Beef needs to up its game with genetics

The longer I live, the more I realise that no such thing exists. Sometimes it is 'faces for places' and it is noticeable that sales of our smaller Angus bulls into the dairy herd have increased in recent years.

Some Holstein heifers are now bulled at 13 months, so it is important that the bulls don’t get too heavy at maturity. The type required is different to that of the bulls for use in the suckler market, where growth and muscle are the driver.

Whatever the market, calving ease is a priority with figures to back it up.

I always enjoy meeting our clients and hearing their views. I was particularly intrigued by the opinions of two local dairy farmers, Bruce Renwick and Sandy Mitchell, both recognised for their ability and foresight, on the place of the genome in their breeding programmes.

One of them had compared the results of selecting his heifer replacements, in the way he had always done based on production records of their parents and had then compared it with selecting them using the recently available knowledge of their genome. Over the whole number, he found little difference which I suppose is as it should be.

The other breeder based his semen purchases on what genomic information was available. He kept a few promising bull calves out of his best cows by those AI sires and occasionally bought an outside bull.

The heifers by the latest AI sires were leaving those by his own and purchased bulls behind. I was amazed how fast this was happening.

The world of beef seems to be a long way behind – so, should we be concerned? We have in mitigation used the little bit of knowledge of the genome that we have in situations where a trait is controlled by a single gene, such as for coat colour or horns.

Many of the things we select for are affected by many, maybe thousands of genes which are as yet undetected. Furthermore, unlike dairy breeds, we can select equally from both sexes.

We know most of what we need to know when a beast is weighed and scanned at 400 days. Long before then, an experienced person has a rough idea of a calf’s potential by visual assessment.

Genomic influence may accelerate progress in selecting future seedstock but, at present, with our limited knowledge, this would be no better than selecting on the weights and scans of around 12 offspring.

Some of the claims made by firms which analyse and interpret genomics require close examination. A decade ago, two of these internationally known companies offered to compare existing EBVs of 100 UK-born Aberdeen Angus animals with their genomic enhanced EBVs.

They wouldn’t do it blind and demanded prior knowledge of the traditional EBVs, which rather defeated the point of the exercise. Things have moved on considerably in 10 years, but not as much in the UK as in North America because of the small sample of our animals available to test.

We use American Angus genetics in our herds for various reasons. The first reason is the huge choice, compared to the UK.

Secondly, their cattle are bred in a much tougher environment than ours. Exposure to generations of droughts, blizzards and extreme temperature variation has produced cattle that find Scotland’s green grass a luxury.

The third reason is that their animals have accurate information on traits which are not obvious to the naked eye, such as feed conversion, meat eating quality and conception in maiden heifers.

A powerful genomic tool available to the dairy industry, called the haplotype, is almost unknown in the world of beef. Haplotypes are chunks of associated DNA which are heritable.

Because of their rarity, they are difficult to identify. Sometimes they are damaging and become dominant in a bloodline before they are picked up.

Occasionally, a sire which carried a detrimental haplotype, which was impossible to detect until recently, has become popular because of his other merits. The detrimental haplotype quickly became a problem but, by then, the bulls influence in the breed made it impossible to cull his descendants.

Pawnee Farm Arlinda Chief was born in 1962. His daughters were exceptional milkers and now 14% of the entire Holstein breed in America carry his DNA. Chief also carried a haplotype which negatively affected fertility.

This meant that when his bloodlines came together, 25% of the embryos died early in pregnancy. The reason for this reduction in fertility was only discovered recently with our increased knowledge if the genome.

It was estimated that Chief had been responsible for 500,000 embryonic deaths at a cost of $420m to the dairy industry. His genetics have, at the same time, resulted in $30bn in increased production.

Obviously, haplotypes when discovered must be managed by avoiding carrier matings, rather than by trying to eliminate them.

Soon, all being well, we may have a new tool in the kitbag, gene editing. No-one could argue with the huge benefit gene editing has been in the human context by removing faulty genes which cause hereditary afflictions such as muscular dystrophy and Huntington’s disease.

The advantages worldwide of improving crop production by inserting genes for drought resistance and herbicide tolerance are well proven. The potential benefits to the livestock world are a little more nebulous.

Polling horned breeds by altering a single gene without any detrimental effect on the breed's existing qualities is an obvious and easy first step.

Controlling genes which increase disease resistance and lower the need for antibiotics are like haplotypes, despite some claims, beyond present technology because of the many genes involved and the possibility of undesirable side effects.

The biggest challenge to gene editing is adverse public perception due to the confusion with genetic modification which replaces a gene with one from a different species. For instance, a recent poll found that only 57% of farmers themselves were in favour.

To have any hope of widespread public support proponents of gene editing must stress the benefits to animal health and welfare and also the reduction in the effect of livestock on climate change.