C. W. Arave and J. L. Albright, Social Rank and Physiological Traits of Dairy Cows as Influenced by Changing Group Membership, J. Dairy Sci, vol.59, pp.974-981, 1976.

D. S. Arey and S. A. Edwards, Factors influencing aggression between sows after mixing and the consequences for welfare and production. A review, Livest. Prod. Sci, vol.56, pp.61-70, 1998.

A. Boissy, Fear and fearfulness in animals. A review, Q. Rev. Biol, vol.70, pp.165-191, 1995.
URL : https://hal.archives-ouvertes.fr/hal-02709615

A. Boissy, I. Veissier, and S. Roussel, Behavioural reactivity affected by chronic stress: an experimental approach in calves submitted to environmental instability, Anim. Welfare, vol.10, pp.175-185, 2001.
URL : https://hal.archives-ouvertes.fr/hal-02674577

M. F. Bouissou, Établissement des relations de dominance-soumission chez les bovins domestiques. I. Nature et évolution des interactions sociales, Ann. Biol. Anim. Bioch. Biophys, vol.14, pp.383-410, 1974.

M. F. Bouissou, Établissement des relations de dominance-soumission chez les bovins domestiques. III. Effet de l'expérience sociale, Z. Tierpsychol, vol.38, pp.419-435, 1975.

M. F. Bouissou, Étude du développement des relations de dominance-subordination chez les bovins, à l'aide d'épreuves de compétition alimentaire, Biol. Behav, vol.2, pp.213-221, 1977.

M. F. Bouissou and S. Andrieu, Établissement des relations de dominance-soumission chez les bovins domestiques. IV. Établissement des relations chez les jeunes, Biol. Behav, vol.2, pp.97-107, 1977.

D. M. Broom, Applications of neurobiological studies to farm animal welfare, Biology of Stress in Farm Animals: An Integrative Approach, pp.101-110, 1987.

R. T. Brown, Early experience and problemsolving ability, J. Comp. Physiol. Psychol, vol.65, pp.433-440, 1968.

, Animals kept for farming purposes. Recommendations adopted by the standing committee of the European Convention for the Protection of Animals Kept for Farming Purposes. Recommendations concerning cattle. Appendix A: Special provisions for bulls kept for breeding or fattening, 1988.

, Repeated regrouping of pair-housed heifers 143

R. Dantzer, P. Mormède, R. M. Bluthé, and J. Soissons, The effect of different housing conditions on behavioural and adenocortical reactions in veal calves, Reprod. Nutr. Dév, vol.23, pp.501-508, 1983.

, Introduction of Sows into Groups. Principal requirements to minimise aggression/ injury at mixing: Management

L. Désiré, A. Boissy, and I. Veissier, Emotions in farm animals: a new approach to animal welfare in applied ethology, Behav. Process, vol.60, pp.165-180, 2002.

A. D. Fisher, G. A. Verkerk, C. J. Morrow, and L. R. Matthews, The effects of feed restriction and lying deprivation on pituitaryadrenal axis regulation in lactating cows, Livest. Prod. Sci, vol.73, pp.255-263, 2002.

T. H. Friend, C. E. Polan, F. C. Gwazdauskas, and C. W. Heald, Adrenal Glucocorticoid Response to Exogenous Adrenocorticotropin Mediated by Density and Social Disruption in Lactating Cows, J. Dairy Sci, vol.60, pp.1958-1963, 1977.

T. H. Friend, F. C. Gwazdauskas, and C. E. Polan, Change in Adrenal Response from Free Stall Competition, J. Dairy Sci, vol.62, pp.768-771, 1979.

N. Hasegawa, A. Nishiwaki, K. Sugawara, and I. Ito, The effects of social exchange between two groups of lactating primiparous heifers on milk production, dominance order, behaviour and adrenocortical response, Appl. Anim. Behav. Sci, vol.51, pp.15-27, 1997.

J. Ladewig, D. Smitd, and . Behaviour, Episodic Secretion of Cortisol, and Adrenocortical Reactivity in Bulls Subjected to Tethering, Horm. Behav, vol.23, pp.344-360, 1989.

J. A. Mench, J. C. Swanson, and W. R. Stricklin, Social stress and dominance among group members after mixing beef cows, Can, J. Anim. Sci, vol.70, pp.345-354, 1990.

M. C. Meunier-salaun, M. N. Vantrimponte, A. Raab, and R. Dantzer, Effect of floor area restriction upon performance, behaviour and physiology of growing-finishing pigs, J. Anim. Sci, vol.64, pp.1371-1377, 1987.

P. Mormède, Le stress : interaction animal-homme-environnement, Cah. Agric, vol.4, pp.275-286, 1995.

P. Mormède, V. Lemaire, N. Castanon, J. Dulluc, M. Laval et al., Multiple neuroendocrine responses to chronic social stress: Interaction between individual characteristics and situational factors, Physiol. Behav, vol.47, pp.1099-1105, 1990.

L. Munksgaard and H. B. Simonsen, Behavioural and Pituitary Adrenal-Axis Responses of Dairy Cows to Social Isolation and Depriovation of Lying Down, J. Anim. Sci, vol.74, pp.769-778, 1996.

L. Munksgaard, K. L. Ingvartsen, L. J. Pedersen, and V. K. Nielsen, Deprivation of Lying Down Affects Behaviour and Pituitary-Adrenal Axis Responses in Young Bulls, Acta Agr. Scand. A. An, vol.49, pp.172-178, 1999.

D. A. Padgett and R. Glaser, How stress influences the immune response, Trends Immunol, vol.24, pp.444-448, 2003.

C. J. Phillips and M. I. Rind, The effects on production and behavior of mixing uniparous and multiparous cows, J. Dairy Sci, vol.84, pp.2424-2429, 2001.

G. Van-putten and R. G. Buré, Preparing gilts for group housing by increasing their social skills, Appl. Anim. Behav. Sci, vol.54, pp.173-183, 1997.

S. Raussi, A. Boissy, E. Delval, P. Pradel, J. Kaihilahti et al., Does repeated regrouping alter the social behaviour of heifers?, Appl. Anim. Behav. Sci, vol.93, pp.1-12, 2005.
URL : https://hal.archives-ouvertes.fr/hal-02680219

H. Roman-ponce, W. W. Thatcher, R. J. Collier, and C. J. Wilcox, Hormonal responses of lactating dairy cattle to TRH and ACTH in a shade management system within a subtropical environment, Theriogenology, vol.16, pp.31-138, 1981.

N. Sachser, The ability to arrange with conspecifics depends on social experiences around puberty, Physiol. Behav, vol.53, pp.539-544, 1993.

N. Sachser, M. Dürschlag, and D. Hirzel, Social relationships and the management of stress, Psychoneuroendocrinology, vol.23, pp.891-904, 1998.

. Sas, . Sas-institute-inc, and . Sas-onlinedoc, , vol.8, 1999.

S. Raussi,

I. A. Sneddon, V. E. Beattie, L. Dunne, and W. Neil, The effect of environmental enrichment on learning in pigs, Anim. Welfare, vol.4, pp.373-383, 2000.

K. Takeda, S. Sato, and K. Sugawara, Familiarity and group size affect emotional stress in Japanese Black heifers, Appl. Anim. Behav. Sci, vol.82, pp.1-11, 2003.

C. Thinus-blanc, Volume discrimination learning in golden hamsters: Effects of the structure of complex rearing cages, Dev. Psychobiol, vol.14, pp.397-403, 1981.

C. Thinus-blanc, Selection of relevant cues in volume discrimination by golden hamsters reared in different environments, Can. J. Psychol, vol.36, pp.520-526, 1982.

C. Tsigos and G. P. Chrousos, Hypothalamicpituitary-adrenal axis, neuroendocrine factors and stress. A review, J. Psychosom. Res, vol.53, pp.865-871, 2002.

G. B. Varty, M. P. Paulus, D. L. Braff, and M. A. Geyer, Environmental enrichment and isolation rearing in the rat: Effects on locomotor behaviour and startle response plasticity, Biol. Psychiat, vol.47, pp.864-873, 2000.

I. Veissier, L. Neindre, and P. , Cortisol responses to physical and pharmacological stimuli in heifers, Reprod. Nutr. Dév, vol.28, pp.553-562, 1988.
URL : https://hal.archives-ouvertes.fr/hal-00898811

I. Veissier, P. Le-neindre, and J. P. Garel, Decrease in cow-calf attachment after weaning, Behav. Process, vol.21, pp.95-105, 1990.
URL : https://hal.archives-ouvertes.fr/hal-02700341

I. Veissier, V. Gesmier, P. Le-neindre, J. Y. Gautier, and G. Bertrand, The effects of rearing in individual crates on subsequent social behaviour of veal calves, Appl. Anim. Behav. Sci, vol.41, pp.199-210, 1994.
URL : https://hal.archives-ouvertes.fr/hal-02715484

I. Veissier, P. Chazal, P. Pradel, L. Neindre, and P. , Providing social contacts and objects for nibbling moderates reactivity and oral behaviour in veal calves, J. Anim. Sci, vol.75, pp.356-365, 1997.

I. Veissier, A. Boissy, R. Nowak, P. Orgeur, and P. Poindron, Ontogeny of social awareness in domestic herbivores: a review, Appl. Anim. Behav. Sci, vol.57, pp.233-245, 1998.

I. Veissier, C. G. Van-reenen, S. Andanson, and I. E. Leushuis, Adenocorticotropic hormone and cortisol in calves after corticotropinreleasing hormone, J. Anim. Sci, vol.77, pp.2047-2053, 1999.

I. Veissier, A. Boissy, A. M. De-passillé, J. Rushen, C. G. Van-reenen et al., Calves' responses to repeated social regrouping and relocation, J. Anim. Sci, vol.79, pp.2580-2593, 2001.
URL : https://hal.archives-ouvertes.fr/hal-02670875