Genomics is fast becoming a reliable breeding tool
GENOMICS were once again a hot topic for debate at the pre-conference workshops at this year’s British Cattle Breeders Conference at Telford.
With genomic information set to be included in the dairy bull proofs released in April, it is important for farmers to use this information as ‘another tool for genetic improvement’.
This advice came from Marco Winters, DairyCo breeding+ director, who highlighted the potentially faster gains which could be made by using the data.
“Genomics will allow us to achieve high reliability almost immediately and allows us to make genetic progress faster,” said Mr Winters.
“The extent of genetic gain will depend on genomic evaluations uptake and which bulls farmers choose to use. Even a modest 15 per cent improvement in PLI would mean about £20 million for the British dairy industry over 10 years.”
He said it would benefit breeders as it would lead to improved selection of young sires and would give farmers ‘earlier access’ to these young bulls.
“A young bull marketed as a ‘genomic young sire’ may be no better or worse than any other bull,” said Mr Winters, “but the advantages of genomic evaluations come through their speed and accuracy.
Until reliability data increases, I would suggest using a mixture of bulls
“Through collaboration with North America and Italy we’ve been able to establish reliabilities of around 65 per cent on young bulls, which is nearly double that of a traditional young sire index, but breeders are reminded this is still below that of most daughter proven bulls,” he said.
As a result he advised farmers to use a combination of proven and young genomically tested bulls rather than putting all their faith into genomics straight away.
“It all depends on how much risk the farmer wants to take. Some farmers may choose to use 100 per cent genomic young bulls but, until reliability data increases, I would suggest using a mixture of bulls.”
He said there would be two lists released in April – the traditional daughter proven bull list and a list including genomic data on young bulls – and he advises farmers continue using both lists for the time being.
“We did talk about having just the one list, but there is a lot of hype around the genomics issue at the moment and we want to make sure farmers understand the differences in reliability between the two lists to begin with. That way the farmer can choose.”
Mike Coffey, head of animal breeding at SAC, also urged caution. “If we are going to go twice as fast in terms of genetic improvement, you need to make sure you are going in the right direction,” he said.
He added the implementation rate was quicker in the dairy sector compared to the beef sector for a number of reasons.
“In dairy there is almost 100 per cent AI use, the phenotypes used to measure the improvements are available in larger numbers and there is also greater scope for the swapping of international data.
“In beef it’s different; there’s a lot of natural service and recording is not as well developed as in the dairy industry.”
He did say projects to further the use of genomic selection in beef were in the pipeline. He highlighted a project the Limousin Society started at the end of last year, which uses carcase data collected by video image analysis (VIA).
“This means we will be able to start selecting for animals that have different ratios of meat in the more expensive areas. For example, increasing loin lengths by 4 per cent would be worth £20m for Scotland when using a wholesale price of £17/kg.”
However, he said for genomics to truly come into its own, it was important for farmers to record sire information on cattle passports and also there was a need to develop more ways of recording.
Asked if there was a potential for genomic evaluations to reduce the gene pool of the UK dairy industry, Mr Winters said genomics could mean the opposite: “Genomic testing is significantly cheaper than progeny testing, which could mean more bulls can be screened prior to use in AI.
“We are constantly monitoring inbreeding levels and genomics will help us to do that better.”
Genomics according to Marco Winter
- Genomic evaluations will be flagged with a ‘G’ to make them easily identifiable
- A genomic index can be calculated from the moment of an animal’s birth by taking a sample of its DNA, which can be any cell in its body, including nasal swabs or cells at the roots of its hairs
- Without genomic indexes, the identification of superior bulls is expensive and time consuming because of the need to wait for milking daughters and a progeny test proof. This process generally takes around five years from the bull’s birth
- Genomic evaluations will not replace progeny testing and the importance of maintaining performance recording is critical for its success