Chemical characterization and toxicological assessment of kraft pulp mill fiber waste as a feedstuff for beef cattle

Pulp fiber waste (PFW), a byproduct of pulp and paper mills, has been suggested as an alternative feed source for cattle. This study assesses two sources of PFW using short-term mutagenicity tests and a long-term animal feeding trial to determine the toxicological potential of PFW. Analysis of PFW demonstrated that heavy metal and trace element concentrations were below the tolerance levels set for cattle, but small amounts of toxic chemicals were present. No mutagenic activity was observed using the Ames test and the feeding trials demonstrated no visual signs of toxicity or collection of toxic chemicals in the liver of the treated animals. These findings suggest that PFW may be a safe food source for cattle but further research is needed.