DNA and efficiency: ‘We want higher outputs from lower inputs’

“There is a worldwide increasing demand for meat, milk and eggs and this is driving the value of these animal-derived products. This is only going increase with the population expected to hit approximately nine billion by 2050.” efficiency

This was the opening message from Teagasc’s Dr. Paul Cormican at the recent DNA Tell Tales conference in Tallaght IT.

Paul outlined what they are trying to achieve from an agricultural point of view. This, he said, is to derive more from less.

There are two principle ways in which we can increase farm output to meet this demand. The first one is by implementing better farm practises.

However, he highlighted a problem with this strategy. He explained that even if a farmer uses a different method one year, there is no guarantee they won’t go back to their old ways the following year. Therefore, the effect is lost and there is no real impact.

He added: “The other way is by animal breeding and genetics. The effects of this are permanent. Animal breeding deals with the calculation of a genetic value – the estimated breeding value of livestock.

“This allows us to select from breeding animals with superior traits for growth rate; egg production; meat production; milk production; and even wool production.

But efficiency is the goal. This is what were are striving for. We want to get higher outputs from lower inputs.

“We’ve been doing this for thousands of years since we first domesticated animals. We select for traits that are under control of additive gene effects. cattle cattle

“Most of the economically important production traits – such as milk production, fat deposition and weight gain – are all under control of additive gene effects,” he explained

“From 1960 to 2007, we doubled the amount of milk we got from the average dairy cow. We got approximately 10t of milk per cow per year. But, as it turns out, this wasn’t such a good thing. We experienced fertility issues.

“In 2006/2007, we started reversing our heavy selection for milk production and we got an increase in the fertility rate and we are making good progress to date.”

Methane production

Paul also touched on ruminants and how they are really efficient at converting grass into a usable product.

He said: “While there are positives to this, there are also some negatives. During the breakdown, the animal produces a lot of methane.”

Paul also discussed the work carried out in Teagasc, Grange, Co. Meath. Here, they examined animals on a restricted diet and those on an ad-lib diet.

“We looked at animals on both of these diets and we got a very big divide. We saw that in restricted diets there are double the amount of species living in the rumen when compared to animals that are fed ad-lib.

“When an animal is restricted, the throughput of food is slowed down and the less efficient an animal is. Resources are turned away from growth and turned towards methane production.

“Feed efficient cows tend to have a far lower microbial diversity, so they are able to make better energy utilisation. Feed inefficient animals have a far more diverse population of microbes in their gut,” he explained.

Paul stated the role DNA sequencing has at both a research level and industry level, adding: “DNA sequencing is revolutionising our understanding of the rumen. Everyday we are identifying more and more potentially exploitable knowledge.

“Feed companies producing concentrates that promote rumen efficiency would be very attractive to farmers,” he concluded.