What Determines Calving Ease

[BRYANT]

I hear so much talk about useing the right bull on heifers ,like low birth weight ,calving ease bull, and heifer bull, ect... but how much of the calf size is determined from the heifer?
What made me think about this was I knew a man with a bunch of longhorn ropeing heifers and them little "pot lickers " did not look like they were big enought to have a calf when the neighbors BIG red bull came for a visit and they just left him in the pasture and bred them. He never had no calving issues with them .I even told him I bet you loose them heifers trying to calve them out and he said there will not be no problems and there was not.
Also I have been calving out some Brahman cross heifers the last 3 years and have had no problems. I had a man tell me the other day "them heifers have so much Brahman in them they can have their calves with out much problem"
So is the problem with heifers the bull or maybe its the heifer throwing to big of a calf ????
Just something I have been think about ???

 

[redcowsrule33]

In my opinion, it's the combination of
1. Calf shape
2. Maternal pelvic area/shape
3. Calf size

Any of these three out of whack, calving ease decreases. That's why you can have a low birthweight bull that calves hard, either the calves are built wrong (like plugs) or the heifer doesn't have enough pelvic size. Some will breed heifers to breeds that guarantee tiny calves so they don't have to worry much about the first two. You lose a generation doing this, and leave the weeding out until the next year, but whatever floats your boat. The heifer has a lot to do with how that calf comes out.

FWIW, some breeds such as Jersey or Brahman have the pelvic size relative to body size and the ability to size the calf to themselves that calving problems on a normal presentation are unusual. I saw a Jersey heifer lay down, push out a calf with both front legs back, and run away. Won't see too many cows do that.