Table 9. Open in new tab Effects of...

Authors

RAC dose

Duration, d

Pigs, #

Methodology

Results

Rocha et al., 2013

0 and 7.5 mg/kg

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

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)

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)

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

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

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.

Authors

RAC dose

Duration, d

Pigs, #

Methodology

Results

Rocha et al., 2013

0 and 7.5 mg/kg

1488

Athayde et al., 2013

0, 5, and 10 mg/kg

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)

Poletto et al., 2010b

0 mg/kg and RAC step-up (5 mg/kg for 14 d, then 10 mg/kg for 14 d)

Marchant-Forde et al., 2003

0 and 10 mg/kg

RAC had no effects on agonistic behaviors.

Schaefer et al., 1992

0, 15, and 20 mg/kg

25–36

RAC and gender had no effects on agonistic behaviors.

Table 9.

Open in new tab

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.

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.

This Feature Is Available To Subscribers Only