Cow Short Cycling

[funky 4-Her]

We've got a first calf heifer at home that were trying to get bred back. She's been bred 4 times now and not catching. She's having short cycles, somewhere around 13 days. Vet checked her said not cystic, not dirty. From the time she starts showing signs of heat 12 hours later shes bloody. She had twins last year if that makes any difference.
Anyone got any ideas what could be wrong with her? Shes a favourite and I dont want to see her go if its an easy fix.

 

[cow pollinater]

Nutrition!
She needs more energy. Bump up the feed and maybe try some suplement if you're not already and wait until she's picked up a little before you breed her again.
Reproduction is low on her priority list behind the calf she has now and taking care of herself so if you want her to reproduce, you have to give her the groceries to get all of her needs met.