[I-15-22] Effect of concentrate level provided at milking robot on eating behavior and rumen fermentation in dairy cows
[Introduction] In this study, we studied whether the levels of the concentrate diet provided at milking robot based on cow’s milk yield would affect eating behavior of partial mixed ration (PMR) and rumen pH of cows. [Method] High yielding cows (n=3, 44 kg milk/d) and moderate yielding cows (n=3, 32 kg milk/d) in a free stall barn with a milking robot were arranged to provide high (8 kg/d) and low (5 kg/d) levels of a concentrate diets during milking, respectively. Daily amount of PMR (TDN 69%) was provided in four portions from 10:00 to 16:00. Feed intake was monitored by access-controlled feed boxes. Rumen pH was monitored by the sensing device inserted into the rumen. [Result] Daily PMR intake did not differ between the groups. However, PMR intake from 10:00 to 18:00 was greater for the low group than high group. Although the daily average of rumen pH did not differ between the groups, hourly average of rumen pH was peaked the initiation of PMR provision (10:00 am), then it decreases rapidly for the low group compared with the high group. The level of concentrate at milking robot may affect eating behavior of PMR which would associate with variation of rumen pH in dairy cows.