Table 3.
Effects of ractopamine (RAC) dose and handling methods on dead and non-ambulatory pigs1,2
| RAC dose | P-values | |||||
|---|---|---|---|---|---|---|
| Measurement | 0 mg/kg | 5 mg/kg | 10 mg/kg | 0 vs. 5 | 0 vs. 10 | 5 vs. 10 |
| Number of pigs | 96 | 95 | 96 | – | – | – |
| Loading observations3 | ||||||
| Dead, % | 0.00 | 0.00 | 0.00 | – | – | – |
| Fatigued, %4 | 0.00 | 0.00 | 0.04 | 1.00 | 0.25 | 0.25 |
| Injured, non-ambulatory, %5 | 0.00 | 0.00 | 0.00 | – | – | – |
| Injured, ambulatory, %6 | 0.04 | 0.07 | 0.04 | 0.49 | 1.00 | 0.49 |
| Unloading observations7 | ||||||
| Dead, % | 0.04 | 0.00 | 0.00 | 0.25 | 0.25 | 1.00 |
| Fatigued, %4 | 0.00 | 0.04 | 0.00 | 0.25 | 1.00 | 0.25 |
| Injured, non-ambulatory, %5 | 0.00 | 0.00 | 0.00 | – | – | – |
| Injured, ambulatory, %6 | 0.11 | 0.25 | 0.22 | 0.14 | 0.22 | 0.78 |
| Final drive observations8 | ||||||
| Dead, % | 0.00 | 0.00 | 0.00 | – | – | – |
| Fatigued, %4 | 0.00 | 0.00 | 0.00 | – | – | – |
| Injured, non-ambulatory, %5 | 0.00 | 0.00 | 0.00 | – | – | – |
| Injured, ambulatory, %6,9 | ||||||
| Low stress handling | 0.00 | 0.35 | 0.07 | 0.01 | 0.38 | 0.01 |
| High stress handling | 0.07 | 0.26 | 0.33 | 0.09 | 0.03 | 0.47 |
1Adapted from Gillis et al. (2007).
2A total of 288 market weight pigs were used in a 3 × 2 factorial arrangement of treatments consisting of ractopamine dose (0 vs. 5 vs. 10 mg/kg) fed for 34 to 36 d and handling method (low stress vs. high stress handling).
3Loading observations were made as pigs were moved with either low stress or high stress handling from their home pen through a handling course and during loading onto a trailer.
4Fatigued was defined as a pig that became unwilling or unable to move in response to the handler's inputs for no physically apparent reason (i.e., no obvious injury).
5Injured, non-ambulatory was defined as pigs that were recumbent and unwilling or unable to move due to an obvious injury such as a broken leg or trauma.
6Injured, ambulatory was defined as pigs able to move and keep up with the contemporary group, but were obviously injured (obvious limp; i.e., foot, leg, or shoulder injury).
7Unloading observations were made as pigs were unloaded after a 3 h journey and moved with either low or high stress handling from the trailer to a lairage pen.
8Final drive observations were made after the pigs were allowed to rest in lairage (low stress = 4 h; high stress = 2 h) and during movements from the lairage pen to the stunning pen with either low stress or high stress handling procedures.
9Indicates a ractopamine × handling method interaction (P < 0.05).