Genomic testing a top priority for Hereford breed

Genomic testing a top priority for the Hereford breed


Beef
MORE TESTING: Increased genetic recording is needed by Hereford breeders to speed the rate of improvement in their herds, according to Dr David Johnston from the Animal Genetics and Breeding Unit, University of New England, Armidale, NSW.

MORE TESTING: Increased genetic recording is needed by Hereford breeders to speed the rate of improvement in their herds, according to Dr David Johnston from the Animal Genetics and Breeding Unit, University of New England, Armidale, NSW.

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More Hereford herds and more animals need to be recorded in Breedplan to improve the accuracy of their estimated breeding values,

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Hereford breeders are urged to increase their use of genetic technologies such as single step Breedplan and the latest BreedObject or risk limiting their rate of progress, according to one of Australia's leading animal researchers.

Dr David Johnston from the Animal Genetics and Breeding Unit at the University of New England, Armidale, NSW, said since Herefords Australia had implemented single step Breedplan in January 2018, about 14,000 animals had now been genotyped, but many more were needed.

He told last week's Herefords Australia Breed Forum in Hamilton that it was critical for the Hereford breed to increase the size of their genomic reference population.

"Breedplan uses estimated breeding values (EBVs) to enable more accurate genetic selections to be made and to do this we need more herds and more traits being recorded," he said.

"The real power of genomic selection is with traits that are difficult to measure on-farm such as female reproduction, feed intake, carcase traits, parasites and disease, as currently these traits have very low accuracies.

"Breeds can survive without genomics but their progress is going to be limited.

"Even if Herefords today were perfect, next year those breeders using those bulls would be 2 per cent less profitable just because of increased costs, so unless they are making some genetic improvement they are not keeping ahead of the costs."

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He said most of the Hereford breed's reference data had come from its involvement in the Beef Information Nucleus (BIN) project, which was a nation-wide progeny testing initiative by Herefords Australia to provide more accurate EBVs on a range of economically important traits.

"Herefords currently has about 2000 BIN records, which yields about 35pc EBV accuracies for non-recorded animals across traits which is low," he said.

"To increase the EBV accuracies from genomics alone to 60pc, you need about 8000 records in the reference population."

According to Dr Johnston, there were sufficient Hereford animals recorded for the growth traits of 400 and 600 day weights as well as P8 fat and eye muscle area.

But he said the Herefords recorded for abattoir carcase, carcase weight and intramuscular fat measurements was low, while records for difficult to measure traits including mature cow weight, retail beef yield, net feed intake and days to calving were virtually nil.

"The lack of measurements on these traits probably gives you direction as a breed on what records are needed, the benefits of genomic selection are currently only very low due to the reference population size," he said.

Dr Johnston also highlighted the benefits of the new V6 BreedObject software which is used with Breedplan to calculate the optimum mix of EBVs based on a producer's breeding objectives.

In BreedObject, the available EBVs on a line of animals are given an economic weighting. The weighted EBVs are combined into a single dollar index for each animal.

In the BreedObject program, the available Breedplan EBVs on a line of animals are given an economic weighting which can be customised for each user. The weighted EBVs are combined into a single dollar index for each animal.

"BreedObject tells you which are the most economically important traits to select for and those ones that have the highest emphasis are the ones we want to be focused on measuring."

He said the program has improved inclusion of feed costs, net feed intake EBVs in indexes, enhanced modelling of pasture and feedlot systems, enhanced cow weight valuing and cow condition score valuing.

"Feed needs to be costed and if you do it will change the ranking of your bull in terms of dollar indexes."

He used the example of one Hereford bull which is currently in the top 1pc of the breed with a high mature cow weight EBV, under a low feed cost example the bull remains in the top 1pc but if feed costs are high, it drops to the top 30pc of the breed.

"It's not about selecting smaller cows, breeders want to select for good early growth and carcase traits combined with a moderate mature cow weight.

"And if producers want to change fertility, they need to be doing a much better job of recording the female reproduction trait, days to calving."

The story Genomic testing a top priority for Hereford breed first appeared on Stock & Land.

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