Dairy farmers cannot afford not to feed protected facts in ration – Volac Wilmar trials shows 40% ROI

These figures, based on spot milk prices of 40p per litre, come from a performance-to-financial correlation model developed by Volac Wilmar feed ingredients that weighs current feed prices and milk contracts against research data on cow performance when feeding rumen-protected fat supplements in either calcium salt or high-C16:0 form.

As a macronutrient, fat is energy dense with 500g of a fat supplement like Megalac increasing energy density by 0.5 MJ/kg DM. It is also a ‘safe’ ingredient in the rumen as it isn’t fermented like cereals so supplies energy without increasing risk of acidosis. In rumen-protected form, fat doesn’t interfere with fibre digestion which otherwise reduces feed efficiency and can lead to milk fat depression.

“Energy density benefits are seen particularly in early lactation rations as milk yield increases rapidly post-calving while dry matter and energy intakes rise at a slower rate," said the company's global technical manager, Dr Richard Kirkland. "This leads to an ‘energy gap’ in early lactation when cows mobilise body fat and lose condition to supply the energy shortfall.

"There is a clear correlation between loss of body condition through early lactation and conception rate to first service – with research indicating conception rate decreases 10% for every 0.5-unit loss in body condition when measured on a five-point scale.”

Established UK research reported 9.4 fewer days open when cows were supplemented with Megalac compared to a non-fat supplemented ration, and a numerical 19-day reduction was recorded in a further study from the University of Edinburgh. Costs per additional day open vary but typically range from around £2.50 to upwards of £5 per day depending on a range of cost elements.

Looking at specific fatty acid profiles, research from Dr Adam Lock’s group at Michigan State University, USA (MSU), has found that individual fatty acids partition nutrients to different areas of cow performance throughout the lactation cycle.

Oleic (C18:1) acid helps partition nutrients toward body fat stores, reducing body condition loss in the critical early lactation period while also improving production. C18:1 also improves total fat digestibility and can enhance fertility through improved egg and embryo development. For improving milk fat production and yield, C16:0 has been found very beneficial, however, research shows increased production in early lactation can come at the expense of additional body condition and weight loss so can be risky in early lactation.

Key inputs, including expected milk yield, milk composition and feed efficiency, come from two recent meta-analyses led by Research Associate Dr José dos Santos Neto in Dr Lock’s group looking at the effects that fatty acids supplied in either calcium salt or high-C16:0 form have on nutrient digestibility and production responses of lactating dairy cows.

High-C16:0 supplements deliver high concentrations of the milk fat-boosting palmitic acid (C16:0), says Dr dos Santos Neto. In the meta-analysis, Dr dos Santos Neto analysed 32 different research publications with fat supplements containing a minimum 80% of C16:0 fatty acids. These fat supplements were found to increase milk yield by 1.60kg per cow per day, milk fat by 0.18% and protein by 0.02%, with no change in dry matter intake. For a typical UK dairy farm this means an increase of 0.10 FPCM/kg DMI (fat and protein corrected milk), resulting in improved feed efficiency.

Calcium salts of fatty acids are commonly used in the dairy industry. These products combine fatty acids with calcium ions producing a rumen-insoluble supplement, with Megalac containing a fatty acid composition of ~48% C16:0 and ~36% cis-9 C18:1. In this meta-analysis, Dr dos Santos Neto analysed 33 studies with a maximum calcium salt inclusion rate of 3% of ration dry matter. He found an increase in milk yield of 1.53kg per cow per day and increased feed efficiency. For a typical UK dairy farm the result translates to an increase of 0.9 FPCM/kg DMI.

Using milk payout data from AHDB, the model assumes manufacturing contracts pay an extra 10.4% for every 1% increase in butterfat and 13.3% for every 1% increase in protein. In liquid contracts, an additional 5.1% is awarded for every 1% of butterfat. This is based off a set milk spot price of 40ppl.

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Along with taking into account outlined findings from the MSU meta-analyses, the model conservatively uses 10 days of reduction in calving interval and cost of open days at £3/cow/open day. This is weighed against total costs of the lactation diet, with feed fat supplements at current market prices of £1400 per tonne of calcium salts and £1600 per tonne of high-C16:0.

“Mega-Fat 88, which is a high-C16:0 fat supplement, had a 40% return on investment when fed on a manufacturing contract and a 20% return on investment on a liquid contract. If milk prices are bumped to 50ppl on a manufacturing contract, there would then be a 72% return on investment when feeding a high-C16:0 supplement,” explains Mr Fransen.

When on a manufacturing contract, Megalac, a calcium salt supplement, had a 30% return on investment, which went up to 50% with a milk price increase to 50ppl. However, the increase in milk yield and feed efficiency, if combined with a fertility improvement, resulted in a 42% return on investment on the liquid contract at 40ppl.

According to the model, at a base of 40ppl, feeding fat supplements remains cost effective below £1990 per tonne for calcium salts and below £2250 per tonne for high-C16:0.