Effect of outdoor grazing-area size and genotype on space and pasture use, behaviour, health and growth traits of weaned rabbits
Providing rabbits with outdoor access lets them express a large repertoire of behaviours and addresses societal expectations surrounding animal welfare in livestock systems. The aim of this work was to study rabbit growth, health and behaviour according to genetic type and pasture-area size. We distributed 192 weaned rabbits into two groups differing in rangeable pasture size, i.e. large pasture (LP): 60 m² (n =4 × 24), and small pasture (SP): 30 m² (n = 4 × 24). Each group contained half Californian 1001 × New-Zealand 1777 rabbits (1001) and half PS119 × New-Zealand 1777 rabbits (PS119). Rabbit growth and morbidity were measured individually weekly for 36 days (from 31 to 67 days of age). Rabbit behaviour was assessed three times a day on days 44, 58 and 70 by direct visual scan and use of space was evaluated six times a week, through rabbit spatial distribution. Finally, amount of corticosterone was measured in hair samples from 18 rabbits of each genotype in LP and SP at day 72. Notable findings: PS119 rabbits were heavier than 1001 rabbits at day 67 (2444 vs 2113 g, respectively; P < 0.05) but we observed no effect of genotype on mortality nor morbidity. Animals expressed a large variety of specific behaviours on pastures, with grazing and resting being predominant. We found a lower level of corticosterone in PS119 rabbits than in 1001 rabbits (2.19 vs 6.34 pg per mg of hair, respectively; P < 0.05). Conclusion: This study found that a 60-m² pasture for 24 rabbits enables the animals to express grazing for the entire fattening period. Rabbit genotype was found to influenced some of their behaviour. The present data set could be used to compare a future trial done in a different season in order to validate or discredit the fact that a 60 m² pasture for 24 rabbits enables them to express grazing continuously over the whole growing period without any impact on their growth and their health. Genotype chosen here in this trial could be also used as a comparison with a different genotype on the previous quoted parameters. The precise description of the data can be found in "Read_me_Metadata_Mendeley.txt" file. The data can be easily used with R software (https://www.r-project.org/).