As housed dairy systems become more popular, CAFRE staff are advising farmers to reconsider the financial benefits of sticking to the traditional grazing.

Michael Verner, a dairying development adviser based at the College of Agriculture, Food and Rural Enterprise (CAFRE) said: “This summer presents us all with an opportunity to get back to basics, graze cows well and drive down our costs of production.

Many herds are now out full-time and typical performance is that daily milk yield is 27.8L/cow/day, feed rate is 0.2kg/L, meal feed is 5.6kg/cow/day whilst the milk from forage yield is 15.5L/cow/day.

“The figures for rolling performance of herds show that the annual milk yield is 7,974L/cow/year and the feed rate is 0.26kg/L. This comes from a meal feed of 2.07t/cow/year and milk from forage is 3,360L/cow/year.

“Many factors have to be considered when grazing cows, but two of the biggest challenges are:

  • Achieving the highest possible grazing intakes while at the same time maintaining grass quality throughout the grazing season; and
  • Setting realistic performance levels (M+) that can be achieved before concentrate supplementation.”


The aim should be to offer cows upright, dense, palatable swards of grass on a consistent basis. You will be constantly balancing grazing pressure and sward growth throughout the grazing season.

Michael Verner added: “Ideally you will be turning cows into pre-grazing covers of 3,000 – 3,200kg of DM/ha to maximise intake/bite and be taking cows out at covers of 1,800kg of DM/ha (6-8cm).

“If cows are offered this grass then intakes of 16-17kg of DM/head/day can be achieved and this has the potential to support milk levels of 20 litres.

To ensure cows are allocated the correct amount of grass each day walking and measuring grass covers on the grazing area on a weekly basis is very important.

“This enables any grass surplus or shortfall to be identified and action to be taken in a timely manner. As a rule of thumb, a herd of 120 cows will require 3-3.5ac/day.

“Not only is grass quality and intake important, so too is water availability. Generally, a cow requires 5L of water for every litre of milk produced, with approximately half of the herd’s daily water requirement being consumed after each milking.

“This is why it is important to provide adequate trough capacity and water flow rates to meet your herd’s demand,” Verner continued.

Quality of grass

In order to supplement your cows accurately you not only need to know how much grass they are eating on a daily basis but you also need to assess the quality of the grass they are getting.

Sometimes both grass intakes and quality are overestimated, with the result that cows are underfed concentrates, leading to a drop in milk yield and, if left unchecked, body condition.

Michael said: “Very often grass will be blamed. In the South Co. Down area for example, grassland farmers are saying that grass today is capable of maintaining the cow and producing at least 18L of milk (some will aim higher) and are supplementing cows at a feed rate of 0.45kg/L for every litre over this.

“Most will be expecting that heifers will produce 2-3L less from grass than mature cows. These levels of performance assume both good grass intakes and quality. As the season progresses and grass quality declines these M+ figures will be scaled back.

What about the cost?

“In the current climate, can you afford not to be making use of the best quality feed on your farm which also is the cheapest forage on your farm?

A herd of 120 cows at grass full-time, could possibly be saving £120-£140/day in diet costs compared to a similarly sized housed herd. The question is, can you afford to miss this opportunity in this current difficult time?”