Feed conversion
Feed conversion efficiency (FCE) is one of the main yardsticks to measure the performance of finishing pigs. It is defined as the number of kilograms of feed required to produce one kilogram of liveweight gain.
Remember a reduction of 0.1 in FCE in the weight range for example, between 32-92 kg, represents a saving of 6 kg in the quantity of feed used/pig.
Factors influencing FCE
- Feed wastage
- Stocking rate
- Slaughter weight
- Disease
- Environment
Feed wastage
The daily feed intake per pig takes account not alone of the feed consumed by the pig but also of feed wasted. It is essential to eliminate wastage as far as possible. Among the factors which contribute to feed wastage and therefore feed efficiency are worn feeders, faulty feeders or trough design, excessive feed allowances and accumulation of stale feed in hoppers.
Stocking rate
Overcrowding of pigs is likely to bring about a reduction in daily feed intake and in growth rate as well as a slight deterioration in FCE.
Effect of floor area/pig on pig performance (30-82 kg)
(Source: Hanrahan 1980)
Slaughter weight
As slaughter weight increases FCE in finishing pigs deteriorates. Results of experimental work carried out by B Lynch, Moorepark suggests that on average a 1 kg increase in slaughter weight (live) results in a deterioration of 0.01 in FCE.
Disease
The effect of disease on FCE will vary depending on the severity of the disease, herd size, the influence of environmental factors, level of immunity in the herd and management practices.
The following table gives an estimate of the effect of diseases on FCE.
Effect of diseases on FCE
| Percentage reduction in feed efficiency | |
|---|---|
| Haemophilus pneumonia | 7 |
| Mange | 6 |
| Atropic rhinitis | 7 |
| Swine dysentery | 9 |
| Enzootic pneumonia | 8 |
(Source: NI Department of Agriculture 1987).
Environment
Temperature is the single most important environmental factor affecting pig performance. There is a critical temperature band within which a pig is comfortable and where it will perform to the limit of the feeding regime. Above or below this temperature range feed efficiency deteriorates.
Cold draughty houses which result in the effective environmental temperature being below the critical temperature of the pig adversely affects feed conversion efficiency. Good quality housing with accurate and reliable environmental control need only produce relatively small improvements in FCE to justify the extra cost over lower quality housing.
