Case-control study to assess the importance of mycotoxins in tail necrosis in neonatal piglets

Tail necrosis in neonatal piglets was reported in several conventional pig herds in Belgium. The primary cause remains unclear. Mycotoxins are frequently mentioned to be involved, although a causal relationship has not been established yet. This case-control study aimed to investigate the involvement of feed-mycotoxins on the prevalence of tail necrosis in neonatal piglets.

Ten conventional pig herds with and ten without clinical signs of tail necrosis in neonatal piglets were visited between November 2014 and April 2015. Control herds were similar to case herds in terms of herd characteristics. No mycotoxin binders were present in the feed. One feed sample, provided to the sow at the time of sampling, was collected per farm. On each case herd, blood samples were taken from 5 sows with clinical signs amongst their offspring, and from 2 affected piglets (aged 1-3 days) per sow. Milk samples were also collected from these sows after injection of 2ml of oxytocine i.m. A similar sampling scheme was used in the control herds. All samples were analyzed for mycotoxins and selected phase I metabolites via validated LC-MS/MS methods. This study was approved by the ethical committee for animal experiments (EC 2014/123) and financed by Veepeiler-Varken.

In total twelve different mycotoxins were detected in the feed and all feed samples contained at least one mycotoxin. DON was found in all feed samples: the average (± SD) concentration in case- and control herds was resp. 484 (± 212) µg/kg and 257 (± 89) µg/kg (P< 0.05). All feed samples were below the EU threshold of 900 µg/kg DON. ZEN was found in 3 case and 2 control herds, with an average of resp. 156 (± 88) µg/kg and 108 (± 54) µg/kg.

DON was detected in 89% of all plasma samples from sows, the average (± SD) concentration was 0.967 (± 0.692) ng/ml and 0.510 (± 0.311) ng/ml (P< 0.05) for the case and control herds resp. ZEN, -zearalenol and β-zearalenol were detected in a limited number of sow plasma samples. DON concentrations in piglet plasma samples were resp. 0.049 (± 0.051) ng/ml and 0.017 (± 0.015) ng/ml (P> 0.05).

DON concentrations in feed were positively correlated with DON concentrations in sow plasma (r = 0.70), but weakly correlated with DON in piglet plasma (r = 0.33). DON concentrations in sow and piglet plasma were also weakly correlated (r = 0.18). Analysis of milk samples and of phase II metabolites, as biomarkers for DON and ZEN exposure is currently ongoing.

Conclusion: These results suggest a possible involvement of DON in the prevalence of neonatal tail necrosis, as there were significant differences in the concentration of DON in sow feed and sow plasma between case and control herds.

Disclosure of Interest: None Declared.