Offence and defence in fights between young pigs (Sus scrofa)

Abstract

Fights were observed between young, unacquainted, domestic pigs. These fights were described in terms of the frequency of bites and the time spent in each of five spatial configurations of the animals. Depending on the rate that bites were given or received, each spatial configuration was characterized as resulting from offence or defence by one of the pigs. Bites were mainly directed at the head and ears, and defensive moves placed these areas out of reach. The most effective offensive move was an attack from the side. Pigs that lost fights tended to turn away from such attacks: winners were as likely to turn towards the attacker. Whether turning away is submission or simply defence is not clear. Factor analysis showed that fights could be described on three dimensions: offence by the loser along with mutual offence and mutual defence: offence by the winner and defence by the loser: and defence by the winner. Long fights involved much offence by the loser and defence by the winner: short fights involved much defence by the loser. When the pigs met again after 24 h, the fights were shorter and involved less offence and more defence by the loser. The transitions between the configurations reflect a balance of offence and defence by the pig responsible making for the transition. This balance is, in turn, affected by attacks from the opponent, fatigue, and the pig's assessment of its relative fighting ability. Retaliation against attacks is partly responsible for the persistence of fighting.

Behaviour of Young Growing Pigs in a Resident‐Intruder Test Designed to Measure Aggressiveness

“…Pigs are thought to use the back, flanks, rump, and facial regions in recognition [Ewbank and Meese, 1974;McGlone, 1990;Meese and Baldwin, 1975], using odour cues [Ewbank and Meese, 1974;Meese and Baldwin, 1975]. The head, ears, neck, and shoulders are also the main targets for biting during aggressive encounters [McGlone, 1985;Rushen and Pajor, 1987]. In our study, pigs that went on to attack showed more head-to-head and T-position-head during social behaviour than non-attacking pigs.…”

“…Non-aggressive pigs may spend more time investigating the rear of the other pig for recognition or may simply be less willing to engage with the intruder, allowing it to move away. Staggered parallel (or asymmetric parallel) was interpreted by Rushen and Pajor [1987] as a defensive move: the intruder turns and moves away from the resident's approach. These results suggest that non-aggressive residents do not engage with the head of the intruder.…”

Behaviour of Young Growing Pigs in a Resident‐Intruder Test Designed to Measure Aggressiveness

“…Pigs are thought to use the back, flanks, rump, and facial regions in recognition [Ewbank and Meese, 1974;McGlone, 1990;Meese and Baldwin, 1975], using odour cues [Ewbank and Meese, 1974;Meese and Baldwin, 1975]. The head, ears, neck, and shoulders are also the main targets for biting during aggressive encounters [McGlone, 1985;Rushen and Pajor, 1987]. In our study, pigs that went on to attack showed more head-to-head and T-position-head during social behaviour than non-attacking pigs.…”

“…Non-aggressive pigs may spend more time investigating the rear of the other pig for recognition or may simply be less willing to engage with the intruder, allowing it to move away. Staggered parallel (or asymmetric parallel) was interpreted by Rushen and Pajor [1987] as a defensive move: the intruder turns and moves away from the resident's approach. These results suggest that non-aggressive residents do not engage with the head of the intruder.…”

Announcing the arrival of enrichment increases play behaviour and reduces weaning-stress-induced behaviours of piglets directly after weaning

“…Mixing piglets after weaning almost always leads to aggressive interacting with (severe) injuries as a result (Meese and Ewbank, 1973;Friend et al, 1983;Rushen and Pajor, 1987). The differences in the amount of aggression and subsequent the amount of injuries found between the conditions can be explained in line with the reasoning mentioned earlier.…”

The effects of cross-fostering on growth rate and post-weaning behavior of segregated early-weaned piglets

“…More submissive behavior of adopted pigs could also be the cause of reduced fighting. This submission could reflect defeats suffered in previous encounters (before weaning) (Rushen and Pajor 1987) or be due to lower access to feed (at the udder), which has been shown to lead to a greater display of submissive acts (Fernandez et al 1995).…”

Behaviour of Young Growing Pigs in a Resident‐Intruder Test Designed to Measure Aggressiveness

“…Pigs are thought to use the back, flanks, rump, and facial regions in recognition [Ewbank and Meese, 1974;McGlone, 1990;Meese and Baldwin, 1975], using odour cues [Ewbank and Meese, 1974;Meese and Baldwin, 1975]. The head, ears, neck, and shoulders are also the main targets for biting during aggressive encounters [McGlone, 1985;Rushen and Pajor, 1987]. In our study, pigs that went on to attack showed more head-to-head and T-position-head during social behaviour than non-attacking pigs.…”

“…Non-aggressive pigs may spend more time investigating the rear of the other pig for recognition or may simply be less willing to engage with the intruder, allowing it to move away. Staggered parallel (or asymmetric parallel) was interpreted by Rushen and Pajor [1987] as a defensive move: the intruder turns and moves away from the resident's approach. These results suggest that non-aggressive residents do not engage with the head of the intruder.…”

Announcing the arrival of enrichment increases play behaviour and reduces weaning-stress-induced behaviours of piglets directly after weaning

“…Mixing piglets after weaning almost always leads to aggressive interacting with (severe) injuries as a result (Meese and Ewbank, 1973;Friend et al, 1983;Rushen and Pajor, 1987). The differences in the amount of aggression and subsequent the amount of injuries found between the conditions can be explained in line with the reasoning mentioned earlier.…”

The effects of cross-fostering on growth rate and post-weaning behavior of segregated early-weaned piglets

“…More submissive behavior of adopted pigs could also be the cause of reduced fighting. This submission could reflect defeats suffered in previous encounters (before weaning) (Rushen and Pajor 1987) or be due to lower access to feed (at the udder), which has been shown to lead to a greater display of submissive acts (Fernandez et al 1995).…”

Behaviour of Young Growing Pigs in a Resident‐Intruder Test Designed to Measure Aggressiveness

“…Pigs are thought to use the back, flanks, rump, and facial regions in recognition [Ewbank and Meese, 1974;McGlone, 1990;Meese and Baldwin, 1975], using odour cues [Ewbank and Meese, 1974;Meese and Baldwin, 1975]. The head, ears, neck, and shoulders are also the main targets for biting during aggressive encounters [McGlone, 1985;Rushen and Pajor, 1987]. In our study, pigs that went on to attack showed more head-to-head and T-position-head during social behaviour than non-attacking pigs.…”

“…Non-aggressive pigs may spend more time investigating the rear of the other pig for recognition or may simply be less willing to engage with the intruder, allowing it to move away. Staggered parallel (or asymmetric parallel) was interpreted by Rushen and Pajor [1987] as a defensive move: the intruder turns and moves away from the resident's approach. These results suggest that non-aggressive residents do not engage with the head of the intruder.…”

Announcing the arrival of enrichment increases play behaviour and reduces weaning-stress-induced behaviours of piglets directly after weaning

“…Mixing piglets after weaning almost always leads to aggressive interacting with (severe) injuries as a result (Meese and Ewbank, 1973;Friend et al, 1983;Rushen and Pajor, 1987). The differences in the amount of aggression and subsequent the amount of injuries found between the conditions can be explained in line with the reasoning mentioned earlier.…”

The effects of cross-fostering on growth rate and post-weaning behavior of segregated early-weaned piglets

“…More submissive behavior of adopted pigs could also be the cause of reduced fighting. This submission could reflect defeats suffered in previous encounters (before weaning) (Rushen and Pajor 1987) or be due to lower access to feed (at the udder), which has been shown to lead to a greater display of submissive acts (Fernandez et al 1995).…”