Culling and mortality in breeding rabbits.

In this study, we determined culling and mortality in adult breeding rabbits on 130 commercial farms in Spain during 2000-2005. The median size of the farms was 595 does (minimum to maximum: 131-5500 does). The median culling age per doe was 14.9 months old and 6 kindlings. The median monthly removal risk (MMR) in does was 9.3%, with 3.4% dead and 5.7% culled (including euthanized does). The MMR was negatively correlated with the degree of intensification of the reproductive rhythm (r=-0.37), age at first mating (r=-0.31) and kindling interval (r=-0.36). The MMR in males was 5.8% (1.2% dead and 4.2% culled or euthanized). Our estimation of the causes of culling does was based on a population of 82,352 does, 50,834 of which were culled or euthanized. The highest causes, calculated using the median of the monthly cumulative incidence (MCI), were 1.3% low productivity (0.9% infertility and 0.4% other causes), 0.5% mastitis, 0.5% poor body condition and 0.3% sore hocks. The causes of culling males were estimated based a population of 6514 males, 5313 of which were culled. The highest causes were 2.0% MCI low productivity (0.9% infertility and 0.5% no libido); 0.3% abscesses, 0.3% sore hocks and 0.2% poor body condition. The mortality and culling risks after first kindling were 8.7% and 7%, respectively. The highest risks of mortality and culling in does occurred during the first three kindlings, but remained stable thereafter. The gestation stage affected mortality; the risk of mortality per day increased as pregnancy progressed. There was a bimodal distribution with a peak of dead females between days 10 and 15 of gestation (0.1-0.2% mortality risk per day (MD)) and another larger peak between days 25 and 33 (0.3% MD). In 1046 on-farm necropsies performed on females we found alterations of the respiratory and digestive tracts compatible with being causes of death in 29.4% and 27%, respectively.