[Effect of the roughage sequence and concentrates in animal feed on carbohydrate digestion and bacterial protein synthesis in the rumen of dairy cows].

In experiments with dairy cows provided with rumen fistulas and duodenal re-entrant canulas, the order of feeding roughage (chopped forage and pellets) and concentrates (maize and barley) was found to influence carbohydrate digestion and bacterial protein synthesis in the rumen. Feeding the roughage 90 min. before the concentrate caused a wider C2:C3 ratio and a sustained course of the pH-value (greater than 6.5) than the ratio other way round. This favoured cellulose digestion in the rumen when feeding chopped roughage. When feeding roughage before concentrates, the nonbacterial N-proportion in the duodenal contents proved greater than in the reverse order and revealed the highest values for roughage fed in pelleted form. Feeding structured roughage as first component of the diet with concentrates given afterwards is, therefore, recommended for dairy cows.