Assessment of Individual and Weekly Productivity of Sows by Parity, Season, and Sow Herd Structure in F₁ Crossbred and Berkshire Sows

Abstract

The objective of the present study was to assess the productivity in Berkshire sows and F₁ crossbred between Landrace and Large White, and to compare them by parity and season. This study was conducted on a farm rearing F₁ crossbred sows and a farm raring Berkshire sows in southern Kyusyu, Japan. We examined farrowing records and first mating records of sows that farrowed from 2018 to 2020. In both breeds, first parity sows had the lowest productivity in all of individual productivity except for farrowing rate in F₁ crossbred sows (P<0.05). The peak of litter size in F₁ crossbred sows was parities 2-4, whereas those in Berkshire sows was parities 3-6. Low litter size and farrowing rate in sows mated during summer were found in F₁ crossbred and Berkshire sows (P<0.05). In the relationship between weekly productivity and sow herd structure in F₁ crossbred sows, an increase of sow number/week decreased both proportions of sows with weaning-to-first mating interval ≤7 days in the week and mean farrowing rate/week (P<0.05). In the relationship between weekly productivity and sow herd structure in Berkshire sows, proportion of sows with weaning-to-first mating interval ≤7 days in the week and mean farrowing rate decreased as proportion of sows with parity 1 increased (P<0.05). The difference of by-parity productivity between F₁ crossbred and Berkshire sows, indicating that producers should change their management system or culling policy according to breeds.