20. The owner or possessor of a stallion must show his permit at the time of serving, when called upon to do so. The permit for serving must be accurately reproduced and occupy a conspicuous place in any advertisement published in the newspaper or elsewhere, in posters, circulars or other mediums of publicity.
In any prosecution for an infraction of this section, failure by the accused to produce the permit for serving shall be sufficient proof that no such permit has been issued to him.
R. S. 1964, c. 126, s. 20.