Custom post to feed

function mycustomfeed_cpt_feed( $query ) {

  // Add to my custom-type post type
  $types = array('post','blood-blog');

        if ( $query->is_feed() )
            $query->set( 'post_type', $types );
        return $query;
}
add_filter( 'pre_get_posts', 'mycustomfeed_cpt_feed' );