AGRICULTURE - HARMONIZATION OF LAWS - DIRECTIVE NO 77/504 - SEMEN INTENDED FOR THE ARTIFICIAL INSEMINATION OF CATTLE - INTRA-COMMUNITY TRADE - POWERS OF MEMBER STATES - GRANTS OF IMPORT LICENCES SUBJECT TO OBSERVANCE OF ZOOTECHNICAL RULES APPLICABLE TO SEMEN OF NATIONAL ORIGIN - PERMISSIBILITY ( COUNCIL DIRECTIVE NO 77/504 , ARTS . 2 AND 3 )