Nutrition and feeding
The pig has one stomach and is similar to humans in anatomy and physiology. The major component of most pig diets are cereals, cereal by products and animal and vegetable proteins – particularly from soya.
The major nutritional objective of the finishing phase is to produce pigs at market weight which meet the specification for best carcass price. Whilst ad libitum feeding is possible, in some circumstances, feed restriction in the final stages of fattening is sometimes deemed ‘necessary’. It used to be common practice to feed pigs on kitchen waste, particularly in smallholder systems. However, due to the disease (particularly foot and mouth) risk associated with it, feeding swill is banned Europe-wide. The use of mammalian meat and bone meal (MBM) was also banned because it caused BSE; the ban was subsequently extended to almost all forms of processed animal protein (PAP).
Given a choice, pigs prefer fresh feed, and of course they enjoy rooting (denied on all indoor units). But the same dry and liquid feed is given because it is easier to handle and it is cheaper, adding to the boredom and frustration of these intelligent animals. Feeds for ‘finishing’ pigs are usually based on cereals and plant proteins, most commonly soya bean meal. Some farms reduce costs by using industrial by-products from the human food and drink sector such as wheat feed, vegetable wastes and brewery and distillery products – many of these are fed in liquid form (48).
The objective of farmers at the ‘finishing phase’ is to produce pigs at a weight which meets the requirements of best price, which usually means meeting a contract grading specification for carcass weight and leanness, usually measured as subcutaneous fat thickness at one or more points on the animal’s back. Pigs have been genetically manipulated to put on muscle rather than fat; however, so-called genetically inferior animals which put on fat in finishing will have food withheld or reduced, as will pigs kept for products such as Parma ham, which require heavier animals at slaughter. Restricted feed – hunger – can lead to aggression and to some animals dominating the feed troughs (48).