Feeding guidelines

This is a guide to feeding grain-based feed to various classes of pigs. It includes daily and dietary nutrients.

Dry sows

Pregnant sows should be fed according to condition. The amount depends on the sow's size and body condition, type of housing, environment, feeding method and health. If the intake is too high during pregnancy and sows become overfat, intake should be reduced while they are lactating. A feeding level of 2-2.5 kg of grain-based feed is suitable for most dry sows. The heavier the sow, the more maintenance that is required and, thus, the greater amount of feed required.

The potential exists to improve reproductive performance and longevity by providing extra protein to replacement gilts to support their structural development.

Lactating sows

Separate lactating (wet sow) and dry sow diets should be used if storage facilities permit.

A lactating sow's requirements depend on her weight, her milk yield and its composition, and her change in body weight and composition. More than 80 per cent of alactating sow's energy requirement is for milk production. It takes 4 kg of milk to produce 1 kg of litter gain.

In general, a sow needs approximately 85 MJ per day and 55 g of available lysine to support a litter of 10 piglets. This can be achieved by feeding 6 kg of a diet with 14.0 MJ DE and an available lysine digestible energy (DE) of 0.55 g/MJ. First-litter lactating sows should be offered a separate diet or supplement to account for their lower appetite compared with older sows.

In general, many herds gradually increase feed from about 2-2.5 kg a day around farrowing to ad lib at four to seven days, though this depends on the herd. A general rule for the maximum amount is 2 kg a day for the sow and 0.5 kg for each piglet, so as not to overfeed a sow with only a few piglets.

Increasing intake

Delayed oestrus after weaning is a breeding herd problem commonly seen in summer. Lactating sows reduce their feed intake in hot environments. Not only can this affect milk production and, thus, the piglets' growth, but sows weaned in poorer conditions have longer wean-to-oestrus intervals, particularly first-litter sows. Minimising the heat load on the sow, through shade, ventilation, water drippers on the skin and other methods, and stimulating the feed intake of the lactating sow through feeding techniques can reduce these problems. Suggested techniques include:

  • feeding more than once a day and feeding in the cooler hours of the day
  • feeding a higher quality, denser diet. The sow will not need to eat as much of a dense diet to obtain the required nutrients. Using oil in the diet for energy provides a concentrated energy source and produces less heat in the animal during digestion than carbohydrates such as grains
  • providing wet feed. However you cannot let the feed go sour, and you need to clean out uneaten food if more than about six hours old and keep the troughs clean
  • providing fresh feed, ensuring you keep stored feed cool and minimise moulds
  • increasing feed palatability. Adding flavouring is a possibility to achieve this
  • checking that the feeder design is not restricting intake. Ensure that large sows can access the feed easily.

Provide access to water without restriction, ensuring it is cool water with a flow rate of 2 L per minute or a trough.


Suckling pigs need fresh diets from about 10 days of age. The diet should contain no less than 16 MJ DE/kg, and be palatable and readily digestible. They should be fed the same diet for the first week after weaning.


This diet needs to cater for the young pigs´ digestive capacity but must be cost effective because of the length of time over which this diet is fed. The diet should be fed to established weaners without restriction until 20-25 kg live weight (about 8-10 weeks of age). The diet's energy level should be at least 14.5-15.0 MJ because their stomach capacity is limited. As feed intake is a major limit to growth during this phase, the feed must be digestible, palatable and fresh. Troughs must be checked regularly for soiling.


This is the period for rapid lean growth, so the diet should be high in energy (14.0-14.5MJ DE) with an available lysine/DE ratio of at least 0.65g/MJ. Diets should be offered without restriction from about 20 kg until 45-60 kg live weight (about 14-16 weeks of age).


Finishers' diets (possibly more than one) should be fed from 45-60 kg at a feeding scale that optimises growth rate, feed efficiency and carcase quality. The scale is determined by the market requirements, price differential between the fat classes, genetic potential of the pigs, sex (eas ntire males can tolerate higher levels of energy intake) and environmental temperatures (as the requirement for energy is higher in the cooler months).

For many commercial pigs, the scale will be to feed without restriction. As a guide, if feed restriction is required, the should be fed a maximum of 30-34 MJ of energy per day. That is, if a diet contains 13.5 MJ DE/kg, they must be offered 2.2-2.5 kg of feed daily to meet these needs. The available lysine/DE ratio should be about 0.55 g/1 MJ.

Split sex feeding

Split-sex feeding improves feed-use efficiency by more closely matching diet specifications to the different nutritional requirements of male and female pigs. As feed represents about 60 per cent of the total cost of production, this practice presents a major opportunity to improve profitability.Male and female pigs differ in their potential to convert feed into lean meat. Females reach their maximum point of lean growth at a lower live weight and feed intake than males.

Female pigs (especially those beyond 50 kg live weight) deposit protein slower, have a higher (worse) feed-use efficiency and deposit more fat than males at similar intakes of the same specification diet. Females also need less energy for basic body functions, which adds to the difference in carcase fat between the sexes.

If the same finisher diet is fed to both sexes, then either the males will not reach their genetic potential (if females are to achieve acceptable fat levels for the market) or females will be fat at slaughter and attract penalties. Male pigs need a higher energy and higher protein (amino acids) diet during the finisher period compared with females.

The level of benefits from split-sex feeding in terms of improved finisher-herd feed conversion, growth rates and carcass composition vary between herds and are influenced by genotype.