Nutritive value of silage made of whole barley crop harvested at various stages of maturity

Abstract

The chemical composition of silage from whole crop barley (Hordeum vulgare L.) harvested at head emergence, milk or dough stage of maturity was estimated and palatability and digestibility trials on sheep were conducted. Crude protein and ADF content in DM decreased with advancing maturity from about 104 to 84 and 350 to 306 g/kg, whereas DM, ADL and N-free extractives increased at the same time from 222 to 317; 27 to 39.6, and 439 to 522 g/kg, respectively. Palatability and voluntary intake of silage produced from barley harvested at milk and dough stages of maturity were higher. The proportion of lactic acid to total acids was similar in all silages (0.85), the percent of NH3-N in total N decreased with advancing maturity from 13.3 to 10.0. Voluntary silage DM intake increased with maturity of barley, but digestibility of crude fibre, NDF, ADF, ether extract and N-free extractives decreased. Silage contained (per kg of DM): 103.8, 93.9, 83.7g of crude protein; 63.8, 57.7, 51.4 g PDIN; 70.9, 67.6, 66.3 g PDIE and 0.68, 0.67, 0.70 UFL at head emergence, milk and dough stages of maturity, respectively. Harvesting of whole crop barley at milk or dough stage of maturity is recommended for silage making.