Hepatic disorders and their relationship with laying parameters
Egg industry has grown exponentially worldwide in the last 25 years, almost doubling its capacity, and a similar scenario is expected for the next 25. This growth will be accompanied by a marked increase in the world population that will undoubtedly need a source of animal protein, and the egg is emerging as one of the most accessible and nutritionally complete sources.
Egg industry, a booming sector in Latin America
Egg industry has grown exponentially worldwide in the last 25 years, almost doubling its capacity, and a similar scenario is expected for the next 25. This growth will be accompanied by a marked increase in the world population that will undoubtedly need a source of animal protein, and the egg is emerging as one of the most accessible and nutritionally complete sources. In Latin America, the sector has showed a marked increase in this period too. In 2019, almost all the countries in the region increased their egg production. Panama, Ecuador, and Colombia showed the most remarkable growth, with 34%, 15.4% and 14.6%, respectively. However, in absolute terms, Colombia’s growth was 6 million hens and Panama 850,000. The rest of the countries in the region also increased their egg production, as is the case of Costa Rica with 3.16% and Peru with 1.47%, the latter showing more moderate growth, as the market regulated itself due to an excess in the productions observed in previous years. Regarding 2020, the current global situation has generated certain ups and downs, but more in terms of price than in production, since during the first half of the year production increased in most of the countries of the region despite the global instability . All these factors suggest that, except for specific situations, the sector will keep growing as expected for the next 25 years.
The liver in the laying process
To satisfy the increase in global egg demand, not only the population of laying hens has increased, but genetic companies have worked to develop highly productive lines, to produce more eggs in the shortest time. However, this generates a high productive stress for the hens, and the liver is one of the organs that suffers the most from it, since it is in charge of synthesizing the main components of the egg, as well as regulating the high metabolism of these birds.
Therefore, the synthesis function of the liver is essential to produce eggs in sufficient quality and quantity, since the main lipids and proteins that will be part of the egg will be synthesized by this organ. Simultaneously, it is responsible of the detoxification and protection against several agents, such as drugs, toxins, or free radicals, among many others.
Main hepatic disorders affecting egg production
- Hepatic mycotoxicosis: Some mycotoxins, such as aflatoxins or ochratoxins, have a negative action in the liver, among other locations. In this organ, they cause inflammation and congestion that can lead to degenerative processes, affecting its functionality, including the capacity of synthesizing egg components. In addition, aflatoxins reduce bile secretion, which leads to less lipid absorption and, on the other hand, they alter coagulation, which can lead to bleeding, indirectly affecting the laying process.
- Bacterial hepatitis: Several types of bacteria and their toxins cause hepatic damage, such as Clostridium, whose toxins can reach this organ, causing friability and degeneration. Other enterobacteria, such as SH2 producers (Salmonella, Proteus, Pseudomonas or Shigella), the cause of avian infectious toxic hepatoenteritis, have a pathogenic effect on the liver, causing bacterial hepatitis. They are located in this organ and are released during stress periods, such as in laying peaks, causing a decrease in the laying percentage and in the microbiological quality of the egg, and may lead to a systemic infection. Furthermore, they can be transmitted to subsequent generations through vertical infection, affecting the productive performance of the next generation.
- Parasitic hepatitis: Some parasites that have an enterohepatic migration, such as Histomonas, that pass through the caecal mucosa and reach the liver, causing necrotic-diphtheroidal foci, affecting liver function, and increasing mortality. This is more frequent in turkeys, but severe cases are currently being described in cage-free layers, which feed on Heterakis, the carrier of this parasite.
- Fatty Liver Haemorrhagic Syndrome (FLHS): It is a frequent disorder, since it appears not only in hot climates, but also when birds are under heat stress conditions, such as high densities, common in many current production systems. There are other triggers for FLHS, such as overweight, long laying periods, restricted locomotion, and deficiencies in calcium absorption. In birds affected by this syndrome, a drop in the laying rate is initially observed and, at necropsy, friable and fatty livers, large blood clots in the abdomen caused by a ruptured liver, as well as sudden death can be seen.
- Hepatic steatosis: It is a degeneration of the liver and there are multiple origins of this liver disorder. Friable, unstructured, and fatty livers can be observed when it appears:
- Drugs: Administrated in excess can damage the liver irreversibly, leading to degeneration and loss of hepatic function.
- Mycotoxins: For example, chronic aflatoxin or ochratoxin intake leads to hepatic steatosis.
- Free radicals: they come from oxidized feed or poor quality or recycled fats that contain harmful components that, once in the liver, are not metabolized and are stored in vacuoles, causing fatty degeneration of the liver.
All these alterations will affect both defensive, metabolic and synthesis functions of the liver, and the capacity of this organ to produce eggs properly. Simultaneously, birds will show immunosuppression, since this organ is also responsible for synthesizing multiple immune effectors.
The protection of the liver through liver conditioner pronutrients
Usually, despite applying strategies to prevent hepatic damage, some agents can reach the liver and damage it. For example, this occurs when a pharmacological treatment is applied, or when there is a high mycotoxin contamination and reaches the liver. Therefore, it is important to keep this organ protected and promote its adequate regeneration, so that the liver is in optimal physiological conditions to work properly. In this sense, liver conditioner pronutrients have proven to be an effective solution to improve the regeneration of hepatocytes, their target cells. Pronutrients are active natural molecules that come from shikimic acid and promote the liver regeneration, which allows a greater synthesis of non-essential amino acids, a better elimination of toxins and free radicals, and an adequate regulation of lipid metabolism and absorption. That is, liver conditioner pronutrients allow the liver to be in adequate physiological conditions, protected against any threat that could negatively affect its function, or recover its function if it has already been affected.
Usually, under field conditions there are several challenges that can affect the liver, such as aflatoxin-type mycotoxins. Graph 1 shows the results of a trial carried out with layers fed aflatoxin-contaminated feed. In one of the groups, liver conditioner pronutrients were administered, and the results were compared to the control. The use of dietary protein and fat was greater with the use of these natural molecules, which leads to a higher laying percentage. This is due to the improved physiology of the liver thanks to the use of liver conditioner pronutrients.
Other strategies for the prevention of liver diseases
To control most of the liver disorders described, several measures must be implemented so that the different causative agents do not reach and damage the liver. Therefore, it is necessary to take into account the following considerations:
Use a mycotoxin binder in feed:
The target is to prevent mycotoxins from damaging the organism. In this sense, those mycotoxin binders based on Silicoglycidol molecule have proven to the most effective against all mycotoxin groups, with a high binding capacity, especially against those that damage the liver, such as aflatoxins or ochratoxin, with 97.3% and 82.9% adsorption percentages respectively.
Silicoglycidol is a patented molecule that has an optimized surface for mycotoxin adsorption. During its activation process, the molecule undergoes a heat treatment and an ionic exchange. This manufacturing process confers the molecule, on one hand, a high adsorption surface, that allows to use the molecule in diet at low doses, and, on the other hand, a greater capacity to bind mycotoxins through hydrogen bonds.
All types of mycotoxicosis can be prevented with Silicoglycidol because it binds all mycotoxins through hydrogen bonds, thanks to its specific properties. In addition, hydrogen bonds are the strongest in nature, so mycotoxins do not desorb at any of the pH along the digestive tract and will be eliminated through the faeces without causing damage to the organism, nor reaching the liver. An added positive effect of this molecule is that it is totally safe for the animals and does not adsorb vitamins, amino acids or other components of the diet, fact that contributes to the economic profitability of the farm.
The use of mycotoxin binders based on the Silicoglycidol molecule increases the laying rate by up to 2.7% compared to other binders. Silicoglycidol effectively adsorbs mycotoxins and prevents them from damaging the organism, including the liver, allowing an increase in the percentage of laying due to a better functionality of this organ.
Administer a microbicide in feed and drinking water:
Some of the bacteria that cause bacterial hepatitis have their origin in drinking water or feed, so it is essential to apply control measures in both. Cimenol ring is a natural molecule with microbicidal capacity against a wide variety of microorganisms found in feed or drinking water, and it has a synergy with citric acid. This acid creates pores in the membrane of the pathogenic bacteria and facilitates the entry of the cimenol ring, which breaks the membrane destabilizing the lipid bilayer from the inside, causing the death of the pathogens. Both active principles are included in Alquermold Natural, a product developed by Biovet, S.A. that, in addition to having a microbicidal effect on water and feed, its effectiveness remains in the digestive tract, acting as an intestinal biocide and controlling intestinal imbalances. Thus, it prevents bacteria from reaching the liver or producing systemic infections. It has proven to be widely effective against Clostridium, Salmonella or Pseudomonas, that cause bacterial hepatitis, frequently isolated in layers.
Include intestinal optimizer and conditioner pronutrients in diet:
These natural active molecules have a metagenetic-based mechanism of action that consists of the induction of the synthesis of functional proteins in the target cells. In the case of intestinal optimizer pronutrients, the target cells are the local immune cells of the intestine, where these molecules increase the synthesis of specific interleukins, such as IL-1, IL-12 and IL-18 that make the intestine less prone to suffer from protozoosis. Besides, intestinal conditioner pronutrients act in the enterocytes, and activate several genes related to intercellular adhesion that improve tight junctions, to the movement of microvilli, to the presentation of antigens, or other genes that regulate the expression of immune effector receptors. The combination of both pronutrients improves local immunity and the integrity of the intestinal epithelium, preventing certain protozoa from reaching the liver and causing damage to this organ and consequently affecting egg production.
Establish adequate feed formulation programs:
These programs should be accurate with adequate inclusion levels of the different ingredients, so that energy levels are adequate to maintain an homogeneous growth and development and, simultaneously avoid overweight that can lead to fatty liver haemorrhagic syndrome (FLHS). The quality of the ingredients should also be considered, such as fats, avoiding using those recycled with harmful components that degenerate the liver. The inclusion of antioxidants and preservatives is recommended in order to avoid additional damage to the liver. Global Vet’s Lab, technical service of Biovet, S.A. offers the possibility of considering all these factors to get a specific formulation for each stage, including those programs for improving the efficiency in each phase, aimed at a better physiological functionality of the organs that participate in the laying process, including the liver.
Egg sector, both globally and in Latin America, has been doubled in the last 25 years and growth expectations are similar for the next 25. In order to satisfy the egg demand, hens genetics have developed highly productive breeds, but with high levels of productive stress that affect the organs related to laying process, especially the liver. This has led to an increase in the incidence of liver disorders and it is necessary to implement specific prevention programs for each of the agents causing these disorders. Additionally, the maintenance of adequate liver physiology is essential to guarantee an optimal production and prevent liver disorders. In this sense, liver conditioner pronutrients are an effective solution that naturally protect and regenerate the liver from several challenges that threaten its functionality. With the use of these molecules, an improvement in the laying rate of 3% has been achieved, as well as a better use of dietary fat and protein, by 3% and 5% respectively, which represents a greater efficiency in egg production with a very positive economic impact in the farms.