HABRI Central

Plasma free-corticosteroid concentrations, aggressive behaviour and levels of motivation to interact socially and explore a novel arena were observed in an experiment to examine whether differences previously observed between pigs in neck-tethers and groups are shown by pigs of different genotypes. Thirty-two pregnant gilts of 2 genotypes were housed in either tether stalls or groups. The 2 genotypes were mainly Large WhitexLandrace stock, but one had been intensively selected on the basis of growth performance. Genotypic differences had previously been observed in protein and energy metabolism, and the present experiment also showed differences in their behaviour (increased activity and a decreased motivation to interact socially in the intensively selected genotype) and free-corticosteroid concentrations (40% lower in the intensively selected genotype) and free-corticosteroid concentrations (40% lower in the intensively selected genotype). In spite of these differences, the behavioural and physiological responses to housing treatments were similar. In tether stalls, pigs of both genotypes had a higher frequency of retaliation and a lower frequency of withdrawal in response to aggressive interactions than group-housed pigs. There were 50 and 56% increases in free-corticosteroid concentrations in response to tether housing in the 2 genotypes, providing evidence of a chronic stress response of a magnitude sufficient to suggest a risk to welfare in the design of tether stall used in this experiment.

Researchers should cite this work as follows:

1. Aggression
2. Animal behavior
3. Animal genetics
4. Animal housing
5. Animal physiology
6. Animal reproduction
7. Animal rights
8. Animal welfare
9. Blood
10. Genotypes
11. Gestation
12. Glucocorticoids
13. Growth
14. Mammals
15. Meat animals
16. motivation
17. peer-reviewed
18. physiology
19. pregnancy
20. Selection
21. Swine