Document type: doctoral thesis for theUniversity of Toulouse
Author: Manon Fetiveau
Preview: In rabbit farming, 95% of rabbits are housed at high density in wire cages, without enrichment, in closed buildings with no outdoor access. There is therefore a need to better respond to the needs of the animals, particularly in terms of behavior, by designing breeding systems that better take into account animal welfare. In this context, we studied the influence of various biotechnical (genetic type of animals, surface and access time to the grazing area, enrichment of the grazing area) and anthropic (nature of the human-rabbit relationship) factors on the welfare (expression of behaviors, spatial distribution, hair corticosterone level, reactivity and emotional state), health (viability, sanitary state, fecal oocyst count) and growth of rabbits raised in systems with access to a grazing area. In a first trial, we showed that outdoor access allowed rabbits to express more locomotion-related behaviors compared to individuals housed in indoor pens without access to the outdoors (20.0% vs. 7.2%) and less iother small companion animalstivity (34.2% vs. 70.0%). We also showed that the growth of rabbits without outdoor access was slightly higher than that of rabbits with outdoor access (+ 3.6 g/d). In a second trial, we showed that the genetic type of the animals influenced their growth (2444 vs. 2113 g at 67 days of age in 1777 x PS119 rabbits compared to 1777 x 1001) and the time spent on expressing some behaviors, but not their health (mortality: 9.9%) Grazing was the most expressed behavior (25.9% of the observed time) in all animals outdoors while Resting was the most expressed in indoor pens (34.2% of the observed time). The 1777 x PS119 rabbits had lower levels of hair corticosterone than the 1777 x 1001 (2.19 vs. 6.34 pg per mg), suggesting less sensitivity to stress. In a third trial, we showed that limiting the access time to pasture or enriching it with hiding places did not alter the growth (2534 g at 76 d of age) or the health of the rabbits (18.7 g at 76 d of age). However, it did change their rate of grass intake (1.9 vs. 0.9 g DM/rabbit/hr with 3 hr/d vs. 8 hr/dr of outdoor access; 1.8 vs. 0.9 g DM/rabbit/hr, grazing area without or with hiding places). In a fourth trial, we showed that the living environment of the animals had a strong influence on the expression of their specific behaviors. Indoors, the dominant behavior was resting (67.8% and 56.6% vs 31.2% in pens, cages and runs). On the outdoor range, grazing was the dominant behavior (found in 37% of observations). On the other hand, the extreme weather conditions (heat wave) and the poor health status of the young rabbits led to high mortality in the outdoor run (48.8%) and in the cages (23.9%). In a final trial, we showed that rabbits that received positive interactions with humans showed a stronger affinity (90.2% vs. 45.9% of accepted petting, between positive vs. neutral relationship) and a stronger proximity to humans (11.7% vs. 0.7% of contact occurrences with humans, respectively). They appeared "confident" and "comfortable" in contrast to individuals who received neutral interactions with humans who appeared "worried" and "indifferent" but only in a so-called complex living environment. These results show that rabbits need and are strongly motivated to graze. The living environment offered to the animals, its surface, its enrichment and its complexity, have a strong influence on the expression of their specific behaviors. The use of genotypes better adapted to outdoor life could limit their stress to different stimuli.
