A newborn miniature horse in Barnstead New Hampshire could lay claim to the title of smallest horse in the world.The pinto colt, Einstein, arrived Friday morning weighing just 6 pounds and measuring 14 inches in height.Einstein's breeder is reaching out to the "Guinness Book of World Records.""I have been at this for 20 years-plus and I have never seen one this tiny or even close to it," said Judy Smith, of Tiz Miniature Horse Farm.