my uncle had a 3/8 whip 3/8 grey 1/4 collie and it was mustard , would take hares during the day and rabbit under the lamp, the bit of collie in there gave it a better coat and abit more stamina, stood around 24 tts , chased a rabbit on the fell into a hole and went over and broke its neck, shame he didnt have any pups off it befor hand