica de la carne y grasa

Pigs with an initial average weight of 53 kg were allocated to three feeding treatments: T1) control diet containing vegetal and animal protein supplements, T2) diet of only vegetal protein supplements and T3) control diet restricted to 90 % of the amount offered to T1 plus free access to pasture. Productive performance parameters and carcass traits at slaughter were determined. Intramuscular fat content of Longissimus dorsi, lipid profile of the subcutaneous and intramuscular fat, content of iron, zinc, magnesium, sodium and vitamin E were analyzed. The melting point of the back fat was also analyzed as an indicator of the technological aptitude for the manufacturing of fermented products. Fat from each treatment was used to manufacture salamis that were sensory evaluated. Carcass quality parameters did not show statistically significant differences. Access to pasture showed an increase in linolenic acid content and a better relationship n6/n3 in the subcutaneous fat. There were no significant differences in the fat melting point. Salami samples were different with a confidence level of 95 % for texture attributes and purchase intent.Se sometieron cerdos con peso medio inicial de 53 kg a tres tratamientos: T1) dieta testigo conteniendo suplementos proteicos de origen vegetal y animal, T2) dieta basada exclusivamente en suplementos proteicos de origen vegetal y T3) dieta testigo restringida al 90 % de la cantidad ofrecida al T1 más libre acceso a pasturas. Se determinaron parámetros de comportamiento productivo y características de la canal en planta de faena. Se determinaron contenido de grasa intramuscular del Longissimus dorsi, perfil lipídico de la grasa subcutánea e intramuscular, contenido de hierro, zinc, magnesio, sodio y vitamina E. Se determinó también el punto de fusión de la grasa dorsal como indicador de aptitud tecnológica para la elaboración de productos fermentados. Con grasa procedente de cada tratamiento se elaboraron salames que fueron evaluados sensorialmente. En los parámetros de calidad de canal evaluados no hubo diferencias estadísticamente significativas. El acceso a pasturas determinó un incremento en el contenido de ácido linolénico y una mejora de la relación n6/n3 en la grasa subcutánea. No hubo diferencias significativas en el punto de fusión de la grasa. Las muestras de salame resultaron ser distintas, con un nivel de confianza del 95 % para los atributos textura e intención de compra