Income over feed cost IOFC

8

3. RESULTS AND DISCUSSION

1. Nutrient Intake and Feedlot Steer Performance

The RF and control treatments gave similar average nutrient intake during the experimental period Table 3. Daily intake of each steer was approximately 9.5 kg day -1 at dry matter DM basis. The proportion of concentrate and forage intake was 91.5 and 8.5, respectively. Similar pattern to that of DM intake, crude fiber intake, crude protein intake, ether extract intake, nitrogen free extract intake, total digestable nutrients TDN intake and gross energy intake GEI also gave similar results on both treatments. Table 3. Total nutrient intake of feedlot steer administered with RF and without rumen mechanical stimulator Control in short-time rearing. Item Treatment SEM P-value Control RF Average Intake of Nutrient Dry Matter kg h -1 d -1 9.589 + 0.007 9.590 + 0.025 0.002 0.876 Crude Fiber kg h -1 d -1 1.760 + 0.002 1.759 + 0.005 0.000 0.852 Crude Protein kg h -1 d -1 1.292 + 0.001 1.293 + 0.003 0.000 0.572 Ether Extract kg h -1 d -1 0.397 + 0.001 0.397 + 0.001 0.000 0.423 NFE kg h -1 d -1 4.904 + 0.004 4.905 + 0.014 0.001 0.902 TDN £ kg h -1 d -1 6.208 + 0.005 6.210 + 0.016 0.001 0.729 GEI MJ h -1 d -1 16.472 + 0.013 16.475 + 0.045 0.003 0.811 Concentrate : Roughages 91.5 : 8.5 91.5 : 8.5 Notes: NFE=Nitrogen free extract ;TDN=Total Digestible Nutrient. £ = National Research Council, 1984; GEI=Gross Energy Intake; Different upper case letters within rows indicate differences among treatments P≤0.05. Nutrient intake is influenced by the chemical composition within the concentrate and forage. This result indicated that RF treatment was unable to increase feed intake of steers when reared in short-time period. Previous studies also reported that RMS administration resulted in a similar nutrient intake compared to control such as in Thai native steers Bos indicus Angthong et al., 2011, lactating Holstein Matsumoto et al., 2011 and Holstein steers Horiguchi Takahashi, 2004. Table 4. Performance, gain:feed ratio and income over feed cost IOFC of feedlot steers with RF and without rumen mechanical stimulator administration control in short-time rearing. Item Treatment SEM P-value Control RF Performance Total Gain kg h -1 d -1 184.30 + 26.4 171.00 + 27.7 2.721 0.286 ADG kg h -1 d -1 1.98 + 0.28 1.83 + 0.29 0.029 0.287 Gain : Feed ratio 0.21 + 0.03 0.19 + 0.03 0.003 0.288 IOFC Rp h -1 4,248,709 + 950,414 b 2,768,625 + 998,981 a 121,535 0.003 Notes: ADG=Average Daily Gain; IOFC = Income Over Feed Cost; Different upper case letters within rows indicate differences among treatments P≤0.05.