Dairy cows eating silage© Tim Scrivener

West Sussex dairy farmer Tim Gue credits genomics with increasing milk yields while simultaneously lifting fertility of his 420 pedigree Holstein herd.

Mr Gue was one of the early adopters of the technology.

He started testing a select number of animals from his Huddlestone Holstein herd, Steyning in 2010, shortly after the technology’s release.

After being impressed at how accurate the technology was, he began screening all heifer calves in the autumn of 2011 as a tool for breeding herd replacements.

See also: UK dairy farms benefiting from using genomics

“This better selection intensity coupled with the use of genomic sires has given us the huge genetic gains made in the past few years.”

In fact, Mr Gue says this year alone genomics has added £5,480 to their genomic profitable lifetime index (GPLI) against a cost of £4,000 (£30 a head), without taking into account the cost benefit afforded to future generations.

“The £5,480 is the difference in PLI between the animals we selected to breed replacements from this year, cows and heifers, selected by top genomic PLI as opposed to the animals we would have selected if we looked at the data with no genomic information.”

He says testing young heifers allows him to fast-track genetic gain by providing him with information about an animal’s genetic merit before her first service at 12-14 months.

“What we are really looking for is the bottom 25%.

“Finding these is where the profit is in this technology because we don’t want to make the mistake of breeding them to breed our replacements.

“Not breeding from the worst is where the financial gains are made,” Mr Gue told delegates at the British Cattle Breeders Conference last week (23-25 January).

What we are really looking for is the bottom 25%. Finding these is where the profit is in this technology because we don’t want to make the mistake of breeding them to breed our replacements Tim Gue, dairy farmer

To date 85% of females from the herd have been tested.

Mr Gue selects heifers to test based on four key transmitting traits: PLI, fertility, lifespan and combined fat and protein.

The best 80 heifers are served to sexed semen to further reduce the interval generation – age of parents at the birth of their offspring – with conception rates hitting 70%.

The cut off for genomic PLI is £300 and any heifers under this are mated to beef.

Fertility

In the past five years, Mr Gue says genomics has helped him lift milk yields while improving fertility at the same time.

One-point predicted transmitting ability (PTA) for fertility is worth a whole day off their calving index to his herd, he says.

This has seen calving interval lower significantly from 410 days in 2010 to 390 for older cows and under 380 for younger animals.

Yet cows are still producing an exceptional amount of milk, he says, with older animals averaging 11,000 litres/year and heifers predicted to produce 12,000 litres as mature animals

This has risen by 1,000 litres a cow since 2011 on average and Mr Gue predicts this trend will continue and expects yields to increase by a further 500 litres a cow a year over the next three years if genomic predictions are realised.

What is genomics?

Genomics gives an early and more accurate prediction of a young sire’s genetic potential than has been possible in the past, allowing bulls to be used at a much younger age, rather than waiting for them to be progeny tested.

It is calculated by extracting DNA from an animal’s hair follicle, for example.