Poor gut health directly increases the feed conversion ratio in pigs: the gut digests less efficiently, absorbs fewer nutrients, and uses more energy for repair and defence. The result is that a pig needs more feed to reach the same weight. Pig farmers who optimise gut health thereby also improve their feed efficiency in a structural way.
In this article, we answer the most frequently asked questions about the relationship between gut health and feed conversion in pigs, from the biological mechanisms to the practical approach on the farm floor.
What happens in the gut when feed conversion deteriorates?
When feed conversion deteriorates, the gut almost always shows a compromised intestinal wall, a disrupted microbiome, or a combination of both. The intestinal villi become shorter and the crypts deeper, reducing the absorption surface and lowering nutrient uptake. The pig eats more, but utilises less.
The intestinal wall fulfils two crucial functions simultaneously: absorbing nutrients and keeping harmful substances out. When the so-called tight junctions — the protein connections between intestinal cells — weaken, increased intestinal permeability develops. Bacteria, toxins, and undigested protein fragments then enter the bloodstream. The immune system responds with an inflammatory reaction that costs energy and inhibits growth.
At the same time, the activity of digestive enzymes decreases in a damaged intestinal wall. Proteins, fats, and carbohydrates are broken down less effectively, leading to undigested residues in the large intestine. These residues feed harmful bacteria, further reinforcing dysbiosis. The result is a negative spiral in which higher feed intake does not lead to better growth, but instead to more excretion and higher costs.
Which gut problems cost pig farmers the most in feed efficiency?
The gut problems that most strongly undermine feed efficiency in pigs are subclinical intestinal inflammation, dysbiosis, and enteritis. These conditions are more dangerous than acute outbreaks because they remain invisible for a long time while generating daily feed costs without visible signs of disease.
Subclinical inflammation is a creeping problem. The pig eats normally, grows slightly slower than expected, and has a slightly higher feed conversion ratio, but there are no clear symptoms. Yet the immune system continuously consumes energy that would otherwise go towards muscle growth. Research in pig farming confirms that chronic low-grade inflammation is one of the largest invisible cost factors.
In addition to inflammation, the following gut problems are particularly costly for feed efficiency:
- Dysbiosis: a disrupted balance in the gut flora in which pathogenic bacteria such as E. coli and Clostridium gain the upper hand
- Post-weaning diarrhoea: a common problem in piglets immediately after weaning, with a major impact on early growth and later performance
- Ileitis: caused by Lawsonia intracellularis, leads to reduced nutrient absorption in the small intestine
- Leaky gut: weakened tight junctions that lead to chronic inflammation and reduced utilisation of nutrients
All of these conditions share one common consequence: the pig needs more feed to reach the same final weight, directly affecting the margin per animal.
How does the gut flora influence nutrient utilisation?
The gut flora in pigs influences nutrient utilisation in multiple ways: a healthy microbiome supports digestion, produces useful metabolites such as short-chain fatty acids, and keeps pathogens in check. In dysbiosis, this reverses and the flora competes with the pig for available nutrients.
A stable, diverse gut flora in eubiosis produces butyrate and other short-chain fatty acids (SCFAs). Butyrate is the primary energy source for intestinal epithelial cells and directly contributes to the integrity of the intestinal wall. A gut with sufficient butyrate has stronger tight junctions, taller villi, and better absorption capacity. This translates directly into a lower feed conversion ratio.
When the microbiome becomes unbalanced, the composition of fermented products changes. Instead of butyrate, more toxic metabolites are produced, such as ammonia and biogenic amines, which damage the intestinal wall and burden the liver. The gut flora therefore determines not only how much a pig absorbs, but also how much energy it expends neutralising harmful by-products.
Good gut health in animals therefore begins with actively supporting a healthy microbiome balance through nutrition and targeted additives.
What is the role of betaine in gut health and feed conversion?
Betaine supports gut health in pigs through four mechanisms: it strengthens the barrier integrity of the intestinal wall, reduces oxidative stress and inflammation, improves intestinal villus structure, and promotes a healthy microbiome balance. This leads to better nutrient utilisation and a lower feed conversion ratio.
As an osmolyte, betaine helps intestinal cells maintain their water balance under stress conditions such as heat or infection. Cells that are osmotically protected function better and recover more quickly from damage. Scientific research shows that betaine increases the expression of tight junction proteins such as occludin and claudin-1, literally reinforcing the intestinal barrier.
In addition, betaine improves the intestinal villus structure in pigs: taller villi and shallower crypts increase the absorption surface and improve nutrient uptake. Combined with its modulating effect on the microbiome — whereby betaine promotes a stable, beneficial bacteria-dominated flora — a gut environment is created that performs structurally better.
As a methyl donor, natural betaine also supports the transmethylation cycle, contributing to a more efficient fat metabolism and a higher lean mass. The net result is better carcass quality and a lower feed conversion ratio, even under challenging conditions.
When is pig gut health most vulnerable?
Pig gut health is most vulnerable during weaning, at feed transitions, during periods of heat stress, and when there is a high infection pressure in the barn. These are the moments when the balance between intestinal integrity and microbiome stability is most rapidly disrupted.
Weaning is by far the most critical phase. The piglet suddenly loses maternal milk as a source of immunity and nutrients, is exposed to a new environment, and is offered solid feed. The gut flora must adapt in a short period of time. During this phase, the risk of post-weaning diarrhoea and dysbiosis is greatest, with direct consequences for feed efficiency in the weeks that follow.
Heat stress is a second critical moment. When pigs need to dissipate heat, they reduce blood flow to the gastrointestinal tract. The intestinal wall receives less oxygen and nutrients, the tight junctions weaken, and permeability increases. This raises the risk of endotoxaemia and chronic inflammation, even if the temperature peak is brief.
Finally, feed changes, antibiotic treatments, and high stocking density are situations in which the gut flora comes under pressure. In all these cases, preventive support via feed or drinking water is more effective than curative intervention.
How do you measure the impact of gut health on feed conversion in practice?
The impact of gut health on feed conversion in pigs is measured in practice through a combination of technical performance indicators, clinical observation, and targeted gut examination. The feed conversion ratio (FCR) is the most direct figure, but only provides a signal after the fact. Earlier indicators are needed to make timely adjustments.
A practical approach consists of the following steps:
- Monitor FCR weekly per section and compare with benchmark values for the relevant breed and growth phase. An increase of more than 0.1 points is an early warning signal.
- Observe manure consistency daily. Watery or slimy manure indicates a disrupted microbiome or increased intestinal permeability.
- Record water intake per animal per day. A sudden increase may indicate intestinal irritation or heat stress; a decrease may indicate reduced appetite due to inflammation.
- Have periodic gut examinations carried out at slaughter or via post-mortem examination of fallen animals. Villus height, crypt depth, and the presence of pathogenic bacteria provide a reliable picture of gut condition.
- Use production data across multiple rounds to identify trends and evaluate the effect of feed or additive changes.
By linking FCR to gut health parameters, you gain a more complete picture of where feed costs are being lost. This enables targeted interventions rather than broad preventive antibiotic use, which aligns with the growing demand for No Antibiotic Ever strategies in pig farming. Products such as Grovax, with organic acids, butyrate, and medium-chain fatty acids, fit within such a strategy.
How Jodoco helps with gut health and feed conversion in pigs
At Jodoco, we develop science-based feed and drinking water solutions that structurally support pig gut health and thereby improve feed conversion. Our approach combines natural betaine with organic acids, butyrate, and essential oils for a broad spectrum of action.
Specifically, we offer:
- Jodobet: natural betaine as an osmolyte and methyl donor, strengthens tight junctions, improves villus height, and supports a healthy microbiome balance
- Grovax: combination of organic acids, slow-release butyrate, and medium-chain fatty acids (MCFAs) for active intestinal barrier protection and antimicrobial action, suitable for NAE strategies
- Jodoplume: drinking water solution with betaine and organic acids for rapid support during heat stress or infection pressure
Our products are developed in our own laboratories and validated in collaboration with research institutes and universities. With more than 25 years of experience in betaine applications, we are ready to work with you to determine the right strategy for your operation.
Would you like to know which approach best suits your pig farming business? Contact us and we will be happy to think along with you.
