Effect of By-Product Mixing Silage Feeding on the Eating and Ruminating Behavior of Hanwoo Steer

This study was carried out to investigate the effects of by-product mixing silage feeding on the eating and ruminating behavior of fattening Hanwoo steer. A total of 12 Hanwoo steers (21 months old) were divided into three feeding groups and assigned to 3 dietary treatments: control (C: concentrate + ad libitum feeding of rice straw), and by-product mixing silage groups (T1: concentrate + 1 kg restricted feeding of by-product mixing silage + ad libitum feeding of rice straw, T2: concentrate + ad libitum feeding of by-product mixing silage). Eating behaviors were observed for 48 hours. Total feed intake was high in the order of T1 > C > T2, but not significantly different among the treatments. The eating and chewing time were significantly higher in C than by-product mixing silage treatments (P<0.05). Ruminating and resting time were not significantly different among the treatments. Number of bolus, number of total chews and number of chews per bolus were not significantly different among the treatments. But ruminating time per bolus and FVI (feed value index) were significantly higher in C than T1 and T2 (p<0,01, 0.05). Bolus per minute was the highest in T1 (p<0.01). Number of drinking was significantly higher in T2 than C and T1 (p<0.05), but defecating and urinating were not significantly difference among the treatments. Eating rate was the highest in T2 (p<0.05), but ruminating and chewing efficiency were not significantly difference among the treatments. Consequently, there was no big difference on eating behavior when feed by-product silage comparing with rice straw. Therefore, it is thought that by-product mixing silage could be the alternative for the rice straw.