Effect of Kinds of Forage on Feed Intake and Time Spent for Eating and Rumination of Japanese Black Cows

To determine effect of kinds of forage on feed intake and behavior of eating and rumination of Japanese Black cows, animals were given ad libitum of 8 kinds of forage such as alfalfa as legume hay, Italian ryegrass, perennial ryegrass, timothy, oats hays as temperate grass hay, bermudagrass, sudangrass as tropical grass hay, and rice straw. Dry-matter intake based on metabolic body size (g/kg0.75) was more than 100g/kg0.75 for legume hay, some temperate grass hays (timothy and oats hays), but 70g/kg0.75 for some temperate grass hays (Italian ryegrass and perennial ryegrass hays) and rice straw. Intake for tropical grass hays ranged from 80 to 90g/kg0.75. The time spent for eating ranged from 340 to 404min/day without any significant difference among forages. On the basis of dry-matter intake, however, animals spent less time for eating legume hay, some temperate grass hays (timothy, oats) and tropical hays than some temperate grass hays (Italian ryegrass, perennial ryegrass) and rice straw. The time spent for rumination was significantly different among forages, ranging from 369min/day for legume hay to 534min/day for a temperate grass hay (perennial ryegrass). The time spent for eating and ruminating did not always reflect the difference in dry-matter intake.