Reference Intervals for Haematological and Biochemical Blood Parameters in One- and Twenty-One-Day-Old Piglets: Association with Farm, Sex and Dam Genotype

Reference intervals (RIs) for newborn and suckling piglets are scarce, and their dependence on farm, sex and dam genotype is insufficiently known. We determined RIs for 19 haematological and biochemical blood parameters in piglets from three commercial farms on day 1 (n = 572) and day 21 (n = 487) of life. Because the distribution deviated from normality (all parameters on day 1, 18 of 19 on day 21), non-parametric RIs (2.5th–97.5th percentile) with 90% confidence intervals were calculated in line with veterinary clinical pathology guidelines. The effects of farm, dam genotype and their interaction were tested by two-way analysis of variance (ANOVA) on litter means, and the intraclass correlation coefficient (ICC) was estimated by variance components analysis. Sex was not associated with any parameter. The farm effect was significant for 13 of 19 parameters on day 1 and 11 of 19 on day 21, the dam genotype effect only for alanine aminotransferase on day 21, and the interaction for none. The ICC was at least 0.30 for five parameters on each day, indicating considerable litter-level variability. The intervals can be used to assess piglet health in commercial production, taking farm, age and analytical platform into account.