Grazing and how to support it

Grazing is about to increase as the spring approaches, making it time to think about how we use supplementary feed to make the most of grazed grass.

Grazing and supplements - ways to feed your cattleWith grass the cheapest feed available to cows, any kind of supplementation must complement, not restrict, grazing – balancing limitations in grass to improve on farm margins.

To maintain milk yield and constituent quality throughout the season, and to support low grazing supply, buffer feeding must be used.

Buffer feeds need to be formulated to balance high degradable protein, high oil and seasonal variations found in grazed grass, using forages such as maize and whole-crop silage.

Cows graze most at dawn, dusk and in the hour directly after each milking, so this is the time to be turning them out to make the most of grass. You would avoid buffer feeding at these times.

Opting for buffering before afternoon milking often works best. Buffer feeding is best used when it supports grazing, not replaces it, so feed a measured, restricted amount of buffer to fill the gap between supply and demand. This promotes cows’ appetites to graze covers down low, maintaining grass quality for the season.

If it gets to the point where cows only go out for a walk and a lie down, grass utilisation is very poor and you may as well shut them in full time.

Grazing management

Where grazing is managed well, Dry Matter Intakes (DMI) of grazed grass should exceed 14kg/day. To achieve this and maintain good grass utilisation, no buffer is needed, leaving all supplementary feeding to concentrates.

Walking through good grazing landCorrect concentrate supplementation under these conditions can improve grass utilisation and maintain milk constituent quality – an ever more important factor on many milk contracts.

Concentrate feeding is an opportunity to be more than just the DMI gap between grass supply and herd demand. Although only a few kilos of dry matter per day, this is a chance to balance the pitfalls in grazed grass, which varies as the grazing season progresses. Early season grass is higher in fibre and can be lower in rapidly fermentable carbohydrates (RFC), so supplementary energy and protein is needed.

Conversely, fresh growth in May is low in fibre, low in dry matter but high in RFC and rumen degradable protein. This presents a need for more supplementary digestible fibre, such as Sugar Beet Pulp or Nutritionally Improved Straw (NIS) and lower protein supplementation.

Supplementation can be better managed when grass is routinely measured. Analysing grass measurements not only provides seasonal production information, making it easier to asses grass quality, but also means you can make more informed decisions to best match grass supply with demand from your herd. This means you can make better decisions around buffer supply and when best to increase access to grazing.

Here are the key action points to best manage supplementary feeding at grass:

  • Measure grass growth to help inform decisions
  • Plan grazing to predict supply of grazing against demand from the start of the season
  • Set up grazing platform with good access, paddocks and water supply to best utilise grass
  • Have buffer feed formulated to best balance grazed grass on farm
  • Feed a measured amount of buffer, fed before afternoon milking to best utilise grazing
  • Choose supplementary concentrates that effectively balance grass at its current state, which will vary as the season progresses

Putting thought into how best to plan and manage your grazing supplementation now will reap rewards as the grazing season progresses, to best capture a good margin for milk sold over the grazing season.

Speak to a member of the Wynnstay Dairy Technical Services team to find out how we could help you improve margin over litres sold and maintain production over the coming months.

Mark Price
Dairy Specialist

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