factors that triggered the outbreak.
Infectious diseases play a relatively unimportant role in piglet survival up to weaning on most farms. However, looking at the data in herd-recording programs, piglet scours, or diarrhea, is one health problem that may cause a significant number of deaths. Scours can be caused by bacteria such as E. coli and clostridium, viruses such as rotavirus and even parasites such as coccidia.
Irrespective of the cause, a new outbreak of scours should be tackled in the same way in order to minimize piglet deaths and loss of growth. In fact, very often, death loss may be low, but the insidious loss of performance can be extremely costly. Regular monitoring of weaning weight allows any loss of growth during the suckling period to be identified and the reasons found.
When an outbreak of scours is identified, it is essential to get an accurate diagnosis rather than just take a guess at treatment. Laboratory analysis, in conjunction with the farm’s veterinarian, should be carried out to identify the causal organism. Clinical signs such as the severity of the diarrhea, the age of pigs affected and the level of mortality can help the veterinarian to make a diagnosis and determine the best treatment.
As with many diseases, finding the most effective treatment is only one aspect of dealing with a health problem and there are a range of management measures that should be considered in addition to investigating the
Because diarrhea causes dehydration, affected litters should be given an electrolyte solution in trays several times a day. Dehydration will quickly cause deaths in a severe outbreak of scours. Also, piglets that are sick should have their environment enhanced by providing an additional heat lamp or providing some bedding where possible.
Drafts are a major trigger factor for piglet scours and one that I always investigate. If there are drafts at pig level (for small piglets, air speed should be no more than 0.2 metres/second, which is very slow!) air inlet settings should be checked and adjusted where necessary. Drafts may also result from openings in the building structure such as incorrectly baffled fans, gaps under doors or gaps in wall or ceiling panels.
Immunity plays a key role in avoiding piglet scours. Identifying the causal organism will allow the veterinarian to check whether it is included in the sow vaccines used on the farm. While vaccines against E. coli are widely used, in the case of a bacteria such as clostridium experienced for the first time, a new vaccine may be required.
If a vaccine is being used to prevent scours but is not as effective as it should be, a review of vaccination timing and technique should be carried out. Problems such as incorrect storage temperature, wrong needle size, poor injection technique and inadequate hygiene have all been implicated in ineffective vaccination. Even where the vaccination program is carried out correctly, piglet immunity may be compromised by inadequate colostrum intake. Because piglets gain all their immunity from the sow until they gradually develop their own, they need to ingest enough colostrum immediately after birth to give them sufficient protection. With the rapid increase in litter size seen over the last 10 years, this has been much more of an issue recently. As part of the measures taken to prevent scours, a review of colostrum management routines should be made. It may be necessary to consider techniques such as split suckling, depending on the litter size and any other measures employed.
Another aspect of immunity is the acclimatization of incoming gilts to the herd’s disease challenge. If gilts do not develop sufficient immunity themselves, they will be unable to pass it on to their piglets. It is quite common for scours to be much more prevalent in gilt litters for this reason.
Some outbreaks of scours may have no infectious agent involved and the most common reason that I experience on farms is overfeeding of the sow and gilts just prior to farrowing, especially when sows are overconditioned. Typically, this problem occurs at seven to 10 days after farrowing due to overproduction of milk in sows that had a sub-clinical mastitis or loss of milk production at farrowing. This can be avoided by ensuring the correct sow condition at farrowing and dropping feed level to 2.0 kg for sows and 1.8 kg for gilts for a period of at least three days prior to farrowing.
Another aspect of management that should be reviewed is hygiene. First, measures should be taken to prevent the spread of the disease organisms between pens, for example through avoiding fostering of pigs that are scouring and the use of disinfectant boot dips. Farrowing-room hygiene routines such as washing and disinfection should be reviewed to ensure they are up to standard.
Although E. coli is the most common reason for scours, recent studies in Ontario suggest that coccidia infections are resulting in a significant loss of piglet growth on farms surveyed. Seventy per cent of the 50 farms surveyed had coccidia oocysts present and on farms with coccidia infections, an average of 29 per cent of litters were infected. The researchers suggested that the banning of Baycox, the drug widely used as a treatment, in 2005 has exacerbated the problem.
A comparison of weaning weights on the farms surveyed suggested that weaning weights were reduced by 0.4 kg per pig on farms with a coccidia problem, resulting in a significant loss of production. Therefore, when investigating a new outbreak of scours, it is worth checking for this disease organism.
Bernie Peet is president of Pork Chain Consulting
of Lacombe, Alberta, and editor of Western Hog Journal