Digestibility of common reed (Pharagmites communis Trin.) silage as ruminant feed and effects of inclusion levels in the diet of breeding cows on feed intake, ruminal fermentation and blood metabolites.

To examine the digestibility of common reed (Pharagmites communis Trin.) silage and effects of inclusion levels in the diet of breeding cows on nutrient intakes, ruminal fermentation and nutrient status, two digestion trials using four sheep and cows, respectively, at the maintenance stage were conducted. In the trial using sheep, common reed silage contained 20% crude protein (CP) and 50% total digestible nutrients (TDN) on a dry matter basis. In the trial using cows, treatments were the control (92.4% Sudangrass hay and 7.6% soybean meal) and CS25, CS50 and CS80 (replacing 25%, 50%, and 80% of the control with silage, respectively). The intake and sufficiency rate of CP increased by increasing the silage level in the diet (P < 0.05), and the CP requirements of cows at maintenance was satisfied in CS80. In contrast, the sufficiency rate of TDN decreased in CS80, although it was 99.8%. Ruminal pH and NH3 -N concentration changed among the treatments (P < 0.05); however, the blood metabolites were not affected by silage. The results indicated that including common reed silage of up to 80% in the diet of breeding cows was possible and did not have adverse effects on the blood metabolites.