I have used ruby red Devon bulls on our dairy heifers for donkeys year's and used to breed our own as had a few pedigree cows, last of the bull was lost to tb in the autumn and a couple of the beef guy's who purchase our Devonx heifers for suck cow replacements have asked I'd we would change to hereford's. So is there any difference between the horned and polled bull as to easily calving?