at what age

clacko · Post by **clacko** » Wed Mar 10, 2010 12:11 am

i think this has been asked several times before but here goes,
what would be the earliest a bull calf could become fertile, reason being i have held back his dam as we are a newish herd, to try and bring a bit of uniformity to calving rather than calving 9 months out of 12, just weaned him at 29 weeks as dam has now gone back to bull with a couple of hiefers, have thought about giving dam a shot of estrumate as a precaution, as i have not seen her bulling for the last 6-8 weeks.
paul

Duncan MacIntyre · Post by **Duncan MacIntyre** » Wed Mar 10, 2010 12:36 am

About 5.30am.

Duncan

clacko · Post by **clacko** » Wed Mar 10, 2010 12:46 am

was asking about fertility duncan, not what time you rise in the morning!!!!! :D

Broomcroft · Post by **Broomcroft** » Wed Mar 10, 2010 7:11 am

I don't know but would feel certain by 6 months of age no problem and before. I know the heifers are by 5 months and I've got two to prove it

. You could PD your dam. I think our vet says estrumate has a 50% chance of making your dam infertile, or was it the other one they use later on?

Broomcroft · Post by **Broomcroft** » Wed Mar 10, 2010 7:24 am

Can't edit. You need to leave a gap before PD'ing and re the age, I would think every bull calf is different.

Louisa Gidney · Post by **Louisa Gidney** » Wed Mar 10, 2010 10:50 am

It has a lot to do with scrotal circumference relative to body weght. I've been playing with this topic of late & there's lots of stuff on the web if you search on google.
Need to check, but if you measure your boy & he's c. 30cm sc, he's likely to be fertile.

domsmith · Post by **domsmith** » Wed Mar 10, 2010 10:14 pm

This comes up alot, and all dexter owners say the same they are fertile very young.
mine on the other hand dont follow this rule, my bulls are just weaned today as it happens at nearly a full year old. they are strong and literally fighting fit. but i am yet to get a heifer calf in calf from them.
i always feel i am riding my luck, but i seem to keep riding.
this year might be the year i change my system time will tell.

dom

Minnie · Post by **Minnie** » Wed Mar 10, 2010 11:26 pm

Interesting that this comes up now as I have a young bull as well and not sure if he's started working or not. Currently he's in with a 14 month old heifer but I've found where we are that the girls don't seem to cycle over the winter and begin a bit older than a previous place I've lived. Close to Sydney we had calves (not dexter) cycle at 5-6 months, but up in Northern NSW it's more like 14-18mths. Obviously some climatic thing, so I'm thinking my little bull came from south he may take a bit longer too up here. BTW I told DH to grab the tape. :laugh:

wagra dexters · Post by **wagra dexters** » Thu Mar 11, 2010 4:09 am

We have a couple of yearling heifers that were born a week before their sire was 18 months old. He was run with the cows to mop up after an AI program.

Perhaps Duncan can verify, I have an idea that running smaller young bulls with larger heifers and cows can cause rectal prolapse in some bull calves, or maybe only if there is a predisposition.

I do know for sure that if the bull is too short for the cow, the cow can be damaged inside.

Margaret