Lighting in and around the parlour will influence how well a cow milks. However, the impact of lighting on the smooth operation of the milking process is often not given enough consideration on dairy farms.
Dark entrance and exit points, shadowing in stalls and poorly lit udders will not only unsettle cows and risk lower milk yields, but can impact on milk quality, says milking technology specialist Ian Ohnstad.
“How can cows be milked properly if the operator can’t easily assess the cleanliness of the teats?’’ says Mr Ohnstad, of The Dairy Group consultancy.
“Farms often invest significant sums of money in new milking facilities or streamlining existing facilities, while paying relatively little attention to the levels and evenness of lighting for their cows and staff.”
Below, Mr Ohnstad talks through the fundamentals of good lighting, from location to intensity.
Where to position lights
Behaviour studies show the brighter a cow’s environment, the more welcoming it is to her.
By making the light intensity of the parlour greater than the collecting yard, cows will be drawn into the building.
Lights are often sited where they are most convenient for the electrician rather than in the best position for a cow.
There are cases where farms were struggling to get cows to willingly enter the parlour and have found the reason why when the lights are switched on – the orientation of the light is such that it is shining right into the cows’ eyes.
The exit point should be inviting too – so often cows will exit a parlour down a dark and poorly lit passage, which doesn’t encourage her to leave.
Shining light on to udders and teats has multiple benefits, but it is not just old parlours that are disappointingly dark at teat level, modern systems are too.
Technology company GEA recognised this when it trialled a system that lit the udders from below, to shine light underneath the udder, but currently it hasn’t taken this product to market in the UK.
Some farmers have found their own cheap solutions to specific lighting issues, including mounting LED rope lights on to the pit kerbing down the length of the parlour.
- Ensure entry and exit points of the parlour are well lit, as well as the milking operator area.
- Avoid dark shadows in the stalls – shadowing will deter cows from moving smoothly into the stalls.
- Before positioning new lights, assess the potential lighting system from where the cow will enter, stand and exit.
- The light needs to be on the cow, not shining directly into her eyes at the entry area; this is a very common fault.
- Bear in mind that, due to physiological differences and the position of their eyes, cows perceive light differently from humans.
- Cows don’t like the reflection of light on metal plates, wet floors or footbaths. Check for these issues if cows are resisting coming into the parlour.
- Keep lights clean – dirty fittings can reduce output by 50%, and the cleaner the lights, the fewer fittings that will be required.
Required light intensity
Although 200 lux is the general target, increase this to 500 in the pit.
The operator area needs to be lighter than 200 to create bright working conditions that allow no opportunity for error or for problems to be missed.
The collecting yard should be darker to enhance the cow’s tendency to want to move from poorly lit areas to well-lit ones.
- Light intensity should increase from collecting yard to parlour and be brightest in the pit (500 lux).
- Take lux measurements regularly during the lifetime of the system to ensure there is the same light intensity as at installation.
- Consider also the height at which lighting is positioned; doubling the distance to a lamp from the surface it is illuminating reduces the lighting level by a factor of four.
Continuous rows of strip lights touching end to end are the most popular.
Opt for LED instead of fluorescent because these are more energy efficient – but they do cost significantly more.
Metal halide lamps are another common type of lighting used in parlours, but their high wattage can greatly increase electricity consumption.
They can also cast shadows from the stallwork and equipment and can under-light the pit area. But they can work well in large parlours with a high ceiling.
Choose a model that comes with a diffuser to manipulate the direction in which the light is thrown. You want a light to throw light out and around rather than downwards.
A double bank of strip lights is better than one as this will allow light to be diffused correctly.
The diffuser on the strip lights on the right-hand side of the parlour pit should illuminate the left side of the parlour and vice versa.
- Thinking about spending more money on lights can save you on energy consumption in the long-term.
- Be aware that overdoing lighting in parlours with a lot of equipment can create shadows, so carefully plan their positioning to minimise this issue.
How lighting can affect auto ID systems
High-frequency signals in light fittings can play havoc with the radio frequency of ear-tag readers.
Quite often interference from lights is identified as the source of poor performance with an auto ID system.
For example, high-frequency lighting can seriously affect auto ID. The reader will flash but it doesn’t identify the cow and that means she is placed in the wrong stall, so milk yield, feeding and milk recording are all affected.
To check if the performance of the identification system is affected by lighting, switch off all lights and milk for an hour, if possible, without lighting.
Older switch-start or magnetic ballast fluorescent tubes may be the only viable option for rectifying this problem.