Fat quality in carcasses of organic pigs: Influencing factors in feed, farm and animal health

Summary

Since 2022 the EU organic regulation requires growing- inishing pigs to be fed with 100 % organic feed. Until 2021, it was permitted to use up to 5 % conventionally produced feed components which typically included potato protein with a favourable amino acid profile. A disadvantage of alternative organic components, such as soy cake, is that they often contain high concentrations of olyunsaturated fatty acids (PUFA). In Switzerland, slaughterhouses apply a penalty to carcasses with PUFA concentrations in backfat exceeding 15.6% in order to reduce oxidation and maintain good processing properties. The goal of the study presented here was therefore to evaluate factors influencing PUFA concentrations in carcass fat. We visited 18 organic farms with growing-finishing pigs, which were classified as either “PUFA high” or “PUFA low” based on routine PUFA measurements from 2022 and 2023. During the farm visits, we assessed animal health (tail and ear lesions, diarrhea, lameness, skin lesions), farm management (feeding technique, climate, pen cleanliness, water and roughage provision), collected faecal samples for parasitological analysis, and feed samples for nutrient content analysis. Additionally, we collected individual fat samples after slaughter from five farms (analyzed via NIRS) and recorded abattoir findings such as discarded organs and abscesses. We performed linear mixed-effects models with PUFA level (high vs. low) as a fixed factor and farm as a random effect. Data from the on-farm animal health assessments showed that “PUFA high” farms had higher incidences of diarrhea, ear lesions, and short tails. Results from the individual fat analyses indicated a large variation in PUFA concentration within batches of carcasses from the same farm, suggesting a strong individual and age effect. Furthermore, there was a positive association between PUFA concentration in the grower feed and PUFA concentration in the carcass. These preliminary results suggest that farms with more health issues are more likely to have high PUFA concentrations in their carcasses and thus face penalties from slaughterhouses. Final results from all aspects of the study will be presented at the conference