Crossing Dexters

[Joey Baker Cresswell]

I have four non-short Dexter heifers which are related to both my bulls. I don't want to get a new Dexter bull just yet but want to breed from these four this year before they get too fat. I was hoping to borrow an Angus bull but this is not going to be possible. My tenant has a very nice Charolais bull which he would let me use. The bull is not massive and the heifers are not particularly small for Dexters but not sure if this would be a good idea just for this year with the hope that they would produce cross bred calves for beef? Does anyone have any experience of this?

[Woodmagic]

I wont usually recommend inbreeding, although I practice it, but in the case of your four heifers, if the choice is between putting them back to related bulls or crossing with a bigger breed, I would suggest inbreeding was probably the safer option. If your stock is good enough you could be very pleased with the outcome. Remember the dangers of inbreeding are the risk of doubling up on an undesirable gene. If your animals are good you will be doubling up on those good genes, and finish with animals capable of breeding true to those desirable attributes. To cross a heifer even well grown with a bigger breed is risky and may give a difficult calving, or a dead calf.
Beryl (Woodmagic)

[Broomcroft]

We inbreed as well, and I wouldn't recommend it either. If you've got quality animals, you should get quality calves but be prepared to cull anything that comes through with faults. If you breed bad to bad, you'll get very bad. If the bulls are half-brothers of the females, they will only "share" 12.5% of the same genes. I have a table of how many genes wold be shared with different relationships if you PM me I'll send it to you.

I also use a "small" (meaning chest high, not shoulder high!!) Angus bull to dexters, but not to heifers, even our bigger ones. It's the same with other breeders I know who use dexters and other larger breeds.

Personally, I would never use a continental because they have enough difficulties with calving even within their own breed let alone with a smaller female. At least Angus have a reputation for a shorter gestation period and smaller calves.



Edited By Broomcroft on 1257349603

[Louisa Gidney]

It now looks as though Zanfara Orlando, who was visting a Dexter herd near Alnwick in Aug/Sept, will be heading back to the Alnwick area later this month.
Orlando is very inbred, and to my extremely fond eye has grown into a splendid boy. Outcrossing with unrelated Dexter females should give a bit of a heterosis boost to his calves.
It wasn't planned, but Orlando covered his mother this year. Since I didn't want her calving pattern out of synch, I didn't inject her so await the progeny with interest. It will taste all right even if it looks hideous!

[Martin]

Charolais would probably be the worst bull you could choose for Dexter heifers no matter how big they are. A freind of mine who milked Jerseys used a Charolais for a year and swore 'never again'. He lost 2 very good cows and had problems with most others, I assisted with 4 or 5 births that had to be 'jacked out'. Large heads and shoulders being the problem.

[domsmith]

If its heifer you need to stick to dexter sire, we calved a charolais out of a maiden heifer and it was not that bad but i think we were lucky.

i would inbreed rather than cross, or how about AI

better safe than sorry, evean an angus can give you problems, we have had them with dexter cows to the angus bull.

dom

[Broomcroft]

Here's the inbreeding coefficient table I referred to copied out of a publication:

"The inbreeding coefficient, as used in linebreeding, is a measurement of the probable chance that any genes will double when two animals are mated. This probability increases with the degree of relationship between the two individuals. By knowing the probability in such instances, a breeder can safely decide whether to try linebreeding in some cases.

Inbreeding coefficients and their related probabilities (percent chance of genes doubling) can be seen in the following table:

INBREEDING COEFFICIENTS FOR VARIOUS MATINGS

Half first cousin (1 common grandparent) 3.12%
First cousin (2 common grandparents) 6.25%
Grandparent-Grandoffspring 12.50%
Half brother-sister 12.50%
Parent-offspring 25.00%
Full brother-sister (1 generation) 25.00%
Full brother-sister (2 generations) 37.50%
Full brother-sister (3 generations) 50.00%

One can see from the previous table that as relationship increases, so does the inbreeding coefficient and the probability that genes will double in each mating.

Knowing this probability is very important to breeders who incorporate linebreeding into their programs as the doubling of genes can either greatly improve or massively decline the quality of livestock as not only the good genes are doubled. The bad genes have the same probability of doubling and becoming dominant."

These figures assume there is no other relationship.



Edited By Broomcroft on 1257366499

[AlisonKirk]

In 1998 we purchased a Charolais bull for use on our Angus X Friesian cows / heifers (we had previously always hired a bull and experienced very few calving problems). He was a good bull and not over big, but we did experience some difficult calvings, both with cows & heifers - calves stuck at their hips & sometimes shoulders too big. His progeny were ideal for the commercial market & sold well as stores.

We carried out some research and were advised that some of the Charolais bloodlines had been influenced by the introduction of white Belgian Blue bulls.

I would rather put father onto daughter and slaughter for beef. Alternatively, why not give A1 a try?


Alison Kirk
Boram Dexters

[redhill]

for what its worth I do not think it matters how big the bull is at the moment its how big he's going to get that matters, if he is going to finish up big then these genes are in him and will almost certainly influence the size of his ofspring, I would agree with the answers above DO NOT use this bull (even if you only finish up with having to take one calf out by the side door you are looking in excess of £100) unless you know for certain that you have a very undesirable gene in both your bulls (in which case I would say get rid of them) do not be afraid of using one of them as your heifers are non short you would be very unlucky indeed if you had even one calf out of the four with any problem and you could find that you finish up with a superb animal.
Bill, Castlemears Dexters

[Joey Baker Cresswell]

Thank you for all your replies. Louisa has very kindly offered me her Dexter bull so that will solve the problem until I get a new Dexter bull next year.