The use of supplementary lighting in dairy cow housing to increase milk production

Abstract

Supplementary lighting provision has the potential to increase dairy cow milk yields with minimal additional capital costs. Recent developments in light emitting diode (LED) lighting technology has produced low power, high output luminaires suitable for on-farm use. Light levels (lumens) decline according to the inverse square law so luminaires need careful positioning. Specialist light meters must be used to assess provision as the human eye is too adaptable to objectively assess light levels. Providing in excess of 150 lux at cow eye level for 16–18 hours a day has been shown to lift milk yields by around 2 litres/cow/day with a 2–3 week lag in effect and a 7–9 week lag in feed intake increases. Natural day length is insufficient for most of the housed period in UK systems. Lighting adequacy should be assessed by a single time point survey of the building to determine provision in different parts of the building. Duration of high light levels is best assessed with suitable data loggers placed in the shed for several days. Fitting similar data loggers to individual cows will give a better understanding of the light that the cow actually receives. In general the current stock of un-improved dairy cattle housing is inadequately lit. The cost of making improvements to existing cattle sheds is generally in the tens of thousands of pounds, but if installed correctly can help lift milk yields by several litres per cow per day.