Abstract
In situ digestion trial and measurement of chewing time were done to clarify the effect of ammonia treatment to low quarity roughage on eating and ruminating behavior by dairy cattle. Late cut orchardgrass (seed-setting stage) was treated with anhydrous ammonia (3% of the grass fresh matter) in a sealed vinyl sheet for 60 days. The treated samples in nylon bags were incubated in the rumen of dairy cattle for 3, 6, 12, 24 or 48 hours, and in situ dry matter disappearance was determind. Eating and ruminating time was measured for 24 hours successively with dairy cattle fed on the treated and the untreated hay. Increase of OCC, Oa and in situ dry matter disappearance was recognized to improve the nutritive value in ammonia treated hay. Difference in eating time between treated and untreated hay was not found. Ruminating and chewing time slightly decreased in ammonia treated hay compared to untreated hay. It appears that these tendencies resulted from the decrease of OCW and the consequent structural changes. Roughage value index of the treated hay was estimated to be 17 min/kg DM lower than that of the untreated hay. In previous studies, anhydrous ammonia concentration of about 3% of fresh matter was determined to improve preservation and nutritive value of moist roughage. The result of the experiment showed that 3% of anhydrous ammonia has a potential for improving the nutritive value of low quality roughage.
