Tuesday 28 July 2020Farmers Guardian - Closing the loop with co-products

Written by Aly Balsom published by the Farmers Guardian 

Co-products have an increasingly vital role to play in safeguarding the sustainability of global agriculture and our planet, says Duynie Feed.

Duynie Feed believes co-products should be pushed centre stage as the farming industry looks to further drive improvements in its environmental and sustainability credentials.

As we see ourselves in the midst of a ‘climate emergency,’ everybody has a responsibility to consider how they can maximise resource efficiencies, says Duynie Feed sustainability manager Corine Croft.

She believes co-products, which are produced as a ‘waste’ product of the food, beverage and biofuel industries, can do just that; all while helping farmers to run productive and profitable businesses.

The term ‘co-product’ is used to differentiate safe, wholesome materials from wastes.

By feeding livestock co-products, such as brewers grains or potato peelings (see table), farmers are helping to ‘close the loop’ in food production (see graphic, below).

For example, a product grown on an arable farm is processed by the food industry.

This process produces a co-product which is then fed to livestock to produce meat or milk.

The manure from the livestock can then be applied to arable land as part of a ‘virtuous circle’.

Corine says: “We need to go from a linear economy, where we discard food, to a closed loop system.” With humans eating more and more processed foods, co-products are likely to become increasingly available.

They have a substantially lower carbon footprint (see chart) than compound feeds and could also help farmers lower their environmental impact in-line with growing pressure from supermarkets and processors.

Duynie Feed managing director Phil Sparks believes more farmers should consider feeding co-products, particularly if they can source them locally.

He says: “I would like our farming industry to have more acceptance that these factory-based co-products are valuable.” Phil believes there is a co-product to suit most farm requirements, with most also proving cost effective.

However he stresses the importance of understanding a co-product’s ‘relative feed value’.

Duynie Feed will calculate this by comparing a product to soya and rape meal for a protein feed and barley and wheat for an energy feed product.

Specific choice will also depend on which forages are already available on-farm and what the farm is trying to achieve.

Phil Sparks

Phil Sparks


Duynie Feed nutritionists can advise on the best option for an individual farm situation.

For example, if a farmer is looking for a protein source, they could consider pot ale syrup, distillers grains, brewers grains or rapemeal.

Location and the relative feed value will determine which specific co-product is most cost-effective.

For example, pot ale syrup tends to be better value in Scotland because of the locality to the whisky industry, but it is less cost effective in England due to distribution cost.

Brewers grains are generally available nationwide as there are breweries in a variety of locations.

Potato and vegetables are grown nationally, however the major processing sites tend to be in the east of the UK.

"We need to go from a linear economy, where we discard food, to a closed loop system"

Corine Croft

The fact food processors have set standards of production means co-products are very consistent compared to home-grown feeds.

They can also be fed as part of a moist blend, which brings additional benefits to ration balance and palatability.

For example, 12-14 per cent dry matter potatoes peelings, which Phil describes as ‘barley on speed’, can be blended with wheat feed syrups or brewers grains to create a balanced feed.

Some co-products do require specific storage.

For example, wheat syrups or potato products would need to be stored in silos.

Duynie feed can assist with storage solutions, for example its liquid silos service.

Citrus pulp or brewers grains, for example, can be layered through the clamp with grass or maize silage to enhance the overall feed value and volume.

Other innovative uses of co-products include citrus pulp or liquid potato products being used to replace plastic sheeting on silage clamps.

Phil says this capping effectively means you ‘eat the covering’, while the product is heavy enough to replace any additional weight on top of the clamp.

Benefits of co-products

Benefits of co-products

  • Reduced carbon footprint (see bar charts, above):

Co-products have roughly half the carbon footprint of compound feeds. This is because most of the carbon footprint is allocated to the primary product (for example, producing a potato chip)

  • Locality:

At Duynie Feed, most of the co-products are sold locally to ‘close the regional loop’ and reduce carbon footprint

  • Sustainability:

Feeding these products to livestock prevents co-products from food production from going to waste, while producing a nutritious product in the form of meat and milk and ‘closing the loop’

  • Profitability:

Co-products are generally cost-effective and consistent and can be incorporated into a well-balanced ration to boost performance and optimise returns

  • Performance:

Co-products can help maximise the use of homegrown forage by aiding palatability and cohesion between various aspects of the ration (reducing sorting)

Long-term goals

Long-term goals

Ultimately, Corine believes using co-products as part of a wider, integrated system will help farmers achieve their business goals.

She says: “Every farmer has a strategy to create a long-term business to hand over to their daughter or son.

And with the demands of society and processors, collaboration between arable and livestock farmers is about creating a longterm sustainable system.” Corine also believes this type of system highlights the huge role farmers play in sustainability and goes against campaigns to stop people eating meat.

She says: “Farmers are an indispensable part of the food chain.

Farm animals have an important role in closing that loop.

If we did not have livestock any more, what would we do with the co-products like brewers grains? Farmers should get more acknowledgement of what they do.”

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