Effects of feeding methods of total mixed ration on behavior patterns of growing hanwoo steers

A study was conducted to investigate the effects of methods of feeding a total mixed ration (TMR) on behavior patterns of growing Hanwoo steers. A total of 15 growing steers (13 months old) were assigned to the control (fed roughage and concentrate mix separately), TMR1 (fed restricted TMR), and TMR2 (fed TMR ad libitum) groups. Individual behaviors of steers were observed for 48 hours. Compared with the control, feeding restricted TMR (TMR1) resulted in short eating time, long ruminating time, short chewing time, high frequencies of defecation, urination, and drinking of water, great numbers of boluses and chews, long ruminating time per bolus, low feed value index, high eating and chewing efficiencies (p<0.05). Compared with feeding restricted TMR (TMR1), feeding TMR ad libitum (TMR2) resulted in 1.2 kg more daily feed DM intake, long eating and chewing times, short resting time, great frequencies of defecation, urination and drinking of water, more numbers of boluses and chews, long ruminating time per bolus, low feed value index, low eating and high ruminating efficiencies (p<0.05) and similar chewing efficiency (p>0.05). Considering all these results, the wet TMR feeding system induced generally more desirable eating and ruminating behaviors of growing Hanwoo steers, but made the barn floor wetter due to more defecation and urination.