Variation in fattening pig exterior, gait and weight gain in commercial organic herds

Abstract: Pigs in Swedish organic production systems have been shown to have more findings of arthritis at slaughter, compared to pigs in conventional pig production. With this in mind a study was performed, to primary, investigate variation in exterior, gait and weight gain between sire breeds and, secondly, to investigate variation between herds, season, gender, age and assessment occasion on these recordings. Swedish commercial hybrids, crosses between Norwegian Landrace and Swedish Yorkshire were inseminated with either Hampshire or Duroc as terminal sire. All the pigs had known pedigree as each semen dose contained sperms from one individual boar. All piglets were individually tagged closely after birth, and exterior and gait assessment were performed at two separate occasions, early and late during the fattening period. At the assessment, exterior and gait parameters (lameness, back, leg, swollen joints and movement) were investigated. Data was collected and analyzed using SAS software, using three different statistical models. For the first two settings the results show that sire breed had little effect, while herd, gender, season, age and assessment occasion has some effect on the exterior and gait parameters. For the third setting the result showed that all the parameters; sire breed, birth herd, gender and season had some effect on weight and growth performance.