Information provided by genomic evaluation has been widely used by dairy farmers when selecting young bulls but now the technique can be routinely applied to evaluate genetic potential of females.
By revealing the genotype of female calves as soon as they are born, genomic evaluation will enable farmers to make management decisions based on accurate genetic information which could bring significant improvements to herd performance.
Marco Winters, head of genetics with AHDB Dairy, believes genomic evaluation can offer a number of benefits to commercial dairy producers as well as elite pedigree herds.
He says: “The benefit of using young bulls with genomic data has been apparent for some time, but the technology is equally as effective when used to evaluate young females.
“Elite herds are already using the technique to identify the best bull dams but now some commercial dairy herds are also implementing a programme of genomic evaluation to routinely assess youngstock.”
The cost of the process has fallen dramatically since it first became commercially available in the UK three years ago. A number of different companies provide the service and the cost of a single test is now about £30.
Mr Winters believes the affordability of genomic evaluation means the benefits from it quickly outweigh the cost. He says: “Screening heifer calves shortly after birth allows the farmer to cull out the worst 5 per cent to 10 per cent of animals coming through.
“Given the estimated costs of rearing a heifer to her first lactation are estimated to be between £1,500-£2,000, selecting out calves with the poorest genetics can deliver substantial cost savings.”
Decisions can also be made in relation to the remainder of the herd based on this genomic evaluation, says Mr Winters.
“For example, the top third of maiden heifers can be identified and farmers can combine the power of sexed semen and genomics to maximise genetic gain.
“Similarly, those females in the middle third will be kept as replacements but standard dairy breed semen could be used. The bottom third, excluding those to be culled out, might be put to a beef bull to increase calf value.”
The genetic test and evaluation procedure which AHDB Dairy provides for males and females is identical, says Mr Winters, ensuring compatibility and allowing informed breeding decisions to be made to improve specific traits.
A genomic test can reveal carriers of recessive genes in the herd and, where the recessive gene is linked to early absorption or abortion of the calf, avoiding the use of a bull with a similar recessive gene can eliminate problems.
Mr Winters believes vets and nutritionists are now seeing the power of genomic evaluation.
“Vets are now interested in the genetic profile of animals because it can be used to predict how an animal might respond to a drug treatment or a vaccine. Similarly, not all animals respond to a feeding programme in the same way, so genotypes may help guide nutritionists as to how to feed an animal for the best results.”
Lucy Andrews-Noden of Priestcliffe Consulting agrees the potential offered by genomic evaluation to both pedigree and commercial herds is enormous. She is working on a smartphone application which will allow farmers easy access to genomic information about animals in their herd.
She says: “Genomic evaluation can provide information about 31 different genetic traits with 60-70 per cent accuracy. This compares to the accuracy of data based on parent average of 30-35 per cent.
“In essence, genomics can provide data on a calf of the same quality and reliability as would be obtained from actual records collated over the period up until the end of the second lactation.”
Mrs Andrews-Noden favours the ear notch system where a small notch of tissue is removed using an entirely sterile process at the same time the calf is tagged, minimising stress for the calf and farmer.
“We can use the same tissue notch to undertake a BVD test while also using it for the genomic evaluation,” she says.
Mrs Andrews-Noden acknowledges concerns regarding the ownership of data and the uses made of it thereafter. She says: “The way to get farmers to embrace genomic evaluation is to ensure information from it is not used as a stick to beat them with. It should be viewed as a valuable tool in a big tool box which can be used to achieve improved herd management.”
Mrs Andrews-Noden is also excited about a product under development which will screen for traits linked to natural immunity.
“Soon there will be a genomic test for immunity. This will be important for identifying animals at reduced risk of suffering metabolic diseases, such as ketosis and acidosis, and those which are less susceptible to Johne’s, TB and even pneumonia.
“Essentially, genomic testing will allow farmers to make the best investment to secure the desirable health and welfare traits and make decisions about the future genetic advancement of the herd.”
Mr Winters agrees, suggesting the technique will become routine in the near future, even among commercial herds. He admits the service in the UK will currently only evaluate Holstein cows, but a service for Jersey, Guernsey, Brown Swiss and Ayrshire herds will be available soon.
Jimmy Dickinson of Longley Farm Dairies, West Yorkshire, has developed a keen interest in genomic evaluation since he first became familiar with it as a board member of the Jersey Cattle Society. He believes it offers tremendous potential for dairy farmers and processors alike.
He says: “There are benefits from single test results and also long-term advantages from accessing comprehensive data about the genotypes of a large number of cows.”
“It is possible to look at a test on a single animal and identify specific genetic markers. I am particularly interested in whether a cow carries the gene for Kappa Casein BB protein production in milk as this is linked to higher cheese yields.”
There are 16 pedigree Jersey suppliers to Longley Farm and currently there is no UK-based genomic evaluation service for Jersey cows. Mr Dickinson would like to establish a genomic evaluation programme involving all suppliers.
He says: “The pool of 2,000 cows in our supply group is probably the largest 100 per cent pure pedigree Jersey group in mainland UK and it would be sufficient to provide meaningful data.
“The data obtained by newer tests is of a higher density and quality, containing more detail. As data improves, fewer cows are needed to provide reliable genetic information across a range of traits. This opens the door to minor breeds or smaller groups of breeders.”
Mr Dickinson suggests the results of single marker genetic testing might be used to inform a milk pricing framework, with the possible payment of premiums for desirable traits for certain contracts.
Control of data is an issue which concerns Mr Dickinson and he believes, to date, the UK has lost out to the US, the world leader in the field, having a huge genetic database for Holsteins and other breeds, including the Jersey.
“The idea of tagging on with the Americans is tempting, but the reliability of evaluations can be poor if the population is different to the United States; this is definitely an issue for Jerseys.”
He points to the French model as one option which the UK may wish to consider.
“The French are focusing on establishing a comprehensive database for their native breeds, such as the Montbeliarde, so they become the global leaders in the genomics for this breed. In the UK, we are still reliant on US data and if we do not set up our own national databases, we will lose our national identity.”