In an ideal world, all farmers would like to be able to produce more from less, and for commercial dairy producer, Rory Christie that means being able to increase farm income by £1m per year from 1000cows – without extra concentrates.

Mr Christie of Dourie Farm, Port William, hopes to be able to achieve just that as part of the Fast Breeders Project which involves another three spring-calving herds totalling 4250 cross-bred cows led by geneticist Mike Coffey of SRUC.

Farming in partnership with his brother Gregor, Mr Christie’s goal is to increase milk solids from 475kg milk per cow to 750kg within 10 years while also increasing the amount of milk solids produced per kg of live weight from 1kg to 1.5kg.

The Scottish Farmer: Rory's favourite cow, Number 701 weighs 360kg live and produces 6800kg from 600kg concentrates Rory's favourite cow, Number 701 weighs 360kg live and produces 6800kg from 600kg concentrates

“It is an audacious aim, but we want to help ourselves become financially sustainable, said Mr Christie.

To achieve that goal, the group has DNA tested their entire herds to create a SNP key, with some 9000 animals genotyped, to create the world’s first cross breeding index using genomic information, milk production and herd health data.

Mr Christie’s herd of 1100 spring-calving Jersey cross Holstein cows are milked twice daily, and at the same time are also automatically weighed to accurate liveweight data to create a maintenance and fertility index.

The genomic index is currently based on milk fat, protein and somatic cell count data but liveweight and calving interval is being added for the 23/24 season.

However, with large numbers of heifers having to be retained as replacements at a cost of £1600, Mr Christie said he was disappointed to find only 50% of the heifers in the top 50% of the index.

“It is an expensive exercise. I carry nearly double the heifers I need for replacements, so we have a huge sum invested in additional stock per year.”

The other downside is that cow size is increasing rapidly. The genomic trend for maintenance, based on 90,000 weight records, is showing cow size will increase beyond the ideal of 525kg. Mr Christie’s ideal cow post calving weighs in at 360kg live and produces 6800kg from 600kg concentrates.

“They turned to Holstein to increase milk yield and consequently increased size,” explained Prof Coffey.

To understand cow size, all cows are being weighed twice daily after milking to get accurate liveweight data. This information has been used to create a maintenance sub-index.

“They now weigh all their cows regularly and send it to us at SRUC and we calculate genomic breeding values for liveweight. They use it to select cows for breeding and they also evaluate bulls they are planning to use using that SNP key. That means they can evaluate available bulls based on how big the offspring are likely to be when they mate those bulls to their cows,” explained Prof Coffey.

Fertility and maintenance are expected to be added to the Fast Breeders genomic index this year.

Mr Christie now has an elite group of 500 females that are individually mated to sexed bulls with conception rates hitting 45%+ and the plan is to accelerate genetic gain even further.

“We have been applying for funding to use ovum pick up from young heifers and embryo transfer so we can replace the entire bottom three-quarters of the herd with offspring from the top quarter,” said Prof Coffey.

Although they haven’t reached anything like their goal yet, milk yield is improving and is sitting at just under 6000 litres at Dourie from circa 1t of concentrate.

“Size does matter, where as breed does not. Hybrid genetics will drive us forward at pace, said Mr Christie who encouraged producers to increase selection intensity as far as they dare and only breed from animals that really make a difference.

The next step as part of the project is to understand how genetics influences methane production.

Professor Coffey added: “One of the reasons I understand that a lot of people don’t crossbreed is because they can’t get genomic breeding values. With this project and the SNP key now established, it is feasible for other farmers who are already cross breeding to genotype their animals and get genomic predictions.

“Other farmers that are not cross-breeding may be encouraged to do so because they know they can get genomic breeding values through this route.”