CHEMICAL COMPOSITION AND DIGESTIBLE ENERGY OF BARLEY

Abstract

Digestibility of energy (D) and digestible energy (DE) content of 16 cultivars and lines of barley (Hordeum vulgare and H. distichum) were determined by mouse-feeding and related to 1,000-kernel weight (KW), plumpness (seed size), hull, protein, lysine, starch, amylose and gross energy (GE) of the cultivars. The experimental design allowed paired comparisons to be made of D and DE between the hulled vs. hulless types, small vs. large-seeded, normal vs. high lysine, low vs. high amylose, and good vs. poor malting quality of the cultivars. The data obtained showed that KW, plumpness and lysine contents of barley had little effect on D and DE. Although four cultivar pairs (II, III, IV, and VIII) had variable starch composition, only in pair IV did high amylose content reduce D. The data appeared to suggest that good malting quality in barley is not incompatible with high D and DE as determined by mouse-feeding. The hull content of the cultivars had a major influence both on D and DE. The mean D and DE values for the six hulless cultivars were 85.7% and 3,918 kcal/kg compared with means of 79.2% and 3,627 kcal/kg for the 10 hulled cultivars.