Ingestión voluntaria y digestibilidad de forraje de raigrás inglés, raigrás híbrido y trébol blanco ensilado bajo forma de rotopacas o en silos horizontales

• de la Roza Delgado, B. ^[1] ; Argamentería Gutiérrez, A. ^[1] ; Martínez Fernández, A. ^[1]
  1. [1] Área de Nutrición, Pastos y Forrajes. SERIDA. Apartado 13. 33500 Villaviciosa. Asturias (España)
• Localización: Pastos: Revista de la Sociedad Española para el Estudio de los Pastos, ISSN 0210-1270, Vol. 37, Nº. 2, 2007, págs. 203-227
• Idioma: español
• Títulos paralelos:
  • Voluntary intake and digestibility of big-bale and horizontal silages made of a perennial ryegrass, hybrid ryegrass and white clover mixture
• Enlaces
  • Texto completo
• Resumen
  • español

    Se compararon ensilados horizontales de hierba frente a los de rotopacas para determinar si existen razones de índole nutricional a favor de estos últimos. Una superficie de 10,6 ha de pradera (Lolium perenne L., Lolium x hybridum L. y Trifolium repens L.) recibió durante dos años cortes para ensilar en primavera. En cada uno se elaboraron ensilados trinchera y/o plataforma y de rotopacas. Éstos presentaron un promedio superior de proteólisis y fermentación alcohólica. En el primer año, su ingestión voluntaria de materia seca en ovino adulto (g/kg 0,75) fue inferior: 32,2 vs 37,3 vs 41,0 en el primer corte y 42,2 vs 47,7 vs 49,0 en el segundo para rotopacas, ensilados plataforma y ensilados trinchera, respectivamente. Su digestibilidad aparente a nivel de mantenimiento de los principios nutritivos fue también más baja en el primer corte del primer año (condiciones meteorológicas adversas); para materia orgánica, los respectivos valores fueron 0,65; 0,70 y 0,75. En los restantes cortes, no hubo resultados consistentes y en ocasiones aparecieron diferencias significativas a favor de las rotopacas, pero siempre de escasa magnitud; como máximo, para materia orgánica, 0,74 frente a 0,70 en ensilado trinchera para el primer corte del segundo año. Se concluye que, a pesar del uso masivo de éstas como forma de ensilado, no hay razones de índole nutricional a su favor frente a los tradicionales ensilados horizontales. Palabras clave: Pradera, tipo de silo, modificación de valor nutritivo, fermentación.

  • English

    Two different systems of silage-making were compared (horizontal silages vs big-bale silage) in order to determine possible nutritional reasons in favor of big-bale system as a method of forage preservation versus the conventional silage systems. An area of 10.6 ha of sown pasture (Lolium perenne, L. x hybridum and Trifolium repens) was mown twice in the 1st year, in the spring, after 6 months growth. In the 2nd year, 6.4 ha, were mown in the same way and other 4.0 ha were mown only once in May, after 8 weeks growth.

    In each cut, a horizontal silage (clamp- and/or bunker-type) and a big-bale silage were elaborated. The forage placed in horizontal silages was acid-treated (formic acid 3.5 L/t of forage) and not wilted. The big-bale silages were elaborated after wilting and without additive. Wilting incremented the ash content due soil contamination and reduced crude protein content. Chemical composition of the silage was very variable although on average big bales silage showed a greater proteolysis and alcoholic fermentation than the horizontal silage. Intake and digestibility trials were made, based on six wether sheep, using each type of forage as a sole feed at maintenance feeding level. In the 1st year, the original grasses intake were 40.5g DM/kg0.75 and 43.7 for the 1st cut, and 58.4g DM/ kg0.75 and 58.0 for 2nd cut, for green and wilted forage, respectively. Besides, silages intake always was lower than that of the original grasses and lower in the big bales than in the horizontal silage: 32.2g DM/kg0.75 vs 37.3 vs 41.0 in the 1st cut and 42.2 vs 47.7 vs 49.0 in the second, for big bale, clamp and bunker silages, respectively. Nevertheless, the silage of the 2nd year showed a higher intake than the original grasses. The apparent digestibility of the nutritional principles was lower in big-bale than in bunker-silos for the 1st cut of the 1st year, in which the climatic conditions were adverse for wilting. In the remaining cuts, there was no consistent trend and although on occasions there were signifcant differences in favor of the big bales, they were of limited magnitude. It was demonstrated that despite the massive use of big bales as a method of silage making, from the nutritional viewpoint there is no evidence in favor of this system compared to the traditional one of horizontal bunker silages.