Here we look at the role nutrition may have on disease syndromes but for more extensive information on nutrition itself the reader is referred to specific books dealing with this (for example, The Science and Practice of Pig Production or Piglet Nutrition Notes).

A major role for the stockperson on the farm is to judge the interaction between the pig, its age and/or productive cycle against the quality, content and intake of feed. The role of management in this respect has an important influence not only on the levels of disease in the herd but also whether the pig maximises its biological potential.

The essential nutrients include protein and amino acids, energy, essential fatty acids, water, vitamins and minerals. A guide to the normal requirements is shown in Fig.14-1 both by weight of pig and ration type.

If you feel you have a feed-related problem, study the list of clinical problems associated with nutrition

First identify the problem by symptoms and this will suggest potential nutrient deficiencies or problem areas. You would be advised at this time to consult with your feed supplier because a knowledge of the composition of the diet will then assist in determining more specific areas, for example insufficient energy or lysine for the particular age group of pigs in that environment. Fig.14-3 relates the clinical signs to possible causes where there are deficiencies or excesses of minerals and similarly Fig.14-4 of nutrients and vitamins, although it would be uncommon today to see many of them. Details of individual nutrients are given in subsequent pages within the Feed and nutrition section.

The most common problems on farms today however relate to the failure of the diet to satisfy the amino acid and energy requirements for the pig.

Clinical problems associated with nutrition

Abortion

• Energy
• Fungal toxins present
• Iron

Anaemia haemorrhage

• Aflatoxin
• Anticoagulants
• Coal tar poisoning
• Copper
• Iron
• Protein
• Vitamin E - Selenium (gastric ulcers)

Bone fracture, malformed bones, lameness

• Calcium *
• Magnesium
• Manganese
• Nicotinamide
• Phosphorus *
• Vitamins * - A, D3, E

Diarrhoea, colitis

• Excess protein, tapioca
• High levels of wheat
• Increased levels of potassium and magnesium
• Iron
• Nicotinamide
• Pantothenic acid

Haemorrhage

• Vitamin K

Nervous symptoms, incoordination, lameness

• Biotin
• Calcium
• Copper
• Magnesium
• Manganese
• Pantothenic acid
• Phosphorus
• Vitamins * - A, B6, D3, * E
• Water *

Poor growth, poor appetite

• All aspects of nutrition *
• Amino acids * - lysine, arginine, histidine, isoleucine, methionine, cystine, threonine, tryptophan
• Energy *
• Feeds of poor digestibility *
• Iron *
• Magnesium
• Phosphorus
• Potassium
• Protein *
• Sodium chloride *
• Vitamins -* A, B6, B12, * D3, choline, riboflavin, pantothenic acid niacin
• Water *
• Zinc

Poor litter size

• Choline
• Energy *
• Folic acid
• Lysine *
• Other essential amino acids
• Vitamin E *

Reproductive failure

• Choline
• Energy *
• Folic acid
• Iodine
• Lysine *
• Manganese
• Other essential amino acids
• Riboflavin
• Vitamins - B12, * E

Respiratory diseases

• Energy
• Protein
• Vitamin E

Skin changes

• Iron *
• Essential fatty acids * - linoleic acid
• Nicotinamide
• Potassium
• Riboflavin
• Salt
• Zinc

Sudden death

• Selenium *
• Thiamine
• Vitamin E *
• Water - salt poisoning

* Likely to occur. Others uncommon or rare.