Effects of group size and feeder space allowance on welfare in finishing pigs
- 18 August 1999
- journal article
- research article
- Published by Cambridge University Press (CUP) in Animal Science
- Vol. 69 (3), 481-489
- https://doi.org/10.1017/s135772980005133x
Abstract
Compared with small groups, housing in large groups offers the pig more total available space, resulting potentially in an increased degree of control over its (micro) environment. For the producer, large groups require fewer pen divisions and offer more possibilities for the sharing of resources such as feeders and drinkers. However, whilst large groups may offer benefits to higher ranking animals in the group, there may be serious disadvantages for those further down the social hierarchy, who also need to compete for access to resources. This study investigated the interactive effects on welfare of food availability (one single space hopper per 20 or per 10 pigs) and group size (20, 40 or 80 pigs per pen), at constant stocking density (0·55 m2per pig) in part-slatted pens. Groups provided with two feeding spaces per 20 pigs were less active than groups with one feeding space per 20 pigs. The number of aggressive interactions per pig at the food trough was not affected by group size but decreased with number of feeder spaces per 20 pigs. The number of skin lesions increased with group size. Average daily gain in the first half of the finishing period was negatively influenced by group size and positively by number of feeding spaces. No effect on weight gain was found subsequently. Within-group variation in growth was not affected by group size or number of feeder spaces. No differences between treatments were found in the number of pigs removed for health reasons. Interactive effects of the two treatments were found on some behaviours but not on any of the performance variables measured. It is concluded that, from a welfare point of view, the number of pigs per feeder space should be lower than 20, although performance levels appear acceptable at 20 pigs per feeder. Further research will have to identify whether the effects of group size on general aggression is common to all finishing pig systems, or whether the presence of straw can serve as a mitigating factor.Keywords
This publication has 10 references indexed in Scilit:
- Production, behaviour and welfare of growing pigs as influenced by drinker allocation and group sizeProceedings of the British Society of Animal Science, 1998
- Effects of number and siting of single-space feeders on performance and feeding behaviour of growing pigsThe Journal of Agricultural Science, 1994
- Measuring BehaviourPublished by Cambridge University Press (CUP) ,1993
- Effect of straw on the behaviour of growing pigsApplied Animal Behaviour Science, 1991
- Social facilitation in the feeding behaviour of pigs and the effect of rankApplied Animal Ethology, 1984
- An analysis of agonistic interaction patterns in group-housed dry sows — Aggression regulation through an “avoidance order”Applied Animal Ethology, 1982
- Behavioural results and performance of bacon pigs fed “AD libitum” from one or several self-feedersApplied Animal Ethology, 1982
- Porcine Aggression: Measurement and Effects of Crowding and FastingJournal of Animal Science, 1980
- Agonistic behavior of caged chickens related to group size and area per birdApplied Animal Ethology, 1975
- The establishment and nature of the dominance hierarchy in the domesticated pigAnimal Behaviour, 1973