Table 4.
Dry matter intake, gain-to-feed ratio, and ADG in feedlot animals fed high-grain diets1 supplemented with no additives (CON), monensin (MON, 33 mg/kg DM), 3-nitrooxypropanol (NOP, 125 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 | 506.9 | 503.9 | 512.2 | 513.3 | 3.80 | 0.06 | 0.81 | 0.60 | — |
| Final BW, kg | 697.5 | 692.2 | 693.6 | 696.5 | 5.24 | 0.97 | 0.82 | 0.44 | — |
| ADG, kg | 1.80 | 1.79 | 1.73 | 1.74 | 0.040 | 0.08 | 0.98 | 0.76 | <0.01 |
| Daily DMI, kg/animal2 | 12.1 | 11.4 | 11.4 | 11.0 | 0.27 | 0.06 | 0.06 | 0.51 | <0.01 |
| Gain:feed | 0.150 | 0.152 | 0.152 | 0.159 | 0.0020 | 0.58 | <0.01 | 0.66 | <0.01 |
| Behavior cattle3 | |||||||||
| No. of steers (pens) | 16 (2) | 16 (2) | 16 (2) | 16 (2) | |||||
| Meal duration, min/d | 89.0 | 89.4 | 87.4 | 79.3 | 3.93 | 0.22 | 0.40 | 0.31 | <0.01 |
| Head-down duration, min/d | 35.3 | 41.1 | 38.0 | 26.6 | 3.70 | 0.32 | 0.62 | 0.18 | <0.01 |
| Meal frequency, events/d | 8.52 | 8.49 | 7.92 | 7.40 | 1.820 | 0.29 | 0.75 | 0.87 | |
1 Data combined from Main and CEB feedlots. Main feedlot had 24 pens, 8 animals per pen, and 6 pens per treatment and CEB feedlot had eight pens, 6 animals per pen and 2 pens per treatment. Location effect was not significant.
2 DMI 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 per pen; 16 animals per treatment).