Economic success of a poultry farm is directly linked on gut comfort. Maintaining a proper gut welfare in poultry is basic to achieve the desired production efficiency of the flock. In addition, gut welfare in poultry may also have an impact on food safety.

However, the genetic improvement obtained in the last decades on the growth rate and feed conversion ratio of birds has supposed big pressure for the digestive system of broilers, making them prone to suffer enteric disorders, which cause high economic losses yearly to the industry worldwide.

Causes of enteric disorders in poultry

An usual mistake when talking about intestinal welfare in poultry is to only focus on the control of enteric disorders of infectious origin, like coccidiosis or necrotic enteritis, because these diseases have several predisposing factors, stressful conditions that will alter the feed intake and nutrient absorption, decreasing the gut motility, disrupting the balance of the digestive system and facilitating the proliferation of microbes.

Thus, several elements should be considered for the design of a proper strategy to achieve maintain gut welfare in poultry. Among the items to be assessed there are: feeding, housing and management conditions, together with the biosecurity and health plan of the farm.

Whenever any of the factors reviewed above caused bacterial proliferation, the control in the last decades had been based on the use of antibiotic growth promoters (AGPs). However, there is a growing trend to limit and reduce the utilisation of antibiotics due to the appearance of resistant strains of bacteria, and also due to the consumer interests in avoiding the consumption of products that may contain traces of AGPs.

Achievement of a proper and maintained gut welfare in poultry and performance without the use of antibiotics is a challenge that can be accomplished by the use of a blend of tools, including management, biosecurity and feeding practices, combined with the use of alternative feed additives.

Key points to maintain gut welfare in poultry

Understanding the role of the factors mentioned above is crucial to plan strategies to enhance gut functionality, promote the balance of the microbiota and ensure a proper feed utilisation.

Therefore, the maintenance of a proper gut welfare in poultry should be based on working on host welfare, the integrity and barrier of the intestinal mucosa, and the control of the microbial ecosystem, including modulation of gut microflora and control of intestinal pathogens. There are several feed additive solutions which are effective for these different purposes.

• Maintenance of intestinal integrity

The efficiency of the absorption of nutrients is causally related to the welfare and integrity of the intestinal mucosa. The longer and healthier the villi, the greater the surface of absorption and the better the physical barrier between intestinal lumen and blood. Enterocyte lining is sealed together by tight junctions, which avoid the entrance of toxics and pathogens to the blood and control the inflammatory response.

Pronutrients are active molecules from plant extracts which have a metagenetic mechanism of action. They can stimulate the synthesis of functional proteins in the target cells, improving cell functionality. There are several types of pronutrients, which have different target cells. Furthermore, they have several additional advantages: as they are a natural solution, there is no risk of resistances and no residues are left in products, thus, they do not need a withdrawal period.

Enterocytes are the target cell of intestinal conditioner pronutrients. This type of pronutrients promote enterocytes physiology, enhancing the regeneration of this cell and its barrier function.

Several in vitro trials demonstrated that intestinal conditioners induced the expression of genes related to cell adhesion, proliferation, cilia, vesicles and metabolism of enterocytes. Therefore, they promote enterocytes activity and gut integrity, enhancing the absorption of nutrients and the defence function.

Intestinal conditioners are highly recommended to enhance gut welfare and development, improve animals’ growth and reduce feed conversion rate. For instance, experimental results obtained, extrapolated to 1 million broilers, showed that intestinal conditioners can increase meat production by 147 tons while reducing feed utilisation by 324 tons compared to animals using BMD and halquinol.

• Control of intestinal pathogens and toxic compounds

Microbial and mycotoxin challenge present in feed should be always assessed, together with other potential sources of infectious and toxic challenges. There are pathogens that may directly affect the gut, including viruses, like rotavirus; bacteria like E. coli and Salmonella; fungi, like Candida, and parasites, like Eimeria.

– Bacteria and fungi

Measures at feed production level should be implemented to minimize the risk of mold spoilage, like the use of feed preservatives. Control of intestinal pathogenic challenges should be done using an antimicrobial solution. Currently, there are natural microbiocidal solutions available to control the existing challenges in feed and in the intestine.

Cimenol ring is one of the most known ones for its selective fungicidal and bactericidal properties. Evaluations in live animals have shown its effectivity to reduce the colonization of several pathogenic bacteria, like Clostridium perfringens,  E.coli, Salmonella, Campylobacter, and also the promotion of a beneficial microbial ecosystem, reducing the population of sulphate reducer bacteria and increasing Lactobacillus population, leading to an overall increased tissue health.

This means that the antimicrobial properties of cimenol ring are useful and effective to prevent feed spoilage and also to control the gut microbiota and infectious gut disorders, favouring the beneficial flora and controlling the growth of pathogenic bacteria like Clostridium perfringens, E. coli and Salmonella.

Commonly used solutions are products based on organic acids (also named mould inhibitors or acidifiers). The superiority of cimenol ring to organic acids is clearly demonstrated in the graph below, were cimenol ring (0.5kg/t) achieves a 100% reduction in the UFC count of fungi in broiler feed, compared to organic acids (2kg/t), which only reduce it by 32%.

– Parasites

Most known intestinal parasite in poultry is Eimeria, especially harmful in chickens. The control of coccidia invasion is the key to prevent additional bacterial infections that may appear once there is a loss of intestinal integrity, like necrotic enteritis caused by Clostridium perfringens.

Novel strategy to prevent coccidiosis is to perform an immunological control of the disease, through the use of natural dietary supplements like intestinal optimizer pronutrients.

Intestinal optimizer pronutrients enhance the local immunity of the intestine, since they stimulate the expression of interleukins (IL-1, IL-12, IL-18) by intestinal polymorphonuclear cells (PMNs). Interleukins are proteins that act as chemical mediators in the cellular immune response and attract defence cells to the affected area, playing a fundamental role in the response to coccidia invasion.

For this reason, intestinal optimizers can be used in the control of coccidiosis, as they stimulate the gut immune physiology of the animal to fight against coccidia challenge. Intestinal optimizers are a great tool to be included in the anticoccidial plan of the farm, as they offer a great versatility, allowing a complete or partial replacement of coccidiostats, as a cleaning of the drug plan previously done in the farm, and can also be used as a complement of vaccination programs.

The advantages of using intestinal optimizers are demonstrated through the productive results obtained: partial replacement of coccidiostat from day 22 achieved a higher weight (+2.88%), while ‘on top’ utilisation accomplished a 9.7% increase in final weight and a lower FCR (-4%) and mortality (-6%). When combined with vaccination, it is also visible the reduction achieved on coccidiosis mortality (-34%) and total oocyst shedding (20%).

– Mycotoxins

Mycotoxin binders should be included in feed to capture the mycotoxins and avoid its negative effects in the intestine and internal organs. Silicoglycidol is a patented molecule that, after a deep research and treatment process, has an optimized structure that makes it the most complete and safe mycotoxin binder molecule in the market.

The optimized structure of Silicoglycidol ensures a wide spectrum of action and a high effectivity at low dosage. In addition, it is demonstrated it does not capture amino acids or vitamins from the diet, unlike other binders, and it remains effective independently of the pH conditions in the gut.

Commercial trials showed that Silicoglycidol administration at 0.5 kg/t in 1 million broilers was able to reduce feed utilisation by 18 tons while enhancing meat production by 10 tons. Thanks to Silicoglycidol features, it is offered a great benefit to economic ratio.

• Maintenance of host welfare

Management, environmental factors, feeding, general health status and biosecurity should e always considered as potential stress factors that may affect host welfare, and therefore, have a repercussion on feed intake, gut welfare and productivity.

Proper vaccination plan in breeders and chicks against immunosuppressive diseases like Newcastle Disease, Infectious bronchitis and Gumboro disease are basic topics to include in a general health program and may also have a preventive effect on gut disturbance. In addition, it is important to comply with the biosecurity practices to avoid entrance and spread of pathogens and thus, ensure a low risk in the farm. In this way, it is less provable to alter general immunity and gut function.

Good control on environmental conditions are key for intestinal comfort. Extreme temperature and humidity conditions (either caused by heat, cold, dry or very humid environment) and drastic variations in such parameters should be avoided. Proper ventilation will ensure there is no condensation and will have a positive effect on litter moisture.

Regarding feeding practices, the increase in the number of dietary phases allows to improve the precision of feed formulation according to animal needs, and avoids the excess of nutrients, like fats and proteins, which may promote microbial proliferation. It is important to highlight that the transition between starter and grower diets usually takes place at 2-3 weeks of age, when young animals may still have not an stabilized microbiota. Because of this, making an earlier and more gradual transition from starter to grower diet may favour on the reduction of the challenge.

Feed quality assurance programs should be stringent and well-balanced composition is mandatory. The use of exogenous enzymes may boost digestion of the feed formula and, thus, it will generate a positive impact on cost savings. It is recommended to include a complete enzymatic formula, based on subtilisin, xylanase, amylase and cellulase, that increases utilisation of the diet, thus improving feed conversion efficiency and production performance.

Conclusions

The gut is a key organ for poultry welfare and productivity of the farm. There are several factors to be considered for optimisation of gut welfare in poultry. Understanding the influences that have among each other, together with the defects of each farm, are key to design a proper strategy to boost the gut physiology and the animal’s performance and health.

To ensure that the intestine functions are not impaired, it is necessary to combine several measures, including management and nutritional ones, and also the use of well-chosen feed additives.

Feed additives are highly useful tools in the strategy to maintain gut welfare in poultry, each one aiming to provide a solution to one of the key points:

• Intestinal conditioners for intestinal integrity, seen as an improvement of productivity: Per 1 million broilers, it is obtained 147 more tons of meat while 324 tons of feed less are used, compared to BMD and halquinol.
• Cimenol ring for the control of pathogenic microorganisms in feed and in the intestine. Best choice, rather than other marketed solutions: reduction of 100% Fungi CFU in broiler feed compared to 32% of organic acids.
• Intestinal optimizers for coccidiosis prevention. Control of intestinal immunity allows to obtain a higher final weight, compared to monensin (+2.88%).
• Silicoglycidol for mycotoxicosis prevention. Positive effect showed in productivity: +10 tons of meat produced and -18 tons of feed utilisation.
• Enzymes to enchance feed digestibility.

In this way, these solutions boost the performance of the animals and allow them to grow to its maximum genetic potential.

The mentioned solutions are researched, developed, manufactured and marketed by Biovet S.A. under the following commercial names:

• Intestinal conditioners: Alquernat Nebsui, available in powder and liquid presentation.
• Intestinal optimizers: Alquernat Zycox, available in powder and liquid presentation.
• Cimenol ring: Alquermold Natural, available in powder and liquid presentation.
• Silicoglycidol: Alquerfeed Antitox, available in powder presentation.
• Complete enzymatic core: Alquerzim A, available in powder presentation.