Occurrence of mycotoxins in straw used in pig deep litter systems in Australia

Abstract

Mycotoxins are secondary metabolites produced by fungi under certain stress periods (Smith and Seddon 1998). When ingested, mycotoxins cause insidious losses, ill thrift and reduced disease resistance. Zearalenone is known to cause hyperestrogesium in pigs and hence a reduction in fertility in both sows and boars can occur (Binder 2004). Certain mycotoxins such as zearalenone (ZEA) and deoxinivalenol (DON) are produced by fungi of the fusarium species on crops in the field. Fusarium pseudograminearum (Crown Rot) produces both DON and ZEA in decreasing levels up the tiller of winter cereals (Blaney et al. 1987). Most studies carried out so far analysed the occurrence of mycotoxins in the grain and less is known about the prevalence of mycotoxins in the straw of the crop. Housing of sows during gestation on straw is becoming a favoured production system due to environmental and public perception pressures. The intake of straw by weaners on straw based systems has been found to account for 11.5% of total feed intake (Barneveld et al. 2004), such that there could be a considerable risk for increased ingestion of mycotoxins in animals on straw based systems. The objective of this study was to investigate the occurrence of mycotoxins in straw used for deep litter in Australian deep litter pig production systems.