In pig production systems, performance gaps often widen long before anything appears problematic in the pen. Subtle changes in digestion, immune activity and nutrient utilisation can quietly erode efficiency, even when feed intake and general health seem normal.
At the centre of this hidden performance loss is the gut. As production pressure increases, maintaining intestinal stability becomes critical to sustaining growth, feed conversion, and uniformity within groups.
According to Cara Nel, monogastric development manager at Vitam International, intestinal health plays a central role in feed efficiency, growth, and overall production performance.
“Because nutrient absorption takes place through the intestinal tract, gut health is one of the most important drivers of feed efficiency. When intestinal integrity is compromised, nutrient digestibility declines and maintenance energy requirements increase as the body responds to inflammation. Even mild intestinal inflammation can reduce growth efficiency significantly before producers notice any obvious signs of disease.”
Building a healthier gut
When gut health is compromised, pigs may continue consuming feed at normal levels while becoming less efficient at converting nutrients into growth.
Should the gut deteriorate further, feed intake may reduce, and pigs will have a diminished ability to utilise nutrients.
Maintaining gut health requires a combination of sound management practices and nutritional support.
Nel advises producers to focus on maintaining strong hygiene and biosecurity programmes, minimising feed changes, and supporting beneficial gut microflora.
The use of probiotics therefore plays an important role.
“Products with targeted actions help improve gut function by supporting microbiota balance, creating an environment favourable to beneficial bacteria, maintaining optimal villi height and crypt depth, strengthening tight junctions, and modulating inflammatory responses,” says Nel.
Improving feed digestibility is another important consideration to boost pig gut health. Complex enzyme products, which contain multiple enzyme activities, can improve digestion and nutrient utilisation.
Other practical measures include managing mycotoxins, reducing stress around weaning, ensuring proper water sanitation, and using functional additives where appropriate, particularly those that target inflammation, and help reduce responses in the animal.
Consistency matters
Feed consistency is critical for maintaining stable feed intake, digestive health and, predictable growth performance.
Nel notes that variation in energy levels, amino acid availability or mycotoxin load, can have a significant effect on production outcomes.
“When ingredient quality fluctuates, producers often experience reduced feed intake, greater feed conversion ratio variation between batches, increased digestive disturbances, reduced nutrient digestibility, higher incidences of diarrhoea in weaners, and greater feed sorting and wastage.”
Consistency between diet phases is equally important. Nel says pigs thrive on consistency and gradual adaptation. New raw materials should ideally be introduced during the grower phase rather than appearing for the first time in finisher diets.
Likewise, changes in diet density between production phases should not be too drastic.
Nel notes that gut health problems often develop gradually, making them easy to miss in the early stages.
“One of the first indicators is increased feed intake without proportional weight gain. Pigs consume more feed but fail to achieve corresponding growth, resulting in a rising feed conversion ratio.
“Producers may also notice greater variation within pens, with some pigs progressing well while others fall behind. This unevenness is often associated with inconsistent feed access, feeder competition or compromised gut health.”
Water and mycotoxins
Water quality is a critical component of gut function and performance.
“Water is often overlooked but is critical for feed intake and digestion. Poor water availability or poor- quality water can reduce feed intake almost immediately. Common problems include low flow rates, dirty drinkers, bacterial contamination from dirty pipes, excessive mineral content, and insufficient drinker space,” Nel explains.
Because pigs typically consume two to three times more water than feed by weight, reductions in water intake can rapidly affect growth performance. Proper water sanitation therefore forms an important part of maintaining gut health.
A hidden threat contained in feed is that of mycotoxins. While contamination levels vary according to raw material quality and environmental conditions, mycotoxins remain an unavoidable part of feed production.
Mycotoxins, though often invisible, can wreak havoc on multiple organ systems, diminishing liver and kidney function, fertility, immune response, feed intake, and average daily gain.
Dr Alexandra Weaver, global technical support specialist at Alltech, explains that mycotoxins can accumulate in feed ingredients, leading to reduced nutrient absorption and weakened disease resistance.
“Pigs are one of the most sensitive species when it comes to the impact of mycotoxins on health, development, and productivity. The type and concentration of these toxins in the feed, along with the age and production phase of the pig, determine the degree to which the animals are affected. Young pigs and breeding sows and boars are generally the most susceptible.”
Weaver notes common warning signs that mycotoxins are present in pig feed: visible moulds in pig feedstuffs, reduced feed intake, inconsistent faeces, reproduction challenges, general health deterioration, increased incidence of prolapses, and altered pig behaviour like vomiting, lethargy or overexcitement. Pigs could also show increased skin sensitivity, and reduced performance parameters.
While regulatory guidelines provide maximum allowable mycotoxin levels, Weaver states that even when mycotoxin levels are within allowed limits, average daily gain (ADG) is compromised.
“Studies have shown that ADG can drop by 79g when mycotoxins are within allowable limits. Notably, when at least one mycotoxin exceeded regulatory limits, the loss in ADG increased to 85g, accompanied by a significant reduction in average daily feed intake (ADFI), at 166g.”
Dr Radka Borutova, European technical support manager at Alltech Mycotoxin Management, adds that the ingestion of mycotoxins can leave pigs more susceptible to bacterial pathogens like Salmonella.
“The immunosuppressive effects of mycotoxins, combined with the inflammation of certain organs, can reduce overall immune function and leave tissues more prone to contamination by bacteria and viruses.”
Borutova points to a study that examined the effect of dietary exposure to the mycotoxin fumonisin B1 (FB1) on intestinal colonisation by E. coli.
“Researchers found that colonisation of the small and large intestines by E. coli was significantly increased when FB1 was ingested. The authors concluded that the presence of FB1 in diets is a predisposing factor to infectious disease.”
While eradicating all mycotoxins is challenging, Nel advises that farmers regularly screen and analyse raw materials to keep mycotoxin levels as low as possible.
“Only source ingredients from reputable suppliers and strategically use mycotoxin binders to minimise the negative effects of toxin exposure on health and performance.”
Weaver adds that feed additives like yeast cell wall extract (YCWE) can boost ADG when mycotoxins are present.
“Pigs exposed to allowed levels of mycotoxins in feed that are fed YCWE show a significantly higher ADG compared to those fed mycotoxins alone. Even at higher mycotoxin challenge levels, when YCWE was included, there was both an increase in ADG and a tendency for an increase in ADFI.”
Ultimately, gut health sits at the centre of pig productivity, quietly influencing how efficiently nutrients are converted into growth and how consistently animals perform across a system. For producers, the priority is therefore not only preventing disease, but actively protecting intestinal integrity.
For more information, email Cara Nel at [email protected].
