Genomics might not be the easiest topic to comprehend in any livestock system, but the rewards from genomically testing cattle and understanding the results can be hugely beneficial both in terms of herd health and end profit margins.

Tom Oesch of Swiss Lane Farms, Michigan, was one of the earliest dairy farmers to start genomic testing in 2012 and since then, he has seen significant benefits as a result of genetic improvements and management alterations.

In all some 2200 Holstein cows have been genomically tested using Clarifide® Plus from Zoetis, which over the years have witnessed significant welfare and financial benefits with the spend on medicines alone reducing by almost half from $230 a cow a year to $130.

Such testing has also highlighted a difference in milk yield of 2864 litres between animals in the top 25% and bottom 25%.

Mr Oesch said: “The animals performed exactly as the genomic test predicted, despite the same management conditions, and the animals which showed increased health issues were the ones that the genomic test indicated would.”

His first genomic test on a batch of 500 heifers in 2012 highlighted poorly managed breeding decisions on the heifers.

“We had 48 different bulls in the heifer tank at the start. We got rid of all the straws of semen and now never have any more than 21 units of semen on the dairy. We have also increased the number of young genomic bulls we are using from 10% to 50%.”

In 2014, when the first genomic tested heifers were calving, Mr Oesch saw an increased number of stillbirths. He said: “We brought in vets and consultants and there was nothing from a management point of view they could identify. However, when we looked at Daughter Stillbirth (DSB) rate on the genomic prediction every heifer with a dead calf had a high Daughter Stillbirth rate over 9. That is when we decided to genomic test the rest of the herd.”

Dairy Wellness ProfitTM; Clarifide Plus includes bespoke Dairy Wellness Profit Index (DWP). DWP is based on lifetime productivity and health, giving an overall view as to how profitable a cow will be. Standard genomic testing allows for a prediction on an animal’s potential, Clarifide Plus gives a prediction on the ability of that animal to remain healthy and fulfil it’s potential.

Cow health

By highlighting cows more prone to metritis, Swiss Lane Farms have seen a 77% reduction in prevalence from the worst group to the best group. Tom has also tweaked heifer management, calving them slightly later at 24 months instead of 22 months.

He said: “In the top 25% of heifers we are only seeing 9% of metritis compared to 39% in the bottom 25%. In 2016 though the bottom 25% had a metritis rate 55%.”

Other health benefits include:

• Ketosis – 76% reduction in prevalence from the Worst to Best group

• Displaced abomasum – 92% reduction in prevalence from the Worst to Best group

• Mastitis – 76% reduction in prevalence from the Worst to Best group

• Lameness – 65% reduction in prevalence from the Worst to Best group

• Death loss – 44% reduction in prevalence from the Worst to Best group

• Respiratory disease – 32% reduction in prevalence from the Worst to Best group

• Scours – 38% reduction in prevalence from the Worst to Best group


Prior to using genomics, Mr Oesch selected heifer replacements using milk yield and Net Merit (US equivalent of £PLI). After commencing testing, DWP became his main index.

Any heifers with a DWP of $850 or above are served with sexed semen using a high DWP bull; any with a DWP lower than this will be used as embryo recipients and those with a poor DWP are bred to beef.

Tom added: “The biggest driver of profitability is Net Herd Replacement Cost, which is driven by cull rate, death loss and cull value.

"In the US, cull values are low and replacement rates have stayed at an average of $1750, so every dead cow cost $1750. The only thing that will drive your cull rate down is your heifer inventory. If you have an oversupply of heifers, you want to make sure you are selecting the best ones to breed from, and only genomics can tell you this.”

Dr Dave Armstrong from Zoetis says selecting for traits that have an emphasis on health, longevity and wellness, allows producers to make decisions earlier and invest in raising healthy animals.

“It’s about finding those invisible cows in the herd; the ones that never give you trouble and are productive.”

“Healthier cows stay in the herd longer and make a big difference in a herd’s profitability. Cows selected using Clarifide plus are 106% more profitable over a lifetime compared to selecting by parent average1 and those in the top 25% are on average, more than twice as likely to stay healthy as cows in the bottom 25%,” he said.

He added that it costs £2.31 a day or £1819.01 on average to rear a dairy heifer replacement with the payback taking until the middle of her second lactation. By predicting a heifer’s ability and health earlier, farmers can manage the upfront costs by only keeping the heifers they want, keeping them in the herd longer and significantly increase their overall rate of genetic gain.