3.7    Contamination/ cross-contamination

•         Contamination is the presence of substances in a feed which does not belong to the recipe.

•         If these substances belong to a previous processed batch, it is treated as a cross- contamination.

•          Impurities from macro – ingredients are not critical.

•         Cross-contamination  through   highly   concentrated  additives  can  be  critical  for animals.

Measures for minimizing the cross-contamination risk:

Ø      Separate mixing line for each species.

Ø      Smaller and more flexible mixing lines

Ø      Hygienic design of the machines + conveying elements minimizing the remaining residues.

Ø      Bins and hoppers must have mass flow characteristics.

Ø      Avoid long conveying distances

Ø       Central aspiration system after the addition of the additives is to be avoided.

Localized aspiration system having bag filters with compressed air, blowers is to be provided.