It's a bit of an art, but here are the rules of thumb that I use :
- the one who stands while another animal jumps on her is the one that's bulling
- the one who is jumping on others is not bulling unless you see her stand for another animal
- blood on underside of the tail or below / coming out of the vulva is usually 24-48 hours
after bulling
- clean slime is more likely to be an animal that's bulling today
- the vulva may be a bit puffy when she's bulling - get to know what's normal for your cows' intimate parts!!
- a cow that's bulling will probably be lovey-dovey with you too, and will probably stand for you, arching her back and lifting her tail, if you fondle her around the tail head / vulva.
- the one that's bulling may also feel a bit hot - but then sometimes they are all hot because of all the activity
- if your cow is in milk, she may have a sharp downturn in milk on the day she is bulling - but they don't all
If Knickers is standing for Mary today, I would definitely serve Knickers again. Cycles can in theory be 19 days but all of ours over the years have been 20 or 21 days, so on probability, she was served a bit too soon last time.

she holds this time!