Genetics

Weekly genetics review: Net feed efficiency within a breeding herd

Genetics editor Alastair Rayner, 07/04/2020

 

IN LAST week’s Genetics Review, the focus was on Net Feed Efficiency as a trait focussed on production opportunities and the particular challenges associated with measurement in large commercial feedlots.

As some of the reader feedback from last week’s column to Beef Central suggested – in particular from well-known breeder Jonathon Wright of Blue E in Cowra – the tools for selection on the trait are available within the broader industry.

This view reflects the comments last week of Tasmanian reader David Raff, who also pointed towards the significant developments in technologies including genomics, which can assist breeders in making greater progress in selection for more efficient animals.

Lack of phenotypic data from the field

However, is improving Net Feed Intake across the broader industry as straightforward as using new genomic technologies?

David Johnston

This week noted industry researchers Drs David Johnston and Brad Walmsley of the Animal Genetics Breeding Unit (AGBU) in Armidale offer some insights into the challenges associated with understanding and identifying superior animals.

Dr Johnston describes the greatest challenge in progress as lying in the lack of phenotypic data from the field, regarding cow intake on pasture.

“Basically, this is a really challenging and difficult issue, and without sufficient data at a pasture level, its incredibly difficult to generate information to identify animals with superior traits,” Dr Johnston said.

While genomics is a powerful tool, as he points put, “it is but a part of the picture.  We could pull tail hair samples until our fingers, bleed, but without the phenotypic measurements, we can never achieve accuracy for NFI around our predictions.”

Data collection on cow intake in paddock environments is incredibly complicated, and is the subject of ongoing research work at Armidale and elsewhere across the country. However, intake isn’t a straightforward activity to measure.

Dr Walmsley says the correlation between the pasture sward, the amount of pasture and other factors all complicate the ability to get a true measurement of intake.

“When we talk about efficiency, in simple terms, we have to remember that efficiency is the result of output divided by input. And if input can’t be measured, then it’s impossible to have an accurate description of efficiency.”

So where are the opportunities to make improvements within breeding herds?  One of the issues Dr Johnston identifies is that NFI is really a trait associated with cost, rather than profit.

“So, people often don’t really factor it into their on-farm data collection. It’s much easier for many people to measure and describe the traits of profit – things like growth rate, fatness, calving ease and so on.  Because it’s harder to see, people don’t really think so much about NFI.”

Dr Walmsley also agreed with this point. “We don’t get as much data as we probably really need. Areas such as Mature Cow Weight tend to have lower levels of recording, and therefore it’s hard to make change.”

Providing incentive

The release of Breed Object 6 may offer producers some incentive to start focussing on these areas of measurement, and in particular, on the actual cost to feed cows across an annual cycle.

Brad Walmsley

One of the key inputs to the evaluation of the new Indexes derived from the current version of Breed Object is to have a greater price differential in feed costs. This is very marked between southern and northern production environments.

Dr Walmsley cited several producers who have commented that the practical difference in cost of feed between Victoria and Queensland is a doubling of feed cost, the further north they have operated in.

“What we are seeing,” Dr Walmsley said, “is greater discussion on the cost of maintaining and operating cows in a more variable climate. The impact of cow weight is much more significant in terms of return to producers over the annual cycle than turning steers off five or ten days earlier.”

Mature cow weights

From a practical perspective, both Dave Johnston and Brad Walmsley stressed that most producers were looking to maintain cows pretty much at the current levels of mature weight.

“They don’t want to shrink cows, but keep them where they are. The steers from these programs are still being targeted at the same carcase weights, so cows don’t need to get any bigger either,” Dr Walmsley said.

In terms of making changes across herds for NFI, progress is likely to be slow until more phenotypic data from herds is collected. Dr Johnston is positive that industry programs such as the Angus BIN and Hereford work will make a contribution over time.

However, until the broader industry starts to measure and record cows more accurately, the opportunity for progress is restricted.

One key option for many producers, particularly those with the experiences of consecutive severe drought years is to place greater pressure on their seedstock producers to do more measurement across all traits, including NFI.

“It’s easy just to focus on those that are profitable like weightgain. But a focus across all traits over successive years will start to generate the data we need to make better use of our genetic technologies,” Dr Johnston said.

 

Alastair Rayner

Alastair Rayner is the Principal of RaynerAg, an agricultural advisory service based in NSW.  He regularly attends bull sales to support client purchases and undertakes pre-sale selections and classifications.  He can be contacted here or through his website www.raynerag.com.au

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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