Evaluación nutritiva de harinas y expeller de soja presentes en Uruguay en la alimentación de vacas lecheras

espanolLa composicion quimica y degradabilidad ruminal de los subproductos derivados de la soja pueden verse afectadas segun su proceso industrial de obtencion. El objetivo de este estudio fue determinar el valor proteico en vacas lecheras de harinas y expeller de soja presentes en Uruguay. Se obtuvieron muestras de estos subproductos en distribuidores de alimentos para vacunos de la cuenca lechera uruguaya. Se analizo la composicion quimica, degradabilidad ruminal in situ (determinando: fraccion soluble, tasa de degradacion y degradabilidad efectiva) y su fermentescibilidad in vitro. Se comparo la composicion quimica y degradabilidad ruminal in situ de las muestras con la base de datos del programa NRC (NRC, 2001). Todos los resultados fueron comparados a traves de un analisis de varianza. Las harinas presentaron menor contenido de extracto etereo, materia organica y mayor contenido proteico (P Palabras claves: harina de soja, expeller, proteina degradable en rumen, produccion de leche. EnglishThe chemical composition and ruminal degradability of soybean byproducts can be affected by the industrial processes through which are obtained. The objective of this study was to determine the protein value for dairy cows of soybean meal and expeller present in Uruguay. Samples of soybean meal and expeller were taken from several Uruguayan suppliers. The chemical composition, in situ ruminal degradability (determining: soluble fraction, degradation rate and effective degradability) and its in vitro degradability of protein were analyzed. The chemical composition and in situ ruminal degradability of the samples were compared with the NRC (NRC, 2001) software database. All the results were compared through an analysis of variance. The soybean meal presented a lower content of ether extract and organic matter with a higher protein content (P Keywords: soybean meal, expeller, rumen-degraded protein, milk production.