RELATIONSHIPS OF VARIOUS PHYSICAL AND CHEMICAL CHARACTERS TO DIGESTIBLE ENERGY IN WHEAT AND BARLEY CULTIVARS

Abstract

Seventeen cultivars of hard and soft spring wheat (Triticum aestivum L.), and 29 cultivars of two-row and six-row barley (Hordeum distichum and H. vulgare) were examined for bulk weight (BW), 1,000-kernel weight (KW) and plumpness, and analyzed for gross composition, amylose, gross energy (GE), β-glucan (barley only), and for sedimentation (wheat only). Digestion coefficients and digestible energy (DE) values of the cultivars were determined by mouse-feeding. The ranges in protein, starch, amylose, and GE varied from 5 to 15%, whereas ether extract, fiber, ash and β-glucan contents varied from 1 to 3%. Except for sedimentation in wheat, and plumpness in barley there were no major differences in physical or chemical characters between hard and soft wheats or between two- and six-row barley. In wheat, DE was significantly correlated with BW (−0.59, P < 0.05), KW (−0.53, P < 0.05), plumpness (−0.55, P < 0.05), fiber (+0.72, P < 0.01), ash (−0.52, P < 0.05), sedimentation (−0.57, P < 0.05) and GE (+0.97, P < 0.01). Digestion coefficient was significantly correlated with protein (−0.58, P < 0.05), ash (−0.56, P < 0.05), and sedimentation (−0.57, P < 0.05). In barley, DE was significantly correlated with protein (+0.41, P < 0.05) and GE (+0.82, P < 0.01), and digestion coefficient was significantly correlated with BW (+0.55, P < 0.01), plumpness (+0.45, P < 0.05), ether extract (+0.50, P < 0.01), and fiber (−0.52, P < 0.01). For use as selection criteria the most significant correlations were between DE and GE and sedimentation in wheat, and between DE and GE in barley.