Soaring production and input costs have put more pressure than ever on dairy producers striving to control feed costs, with many looking to extend the grazing season and make more use of forage. However, grass is not a complete feed on its own.

In a recent survey conducted by KW Feeds, 64% of respondents stated they aimed to use less fertiliser this year while at the same time, 68% are expecting to utilise the same amount of forage, and 62% are hoping to take advantage of more grazing this year.

According to Charlotte Ward, KW Feeds ruminant technical manager, extending grazing periods introduces a different series of challenges, not least estimating grass nutritional value and supply, to maintain cow performance.

“Too often the desire to exploit low-cost grass leads to over-estimates of its feed value and dry matter intake, leading to reduced performance, especially in early lactation/higher yielding cows, as well as poorer health and fertility,” she said.

“It is important to be realistic about what can be achieved from grazed grass alone. A balanced buffer ration of suitable quality and quantity is critical to cow health and productivity,” continues Ms Ward.

“As the season progresses, quality and growth rate decline. Now we are in mid-season, this needs to be considered, and we need to be flexible with the buffer feed,” she adds.

The base of the buffer ration should be good quality silage, with maize and/or wholecrop cereal ideal to include, alongside starch to help utilise the high levels of rumen protein in fresh grass. Including 0.5-1.0kg ‘muzzle width’ chopped straw helps provide the structural fibre needed for good rumen function.

These forages then need to be accompanied by carefully selected concentrate feeds to balance protein, digestible fibre and starch.

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Protein in grass is largely rumen degradable, as such, any protein supplied in the buffer feed should be high quality, with a good level of digestible undegraded protein (DUP).

She added that the priority with protein is to meet cow requirements without oversupplying RDP so prevalent in grass. The British rapeseed expeller NovaPro fits the bill perfectly, with its higher DUP:RDP ratio in comparison to soya, allowing for improved protein utilisation.

It is important to remain flexible, adjusting buffer volumes daily if necessary to match changing grass availability and intakes.

“Offer too little and health and performance will be compromised, too much and the grass will not be utilised. Adjust the buffer ration according to available grass throughout the season,” she says.

“There’s a lot to get right if you want to make the most of low-cost grazed grass,” Ms Ward concludes. “If you do get it right, however, the benefits, both in terms of summer yields and fertility, and the foundation you set for winter milk production, will more than offset the additional investment in extra feeds.”