Predictive ability of the feeding system in Iberian pig by means of several analytical methods

The reliability of several analytical methods proposed to predict the feeding system received by Iberian pigs during the fattening period has been contrasted. Samples of subcutaneous adipose tissue were analyzed from 38 batches of pigs fattened in three seasons of montanera (acorn and pastures feeding). They corresponded to the four categories described in the Quality Standard for Iberian pig products: 251 samples of bellota, 164 of recebo, 197 of cebo de campo and 137 of cebo. To perform the study, the following analytical methods were used: fatty acid quantification, NIR, alpha and gamma tocopherol, chemical sensor, triacilglycerides, stable isotopes and neophytadiene. The laboratories received the samples without any information about the fattening system to which they belonged and remitted their predictions with respect to the above categories. The results showed a high percentage of accurate predictions of the methods when the fattening type corresponds to the extreme categories (bellota and cebo), however, the methods had difficulty in discerning between samples from a mixed feeding regime with acorn and feed (recebo) and problems when pigs are fattened with compound feeds including vegetable fats with high levels of oleic acid. Although a simplification into only two categories (cebo/campo and recebo/bellota) results in a success rate higher than 90% for some methods, the combination of two or three techniques with problematic samples allows for differentiating among the four categories with the same accuracy. Se ha contrastado la fiabilidad de varios métodos analíticos para determinar el tipo de alimentación recibida durante el cebo por cerdos Ibéricos a partir de muestras de tejido adiposo subcutáneo, procedentes de 38 partidas de cerdos de tres campa as de montanera. Las muestras correspondieron con las categorías de alimentación contempladas en la Norma de Calidad: 251 fueron de bellota, 164 de recebo, 197 de campo y 137 de cebo. Los métodos contrastados han sido ácidos grasos, NIR, alfa y gamma tocoferol, sensor químico, triacilglicéridos, isótopos estables y neofitadieno. Los distintos laboratorios recibieron las muestras sin información sobre el tipo de alimentación y remitieron sus predicciones respecto a las categorías previamente mencionadas. Los resultados obtenidos mostraron un elevado porcentaje de aciertos de los métodos cuando la alimentación se corresponde con las categorías extremas (bellota y cebo), sin embargo existía una dificultad en clasificar correctamente las muestras de cerdos de alimentación mixta con bellota y pienso (r