Temperature impact on the forage quality of two wheat cultivars with contrasting capacity to accumulate sugars

• Autores: Lorenzo, Maximo; Assuero, Silvia Graciela; Tognetti, Jorge Alberto
• Año de publicación: 2015
• Idioma: inglés
• Tipo de recurso: artículo
• Fuente: Agriculture / MDPI 5 (3) : 649-667. (2015)
• Materia: Trigo; Triticum Aestivum; Variedades; Celulosa Asimilable; Digestibilidad in Vitro; Rumen; Azucares; Temperatura; Bovinae; Varieties; Digestible Cellulose; In Vtro Digestibility; Sugars; Temperature
• Institución: Instituto Nacional de Tecnología Agropecuaria

Wheat is increasingly used as a dual-purpose crop (for forage and grain production) worldwide. Plants encounter low temperatures in winter, which commonly results in sugar accumulation. High sugar levels might have a positive impact on forage digestibility, but may also lead to an increased risk of bloat. We hypothesized that cultivars with a lower capacity to accumulate sugars when grown under cold conditions may have a lower bloat risk than higher sugar-accumulating genotypes, without showing significantly lower forage digestibility. This possibility was studied using two wheat cultivars with contrasting sugar accumulation at low temperature. A series of experiments with contrasting temperatures were performed in controlled-temperature field enclosures (three experiments) and growth chambers (two experiments). Plants were grown at either cool (8.1 °C–9.3 °C) or warm (15.7 °C–16.5 °C) conditions in field enclosures, and at either 5 °C or 25 °C in growth chambers. An additional treatment consisted of transferring plants from cool to warm conditions in the field enclosures and from 5 °C to 25 °C in the growth chambers. The plants in the field enclosure experiments were exposed to higher irradiances (i.e., 30%–100%) than those in the growth chambers. Our results show that (i) low temperatures led to an increased hemicellulose content, in parallel with sugar accumulation; (ii) low temperatures produced negligible changes in in vitro dry matter digestibility while leading to a higher in vitro rumen gas production, especially in the higher sugar-accumulating cultivar; (iii) transferring plants from cool to warm conditions led to a sharp decrease in in vitro rumen gas production in both cultivars; and (iv) light intensity (in contrast to temperature) appeared to have a lower impact on forage quality.
Fil: Lorenzo, Maximo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina
Fil: Assuero, Silvia Graciela. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias. Laboratorio de Fisiología Vegetal; Argentina
Fil: Tognetti, Jorge Alberto. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias. Laboratorio de Fisiología Vegetal; Argentina. Comisión de Investigaciones Científicas de la Provincia de Buenos Aires; Argentina