PR toxin is one of several Penicillium toxins, and species of Penicillium have been found as a major contaminant in silage.

PR toxin is produced by Penicillium roqueforti and is one of several mycotoxins produced by Penicillium.

Penicillium species are abundant in silage and have been found in both corn and grass silage.

The U.S. Food and Drug Administration has no regulations or guidelines on PR toxin in animal feeds.

The effects of PR toxin in cattle are not well defined in the literature. PR toxin is suggested to be the causative agent associated with health issues from consuming moldy corn silage and has been suspected as the potential cause of abortion. Other Penicillium mycotoxins in silage have been associated with herd health problems, including reduced milk production, rumen dysfunction, and acidosis-like symptoms. However, studies have reported that PR toxin does not interfere with rumen fermentation and is undetectable after 48 hours. Interactions with other toxins may cause the symptoms associated with Penicillium mycotoxins.

Gallo, A., G. Giuberti, J.C. Frisvad, T. Bertuzzi, and K.F. Nielsen. 2015. “Review on Mycotoxin Issues in Ruminants: Occurrence in Forages, Effects of Mycotoxin Ingestion on Health Status and Animal Performance and Practical Strategies to Counteract Their Negative Effects.” Toxins 7, no. 8: 3057–3111.

Whitlow, L.W. and W.M. Hagler, Jr. 2017. Mold and Mycotoxin Issues in Dairy Cattle: Effects, Prevention and Treatment. eXtension. Accessed 7/20/21.