The liver is a key organ in pig farming, as it plays a fundamental role in feed digestion, metabolism, and toxin and by-product elimination of digestive and metabolic processes. Thus, its proper physiology and function are essential for animal performance and welfare.

Liver functions and their importance in pig production

The liver is a complex organ which performs a wide variety of functions, including the following:

• Digestion: The liver produces bile, which helps digest fat and assimilate fat-soluble vitamins.
• Metabolism: Participates in the metabolism of carbohydrates, proteins, and fats, among others.
• Excretion of toxins: The liver helps to eliminate toxins from the body, such as those produced by drugs, feed, the body’s metabolism, or environmental factors.
• Protein synthesis: This organ produces essential proteins for blood clotting, oxygen transport, and tissue repair. Furthermore, some of them also have a central role as immune effectors.

In swine production, the liver is a key organ for several reasons, but two stand out. Firstly, this is a vital organ to ensure productive performance: pigs with healthy livers perform better digestion, more efficient metabolism, and have a greater capacity to eliminate toxins. This results in increased growth, improved feed conversion, and reduced risk of diseases given that this organ is also responsible for synthesising immune effectors. Secondly, it is essential for the overall health of the animal: pigs with healthy livers have a higher resistance to diseases, and they are less prone to disorders, such as steatosis and various types of hepatitis.

Factors affecting liver health

Liver health can be affected by various factors since this organ acts as a filter once nutrients and other substances cross the intestinal barrier, including the following:

• Feeding: A balanced and adequate diet is essential for liver health. Pigs need a diet that provides all the nutrients, in adequate quality and quantity, to avoid metabolic disturbances. The diet also has a significant impact on the micro-organisms in the intestine, and a poor formulation could lead to dysbiosis, with overgrowth of pathogens whose toxins can reach the liver.
• Micro-organisms: Various microorganisms, bacterial and viral, can multiply in the liver and cause hepatitis of varying degrees, damaging the liver. It is crucial to detect and prevent liver disease to avoid irreversible damage.
• Contaminants: Exposure to contaminants, such as heavy metals, can damage the liver. Also, contaminants that may be present in some dietary ingredients which are not metabolised and accumulate in liver vacuoles. Mycotoxins play a significant role as potentially hepatotoxic food contaminants, e.g. aflatoxins. It is important to take measures to reduce the exposure of pigs to different types of contaminants.

Measures to improve liver physiology

Pigs’ liver health can be enhanced by taking measures to regulate the previously mentioned factors. These include providing pigs with a balanced and appropriate diet that provides them with all the nutrients they need to maintain a healthy liver; detecting and preventing liver disease to avoid impairment of liver function; and reducing exposure to contaminants.

However, it is not always easy to anticipate potential liver challenges due to their large number. Therefore, the liver requires a boost to its physiology, which can be obtained by supplementing the diet with liver-conditioning pronutrients.

These natural active ingredients are particularly relevant, as they not only prevent liver damage but also restore the liver’s function after different challenges. As pronutrients can stimulate the regeneration of hepatocytes and, therefore, reactivate the physiological activity of the liver after a challenge, their supplementation in feed makes it possible to mitigate the effects produced by toxic substances and to recover normal productive parameters after the challenge. These effects have been demonstrated in several trials carried out in both field and experimental conditions around the world. In a recent trial in the USA, liver conditioner pronutrients were administered to pigs from the 6th to the 10th week of life, and the main productive parameters were observed.

In terms of weight, despite starting the test with almost equal weight, after 28 days, the animals supplemented with pronutrient liver conditioners obtained 370 grams compared to the control. In the case of the feed conversion (FCR), 3 points of improvement were obtained in the animals supplemented with pronutrients, which means better feed efficiency due to a better physiological state of the organ.

This is related to an improved state of liver physiology and function, which was directly evaluated by measuring the main liver enzymes in the blood.

It can be observed that the level of liver enzymes is lower in pronutrient-supplemented animals, indicating a better liver condition.

Conclusions

The liver is a key organ in pigs, as it plays a fundamental role in digestion, metabolism and toxin elimination. Therefore, promoting its proper physiology and function is essential for the performance and overall health of the animal.

In addition to controlling the main factors that can alter liver integrity, pig farmers can rely on pronutrient-based technologies as a powerful tool to ensure optimal liver structure and function.

Thanks to the use of pronutrients in the diet or in the drinking water, a better productive performance is achieved, and greater resistance to different diseases due to the involvement of the liver in the synthesis of immune effectors.