Terminology: Rat Two-generation Reproductive Toxicity

The objective of this test is to obtain information on the reproductive toxicity of a test substance. In this test, a test substance is administered to test animals over two generations successively and reproductive toxicity is examined in a comprehensive manner through a series of tests in which the test substance is administered at the pre-conception period and initial stage of pregnancy, fetus development stage, prenatal period and lactation. In recent years this test has come to be one of the most highly regarded in Europe and the Americas.

[Test Method]
A test was conducted with rats (Spraugue-Dawley) as test animals and parents (P) and their offspring (F1) were divided into groups by sex, breed, and generation consisting of 30 individual test animals each.
Groups were then arranged to form a testing combination consisting of one control group and three exposure groups, to which feed containing Zeomic at concentration levels of 0ppm, 1000ppm 6250ppm and 12500ppm respectively was given every day for the test period.
(P) generation rats were given Zeomic-containing feed for at least 10 weeks before they gave birth to (F1) generation rats, and the (F1) generation rats were fed similarly before they gave birth to (F2) generation rats. (P) generation rats and (F1) generation rats were mated for 14 days by forming certain pairs and female (P) generation rats were kept together with their offspring for 26 days of lactation.
For these individual rats, the weight and feed intake quantities were recorded in a clinical examination like manner.
Microscopic observation was performed for the genital organs, adrenal glands and pituitary gland, as well as for the kidneys throughout the (P) generation and (F1) generation rats as the target organs of toxicity evaluation.

[Test Results for Zeomic]
As a result, both no-observed effect level (NOEL) and no-observed adverse effect level (NOAEL) of Zeomic were determined at 1000ppm. This dose level corresponds to 79mg/kg-bw/day.

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