Effect of harvesting time and wilting of silage on digestibility in cows and sheep

摘要

Round bale grass silage harvested at early (D-value 757 g kg~(-1) DM) or normal (D-value 696 g kg~(-1) DM) time, direct cut or wilted, was used to study effect of harvesting time and wilting on digestibility of main nutrients. Fermentation quality wasgood in all 4 silages. Silages were fed ad libitum to 8 cows (Norwegian Red) in early lactation. Animals were split by two concentrate levels (4 and 10 kg d~(-1)) and used in 4 x 4 Latin square experiments (4-week periods). No major effects of wilting on digestibility of nutrients were observed. Two weeks delayed harvesting time reduced dietary organic matter digestibility in cows from 813 to 759 g kg~(-1) DM at low concentrate level, and from 776 to 748 g kg~(-1) DM at high concentrate level. Corresponding values for NDF digestibility were 788 and 724, and 702 and 626 g kg~(-1) DM at low and high concentrate level, respectively. Energy supply calculated on the basis of digestibility measures of silage and concentrate with sheep agreed well with the calculation from ration digestibility in cows at 4 kg concentrate level. At 10 kg concentrate level, calculated energy supply was higher based on sheep than on cows.