Nutrition and feeding


The pig has one stomach and is similar to humans in anatomy and physiology. The major component of most pigs diets are cereals, animal and vegetable proteins, cereal by-products. A wide range of vegetable products may be included depending on the management system.

Pigs may be fed fishmeal and tallow. The decision made at the 4 Dec 2000 Agriculture Council will prohibit the feeding of bloodmeal, poultry offal and feather meal. (30) (The animal protein sources which have traditionally been used in pig foods are fishmeal, meatmeal - including pig meat, meat and bonemeal, milk by-products, bloodmeal and feathermeal. These products were dried and ground.)

Frequency of Feeding

According to the industry: “There are no advantages in growth terms in feeding older pigs more than once a day and to omit one feed in a 7-day period is generally acceptable”.(1) It is convenient to the farmer - but how does the pig feel when it has not eaten for 48 hours? It is also illegal - by law pigs should be fed ‘at least once a day’. Baby pigs and young animals need frequent feeding or continuous access to food.

Given a choice, pigs prefer fresh feed. But dry feed is more commonly given because it is easier to handle and it is cheaper.

Feed ingredients

The major ingredient in all pig diets is cereal. In the UK barley has been the major component and this partly reflects the vast quantities grown. Wheat and oats are less commonly used, probably because they are less readily available for use as animal feed. Other cereals such as corn, rye, sorghum and rice may be used depending on availability and price.

Vegetable protein includes oilseeds, pulses and microbial protein. The methods of milling cereals means there are many by-products which may be used in pigs' diets. They usually have high fibre being the outer husks of the grain. Root crops may be used to feed adult stock. They can be macerated and put through pipeline feed systems. Potatoes, if cooked to make the starch easily digestible, are used ‘as efficiently as cereals by pigs’. Other feedstuffs such as manioc, dried sugar beet pulp, dried green crops and distillery by-products may all be used too at lower levels. Cow's milk is also used as feed and drink. (10)


In the aftermath of BSE, it is astonishingly that pig meat is still fed back to pigs in swill. Although pure pork waste is now banned, pig products are legally included in swill (a liquid feed made from catering waste).

MAFF vet, Mr Chris Kilner, told Viva! regarding the feeding of swill to pigs:

"It is legal to feed swill - catering waste - to pigs. The new Animal ByProducts Order will make it illegal to feed pure pork waste to pigs, for example waste from a meat cutting plant".

Juliet Gellatley of Viva! asked Mr Kilner if the new Order would allow the feeding of pig products in catering waste to pigs, he replied:

"Yes, pork products in catering waste will remain legal. It's all to do with proportion, catering waste will dilute the pork products with vegetables, bread and so on."

Catering waste (or swill) has to be treated i.e. boiled to 100 C for one hour (or at a lower temperature for longer) before it can legally be fed to pigs.

The Animal By Products Order came into force because SEAC (Spongiform Encephalopathy Advisory Committee) recommended in 1997 that "the risk of TSE transmission from intraspecies recycling of pig and poultry waste be removed at the earliest opportunity". Allowing the feeding of pigs back to pigs in catering waste is, then, a rather large loop hole in the law and still risks the development of a transmissible disease in pigs (prions are not killed by boiling)!

Swill is usually collected by the farmer at source. Canteen wastes will contain meat and vegetable waste as well as confectionery residues. The plant which treats the swill must be licensed by MAFF and swill-fed pigs must be transported directly to the slaughterhouse. These conditions, along with the fact that the composition of the food is unpredictable, make swill much less popular than other feedstuffs. (1)

However, farmers do improperly boil swill. Outbreaks of the highly contagious swine fever in the 1980s in the UK were due to pigs being fed improperly boiled swill (32) and foot and mouth can also spread this way (32). In August 2000, a family of farmers were fined £90,000 for feeding dead animals to their pigs. They were fined under the Animal Health Act for preparing swill containing pig carcasses at their farm in Swinderby, near Lincoln (34). How many others are not caught?