Many dairy farmers remain baffled about buffer feeding – what to feed, why and when – and how to balance rations at grass throughout the grazing season while also making the most of the grass available.

According to James Bendle, technical feed advisor at Davidson's Animal Feeds, the reasons for introducing a buffer feed vary from farm to farm but most commonly are either one or a combination of : - High percentage of freshly calved cows in the herd - Pressure on the grazing platform from herd size - Poor grass growth and/or quality - Weather conditions – too much or too little rain!

- Depression of milk solids - High average daily milk yields He added that understanding what pressures a herd is under and when those pressures are likely to begin to impact performance will influence how supplementary feeding should be introduced and managed. It may be that an additional allocation provided through in-parlour feeders will help bridge any gaps, or a combination of this and a buffer ration.

When?

Mr Bendle added: "In simple terms, buffer feeding should be introduced when any of the above considerations are encountered, irrelevant of what time in the season it is.

"The introduction must also be timely. Well managed grazed grass is still the most cost-effective feed available to dairy producers and any buffer ration must not replace grass in the diet, but act as a complementary addition to the ration. Fixed costs on farm remain the same even when milk at grass declines, so a buffer can be a worthy investment to maintain or improve performance and dilute fixed costs.

"Key to grass utilisation is understanding how much grass you have available and the quality of the grass on hand," he said.

He also questioned how many farms do not make use of silage analysis throughout a typical winter? Or don’t sit down with their advisor to formulate winter rations?

Furthermore, he said farmers should also be analysing grass in the summer and measuring grass growth as analysing grass quality will help balance rations.

"It is more difficult to balance rations, maintain or improve production and importantly identify when buffer feeding may be necessary if some of this information is unknown.

"To add to that, it is widely accepted that the majority of cows will struggle to achieve intakes higher than 20kgDM from grass alone. If the weather takes a turn, or dry matter levels in the sward decline, high production cows can physically struggle to consume enough grass to maintain production."

Mr Bendle highlighted the example below which highlights a number of scenarios for a typical 35kg cow and how grass quality and DM levels can impact performance, showing where the requirement for buffer feeding lies.

• 35kg cow • 11.5ME grass • 13ME compound • 6kg compound in parlour Scenario 1: As above, grass and compound Scenario 2: Reduction in only grass quality to 10.5ME – poorer growing conditions Scenario 3: Reduction in only grass DM from 18% to 14% – wet weather, reduced grass availability Scenario 4: Reduction in both grass quality 10.5ME) and DM (14%) – poor, wet growing season In periods of wet and dry weather, grass growth rates, quality and DM levels can fluctuate quickly, and when all of these factors align, the options are limited; look at cost effective buffer feeding or take a performance hit.

In the Scenario 4 example, which could occur for both periods of wet or dry weather, restricted grazing platform or restricted time at grass, the energy deficit could be in the region of 55MJ, or around 10kg milk yield, highlighting the need to monitor grass conditions and act quickly to maintain performance.

Other factors should also be considered, including protein levels, mineral profiles, especially magnesium, as well as fibre levels within the diet to provide an overall balanced ration.

What?

The question of what to feed in a buffer ration is largely driven by what feedstuffs are available on farm and must be appetising and complementary to grazed grass, Mr Bendle said.

"Timing is also important, as the buffer should not turn cows into lazy grazers, so is often fed pre-milking to ensure cows have an appetite when turned back out to grass."

A buffer also acts as a good mineral carrier for any ration and can help with energy density issues particularly for higher yielding cows.

"If considering a buffer ration this season, understand what issues you are trying to address, what grass is available, the quality of that grass and tailor a specific plan for your farm. Don’t leave it too late to introduce the buffer ration and ensure it is appetising and complementary to what you are trying to achieve," he concluded.

Buffer feeds: • Wholecrop maize • Wholecrop wheat/barley • Straw • Bale/pit silage • Molasses • Bespoke meals/blends Buffer ration – Scenario 4: 55MJ deficit, example buffer: • 6kg bale silage • 1kg straw • 3kg bespoke meal