Assessment of Chemical Composition of Grain Crops Depending on Vegetative Stage for Feeding

Abstract

The following grass: Brоmus inеrmis, Elytrigia bluish, Agropyron pectiniforme that are widely used in diets of ruminants were gathered and assessed for contents of Dry Matter (DM), Crude Protein (CP), ash, crude fat, Neutral Detergent Fibre (NDF), Acid Detergent Fibre (ADF), lignin, hemicellulose, Crude Fiber (CF), nitrogen-free substances. Samples of grain crops were assessed. The samples were taken within earing phase, flowering period, seeding in intact plant and in separate vegetative parts (n = 10). Dry matter regularly increases with developing vegetation phases. This index of smooth brome and wheatgrass has better balance in vegetative parts in earing and flowering phases during the assessment of their feed value. Mass weight of crude protein was in leaves and reproductive organs during all periods of plants development. At earing phase the highest content of it was registered. Higher content of crude fiber was registered in culm and leaves of smooth brome during earing phase. It was higher by 3.4-8.5%. The tendency for more intensive accumulation of crude fiber is observed rather well within seeding phase. Fiber content in culm of smooth brome was by 2.1-2.4% higher. Culm and leaves of wheatgrass in its turn have the highest content of nitrogen-free substances. With growth and development of crop neutral detergent fiber increases from 49.4% (in earing phase) up to 64.1% (in seeding phase) acid detergent fiber increased by 8.2-11.4% and hemicellulose and cellulose - by 0.7-4.4%. Concentration of metabolizable energy in 1 kg dry matter decreases by 17.3-19.7% in the process of physiological maturation of grain crops for feeding. Maximum content of structural carbohydrates was observed in culm part of grain crops, minimum content-in leaves and generative parts of plants had intermediate position. Thus, type of feed crop, phase of its development determine mainly chemical composition and content of carbohydrate fractions not only in whole grain crops but also in vegetative parts. It can further influence on preparation technology and fodder quality.