EFFECTS OF RATIO OF CONCENTRATE TO ROUGHAGE AND KINDS OF HAY IN A RATION ON ESTIMATING THE RUMEN DEGRADABILITY OF PROTEIN OF FORMULATED CONCENTRATE

Formula feed for fattening cattle ground through 2 mm screen was incubated in the rumen of sheep and goats to evaluate effects of ratio of concentrate to hay and kinds of hay in a ration on determining the degradability (dg) value of protein using in sacco technique. Following results were obtained: 1) Residual dry matter (DM) and crude protein (CP) of formula feed decreased as the time of incubation increased. Regression analyses showed that rates of degradation of DM and CP in the rumen were not the same when they were determined under feeding of rations with different percentages of concentrate. 2) Rate of passage of digesta from the rumen differed between feeding of Italian ryegrass hay ration and that of alfalfa hay ration, but was not influenced by the percentage of concentrate in a ration. 3) The dg value was different when it was estimated with results obtained from determinations under feeding of Italian ryegrass hay ration or that of alfalfa hay ration. The percentage of concentrate in a ration had no influence on the dg value of protein in formula feed.