regolith
Well-known member
Non-cyclers are just cows that aren't having observed heats. Usually they're too skinny or are still in post-calving anestrous (quite normal for a cow to take five to six weeks after calving before her first cycle, sometimes we want her bred again before that, if she calved late.)
When they've had timed AI and are still not pregnant and not cycling we call them 'phantom cows' because everyone thinks they're pregnant. With cidr + estradiol the vets used to re-synchronise and mate to observed heats 3 weeks after the timed AI, but they can't do that with estradiol having been banned and the replacement prostaglandin protocol would abort an exisitng pregnancy. The re-synchrony was specifically done to reduce the potential for phantom cows.
I don't really know about the bull causing the cow to cycle, but my observation suggests it's the case and it's one of those 'wives tales' that's been floating around for ever and ever. I get such poor results from synchronising non-cyclers that I don't do it any more.
The one year the vets talked me into re-synchrony with cidrs I did about 43 cows, 20 returned for the second heat (so over 50% apparent catch which was good, though some would have cycled again later) 4 or 6 of those 20 caught to the second insemination. Three weeks later I'd just turned the bull out, went out in the morning to get the cows and found one very exhausted bull valiantly trying to attend to 16 or 17 cows - fourteen of the twenty had all returned overnight, along with a couple of normally cycling cows.
That bull spent the remainder of mating sitting right next to the cowshed waiting for me to cut out cycling cows and put them in with him. He couldn't walk easily again for about a month. The things you learn...
When they've had timed AI and are still not pregnant and not cycling we call them 'phantom cows' because everyone thinks they're pregnant. With cidr + estradiol the vets used to re-synchronise and mate to observed heats 3 weeks after the timed AI, but they can't do that with estradiol having been banned and the replacement prostaglandin protocol would abort an exisitng pregnancy. The re-synchrony was specifically done to reduce the potential for phantom cows.
I don't really know about the bull causing the cow to cycle, but my observation suggests it's the case and it's one of those 'wives tales' that's been floating around for ever and ever. I get such poor results from synchronising non-cyclers that I don't do it any more.
The one year the vets talked me into re-synchrony with cidrs I did about 43 cows, 20 returned for the second heat (so over 50% apparent catch which was good, though some would have cycled again later) 4 or 6 of those 20 caught to the second insemination. Three weeks later I'd just turned the bull out, went out in the morning to get the cows and found one very exhausted bull valiantly trying to attend to 16 or 17 cows - fourteen of the twenty had all returned overnight, along with a couple of normally cycling cows.
That bull spent the remainder of mating sitting right next to the cowshed waiting for me to cut out cycling cows and put them in with him. He couldn't walk easily again for about a month. The things you learn...
