USING protected fat to complement silage is a proven way to maintain yield and fertility in dairy herds, but it can be a mistake to think that quality silage can replace it.

Trident Feeds' Golden Flake has been proving itself on dairy farms in the south and award-winning Northallerton-based dairy farmer, Geoff Spence – a former winner of the NMR/RABDF Gold Cup – includes a balanced C16/C18 rumen protected fat in the diet of his high yielding cows.

However, he recently attempted to cut back on the levels in the ration to reduce costs and rely more on the energy provided in his forage. “In our high yielding group, we’ve always included Golden Flake, a rumen protected fat with a high level of C18fatty acids, to help push yield while maintaining body condition,” said Mr Spence.

“This autumn, because of the high ME value of our first-cut grass silage, we halved the feed rate of Golden Flake from 300g/head/day to 150g/head/day,” he added.

“To our surprise, this decision resulted in an immediate drop in 1.5 l/cow/day, which equated to a loss across the group of 170 cows of £15,720 for the month. In addition, bulling activity was also reduced, and for that reason we quickly reinstated the higher feed rate to get the yield and fertility back on track.”

But, it's an easy one to follow, according to Bethany May, a nutrition specialist with Trident Feeds, who said this dramatic drop in yield was a result of the removal of additional energy in the form of C18 fatty acids, which act as an ‘energy balancer’.

“Energy is a key requirement of the modern dairy cow, as it drives milk production, health and fertility. To meet high yielding cow’s requirements, supplementary feeds are required," she said.

“This season, when forages are feeding well with high ME values, some producers are pulling back on the addition of supplementary energy sources in rations, and relying heavily on forages,” she added.

“However, this reduction in other key energy sources, such as fats and carbohydrates, means in some cases, early lactation energy requirements aren’t being met, and productivity is therefore negatively impacted.”

Miss May explains that cows naturally have a suppressed appetite and intake at the start of lactation, and if energy requirements are not met at this point, they are likely to experience negative energy balance (NEB).

“In response to this, cows will mobilise body fat reserves to help maintain the energy levels required for milk production, and this has been shown to have a knock-on effect on fertility,” she says.

“Traditionally the use of supplementary fats in fresh cow rations has been questioned, especially when forages are high in energy. However, new research supports the use of protected fats, highlighting the importance of choosing the right types of fat to avoid depressed intakes.

“Producers should, therefore, look to include rumen protected fats, that are high in C16 and C18 fatty acids alongside good quality forages to boost energy density and minimise NEB.’’

Own brand protected fats from MVF

A FIRST own-brand protected fat has been launched by Mole Valley Farmers for dairy rations.

The product, Mole Mega-Fat Multi has been designed in partnership with dairy fats specialist, Dr Adam Lock, of Michigan State University and Dr John Newbold, from Volac.

It includes a combination of C16:0 and C18:1 fatty acids which, according to MVF's head of nutrition, Dr Chris Bartram, 'has the optimum combination of these specific fats drives yields, support cow body condition and drives milk fat.'

It is being seen as a simple and cost effective alternative for farmers who traditionally feed C16 and a protected fat separately. Alternatively, it could offer a new route for farmers looking to increase milk fat yield and maintain body condition. The product is typically fed at 400-600g per cow per day.

Dr Bartram adds: “All farmers should carefully consider whether feeding fat is the best strategy for their farm and should ensure it is incorporated into a well balanced diet in order to get the maximum return on investment.”