Abstract
Seven Dairy farms adopting grazing in eastern Hokkaido, Japan, were investigated to explore factors associated with utilization of self-supplied forage. Herbage allowances for grazing animals and production of conserved forage (mainly silage9 ranged from 25 to 42kg DM/head/day and from 2.7 to 4.0t DM/head/year, respectively, indicating that the farms produced sufficient quantities of self-supplied forage. Pasture utilization by grazing was low in most farms with short daily grazing durations (6-8 hours) and low stocking rates (≤3 animals/ha), which presented a possibility of increasing milk production from grassland (milk derived from self-supplied forage) through improved grazing management. Milk production from grassland decreased as production of conserved forage increased, indicating less efficient use of conserved forage in more productive farms. Most farms used relatively high amounts of purchased concentrates (about 3t DM/head/year) and showed low efficiencies of concentrate use for milk production (<3.0kg milk/kg concentrate), which implied that concentrates were used in excess of supplements to self-supplied forage, i.e. concentrates contributed even to milk that could have been produced from forage. The results show that high dependence on concentrates is a major factor responsible for low utilization of self-supplied forage in dairy farms in the region.
