Vitex agnus castus (Monk´s Pepper) belongs to the family of the Lamiaceae and
contains phytoestrogens. Its pharmacologically active substances are flavonoids
(casticin) and iridoids (agnusid and aucubin).
The clinical trial of the phytohormonal castration was accomplished to examine the
development of the primary and secondary sexual characteristics of cocks, the
concentration of androgen metabolites in blood and faeces and the meat quality under
influence of feed containing Vitex. In the course of this study the cocks were randomly
distributed to an examination group and a control group, each with 30 animals and were
nurtured over 22 weeks beginning the first day post natum. The examination group was
fed with a dry extract of Vitex added to the normal feed. The control group was fed
exclusively with the basic feed.
The following parameters were examinated in the course of the clinical trial: body
weight, feed conversion ratio, concentration of testosterone and androstenedione in
serum, concentration of testosterone and 17-oxo- und 17ß-hydroxy-androstane in
faeces, combs (length, height, colour, weight and lesions), length of spur, jowls (length,
height and weight), testes (length, breadth and weight) and meat quality (weight, drip
loss, cooking loss, pH-value and shear force).
The body weight developed significantly different in the two groups and at the end of
the study a cock of the examination group outweighted a cock of the control group.
According to the comb lesions there was a significant difference detectable only on a
singular examination day. The blood tests showed only in the development analysis of
the androstenedione-values a significant difference. In this connection higher values in
the control group were found. The calculation of the feed conversion ratio and the
analysis of the dropping-values (androstane and testosterone) showed heavy
fluctuations. The examinations of the other parameters showed no significant
In summary there was only in singular parameters (body weight, comb lesions and
androstenedione in blood) a significant difference detectable.