An apparatus for collection of semen comprises: i) a frame forming an elongate body; ii) a base supporting the body; iii) a tubular receptacle containing an artificial vagina having a rear end portion pivotally carried on opposite lateral sides within the body, and an inner end portion releasably carried within the body, so that when the inner end portion is released collected semen therein will drain downwardly to an inner end portion; and, iv) a recessed rear access door, said door having an inner side portion positioned adjacent to the opening in the rear end portion of the tubular receptacle and an outer side portion positioned within an interior peripheral top and lateral side portions of the rear entry end of the body, so that downward and lateral components of thrust load exerted by the horse are largely sustained by the frame of the body, and wherein said recessed and protected door also has an enlarged thickness to accommodate a funnel shaped opening in the exterior side portion thereof to guide the horse into a central opening therein. When the horse is able to independently guide himself the apparatus is substantially more convenient and safer to use.