An outcross bull – a bull with a bloodline that has never been used in Ireland before – injects new genetics into a herd, according to the Irish Cattle Breeding Federation’s (ICBF’s) Pat Donnellan.
Donnellan explained that outcross bulls “bring something different to the table”.
He believes that concerns held by some breeders that the Beef Data and Genomics Programme (BDGP) is “narrowing” bloodlines are unfounded.
Also Read: BDGP forcing pedigree breeders to ‘narrow’ bloodlinesOn the topic of outcross bulls, Donnellan said: “Given the focus on €uro-Stars however, the big question for a breeder is always what that bull’s star rating will be here? The less information that is known about a bull’s progeny – calving ease, weights etc – the lower his reliability percentage will be.
The problem with a very low reliability percentage – less than 10% – is that it leaves a lot of room for a bull’s index to change while he is on that journey to being a reliable bull – above 90% – and his genetic ability being fully known.
“Breeder’s could shy away from then using him and bloodlines would narrow.”
Genotyping
However, Donnellan stated that genotyping an outcross bull has “gone a long way to solving this problem”.
Continuing, he added: “Genotyping is the process of determining differences in the genetic makeup of a bull by examining his DNA sequence.
It will move his index up or down depending on how the DNA looks, but one aspect that will always increase is his reliability percentage.
“It’s as if the bull has already sired calves in terms of what effect it has on his €uro-Stars. It prevents him from starting on the floor; the bull can start with an index that is representative of as much information as we can get on him in terms of DNA,” he said.
Challenges
Donnellan acknowledged that it always be a challenge to get a handle on the genetics of an outcross bull.
As well as this, he explained that some outcross bulls are even an unknown quantity in their own country of origin – due to the fact that the recording of data and genotyping may not be carried out or that it is undertaken at a very low level.
Because of this, genotyping is the “only way we can gauge the breeding merit of a bull before he is used here”, Donnellan said.
Narrowing of bloodlines
Bloodlines narrowing in a breed has always been an issue in beef pedigree breeding, he added.
“Before stars and the BDGP came along, certain bloodlines were always more popular than others – with certain influential sires having numerous sons in AI, as well as being behind many bull mothers.
However, the ICBF has made great progress in incorporating figures from foreign countries into a bull’s €uro-Stars here and in 10 or 15 years’ time the transfer of breeding figures and genotypes will be a far more streamlined and routine process.
Because genotyping is now “so widely available”, it gives an outcross bull “a great chance” of being used by a pedigree breeder here in Ireland – thus preventing our bloodlines from getting narrow, Donnellan concluded.