Although there are as many systems of pig production as there are individual farms, these can be divided into two major types: indoor or outdoor pig production.

Indoor pigs farms feature herds of pigs kept in a relatively small, closely controlled area, usually with some form of climate control, often with liquid feeding systems, and (increasingly) ‘high health”. These systems are often referred to as factory’ or ‘intensive’ production.

Outdoor pigs feature breeding pigs (sows and litters) being kept on free-draining arable fields for one or two years per site, using ‘arks’ and electric fencing. More than a third of the UK herd are now being kept this way, with an increasing number of pigs being raised to slaughter weight outdoors too.

Both systems have their ‘pros’ and ‘cons’: let’s start by examining the positive features of both.

Indoors you have the advantage of environmental control: piglets can be born and raised at the right temperature; adult animals can be kept cool in the summer and warmer in the winter – they also don’t get the opportunity to get sunburnt; and airflow, especially the occurrence of draughts, so detrimental to pig health, can be controlled. You can also control the feed intake of housed pigs, and are better able to reduce wastage (so important in these days of increasing feed costs) – it’s also easy to install computer controlled feeding methods, such as automatic sow feeders and liquid feeding for fattening stock. Indoor farms tend to be more productive than outdoors given the ability to control feed and environment – it’s possible to achieve a greater level of supervision and measurement and therefore control of the many variables in an indoor situation. It’s also possible to establish and maintain a high health status for your herd, significantly reducing disease risks and challenges.