Many current intensive livestock production systems require the provision of a controlled environment for housed stock.

n commercial agriculture, pigs and poultry are the animals most often associated with controlled

light / dark periods must optimise production and provide conditions required to maintain the good welfare of stock

. But lighting is costly to provide and run, so choosing the most suitable fitting

visual part of the light spectrum, measured in lux( based upon the livestock you are considering).

In addition to this, the number of hours of light and dark( or photoperiod) in a 24-hour period

the type, size and number of stock to be housed in them. Where the ventilation in existing buildings is not good enough, they should be adapted by improving air inlets and outlets, or by using mechanical

environment, however, there are other animals that can also thrive in controlled conditions at some time during their lives.

Most farmers would think of little more than temperature and humidity as comprising the‘ environment’ for the animal. But, in fact it goes much further than that. Environment embraces other factors like airspeed, air quality, light level and colour and surrounding surface materials.

Well-designed systems will maximise outputs through higher growth and reduced mortality while minimising inputs – mostly feed and energy – as well as improving the health and welfare of the stock. Lighting Good lighting is a fundamental requirement for the efficient operation of any farm. It is required for both the stock and stockmen.

For the stockman, it supports visual acuity, performance and safety both through higher lighting levels and better colour rendering. For livestock, both the duration and the intensity( illuminance) of

layout and control equipment is important.

Animal responses to aspects of artificial lighting are an important factor in designing a lighting scheme. Using an inappropriate artificial light could result in the illuminance( lux) being too high or too low, or an unsuitable spectral output for the livestock. Light levels and spectrum need to be considered for both the light and dark periods of the day. Seasonal requirements of animals should also be considered.

The consequences of inappropriate lighting may affect the health, production and welfare of your stock due to the light-induced biological responses. Optimum lighting can also have a significant effect on production from lactating dairy cows. The key characteristics to consider are:

Spectral composition: the distribution of light wavelengths( how much of each colour is present).

Illuminance: the total amount of luminous power produced in the

should be considered. Rate of change of lighting level

( dawn / dusk simulation). Lighting design is a skill that requires technical knowledge and experience. As well as being affected by the chosen light type and number, the building layout and internal reflectivity have to be considered. A full design takes into account a multitude of factors and can produce light rendering diagrams. [ see picture ] Ventilation Air circulation, dust levels, temperature, relative humidity and gas concentrations must be kept within limits which are not harmful to the animals. Ventilation is a key factor in reducing relative humidity in livestock buildings, vital for aiding the control of pathogen reproduction and longevity.

All new buildings should be designed with the animals’ comfort in mind, with the aim of preventing respiratory diseases. The buildings should be windproof against the prevailing wind and provide enough ventilation throughout the year for

equipment. Building layout should be joined up with handling systems to make movement of animals simple and stress free. Consider also where shadows are created so animals move freely.

Many calf buildings are not capable of delivering adequate natural ventilation through the‘ stack effect’. Well designed, powered ventilation is often required to achieve optimum air exchange rates.

AHDB has taken on responsibility for the Controlled Environment for Livestock publication, last updated in the 1990s, which it will publish later this year.

A ventilation manual and practical pig apps on ventilation system care and maintenance, are available at: http:// pork. ahdb. org. uk / environment-buildings/ pig-buildings-housingdevelopment / ventilation /

AHDB’ s Environment and Buildings team offer farm visits to help provide solutions to buildings which are not working correctly and to aid new building design.