Tolerance testing on target species/animal
categories. For each animal category, a target specie tolerance
testing shall be designed to determine a safety margin.
The aim of such trial is to evaluate for the animals the risk
of an accidental overdosing originated during feed production
(e.g., mixing heterogenicity). The trial shall be conducted
at a dosage being at least 10-fold the maximum
recommended dosage proposed by the applicant. In farm
animals, an experimental duration period of one month for
young and fast-growing animals and three month for adults
such as dairy cattle in lactation should be respected. For
breeding animals, the experimental duration period should
be the total length of a reproductive cycle. The tolerance
test requires at least the assessment of clinical signs (i.e.,
morbility and mortality) and zootechnical parameters (i.e.,
weight gain, feed intake, feed conversion ratio, laying rates,
egg mass, and milk production). When safety margin is less
than 10, to demonstrate the safety of the additive, data on
haematology, blood chemistry, and histopathology must be
available.
Studies on the eVects of the microbial additive on the
microXora of the digestive tract are also required when a
claim is made concerning an eVect on the intestinal microXora.