View Full Table | Close Full ViewTable 1.

Physiological comparisons between fatigued and normal pigs at the packing plant1

 
Measurement Fatigued2 Normal
Number of pigs 35 35
Physical indicators of acute stress, %
    Skin discoloration 77.1a 0.00b
    Open-mouth breathing 44.1a 0.00b
    Muscle tremors 82.9a 2.86b
    Abnormal vocalizations 30.0a 0.00b
Rectal temperature, °C 38.4 38.9
Blood serum parameters
    Cortisol, ng/mL 230a 141b
    Epinephrine, nmol/dL 365a 9b
    Norepinephrine, nmol/dL 396.4a 5.9b
    Creatine kinase, IU/L 20,674a 4339b
Blood plasma parameters
    Glucose, mmol/L 106.0a 86.0b
    Lactate, mmol/L 33.1a 11.5b
    pH 7.11a 7.35b
    Bicarbonate, mmol/L 14.5a 28.8b
    Base-excess, mmol/L –16a 2.1b
Glycolytic potential, μmol/g
    Liver 66a 196b
    Longissimus muscle 125a 152b
    Semitendinosus red muscle 70a 90b
    Semitendinosus white muscle 89 121
1Adapted from Ivers et al. (2002).
2Fatigued pigs are defined as non-ambulatory, non-injured pigs.
a,bMeans with different superscripts differ (P < 0.05).



View Full Table | Close Full ViewTable 2.

Effects of ractopamine (RAC) and handling treatment on the percentage of fatigued pigs in handling model studies1

 
RAC × Handling treatment subclasses2
Gentle handling3
Aggressive handling4
Study Pigs, # RAC duration, d 0 mg/kg 5 mg/kg 20 mg/kg 0 mg/kg 5 mg/kg 20 mg/kg
Miller, unpublished data 150 31 0.0%a 0.0%a 0.0%a 39.0%b
Ivers, unpublished data 144 31 0.0%a 5.6%a 25.0%b 61.1%c
1Fatigued pigs were defined as non-ambulatory, non-injured, and/or pigs showing clinical signs of acute stress (open-mouth breathing, skin discoloration, and/or muscle tremors) with rectal temperatures ≥ 40.6°C.
2RAC × handling interactions existed for the percentage of fatigued pigs (P < 0.05).
3Gentle handling: pigs were moved slowly without electric prods.
4Aggressive handling: pigs were moved rapidly with 18 (Ivers, unpublished data) or 32 (Miller, unpublished data) applications of an electric prod.
a–cMeans with different superscripts differ (P < 0.05).



View Full Table | Close Full ViewTable 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).



View Full Table | Close Full ViewTable 4.

Effects of ractopamine (RAC) and U.S. region on the rate of transport losses from loading at the farm to stunning at the packing plant1

 
RAC dose
P–values
Transport losses2 0 mg/kg 5 mg/kg 10 mg/kg 0 vs. 5 0 vs. 10
Midwest Region
    Number of pigs loaded 5577 5580 5568
    Fatigued, % 0.86 1.66 1.32 0.01 0.10
    Injured, % 0.26 0.53 0.59 0.05 0.03
    Dead, % 0.15 0.38 0.33 0.05 0.12
    Total transport losses, % 1.33 2.63 2.26 < 0.001 0.01
Southeast Region
    Number of pigs loaded 5795 5778 5776
    Fatigued, % 0.63 0.48 0.61 0.40 0.93
    Injured, % 0.43 0.30 0.61 0.35 0.28
    Dead, % 0.21 0.12 0.32 0.33 0.35
    Total transport losses, % 1.35 0.85 1.55 0.07 0.58
1Adapted from Swan et al. (2007).
2Transport loss classifications during loading at the farm, unloading, and moving through the plant included fatigued (defined as pig that became unwilling or unable to move in response to the handler’s inputs for no physically apparent reason (i.e. no obvious reason), injured (defined as a pig that was recumbent and unwilling to move due to an obvious injury such as a broken leg or trauma), and total transport losses (included all fatigued, injured, and dead pigs recorded during transportation procedures).



View Full Table | Close Full ViewTable 5.

Summary of handling and transport conditions by U.S. region1

 
Region
Measurements Midwest Southeast
Number of trailer loads 96 96
Distance pigs moved, m
    Loading 49 67
    Unloading 133 78
    Final drive 103 66
Electric prod usage, % loads2
    Loading 100 100
    Unloading 52 0
    Final drive 97 0
Event times, min3
    Loading 47 47
    Transportation 111 50
    Wait at plant 69 45
    Unloading 53 20
    Lairage 106 300
1Adapted from Swan et al. (2007).
2Electric prod usage was measured during transportation procedures that were defined as the exit from the farm pen to loading onto the truck (Loading), animals exiting the truck through arrival at the holding pen (Unloading), and exit from the lairage pen to the stunning area (Final drive).
3Duration of loading, transportation, waiting time prior to unloading, unloading time, and lairage time.



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Effects of ractopamine (RAC) dose on the mortality of market weight pigs during the feeding period

 
RAC dose
Study Pigs, # Duration, d 0 mg/kg 5 mg/kg 7.5 mg/kg
Parks et al., 2007 1671 24.5 1.79 2.15 2.16
Hinson et al., 20121 1635 21 1.20 0.62 0.82
Hinson et al., 2012 1708 21 0.96 0.43 0.29
Pompeu et al., 2013 1102 27 0.18 0.36
Ritter, unpublished data 694 18 1.15 0.86
Tavárez et al., 2012 261 28 0.77 0.00
Gerlemann et al., 20132 1744 26 0.17 0.26
Gerlemann et al., 2014 1740 28 0.46 0.34
Christianson et al., 20142 2471 23 0.12 0.49
Pelger, unpublished data2 742 27 0.00 0.53 0.54
Ritter et al., 2011 1476 24 0.41 0.61 0.41
Total Pigs Evaluated 15,244 24.13 5191 2602 7451
Weighted Average Mortality for 0 vs 5 mg/kg4, % 1.08 0.92
Weighted Average Mortality for 0 vs 7.5 mg/kg4, % 0.54 0.56
1Includes a 7.5 mg/kg treatment, a 5 to 7.5 mg/kg step-up program, and a 5 to 10 mg/kg step-up program.
2Includes both a 7.5 mg/kg treatment and a 5 to 10 mg/kg step-up program.
3Weighted average duration of feeding.
4Weighted average treatment mortality was calculated using only studies where direct comparisons where available, with each study weighted by sample size.



View Full Table | Close Full ViewTable 7.

Effects of ractopamine (RAC) dose on lameness of market weight pigs

 
Authors RAC doses Duration, d Pigs, # Treatments Measurements Results
Campos et al., 2012 0 and 5 mg/kg 34 112 Fed 4 different available phosphorous (AP) concentrations (0.109%, 0.209%, 0.309%, and 0.409%). Bone strength, calcium, phosphorus, and ash concentrations of metatarsals. No effect of RAC on parameters evaluated, and no interaction with phosphorus level. Authors recommend feeding 0.33% AP to RAC and control pigs.
Poletto et al., 2009 0 mg/kg and RAC step-up (5 to 10 mg/kg) 31 32 Treatments: diet (RAC vs. control), gender (barrows vs. gilts), and social rank (dominant vs. subordinate). Number of splits, cracks-erosions, and bruises on the front and rear hooves. Average of 2.1 more total lesions across all hooves with RAC. One RAC pig required treatment for lameness vs. 2 control pigs.
Pardo et al., 2004 0 and 10 mg/kg 28 120 Different combinations of RAC, phytase (0 vs. 500 FTU/kg), and inorganic P (0.45 vs. 0.65%) were fed. Metacarpal bone ash, force, and stress. RAC did not compromise bone traits. However, bone traits improved when inorganic P was increased 0.2%
Lutz and Stahly, 2003 0 and 20 mg/kg 35 120 Fed 6 different available phosphorous (AP) concentrations (0.08%, 0.13%, 0.18%, 0.23%, 0.28%, and 0.33%) and kept the Ca:AP ratio constant at 2.5:1. Ham-loin bone weight and mineral content of the fifth vertebrae and femur. RAC reduced bone weights and bone mineral content. Authors recommend increasing AP in RAC diets by 0.02 to 0.03%.
He et al., 1993 0 and 20 mg/kg 43 48 Treatments evaluated included diet (RAC vs. control), gender (gilt vs. barrow), and crude protein (17 vs. 20%). The incidence and severity of osteochondrosis, as measured by bone accretion rates, joint-cartilage soundness and uronic acid concentrations. RAC did not affect bone accretion rates, the incidence or severity of joint-cartilage soundness, uronic acid concentrations.



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Effects of ractopamine (RAC) dose on home pen and lairage pen behavior of market weight pigs

 
Authors RAC dose Duration, d Pigs, # Measurements Results
Athayde et al., 2013 0, 5, and 10 mg/kg 28 340 Behavior scan sampling in the home pen was conducted (6 times per d, 3 d per wk) on: calm behaviors (lying, standing, and sitting); moving behaviors (nosing, biting, walking, exploring, running, playing, and mounting); and feeding behaviors (eating feed and drinking water). RAC had no effect on behavior when the 13 behaviors were grouped and summarized as calm, moving, or feeding behaviors. Relative to controls, 5 mg/kg RAC increased nosing by 1.11% and drinking by 0.48%, and reduced playing by 0.20%, while RAC 10 mg/kg increased standing by 0.54%.
Rocha et al., 2013 0 and 7.5 mg/kg 28 1488 Behavior scan sampling was conducted (every 2 min during the first h of lairage) on: lying, sitting, and standing behaviors. RAC did not affect the % of pigs standing, sitting, or lying in the lairage pen at the packing plant.
Poletto et al., 2010a 0 mg/kg and RAC step-up (5 to 10 mg/kg) 28 32 Behavior scan sampling was conducted on subordinate and dominant pigs in the home pen (every 10 min for 24 h on d 2, 5, 8, 12, 15, 19, 22, and 26 of RAC feeding) on: activity (alert, walking, nosing or rooting, bar biting, sham chewing, chain chewing), non-agonistic interactions (drinking, feeding), inactivity, and posture (standing, lying, sitting). RAC increased % sitting (1.5%) and decreased % lying (2.3%), but did not affect % standing. RAC pigs spent 3.9% more time being active via increases in alertness (2.2%), bar biting (0.2%), sham chewing (0.7%), and feeding behaviors (0.9%). Differences in activity were statistically significant only on d 12, 15, 19, and 26.
Benjamin et al., 2006 0 and 10 mg/kg 28 288 Willingness to approach a novel handler sitting in the home pen after a disturbance was measured by latency approach time for 5 out of 6 pigs to contact and touch the handler on d 7 and 28 of RAC feeding. Feeding RAC at 10 mg/kg did not affect willingness to approach a handler after a disturbance.
Marchant-Forde et al., 2003 0 and 10 mg/kg 28 72 Behavior scan sampling in the home pen was conducted (every 5 min for 22 h, one time per wk) on: inactivity vs. activity (walking, rooting, manipulating pen mates/pen components, and belly nosing), alertness, chewing, agonistic interactions, drinking, feeding, and posture (lying, standing, and sitting). Pigs were also subjected to weekly disturbance tests, and latency to lie down after disturbance was recorded. Over the 4 wk feeding period, RAC pigs spent more time active (3.5%), feeding (0.8%), lying sternally (5.8%), and less time lying laterally (7.3%) than controls. RAC fed pigs spent 5.6% more time active and 1.9% more time alert during wk 1 and 2. Differences were not significant on wk 3 and 4. RAC pigs took on average 297 s more to lie down after disturbance during wk 1 and 2.
Schaefer et al., 1992 0, 10, 15, and 20 mg/kg 38.5 86 Behavior scan sampling was conducted in the home pen (every 5 min for 4 h) on: investigating/walking, drinking, feeding, sleeping (individually and in groups), nosing (nose to nose contact and nose to body contact), agonistic, and sexual behaviors. Relative to controls, 20 mg/kg RAC pigs spent 8.3% less time walking and investigating, and 10 mg/kg RAC pigs spent 0.9% less time engaged in nose to nose contact. RAC groups (10, 15, and 20 mg/kg) spent 15% more time sleeping than controls in the 30 min following a meal. No abnormal, stereotyped, or agonistic behaviors were observed in pigs fed 10, 15, or 20 mg/kg of RAC.



View Full Table | Close Full ViewTable 9.

Effects of ractopamine (RAC) on agonistic behavior in market weight pigs

 
Authors RAC dose Duration, d Pigs, # Methodology Results
Rocha et al., 2013 0 and 7.5 mg/kg 28 1488 Continuous observation of agonistic behaviors during the first hour of lairage was conducted on the number and duration of fights (a sequence of 2 or more pigs biting, head knocking, pushing, and shoving lasting greater than 3 s). Skin damage and bruising were evaluated using a 5-point photographic scale) in the cooler the d of slaughter. RAC fed immune-castrates had 4 more fights than non-RAC immune-castrates, and 10 more fights than RAC fed surgical castrates (P < 0.05). RAC pigs fought for shorter durations (5 s; P = 0.05) than control pigs. RAC had no effect on overall skin damage score.
Athayde et al., 2013 0, 5, and 10 mg/kg 28 90 The number of skin and carcass lesions were evaluated on the shoulder, loin, and ham of pigs before loading, after unloading, during lairage, and 24 h after slaughter. RAC and gender had no effects on the total number of skin or carcass lesions.
Poletto et al., 2010a 0 mg/kg and RAC step-up (5 mg/kg for 14 d, then 10 mg/kg for 14 d) 28 32 Continuous observation was conducted in the home pen (for 3 h periods, once per wk for 5 wk) on the number of agonistic social interactions (Offensive behaviors: bites, head knocks, pursuit, threats; Defensive behaviors: freeze, avoidance or flight) and constituent actions displayed by 2 pigs. The average number of agonistic interactions increased (55%) in RAC fed gilts and decreased (approximately 26%) in all other RAC × Gender treatments. RAC fed gilts increased bites (96%) and pursuits (335%) per agonistic interaction vs. baseline, while decreased bites (34%) and pursuits (46%) occurred in the other RAC × Gender treatments (P < 0.001). Head knocks per agonistic interaction increased for RAC fed barrows (14%) and CON gilts (21%) vs. baseline, and decreased head knocks (20%) occurred in the other RAC × Gender treatments (P < 0.05). The total number of agonistic social interactions was not affected by RAC.
Poletto et al., 2010b 0 mg/kg and RAC step-up (5 mg/kg for 14 d, then 10 mg/kg for 14 d) 28 32 Dominant and subordinate pigs from each pen were subjected to six 300 s resident-intruder (R-I) tests on d –6, –5, 9, 10, 23, and 24 of the feeding trial. The latency to the first attack (physical bite or a sequence of bites) and number of attacks over the 300 s tests by resident and intruder pigs were recorded. RAC did not affect the latency to first attack. There was a significant RAC × gender × social rank interaction for the increased likelihood of resident dominant control gilts initiating bites compared to subordinate control (272%) and subordinate RAC fed gilts (276%), but not different from dominant RAC fed gilts. At 30 s of the R-I tests, increased cumulative resident pig attacks occurred by the RAC dominant gilts (38%) and RAC subordinate gilts (42%) vs. the average frequency (11%) of the other treatments. At 300 s, higher cumulative attacks occurred by control dominant gilts (92%), RAC dominant barrows (79%), and RAC subordinate gilts (79%) compared to control subordinate gilts (46%) and barrows (54%), and RAC subordinate barrows (46%). Within RAC, the odds of biting increased for dominant resident pigs (gilts = 228%; barrows: = 185%), and subordinate barrows were 58% more likely to initiate bites than subordinate RAC fed gilts.
Marchant-Forde et al., 2003 0 and 10 mg/kg 28 72 Behavior scan sampling in the home pen was conducted (every 5 min for 22 h, one time per wk) on agonistic interactions. Pigs were also subjected to weekly disturbance tests, and latency to lie down after disturbance was recorded. RAC had no effects on agonistic behaviors.
Schaefer et al., 1992 0, 15, and 20 mg/kg 25–36 86 Behavior scan sampling in the home pen was conducted on Lacombe bred gilts and barrows every 5 min (between 0800 and 1200 h) for the frequency of the following for agonistic behaviors: parallel pressing. Reverse parallel pressing, head-to-head knocks, head-to-body knocks, biting, and replacing another pig. RAC and gender had no effects on agonistic behaviors.



View Full Table | Close Full ViewTable 10.

Effects of ractopamine (RAC) on handling characteristics of market weight pigs

 
Authors RAC dose Duration, d Pigs, # Methodology Results
Peterson et al., 2015 0, 5, and 7.5 mg/kg 28 216 The time to complete handling procedures was evaluated when pigs were moved individually through a handling course (total distance 50 m) with 1 of 3 handling intensity treatments: gentle, moderate, or aggressive handling. Pigs were then loaded on a trailer and transported for 1 h. Afterward, pigs were subjected to a final handling procedure, which consisted of moving pigs through the same handling course, but for a distance of 100 m and all pigs were moved at their own pace using gentle handling. RAC did not affect the time to complete the initial or final handling procedures.
Puls et al., 2015 0 and 10 mg/kg 28 141 Pigs were subjected to handling and transport procedures to evaluate the distance pigs moved voluntarily, ease of handling scores (1 = very easy to 5 = very difficult), and the number of handler inputs (push or bump with a sorting board) needed. Pigs were moved 50 m through a handling course with 8 shocks from an electric prod (defined as aggressive handling), transported 30 min with 0.46 m2/pig, unloaded, and moved 100 m through the same original handling course with gentle handling applied. RAC pigs voluntarily moved 7 m less than control pigs following handling, loading, and 30 min transportation (85.3 vs. 92.0 m for 0 and 10 mg/kg RAC, respectively). There was no difference in ease of handling during pre-transport handling, but there was a tendency (P = 0.06) for RAC fed pigs to be more difficult to handle during post-transport handling than controls (1.9 vs. 2.4, respectively). RAC pigs did not require more handler inputs during either pre- or post-transport handling.
Rocha et al., 20131 0 and 7.5 mg/kg 28 1488 Handler inputs (vocal sound, physical contact, and rattle noise), pig behaviors (slip/fall, overlap, 180° turn, back up, backward, underlap, vocalize, balk, and squeeze), and loading time were measured to assess RAC levels, castration method (immunocastration vs. surgical) and genetic type (A vs. B). Behavior during loading was recorded from the alley to the barn door and from the barn door to the trailer door. RAC did not affect loading behavior. However, RAC fed pigs required more physical handling interventions during movement in the alley from their home pen to the trailer than control pigs (8.45 vs. 6.83 handling interventions, respectively).
Benjamin et al., 2006 0 and 10 mg/kg 28 288 The number of handler interventions to maintain pig movement and the time needed to complete a handling course were measured as pigs were moved individually through an obstacle course on d 7 and 28. The number of handler interventions and handling time was not different between RAC treatments.
Marchant-Forde et al., 2003 0 and 10 mg/kg 28 72 Handling characteristics were evaluated during weekly movements from the home pen to the weigh scale. The characteristics evaluated included the number of pigs that voluntarily exited the home pen, latency to exit the home pen, duration and handler inputs needed to get pigs into the weigh scale, duration and handler inputs needed for pigs to exit the scale, and duration to return to the home pen. RAC pigs were more difficult to handle, with 51% fewer RAC pigs exiting the home pen voluntarily (approximately 1.5 pigs on average). RAC pigs also took 136% longer to remove from the home pen (approximately 10 s), 83% longer to move from the home pen and into a weigh scale (approximately 5 s), and needed 52% more handler inputs (2 to 3 more pats, slaps, and pushes) than control pigs.
Miller, unpublished data2 0 and 20 mg/kg 31 160 Handling intensity (aggressive vs. gentle) and RAC level were evaluated by measuring the number of handler inputs, laps completed, and handling duration. Pigs were moved individually for 8 laps (approximately 200 m) through a handling course with 0 shocks (gentle handling) or 32 shocks (aggressive handling) from an electric prod. Within the aggressive handling groups, RAC pigs required more pushes (2.98 vs. 1.64 pushes per pig, respectively), experienced more applications of an electric prod (35.6 vs. 33.0 prods, respectively), moved a shorter distance (7.6 vs. 7.9 laps, respectively), and took longer to complete the handling course (265.1 vs. 251.9 s, respectively) compared to control pigs. In the gentle handling groups, RAC pigs took longer to complete the handling course (411.8 vs. 374.6 s, respectively) than control pigs.
1There was a significant RAC × genotype method interaction for handler interventions (P < 0.05).
2There was a significant RAC × handling method interaction (P < 0.05).



View Full Table | Close Full ViewTable 11.

Effects of ractopamine (RAC) on the physical indicators of acute stress1 and incidence of fatigued pigs2

 
Authors RAC dose Duration, d Pigs, # Methodology Results
Noel et al., 2016 0 or 10 mg/kg 32 34 Barrows were individually walked around a circular track (30.67 m perimeter) at an average speed of 0.79 m/s until subjectively exhausted (defined as a barrow stopping forward movement 5 times and/or refused to continue forward movement after 20 s of encouragement by handlers during a single stop). Time and distance to exhaustion were recorded for each barrow and average speed was calculated based on laps per min. There was no difference in the average speed in which barrows moved around the track. Ractopamine fed barrows reached subjective exhaustion earlier (282.40 vs. 395.57 s, respectively) and covered less distance compared to control barrows (372.53 vs. 563.76 m, respectively).
Peterson et al., 2015 0, 5, or 7.5 mg/kg 28 216 The incidence of physical indicators of stress1 and fatigued pigs2 were assessed when pigs were moved individually through a 50 m handling course with 1 of 3 handling intensity treatments: gentle, moderate, or aggressive. Pigs were then loaded on a trailer, transported for 1 h, and then subjected to a final handling procedure consisting of moving pigs through the same handling course for 100 m with gentle handling. Pigs fed 7.5 mg/kg RAC had an increased percentage of skin discoloration compared to 5 mg/kg (30.6% vs. 15.3%, respectively), but were similar to control pigs (18.1%). Across the handling intensity treatments, the overall incidence of skin discoloration and open-mouth breathing was greater after the handling intensity treatments were applied and after the final handling procedure. Pigs fed 7.5 mg/kg RAC had a greater incidence of fatigued pigs compared to 5 mg/kg and control pigs (9.7% vs. 2.8% vs. 0%, respectively).
Puls et al., 2015 0 or 10 mg/kg 28 141 Physical indicators of stress1 and the incidence of fatigued pigs2 were assessed after pigs were moved 50 m through a handling course with 8 shocks from an electric prod (defined as aggressive handling), transported 30 min with 0.46 m2/pig, unloaded, and moved 100 m through the same original handling course with gentle handling applied. During the handling and transport procedures, RAC did not affect the incidence of physical indicators of stress. The incidence of fatigued pigs was similar between the control and RAC fed pigs (2.8 vs. 1.4%, respectively).
Ivers, unpublished data, Study #1 5 or 20 mg/kg 31 144 The incidence of physical indicators of stress1 and fatigued pigs2 were evaluated when pigs were subjected to gentle or aggressive handling while moving through a handling course (approximately 293 m) with crowding in a narrow aisle at the end of the course. Aggressive handling consisted of using an electric prod as the primary driving tool to move pigs. Gentle handling consisted of using a plastic tube as the primary tool (no electric prod) to move pigs through the same course. The proportion of pigs exhibiting physical indicators of stress during or after handling was numerically higher for aggressive vs. gentle handling and for 20 vs. 5 mg/kg RAC fed pigs3. See Table 2 for treatment means and P-values for fatigued pigs2.
Miller, unpublished data 0 or 20 mg/kg 31 160 Handling intensity (aggressive vs. gentle) and RAC level were evaluated by assessing the incidence of clinical indicators of stress1 and fatigued pigs2. Pigs were moved individually for 8 laps (approximately 200 m) through a handling course with 0 shocks (gentle handling) or 32 shocks (aggressive handling) from an electric prod. RAC did not affect the incidence of open-mouth breathing or skin discoloration before or after handling. RAC × handling method interactions existed for post-handling vocalizations and fatigued pigs. See Table 2 for treatment means and P-values for fatigued pigs2.
1Physical indicators of acute stress are defined as presence/absence of open-mouth breathing, skin discoloration, muscle tremors, vocalizations.
2Fatigued pigs are defined as pigs unable to walk, pigs that refused to move with encouragement, pigs too exhausted to return to their home pen, and/or pigs with a rectal temperatures > 40.6°C immediately post-handling.
3Data on the physical signs of stress were not statistically analyzed.



View Full Table | Close Full ViewTable 12.

Effects of ractopamine (RAC) dose on the heart rate of market weight pigs measured in beats per minute

 
RAC dose
Sampling time Authors Pigs, # Duration, d 0 mg/kg 5 mg/kg 10 mg/kg 20 mg/kg 40 mg/kg
Baseline Catalano et al., 2012 32 35 119.0 116.0 110.0 120.0
Baseline Ivers, unpublished data, Study #1x 48 31 131.5 134.3
Handler enters home pen Marchant-Forde et al., 2003 72 28 136.4a 144.6b
Post-Handling James et al., 2013 (Study #1) 46 28 205 203
Post-Handling Ivers, unpublished data, Study #1x 46 31 178.7 191.0
0.5 h Post-Handling Ivers, unpublished data, Study #1x 46 31 146.5 165.9
Loading Marchant-Forde et al., 2003 32 28 NS1 NS
Transport Marchant-Forde et al., 2003 32 28 NS NS
Unloading Marchant-Forde et al., 2003 32 28 NS NS
a,bMeans with different superscripts differ (P < 0.05).
xData were not statistically analyzed, so only raw treatment means are reported.
1NS: LS means were not reported by the authors, but treatments did not differ (P > 0.10).



View Full Table | Close Full ViewTable 13.

Effects of ractopamine (RAC) dose on epinephrine concentrations of market weight pigs

 
RAC dose
Sampling time Samples evaluated Units of measure Authors Pigs, # Duration, d 0 mg/kg 5 mg/kg 7.5 mg/kg 10 mg/kg
Baseline Plasma pg/mL Peterson et al., 2015 216 28 206.0 165.1 209.2
Baseline Plasma pg/mL Puls et al., 2015 144 28 45.6 48.8
Baseline Plasma pg/mL Marchant-Forde et al., 2003 72 28 101.5a 253.0b
Baseline Plasma pg/mL Poletto et al., 2010a1 32 28 71.5 78.7
Post-handling/Transportation Plasma pg/mL Peterson et al., 2015 216 28 889a 1109ab 1275b
Post-handling/Transportation Plasma pg/mL Puls et al., 2015 144 28 468.1a 728.3b
Exsanguination Urine Log10 Rocha et al., 2013 239 28 1.14 1.18
Exsanguination Brain–amygdala μg/mg Poletto et al., 2010b1 32 31 1.61 1.28
Exsanguination Brain–frontal cortex μg/mg Poletto et al., 2010b1 32 31 0.52 0.60
Exsanguination Brain–raphe nuclei μg/mg Poletto et al., 2010b1 32 31 2.89 2.66
Exsanguination Brain– hypothalamus μg/mg Poletto et al., 2010b1 32 31 15.43 17.04
a,bMeans with different superscripts differ (P < 0.05).
1Pigs were fed a RAC step-up diet (5 mg/kg for 14 d followed by 10 mg/kg for 17 d), thus the average dose fed was 7.5 mg/kg.



View Full Table | Close Full ViewTable 14.

Effects of ractopamine (RAC) dose on norepinephrine concentrations of market weight pigs

 
RAC dose
Sampling time Samplesevaluated Units of measure Authors Pigs, # Duration, d 0 mg/kg 5 mg/kg 7.5 mg/kg 10 mg/kg
Baseline Plasma pg/mL Peterson et al., 2015 216 28 903.6 984.3 980.9
Baseline Plasma pg/mL Puls et al., 2015 144 28 291.9 275.5
Baseline Plasma pg/mL Marchant-Forde et al., 2003 72 28 480a 991b
Baseline Plasma pg/mL Poletto et al., 2010a1 32 28 357.1 423.1
Post-handling/Transportation Plasma pg/mL Peterson et al., 2015 216 28 3987 4167 3951
Post-handling/Transportation Plasma pg/mL Puls et al., 2015 144 28 887.2 1053.4
Exsanguination Urine Log10 Rocha et al., 20132 239 28 1.31 1.31
Exsanguination Brain- amygdala μg/mg Poletto et al., 2010b1 32 31 35.46 33.94
Exsanguination Brain–frontal cortex μg/mg Poletto et al., 2010b1 32 31 16.91 18.22
Exsanguination Brain–raphe nuclei μg/mg Poletto et al., 2010b1,3 32 31 43.31 45.54
Exsanguination Brain– hypothalamus μg/mg Poletto et al., 2010b1 32 31 124.21 141.34
a,bMeans with different superscripts differ (P < 0.05).
1Pigs were fed a RAC step-up diet (5 mg/kg for 14 d followed by 10 mg/kg for 17 d), thus the average dose fed was 7.5 mg/kg.
2There was a trend for a RAC × castration method interaction (P < 0.10).
3There was a significant RAC × social rank interaction (P < 0.05).



View Full Table | Close Full ViewTable 15.

Effects of ractopamine (RAC) dose on cortisol concentrations in market weight pigs

 
RAC dose
Sampling time Samples evaluated Units of measure Authors Pigs, # Duration, d 0 mg/kg 5 mg/kg 7.5 mg/kg 10 mg/kg 20 mg/kg
Baseline Plasma ng/mL Peterson et al., 2015 216 28 33.4 33.0 30.9
Baseline Whole blood ng/mL James et al., 2013 (Study #1) 128 28 13.9 14.6
Baseline Plasma ng/mL Marchant-Forde et al., 2003 72 28 45.5 40.9
Post-handling Plasma ng/mL Peterson et al., 2015 216 28 42.8 51.4 51.2
Post-handling Whole blood ng/mL James et al., 2013 (Study #1)1 128 28 44.2a 50.7b
Post-handling Whole blood ng/mL James et al., 2013 (Study #2) 128 28 39.5 43.1
1 h Post-handling Whole blood ng/mL James et al., 2013 (Study #2) 128 28 40.1 46.6
Post-transport Plasma ng/mL Marchant-Forde et al., 20032 72 28 64.6 71.5
Exsanguination Plasma ng/mL Athayde et al., 2013 90 28 63.5 80.2 76.6
Exsanguination Urine Log10 Rocha et al., 2013 239 28 1.52 1.52
a,bMeans with different superscripts differ (P < 0.05).
1Indicates a RAC × handling intensity (gentle vs. aggressive) interaction (P < 0.05).
2Sample was collected during exsanguination and reported as post-transport Cortisol.



View Full Table | Close Full ViewTable 16.

Effects of ractopamine (RAC) dose on body temperature of market weight pigs measured in °C

 
RAC dose
Sampling time Temperature evaluated Authors Pigs, # Duration, d 0 mg/kg 5 mg/kg 7.5 mg/kg 10 mg/kg 20 mg/kg
Baseline Rectal Peterson et al., 2015 216 28 38.74 38.73 38.76
Baseline Rectal Puls et al., 2015 144 28 38.33 38.38
Baseline Rectal Puls et al., 2013 180 21 NS1 NS NS
Baseline Rectal James et al., 2013 (Study #1) 128 28 39.18 39.24
Baseline Rectal Miller, unpublished data 160 31 39.02 39.03
Baseline Rectal Ivers, unpublished data (Study #1)x 72 31 39.33 39.32
Post-handling Rectal Peterson et al., 2015 216 28 38.85 38.98 39.05
Post-handling Rectal Puls et al., 2015 143 28 38.88 39.00
Post-handling Rectal Puls et al., 2013 180 21 NS NS NS
Post-handling Rectal James et al., 2013 (Study #1)2,3 128 28 40.48 40.66
Post-handling Rectal James et al., 2013 (Study #2)4 128 28 40.60a 40.90b
Post-handling Rectal Miller, unpublished data5 160 31 39.77a 39.98b
Post-handling Rectal Ivers, unpublished data (Study #1)x 72 31 41.16 41.19
0.5 h Post-handling Rectal Miller, unpublished data 160 31 39.47 39.57
0.5 h Post-handling Rectal Ivers, unpublished data (Study #1)x 72 31 40.53 40.71
1 h Post-handling Rectal James et al., 2013 (Study #2)6 128 28 39.76a 40.06b
2 h Post-handling Rectal Miller, unpublished data7 160 31 39.12 39.14
2 h Post-handling Rectal Ivers, unpublished data (Study #1)x 72 31 39.27 39.29
Handling to Stunner Rectal Gillis et al., 20078 284 35 38.71 38.79 38.82
Loading to Stunning GI Tract Rocha et al., 2013 135 28 NS NS
a,bMeans with different superscripts differ (P < 0.05).
xData were not statistically analyzed, so only raw treatment means are reported.
1NS: LS means were not reported by the authors, but treatments did not differ (P > 0.10).
2There was a trend (P < 0.10) for the main effect of RAC.
3Indicates a RAC x handling method interaction for post-handling change from baseline (P < 0.06).
4Indicates a RAC x L-carnitine interaction (P < 0.05).
5Indicates a RAC x handling method interaction (P < 0.05).
6There was a trend for RAC x L-carnitine interaction (P < 0.10).
7Indicates a RAC x live weight interaction (P < 0.05).
810 mg/kg RAC tended (P < 0.10) to have higher rectal temperatures than 0 mg/kg.



View Full Table | Close Full ViewTable 17.

Effects of ractopamine (RAC) dose on whole blood pH of market weight pigs

 
RAC dose
Sampling time Authors Pigs, # Duration, d 0 mg/kg 5 mg/kg 7.5 mg/kg 10 mg/kg 20 mg/kg
Baseline Peterson et al., 2015 216 28 7.38a 7.36ab 7.35b
Baseline Puls et al., 2015 144 28 7.38 7.37
Baseline Puls et al., 2013 180 21 NS1 NS NS
Baseline James et al., 2013 (Study #1) 128 28 7.40 7.40
Baseline Dorton et al., 2006 (phase 3 and 4) 18 4 7.39 7.37
Baseline Dorton et al., 2006 (phase 5 and 6) 18 4 7.42 7.38
Baseline Miller, unpublished data2 160 31 7.37 7.35
Baseline Ivers, unpublished data (Study #1)3 72 31 7.37 7.39
Baseline Ivers, unpublished data (Study #2)x 56 24 7.41 7.41
Post-handling Peterson et al., 2015 216 28 7.27 7.26 7.26
Post-handling Puls et al., 2015 144 28 7.30 7.29
Post-handling Puls et al., 2013 180 21 NS NS NS
Post-handling James et al., 2013 (Study #1)4 128 28 7.31a 7.23b
Post-handling James et al., 2013 (Study #2) 128 28 7.28a 7.24b
Post-handling Miller, unpublished data4,5 160 31 7.19a 7.15b
Post-handling Ivers, unpublished data (Study #1) 72 31 7.22 7.19
1 h Post-handling James et al., 2013 (Study #2) 128 28 7.40 7.40
2 h Post-handling Miller, unpublished data 160 31 7.40a 7.38b
2 h Post-handling Ivers, unpublished data (Study #1) 72 31 7.36 7.38
Handling to Stunner Gillis et al., 2007 284 35 7.40 7.41 7.41
a,bMeans with different superscripts differ (P < 0.05).
xData were not statistically analyzed, so only raw treatment means are reported.
1NS: LS means were not reported by the authors, but treatments did not differ (P > 0.10).
2There was a trend (P < 0.10) for the main effects of RAC.
320 mg/kg RAC tended (P < 0.10) to have higher blood pH values than 5 mg/kg RAC.
4Indicates a RAC × handling method interaction (P < 0.05).
5Indicates a RAC × live weight interaction (P < 0.05).



View Full Table | Close Full ViewTable 18.

Effects of ractopamine (RAC) dose on blood lactate concentrations of market weight pigs measured in mmol/L

 
RAC dose
Sampling time Samples evaluated Authors Pigs, # Duration, d 0 mg/kg 5 mg/kg 7.5 mg/kg 10 mg/kg 20 mg/kg
Baseline Plasma Noel et al., 2016 34 32 3.58 4.38
Baseline Whole blood Peterson et al., 20151 216 28 2.63 2.97 3.42
Baseline Whole blood Puls et al., 2015 144 28 2.58a 3.62b
Baseline Whole blood Puls et al., 2013 180 21 NS2 NS NS
Baseline Whole blood James et al., 2013 (Study #1) 128 28 2.19a 2.92b
Baseline Whole blood Miller, unpublished data 160 31 2.94a 4.43b
Baseline Serum Ivers, unpublished data (Study #1) 72 31 4.23 3.87
Post-handling Plasma Noel et al., 2016 34 32 8.99 10.05
Post-handling Whole blood Peterson et al., 2015 216 28 10.47 11.52 11.97
Post-handling Whole blood Puls et al., 20153 144 28 10.35 12.10
Post-handling Whole blood Puls et al., 2013 180 21 NS NS NS
Post-handling Whole blood James et al., 2013 (Study #1) 128 28 12.1a 15.2b
Post-handling Whole blood James et al., 2013 (Study #2) 128 28 11.3a 13.4b
Post-handling Whole blood Miller, unpublished data 160 31 11.1 12.2
Post-handling Serum Ivers, unpublished data (Study #1) 72 31 9.90a 13.8b
1 h Post-handling Whole blood James et al., 2013 (Study #2)4 128 28 6.32 7.44
2 h Post-handling Whole blood Miller, unpublished data 160 31 3.08a 5.03b
2 h Post-handling Serum Ivers, unpublished data (Study #1) 72 31 4.43 4.61
Handling to Stunner Whole blood Gillis et al., 20073 284 35 2.63 2.75 3.01
Exsanguination Plasma Athayde et al., 2013 90 28 40.3 40.8 39.8
Exsanguination Plasma Rocha et al., 2013 238 28 22.6 23.5
a,bMeans with different superscripts differ (P < 0.05).
1There was a trend (P < 0.10) for the main effects of RAC.
2NS: LS means were not reported by the authors, but treatments did not differ (P > 0.10).
310 mg/kg of RAC tended (P < 0.10) to have higher blood lactate values than 0 mg/kg.
4Indicates a trend for a RAC × handling method interaction (P < 0.10).



View Full Table | Close Full ViewTable 19.

Effects of ractopamine (RAC) dose on serum creatine kinase concentrations of market weight pigs

 
RAC dose
Sampling time Units of measure Authors Pigs, # Duration, d 0 mg/kg 5 mg/kg 7.5 mg/kg 10 mg/kg 20 mg/kg
Baseline IU/L Miller, unpublished data1 160 31 1,711a 2,834b
Baseline IU/L Ivers, unpublished data (Study #1) 72 31 1,590a 2,103b
Post-handling IU/L Miller, unpublished data2 160 31 4,811 7,961
Post-handling lU/L Ivers, unpublished data (Study #1) 72 31 2,409a 3,019b
2 h Post-handling IU/L Miller, unpublished data 160 31 2,988a 5,806b
2 h Post-handling IU/L Ivers, unpublished data (Study #1) 72 31 3,801 4,451
Handling to Stunner IU/L Gillis et al., 20073 284 35 6,891 7,467 11,527
Exsanguination U/L Athayde et al., 2013 90 28 5,811a 12,436b 10,707b
Exsanguination Log10 Rocha et al., 20134 238 28 3.65a 3.76b
a,bMeans with different superscripts differ (P < 0.05).
1Indicates a trend (P < 0.10) for a RAC × live weight interaction.
2Indicates a significant (P < 0.05) RAC × live weight × handling method interaction.
310 mg/kg of RAC tended (P < 0.10) to have higher creatine kinase values than 0 and 5 mg/kg.
4Indicates a RAC × genotype interaction (P < 0.05).