Microwave oven forage drying: effects on quality analysis

Roberto J. Crespo1*, Jorge A. Castaño2 y José A. Capurro3

The objectives were to utilize a microwave oven (HM) to determine dry matter (MS) and evaluate its effect on dry matter (MS), organic matter content (MO), in vitro organic matter digestibility (DIVMO), brute protein (PB), acid detergent fiber (FDA), and acid-detergent insoluble nitrogen (NIDA). We utilized the forage species: Medicago sativa L., Trifolium repens L., Trifolium pratense L. and Thinopyrum ponticum Barkw. & D.R. Dewey, and mixtures of: M. sativa-Dactylis glomerata L., Festuca arundinacea Schreb.-T. repens-D. glomerata, and Lolium perenne L.-T. repens. The experimental design was a factorial complete randomized block. We compared drying time (Ts) and quality parameters on stove method (T1), HM at 900 W (T2), and HM at 900 and 400 W (T3), by ANDEVA and Duncan Test (p ≤ 0,05). In T2 and T3, Ts ranged from 6 to 8 min (T. pratense and Th. ponticum, respectively), compared to 48 h for T1. The MS value did not show differences between treatments for M. sativa, T. pratense, M. sativa-D. glomerata, and L. perenne-T. repens, but there were differences for the other forages between T2 or T3 with T1, which could be explained by the forages phenological stage. Differences between treatments were found for FDA (T. repens), DIVMO and PB (Th. ponticum), and PB and MO (L. perenne-T. repens). The use of the microwave oven allows a quick and consistent MS determination, along with a reliable forage quality standard evaluation.

Keywords: dry matter, stove, drying time, brute protein, acid detergent fiber.
1 Universidad Nacional del Centro de la Provincia de Buenos Aires, Facultad de Agronomía, Av. República de Italia 780. C.C.47. CP 7300. Azul, Buenos Aires, Argentina. E-mail: rojacre@yahoo.com.ar * Autor para correspondencia.
2 Instituto Nacional de Tecnología Agropecuaria, Estación Experimental Agropecuaria Balcarce, Ruta Nacional 226, km 73,5, C.C. 276. CP 7620, Balcarce, Buenos Aires, Argentina. E-mail: jcastanio@balcarce.inta.gov.ar
3 Universidad Nacional de Mar del Plata, Facultad de Ciencias Agrarias, Ruta nacional 226, km 73,5, C.C. 276. CP 7620