Efecto del enriquecimiento con bloques de heno y de la diferenciación de grupo por sexo sobre parámetros productivos, uso del espacio y resultados al sacrificio en conejos de engorde alojados en parques

This study assessed the effect of the provision of gnawing hay blocks (A: absence, P: presence) and sex-group composition in the parks (XX: only females, YY: only males, XY: mixed-sex) on growth performance, slaughter results, and use of space in 288 growing rabbits reared in 18 parks (16 rabbits per park) from weaning to slaughter (31-73 days of age). The parks were composed by two communicating modules: a module intended for feeding (wire net floor; four nipple drinkers; one feeder; one gnawing hay blocks in P groups) and a module for resting (plastic slatted floor, two nipple drinkers). The presence of gnawing blocks increased daily weight gain (51.8 vs. 50.6 g/d; p<0.05) and slaughter weight (2818 vs. 2763 g; p<0.05). In the P group, a lower percentage of rabbits was observed in the resting area compared to the A group (49.5% vs. 53.0%; p<0.001). Regarding the sex-group composition, a better feed conversion ratio was recorded in XX and XY compared to YY parks (p<0.05), whereas YY group showed a higher slaughter yield compared to XX (p<0.01) with intermediate values in group XY. No signs of lesions were detected at the end of the trial. In conclusion, the use of a hay gnawing block could improve performance of growing rabbits, whereas the separate housing of females and males in group-housed rabbits does not offer significant advantages.