Causes of mortality in breeding rabbits.

In this study we determined mortality in breeding rabbits on 505 commercial farms in Spain during 2006-2014. We obtained our information by carrying out 3278 visits to 490 doe farms (127 also with males), and 877 visits to farms with males, including 132 visits to 15 artificial insemination (AI) centres. The median size of the farms was 769 does (minimum to maximum: 80-9000 does) and 44 males (minimum to maximum: 10-800 males). AI was used on 85% of the 490 doe farms. Females were serviced at 11 days postpartum on 75% of the farms. The mean Monthly Mortality Risk (MMR%) and 95% Binomial confidence interval (CI) in does were 2.82 (2.71-2.93%), and 1.87 (1.41-2.33%) in bucks, over a population of 2,641,709 females and 90,316 males at risk, in the course of the 9-year study; during the 42-day cycle, MMR% was 3.78 (3.67-3.89%). There were 9547 cohorts of females; 41.5% of the does were pregnant and lactating simultaneously, 28.1% only lactating, 17.4% only pregnant and 13% empty and not lactating. The MMR% of does during the last week of pregnancy was 7.05 (6.63-7.47%) and 4.26 (3.90-4.62%) during the 1st week of lactation. Our diagnoses were based on the macroscopic post-mortem examinations performed by a veterinarian on 2065 female rabbits found dead and 368 moribund-euthanized does. In the total 2433 on-farm necropsies on does and 55 males, we found alterations of the respiratory tract compatible with death in 0.70 (0.64-0.76%) MMR% in does, 0.88 (0.56-1.20%) in bucks; and digestive tract in 0.31 (0.27-0.35%) enteritis-diarrhoea, 0.11 (0.09-0.13%) mucoid enteropathy in does and 0.34 (0.14-0.54%) and 0.07 (0-0.16%) in males, respectively. Other primary causes of death were septicaemia, MMR% 0.23 (0.20-0.26%) in does, and 0.10 (0-0.22%) in males, viral haemorrhagic disease 0.22 (0.19-0.25%) in does, and 0.17 (0.03-0.31%) in bucks, metritis, pyometra, or both, 0.21 (0.19-0.25%), and uterine torsion, 0.20 (0.18-0.22%); 1.2 (1.01-1.39%) in the last week of pregnancy. The median age of 2087/2433 necropsied does was 2 parities (minimum to maximum: 1-34 parities) and the mean 3.9. Some changes in housing, feeding and management, to improve breeding rabbit health, are highlighted.