Table 3.
Dry matter intake, gain-to-feed ratio, and ADG in feedlot animals fed high-forage diets1 supplemented with no additives (CON), monensin (MON, 33 mg/kg DM), 3-nitrooxypropanol (NOP, 200 mg/kg DM), and combination of MON and NOP
| −MON | +MON | Effect, P value | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Variable | −NOP | +NOP | −NOP | +NOP | SEM | MON | NOP | MON × NOP | Period |
| All cattle1 | |||||||||
| No. of steers (pens) | 60 (8) | 60 (8) | 60 (8) | 60(8) | — | — | — | — | — |
| Initial BW, kg | 308.3 | 308.0 | 307.5 | 309.6 | 2.22 | 0.86 | 0.69 | 0.58 | — |
| Final BW, kg | 461.8 | 459.3 | 463.9 | 463.9 | 3.32 | 0.31 | 0.71 | 0.71 | — |
| ADG, kg | 1.45 | 1.43 | 1.47 | 1.46 | 0.020 | 0.21 | 0.41 | 0.99 | <0.01 |
| Daily DMI, kg/animal | 8.41 | 7.64 | 8.08 | 7.64 | 0.100 | 0.12 | <0.01 | 0.12 | <0.01 |
| Gain:feed | 0.172 | 0.184 | 0.183 | 0.189 | 0.0020 | <0.01 | <0.01 | 0.12 | <0.01 |
| Behavior cattle2 | |||||||||
| No. of steers (pens) | 16 (2) | 16 (2) | 16 (2) | 16 (2) | |||||
| Meal duration, min/d | 173.2 | 172.2 | 177.1 | 170.1 | 8.10 | 0.92 | 0.64 | 0.73 | |
| Head-down duration, min/d | 64.0 | 77.7 | 75.8 | 59.6 | 9.70 | 0.77 | 0.91 | 0.20 | <0.01 |
| Meal frequency, events/d | 12.6 | 12.7 | 11.4 | 12.1 | 0.38 | 0.07 | 0.33 | 0.46 | <0.01 |
1Data combined from Main and CEB feedlots. Main feedlot had 24 pens, 8 animals per pen, and 6 pens per treatment, and CEB feedlot had 8 pens, 6 animals per pen, and 2 pens per treatment. Location effect was not significant.
2DMI was determined for the pens weekly as the difference between feed offered and weekly refusals, corrected for DM content. Daily DMI per animal was estimated by pen DMI divided by number of days and number of animals per pen.
3Data were collected from 8 GrowSafe pens (8 animals/pen; 16 animals/treatment).