Behavioural uniformity or diversity? Effects on behaviour and performance following regrouping in pigs

Hayne, S. M.; Gonyou, H. W.

doi:10.1016/j.applanim.2005.08.007

Cited by 17 publications

(19 citation statements)

References 27 publications

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“…Every time pigs are regrouped, a new social order must be formed. This results in aggression in which pigs will fight intensely for approximately 2 h. Less intense fighting will continue to occur over the next couple of days until a relatively stable structure is formed [4].…”

Section: Introductionmentioning

confidence: 99%

The Impact of Grouping on Skin Lesions and Meat Quality of Pig Carcasses

Driessen

Beirendonck

Buyse

2020

Animals

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In practice, unfamiliar pigs are frequently mixed prior to loading in order to obtain groups of uniform weight and to adjust the group size to the dimensions of the trailer compartments. Mixing pigs induces aggressive interactions to establish a new social rank. Fighting results in skin lesions and pre-slaughter stress and, in turn, reduced meat quality. A study was performed to compare the effect of non-regrouping and regrouping at fattening (at 80 kg and kept till slaughter), loading and lairage. A total of 1332 pigs were included over 30 transports from one pig farm to one slaughterhouse (110 km). Skin lesions were determined on 1314 carcasses. Meat quality was measured on 620 pigs. The non-regrouped pigs had fewer skin lesions and better meat quality than the pigs regrouped at loading or in lairage. Pigs mixed at 80 kg at the farm had, in general, a comparable amount of skin lesions and comparable meat quality as the non-mixed group. If mixing is unavoidable, due to large within-group weight variations, mixing at 80 kg can be an alternative to reduce skin lesions at slaughter and to optimise meat quality.

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Section: Introductionmentioning

confidence: 99%

The Impact of Grouping on Skin Lesions and Meat Quality of Pig Carcasses

Driessen

Beirendonck

Buyse

2020

Animals

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“…Social behaviour and resulting hierarchies have been shown to have a high impact on performance and survival in terrestrial animals and in their performance in production systems (Bruno et al, 2018;Burrow, 1997;Hayne and Gonyou, 2006) and a growing body of information from aquatic species (Jobling, 1983;Martins et al, 2008;Montero et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

Agonistic behaviour and feed efficiency in juvenile Nile tilapia Oreochromis niloticus

et al. 2019

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Given the strong effects of behavioural hierarchies on growth in many cultured species and the key role of feed efficiency in aquaculture economics, understanding the nature of the interaction of these variables is important for the sustainability of aquaculture. The relationship between agonistic behaviour, growth and feed efficiency in Nile tilapia, Oreochromis niloticus, was studied by rearing 120 fish in eight aquaria. Fish were video-recorded to estimate the occurrence of agonistic behaviour during a fasting and a refeeding period. Growth, feed intake and feed conversion efficiency (FCE-calculated as the inverse of feed conversion ratio (FCR)) were subsequently measured individually for each fish. Fish showed 58% less agonistic traits during the fasting period compared to the feeding period, but generally, an aggressive fish during the fasting period was also aggressive during the refeeding period. The nature of agonistic behaviours between individuals was used to assess the presence of hierarchical relationships between fish. There were dominance hierarchies established in each experimental aquarium that despite minor shifts were maintained throughout the experiment. Agonistic behaviours were strongly correlated with each other, the aggression Index (AI) and with hierarchy rank. PCA analysis of the agonistic behaviours summarising the behavioural information showed little or no correlation between agonistic behaviour, fish growth or FCE. FCE was correlated with body weight gain (BWG). These results suggest that agonistic interactions in juvenile Nile tilapia do not have a large impact on growth and feed conversion efficiency. Highlights ► This is the first study to estimate agonistic behaviour, feed efficiency and growth at the individual on juvenile Nile tilapia reared in groups for an extended and continuous period of time. ► Estimates the relationships between agonistic behaviour, growth and feed efficiency in juvenile Nile tilapia. ► Hierarchical rank and agonistic behaviour do not affect Nile tilapia growth and feed efficiency. ► Aggressiveness and hierarchy are not good indicators of the feed efficiency in juvenile Nile tilapia when fish receive enough feed and using a dispersed feed supply.

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“…Abrupt mixing of commercial pigs is common and results in fighting that cannot be reduced in the long term by low cost environmental changes (Luescher et al, 1990;Hayne and Gonyou, 2006). This aggression is associated with a reduction in the rate and efficiency of BW gain and poorer meat eating quality, carcass gradings, and maternal ability (Rundgren and Löfquist, 1989;Tan et al, 1991;Warriss et al, 1998;Løvendahl et al, 2005).…”

Section: Introductionmentioning

confidence: 99%