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Gut health plays an essential part in the absorption of nutrients and resulting feed efficiency. If gut health is compromised at any point, the pig won’t achieve expected growth rates and days to finish will be increased.
Like humans, pigs are monogastric, so their digestive systems work in a similar way to our own.
Most of the nutrient absorption takes place in the small intestine. Digestive enzymes break down the proteins, fats and carbohydrates, which pass into the bloodstream via tiny, finger-like projections called villi that line the jejunum and ileum.
Many gut health and digestive problems are picked up from the pig’s environment. Bacterial pathogens, such as salmonella, strep. suis and lawsonia intracellularis are readily introduced via their mouths.
Young, pre- and post-weaning piglets with immature digestive systems are particularly at risk.
Post-weaning ileitis
Ileitis is one of the most common digestive diseases in growing pigs and is caused by the lawsonia bacteria.
The word means ‘inflammation of the ileum’ and the disease is caused when the infected villi become swollen and unable to absorb nutrients, especially lysine.
If the villi are damaged, lysine cannot be fully absorbed and it passes into the large intestine, where it disturbs the microbiome. This can result in diarrhoea or faecal looseness that can often be grey or pasty in appearance.
Most pigs will recover from visible signs. However, they continue to eat less, affecting development and leading to lower than expected growth rates. They may also be more susceptible to secondary infections, such as salmonella.
The dose of bacteria ingested by pigs will determine disease severity, as well as the pigs’ diet, genetics, immune response, including maternal antibody presence, intestinal microflora and general health and stress.
However, some pigs may display few external signs, but still be affected internally.
One of the unique features of ileitis is the long-term damage to gut integrity. Thickening of the gut caused by the disease remains for the rest of the fattener’s life. Because the ileum is so essential to the way feed is digested, farmers see a significant impact to FCR and ADWG right up until slaughter.
The effect of ileitis can be seen post-mortem. Thickening of the folds and ridges can easily be seen and felt in diseased ileums. They may also have large, raised nodules and appear dark or bloody.
Within groups of finished pigs, it’s common to see a range of severity and this may explain why batch unevenness is such a feature of subclinical ileitis.
Farmers can improve general gut health across the herd in conjunction with both their vet and their nutritionist.
Particular attention should be paid to weaning management and water quality. Hygiene across the unit is essential, as most digestive diseases are transmitted via infected faecal matter.
Your vet can test for specific pathogens and recommend treatment methods accordingly.
Management of ileitis on farm has relied heavily on the use of zinc oxide and in-feed antibiotics, but with recent legislation changes, farmers are increasingly adopting vaccination as a control measure.
Improved performance with vaccination
The Porcilis Lawsonia vaccine can be given by intramuscular injection or intradermally using the IDAL vaccination device.
It can be given from three weeks of age and gives 21 weeks of immunity to protect growing pigs through the fattening stage.
Vaccination with Porcilis Lawsonia has been proven to reduce diarrhoea, reduce intestinal lesions and reduce loss of daily weight gain.
Porcilis Lawsonia has been shown to increase ADWG by an average of 57g compared with unvaccinated pigs and the same field trial also showed a reduction in FCR from 2.47 to 2.21.
A recent study in a British indoor farrow-to-finish unit showed that vaccination with Porcilis Lawsonia also improved ADWG and days to finish when compared with in-feed antibiotics.
It is possible to administer Porcilis Lawsonia at the same time as other MSD Animal Health vaccines against porcine circovirus, mycoplasma hyopneumoniae and PRRS to provide four-way protection against the most significant diseases affecting young pigs. Your vet will advise the most appropriate vaccination strategy for your farm.
“Disease of all kinds affect pigs’ wellbeing,” explains Maureen Prendergast, swine technical manager with MSD Animal Health.
“As well as the distressing physical signs of illness, there can be other, more subtle, indications that pigs are not thriving.”
Experienced staff often recognise that activity levels are reduced when pigs are unwell and that the pens may seem quieter.
“Like us, pigs of all ages show a reluctance to eat and drink when they are under the weather,” continues Maureen.
“Piglets, especially, will stay where it is warm and show little interest in food or drink unless it’s positioned very close by.
"Even when very thirsty or dehydrated, they won’t travel far to drink. Some farmers that have installed water systems that measure consumption have observed that a drop in water usage can actually predict incidence of disease.”
Behavioural vices occur as a result of many environmental, social and health issues. Issues such as tail-biting are commonly found in stressed pigs.
“Anecdotally, we’re getting feedback from farmers about improvements in tail-biting when ileitis in young piglets is effectively controlled. We aren’t exactly sure why, but it may be due to the reduction in stress.
"There is an increasing amount of research into this aspect of animal welfare at the moment, so hopefully in future we will be able to reduce these behaviours with better understanding, environmental enrichment and improved health.
“A healthy pig is a happy and sustainable pig and that is what the industry is working towards.”
Farmers should discuss their vaccination regime with their vet who can also advise on infection control and on-farm biosecurity.
Further information is available from your veterinary practitioner or MSD Animal Health, Red Oak North, South County Business Park, Leopardstown, Dublin 18, Ireland.
MSD Animal Health can be contacted at 01-297 0220 or emailed at vet-support.ie@msd.com.
