|
|
||||||||
Station de Recherches Porcines, INRA, St. Gilles 35590 L'Hermitage, France and Laboratoire de Psychobiologie des Comportements Adaptatifs, Rue St. Saens, 33077 Bordeaux Cedex, France
Abstract
Fifteen groups of eight pigs were allocated .34, .68 or 1.01 m2 lying area per pig between 25 and 100 kg live weight. These values were chosen in accordance with Petherick's model to prevent all pigs from lying in full recumbency (.68 m2/pig) or on their sternum and belly (.34 m2/pig). Productivity decreased in the groups of pigs allowed only .34 m2/individual from 20 wk following the beginning of the experiment (70 to 80 kg). Behavioral changes were observed as early as 8 wk after the beginning of the experiment (60 to 70 kg). Severe area restriction increased time spent at the feeder. Aggression did not vary as a linear function of area allocation. Analysis of the main behavioral activities over a 10-h observation period revealed higher feeding time and lower social activity in pigs kept at .34 m2/pig. Sternum resting was more frequent than resting on the side when body weight reached 60 to 70 kg. Pigs that were submitted to the lower area allocation displayed enhanced resistance of their pituitary-adrenal axis to the dexamethasone suppression test and enhanced reactivity to adrenocorticotropic hormone injection. These findings demonstrate that behavioral and physiological responses are earlier and more sensitive indicators of adaptation to the environment than productivity.
1 The authors thank B. Carissant, G. Conseil, F. Legouvec (INRA, St. Gilles) and R. Bonhomme, Y. Langlois (INRA, Bordeaux) for their technical assist ance, A. Aumaitre, J. M. Faure for their comments on the manuscript.
2 Station de Recherches Porcines, INRA, St. Gilles 35590 L'Hermitage, France.
3 Laboratoire de Psychobiologie des Comportements adaptatifs, Rue St. Saens, 33077 Bordeaux, France.
This article has been cited by other articles:
![]() |
I. Veissier, S. Andanson, H. Dubroeucq, and D. Pomies The motivation of cows to walk as thwarted by tethering J Anim Sci, October 1, 2008; 86(10): 2723 - 2729. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. R. Street and H. W. Gonyou Effects of housing finishing pigs in two group sizes and at two floor space allocations on production, health, behavior, and physiological variables J Anim Sci, April 1, 2008; 86(4): 982 - 991. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |