The environmental impact of farming is a hot topic at the moment and one of the main bugbears is the use of soya in animal feed, which is becoming a growing concern for consumers and retailers. Lynsey Clark reports.
The link between soya production and deforestation in countries such as Argentina and Brazil, has been widely documented, and with much of the soya used in the UK coming from those countries, pressure has been mounting for change.
Marks & Spencer recently announced that it has worked with its 44 British farmers producing M&S RSPCA Assured milk, to eliminate soya from the production of all of its milk – and it is thought likely that other retailers may follow suit.
With that in mind, Scotland’s Rural College, SRUC, has been trialling the use of alternative proteins in the dairy rations at its research farms in Dumfries and Galloway, and analysis so far shows little change in milk output or composition.
Farm manager, Hugh McClymont, explains: “We had not been specifically asked by our milk buyer to stop using soya, but with questions over the sustainability of soya and its association with large-scale deforestation in South America, we felt it was time to start looking into alternative protein sources. It is always beneficial to try and stay ahead of the game.
“We carry out a procurement exercise bi-annually, analysing the blends that we use in our rations and the prices that we are paying, so in the run up to this taking place in April, 2020, I asked our nutritionist, Lorna MacPherson, to work on some soya-free rations.”
Dr MacPherson, of Dairy Consultant with SAC Consulting, explains she formulated three feed blends, designed to have the same levels of protein, bypass protein and energy content as the soya-based blends. Soya hulls were also replaced with sugar beet pulp and a small amount of palm kernel, to maintain NDF levels.
She says: “We used protected rapemeal as the main alternative source of protein. It has been around for a while and is a viable alternative to soya that is easily available and is grown in the UK.”
There are different ways that rapemeal can become protected – it is treated by either a heat or chemical process to increase the bypass protein content, lowering its digestibility in the rumen and increasing the proportion that passes through the rumen intact for digestion in the small intestine. It also increases the availability of the essential amino acids lysine and methionine to the small intestine, which can benefit milk yield and milk protein content.
“It was not a difficult process to reformulate the blends – it was a matter of tweaking them until we got the balance right. Soya is around 48% protein, so we had to add extra protein into the blends to make up the difference.”
Three different blends were needed for the three milk producing units managed by Mr McClymont, at Crichton Royal, Acrehead and Barony – each home to herds of high yielding cows, mainly fed the same TMR all year round.
Crichton Royal is home to the Langhill Research herd, milking 185 high genetic merit and average genetic merit cows, producing an average 10,500 litres annually.
Acrehead has 180 commercially-bred cows, milking mainly through the parlour, with 50 on a robot and averaging 10,300 litres.
At SRUC’s Barony campus herd, 182 cows are milked twice a day, averaging 10,500 litres per cow annually.
The milk quality across the herds averages 4.4% butterfat and 3.45% protein and with their milk buyer Arla paying on milk composition, Mr McClymont explains it was critical that the milk quality did not drop throughout the process.
He says: “We started feeding the soya-free blends in April and at that time, with lockdown and the possibility of staff being absent due to having to isolate or from illness, we made the decision to switch from three times a day milking at eight-hour intervals, to twice a day, at 12-hour intervals.
“We have high yielding Holsteins, but also high quality milk and I did fear that the quality would suffer. Overall, there has been around a 5% drop in milk, which can most likely be put down to the change to twice daily milking, but, importantly, we have maintained the quality. That being the case, at the six-monthly review at the end of September, we decided to keep going with the soya-free rations, as we see no reason to change.”
Having the three different blends, allows flexibility on what blends are fed to different classes of stock, depending on protein levels in the forages and the amount of concentrates fed.
All forage is home-grown, with 5,000 tonnes of grass silage, 1,200 tonnes of wholecrop cereal silage and 1,800 tonnes of maize silage produced at Crichton. At Barony, the ration is based on grass silage and wholecrop silage, with 3,500 tonnes of grass silage and 1,200 tonnes of wholecrop cereal silage produced there.
One downside of a soya-free ration that Dr MacPherson points out, could be less space in the ration for your own forage or cereals.
She says: “Although both conventional and protected rapemeal are cheaper per tonne, farmers will have to feed more of these alternatives to reach the same protein content in the diet when replacing soya, which could leave less space for your own forage or cereals.
“And, it should be said, that not all soya is produced in an unsustainable way – soya can be sourced that is certified responsible, with zero-deforestation assurance.”
However, she says that this trial has proved that farmers should not be scared of removing soya. She says: “Hopefully this will give others the confidence that it can be done. The environmental impact of farming is at the forefront now and this is a small change that can reduce your carbon footprint.”
This was echoed by Mr McClymont, who has been based at Crichton for 40 years. He adds: “Not feeding soya will make a huge difference in our next carbon audit and will help demonstrate to our milk buyer where we were and where we are going – producing milk in a more sustainable way.
“We as an industry will have to be more environmentally focused in the future. The public perception is so important - we need to be transparent and to be able to defend our businesses and what we are doing.
“Just because you have always done something, does not make it right. I really believe that if we do not evolve, we will be left behind.”