ThePigSite Pig Health
Management Control and Prevention(494) "How important are worms"? This is a question often posed with the pressures and perceived necessities to routinely treat. In indoor systems where all-in all-out procedures are used, internal parasites will not build up in sufficient levels to require routine treatment.
The objective therefore is to manage the environment to prevent the pig gaining access to faeces after the larva have become infective. It can be seen from Fig.11-5 that in practical terms this is approximately 5-7 days. A routine parasite examination of faeces every six months will establish the status.
Field experiences over many years have shown that if sows are housed in stalls or tethers and they have no access to faeces, internal parasites are almost eliminated, with the exception of the ascarid or large white worm. The infective period for this larva is two to eight weeks and generally the longer period. However the egg will survive outside the pig for long periods of time. Provided good hygiene is practised on the farm and faeces and liver surfaces are monitored, it is not necessary to treat.
The danger areas for the build up of infections are the permanently populated areas such as boar, mating and gilt holding pens. Provided these are cleaned out regularly, herds can be maintained with negligible levels of parasites.
Parasite control in loose-housed sow herds is less predictable but again depends on hygiene, drainage and the regular removal of faeces. Field experiences with the foregoing provisos, also demonstrate it is not usually necessary to treat, but each herd must be assessed individually together with its history. Faeces should be examined every three months.
In finisher herds the adoption of multi-site operations or segregated systems all-in all-out have virtually negated the necessity for treatment.
In outdoor herds however parasite control is difficult. Twice yearly worming and in-between faeces examination gives good control and an insurance against the build up of infections.
Because the exposure to parasites in many commercial systems is low the corresponding immunity levels in the pig are also low. This will mean that within any given herd a number of animals will be highly susceptible and therefore the number of larvae required to produce disease is minimal.
Key Points to the Control of Roundworms
- In intensive reared indoor pigs on concrete or slats treatment is unlikely to be necessary.
- If sow stalls or tethers are used - treatment of sows is unlikely to be necessary.
- If sows are loose-housed - how often are faeces removed?
- If sows are outdoors - worming is probably necessary.
- If sows are housed in permanent paddocks worming is essential.