Abstract
We have measured the four lifetime components of sow nonproductive days (NPD) and proportions of the four lifetime NPD components by farm productivity groups, by using 44,720 lifetime records on 101 Japanese commercial farms. Lifetime NPD were divided into four components : first-mating-to-conception interval at parity 0 (FMCI), lifetime weaning-to-first-mating interval (WMI), lifetime sow first-mating-to-conception interval (MCI), and last weaning-to-culling interval (WCI). Three farm productivity groups were formed on the basis of the upper and lower 25th percentiles of pigs weaned per mated female per year : high-, intermediate-, or low-performing farms. Mean lifetime NPD (±SEM) was 87.4±0.31 days. Mean FMCI, lifetime WMI, lifetime MCI and WCI were 5.8±0.10, 27.4±0.11, 14.9±0.16, and 39.3±0.23 days, respectively, and comprising 6.6, 31.4, 17.0, and 45.0%, respectively of lifetime NPD. High-performing farms had lower lifetime NPD and four NPD components than low-performing farms (P<0.05), although there were no differences between the farm groups in sow life days. On high-performing farms, the relative contributions of the NPD components in FMCI, lifetime MCI, and WCI were 1.9 to 5.4% lower than those on low-performing farms (P<0.05). In order to improve sow lifetime efficiency it is important to decrease the duration of each NPD component. Additionally, the relative contribution of WCI is the largest of the four NPD components, so controlling this is especially critical.
