Good ventilation lifts performance

AHEAD of two Dairy Efficiency seminars being this month, FG meet another of the international speakers who will present his ideas on improving dairy businesses.

Many UK dairy herds are under-performing because of a lack of adequate building ventilation, according to John McFadzean of Canadian-based Sun North Systems.

He believes that controlling temperature, humidity and airflow in housing will become increasingly important, due to the growing trend towards larger dairy herds and 12-month housing periods.

Optimum temperature for housed cows is 3-4degsC, says Mr McFadzean. On most UK units, average temperatures are well above this level. When cows are kept in an environment that is too warm, their discomfort can adversely effect milk yield, longevity and fertility, as well as increasing the risk of respiratory diseases, he says.

Maintaining humidity at no more than 60-70 per cent is also important. Not only does it benefit cows, it also reduces the level of bacteria, many of which thrive in a warm, moist environment.

When considering air flow through the building, the aim should be to achieve around four complete changes of air per hour.

Improving environmental conditions for the herd is relatively straightforward, says Mr McFadzean.

The simplest and most effective method is to partially remove both long sides of the building and replace the wall with a single layer curtain that can be raised and lowered, either manually or using an automatic system. Curtains will also let light into the building, with potential savings on electricity bills, he says.

A combination of the two operating methods is another option for taller openings. The curtain can be split in half, with the top section running automatically and manual controls for the lower half. Electronic systems are more expensive to install so dual controls will help to keep costs down, says Mr McFadzean.


Part of any good ventilation system is an ‘exhaust’, to remove stale air and excess moisture. One suggestion is to use an insulated chimney flue about 60 square cm (24 inches) with a cap to keep out rainwater.

Mr McFadzean also recommends using roof insulation made from fibre glass or styrofoam, to keep housing cool in summer and warm in winter. This will minimise the risk of condensation.

Adding roof insulation moderates extremes of temperature, maintaining a more constant environment in the building.

Most existing units can be adapted at fairly low cost, although planning regulations may impose limitations in some parts of the country, he warns.

Producers with a concrete-walled building can remove the top 1.2m (four feet), to achieve greater air flow. On a greenfield site, ventilation should be given careful thought at the outset, with particular attention paid to the method of insulation.

“Good ventilation is an essential element of cow management,” says Mr McFadzean. “It is common to find buildings ideally suited to the people working in them but with not enough consideration given to creating the right environmental conditions for the cows.”


Dairy Efficiency seminars

The Dairy Efficiency seminars, organised by Wilson Agriculture and supported by Farmers Guardian, provide an opportunity to meet dairy advisers from leading international companies offering the latest advice on driving efficiency in business.

The seminars will cover:

  • Cow comfort solutions
  • Designing the optimum parlour
  • Cattle sorting and handling
  • Waste removal and utilisation
  • Housing layout and design
  • Bedding systems
  • Ventilation systems
  • Feeding optimisation
  • Cattle traffic
  • Financing and tax implications


  • Tuesday, April 13 at Greenmount Campus, County Antrim, Northern Ireland (30-minute drive from Belfast)
  • Thursday, April 15 at Harper Adams University College, Shropshire


For more details and to sign up, call 02870 868 430.


Speaking at the seminars

John MacFazdean of Sun-North Systems, travels globally, talking about new technology and ventilation systems in a variety of different climates. He will be joined at the Dairy Efficiency seminars by:

  • John DeJonge of Artex Barn Solutions - a dairy consultant who runs a manufacturing company specialising in cow cubicles.
  • Chris Keane of Promat has focused on cow comfort and ergonomics for the last decade.
  • Donald Gribble of Five G Consulting - a designer of USA and Canadian greenfield sites from several hundred to several thousand cows.
  • Ian Ohnstad of the Dairy Group, A leading consultant in the UK, he visits the USA, Australia, Africa, New Zealand and Japan to offer independent advice on parlour specification and operation, hygiene, mastitis control and building design.

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