Experimental results in the field of housing, behaviour and welfare of rabbits at Kaposvàr University between 2008 and 2012

We summarize the results of the experiment carried out at the Kaposvár University during the last 5 years.. Exp. 1. The objective of this study was to analyse the effects of the sex-composition of group on the production and behaviour of growing rabbits. The rabbits placed to the same pen were full sibs (FS), only females (F), only males (M), or mixed sexes (M). The sex-composition of the groups had no effect on the production. No differences were found on behavioural patterns. Lesions on the body caused by the aggressive animals were initially observed at the age of 7 weeks. It was more frequent for the F group at the ages of 7 and 9 weeks, but on the contrary, at the age of 11 weeks the occurrence of the lesions was 40.5% in the M group, which was higher than that of the other groups (23.8-28.6%). Based on the results it could be concluded that housing the growing rabbits segregated by sex, especially only males, was disadvantageous. Exp. 2. The objective of this study was to test a pen prototype. The basic area of the pen was 4.4m2, the floor and the platform were made of plastic mesh; 65 rabbits per pen were housed. The basic area of cage was 0.54m2, the floor was wire mesh and the platform was made of plastic mesh; 8 littermate rabbits per cage were housed. The rabbits housed in cages had higher body weight at the ages of 11 weeks (2540 vs. 2443 g) and average daily gain, better feed conversion ratio, on the contrary they had lower mortality rate (5.2 vs. 31.5%) compared to rabbits housed in pens. Among the pen-housed rabbits injuries originated to aggression were detected at the age of 9 weeks contrary to the cage-housed rabbits where injured rabbits were detected only at the end of the experiment. The ratio of the mid part and the perirenal fat to the reference carcass were higher for the rabbits housed in cages, while the ratio of the hind part to the reference carcass was significantly larger for the rabbits housed in pens. Based on the results it can be concluded that housing the rabbits in larger groups (pen with plastic mesh floor) is unfavourable from the aspects of production and animal welfare. Exp. 3. Location preference of growing rabbits was evaluated depending on the different floor types (plastic mesh, wire mesh and deep litter), at the temperature of 10°C. The rabbits showed the highest preference for plastic mesh, at every age they spent more time there (70 and 52%, at the ages of 5.5 and 10.5 wk, respectively) than the expected value (33.3%). The preference of the wire mesh floor was lower (between 20 and 33%). Deep litter was the least frequently chosen floor type at all ages (8 and 14%, at the ages of 5.5 and 10.5 wk, respectively). Comparing the productive and carcass traits of rabbits housed on the three different floors, only a slight decline was observed in group of deep litter. Exp. 4. The objective of this experiment was to analyze growing rabbits’ preference between different areas of pen depending on the elevated platforms' floor-type. Two types of flooring of the elevated platforms were used: wire mesh and deep litter floor. When the platform was deep litter, more rabbits used the area under the platform (54 %) than stayed on the platform (12 %). When the platform was wire mesh more rabbits stayed on the platform than under it, because of the rabbits on the platform may urinate on the rabbits underneath the platform. However, when manure-trays were insert under the wire mesh platform, the rabbit preferred the most safety part of the pen, most of them stayed under the platform. The results demonstrate that the wire-net platform with the manure tray provides the optimal environment. At the same time a platform with deep litter could be a good compromise between wire mesh and deep litter floor, because it could be considered positively by consumers. Comparing the productive and carcass traits of growing rabbits housed in cage, pen without and with elevated platform (wire mesh or deep litter), significant differences were found only between cage and pen with deep litter platform, rabbits housed in cages generally had the best performance. Exp. 5. The nursing behaviour of rabbit does in a routine (24h, 16L:8D) and in a proportionally shorter (18h, 12L:6D) lighting schedule was compared. In the 24h group, 78% of the nursing events took place during the dark period and in the two hours after light switch on. This tendency could not be observed in the 18h group. Only a small part of the nursing events was recorded during the dark period. Even if the rabbit does, who were born and grew up in 16L:8D (24h) lighting schedule, were housed in 12L:6D (18h) schedule their nursing events were still based on 24 hours intervals and lighting schedule. Contrary to our hypothesis, applying a “reduced day” (12L:6D = 18h) instead of the routine 16L:8D lighting schedule did not increase the number of nursing events per 24 hours. Reproductive performance of the two groups was similar. Exp. 6. The production of single-cged (S) and group-housed does (G) was compared. In group G, four does and one buck were housed in each of four pens with 7.7 m2 with 4 nest boxes in each. In group S half of the does were artifivally inseminated. The average of kindling rate was 77.6, 85.2 and 45.6%, resp. in groups of S-33, S- 42 and G (P<0.001). No significant differences were observed for litter size. The suckling mortality was 14.6 and 38.5% (P<0.001), and the survival of does was 76 and 50%, resp. in groups of S and G (P=0.084). The corticosterone levels (measured in faecal) were 61, 54 and 175 nmol/g. The high mortality of kits was partly connected with stress and aggressive behaviour of does: scratching, biting or killing the kits. Due to high stress, increased mortality and morbidity, and low productivity, group-housing of rabbit does resulted in poorer animal welfare and increased production costs, and therefore, is not recommended. Exp. 7. In this study, the location preferences of rabbit does and their kits were analyzed in two types of pens with elevated platforms (wire-mesh or plastic-mesh). On average the does spent by 25% more time on the platform when they were placed to PP pens compared to the PW pens. After the kits left the nest boxes the does chose the platform more frequently, then after day 21, when the kits started to visit the platform, the does’ platform preference decreased. Usage of the wire-mesh platform by kits was significantly lower than that of the plastic platform. From the aspect of animal welfare cages/pens enriched with platforms can be considered advantageous especially when the platform is made from plastic-mash.