Digestive, bacterial and fungal diseases in poultry farming: impact, diagnosis and prevention

The digestive system is in charge of transforming the feed into assimilable nutrients, a key process in commercial poultry farming to maintain health status and obtain good productive results. It also works as a selective barrier to protect the organism from harmful agents.

Any disease that affects the function of the digestive system will lead to a loss of productive performance, such as growth retardation, poorer conversion rates and feed efficiency, and even high mortality. As an example of the economic impact of digestive diseases, the global cost of necrotic enteritis, caused by Clostridium perfringens, is estimated to be above 2 billion dollars annually, where losses are related to the worsening of productive performance, mortality, treatment costs and condemnations in processing plants.

Therefore, it is important to make an early identification of digestive diseases to apply corrective and preventive measures. The observation of the clinical signs, which, in many cases, begin with a decrease in productivity, and the performance of post-mortem examinations to locate and identify the lesions are two essential tools to reach a correct diagnosis.

Digestive diseases mentioned in this article are of fungal and bacterial origin. Mycoses are less prevalent and they may appear in young animals and cause a relative morbidity and mortality, usually linked to immunosuppressive processes. Differently, bacterial challenges show visible signs and higher morbidity and mortality rates and are usually a primary cause of the disease. The most prevalent infectious diseases in South East Asia and the most characteristic signs and lesions of each one are listed below:

1.1.Clostridiosis

Clostridium perfringens can grow in the transit area between proventriculus and gizzard and also in the mucosa of the small intestine, causing the so-called necrotic enteritis, which consists of reddish round and concave lesions with loss of intestinal villi. This bacterium can produce toxins that may reach the liver.

Clostridium perfringens is part of the normal intestinal microflora and outbreaks are related to an excessive proliferation favored by multiple predisposing factors. Animals affected by necrotic enteritis can show dehydration, diarrhea and, especially, a marked increase in mortality.

1.2.Mycoses

Septate fungi like Aspergillus, Fusarium or Penicillium can grow in the gizzard, where they produce erosions and ulcers in the corneal layer. When separating the muscular and corneal layer, whitish fungal growth can be observed between them, a differential factor with mycotoxicosis, which will only affect the corneal layer without fungal growth.

1.3.Infectious toxic hepatoenteritis (ITH)

There are several agents, including Salmonella and Shigella, which may cause similar signs and can affect young chicks and adult animals.

Greenish content in the gizzard is observed in day-old chicks, along with unabsorbed yolk and enlarged ceca with gas and greenish content. These findings are combined with a high mortality in the first week of life and a lower final weight at the end of the cycle. Older chickens show persistence of Meckel's diverticulum and, in breeder and layer hens, infected greenish dark-colored ovules are observed. No clinical signs may be visible in adults, despite it can appear a drip in mortality and greenish faeces and/or emaciation.

Very often, digestive diseases are produced by microorganisms present in the feed. Traditionally, prevention of these bacterial and fungal challenges from feed origin has been based on the use of organic acids as preservatives, to prevent their growth in feed.

Organic acids are also commonly known as acidifiers or fungal/mold inhibitors. The effectiveness of these products is limited, since their effect does not last over time, as they have a bacteriostatic and fungistatic action and microorganisms develop resistance mechanisms.

For this reason, Biovet S.A. has developed an effective solution for their replacement, Alquermold Natural, based on the synergistic effect of the cimenol ring and citric acid.

Alquermold Natural is a solution with antimicrobial properties, effective against a wide rage of microorganisms, including the ones described in the diseases above. Its activity lasts for at least six months in grain and balanced feed and does not create microbial resistances.

Thus, Alquermold Natural is the ideal tool for the conservation of feed and raw materials, capable of eliminating completely fungi such as Candida, Aspergillus and Penicillium, and bacteria such as Clostridium, which causes necrotic enteritis, E. coli or Salmonella, causal agents of infectious toxic hepatoenteritis, among others.

The wider spectrum of action and the low dosage of Alquermold Natural needed to preserve the nutritional quality of the feed shows the great advantage of the product compared to products with similar indications.

At the same time, Alquermold Natural is also effective at the digestive tract and it can control the growth of these microorganisms once they access into the digestive lumen.

 3. Research on the prevention of digestive diseases of bacterial and fungal origin thanks to Alquermold Natural

The efficacy of Alquermold Natural has been studied in the laboratory, in research facilities and commercial farms. Trials have been conducted to demonstrate the microbicidal capacity of the compound against a wide variety of microorganisms.

It was proved an effective supplement to prevent and treat necrotic enteritis caused by Clostridium perfringens. Using it improves economic benefits compared to non-treated challenged groups, and even compared to non-challenged groups.

In addition, its efficacy has also been compared to other products claiming similar properties, such as organic acids, both in vitro and in vivo.

3.1. ALQUERMOLD NATURAL COMPARED TO ORGANIC ACIDS – IN VITRO

Evaluation performed at independent laboratories aimed to compare the efficacy of Alquermold Natural (0.5 L/t), with a product based on organic acids (1 L/t) and another product which combines organic acids and formaldehyde (2 L/t). The efficacy of the different solutions was assessed in two artificially contaminated substrates, ground corn and balanced feed, with Aspergillus, Clostridium, E. coli, and Salmonella.

Results showed that the powerful antimicrobial effect of Alquermold Natural was able to eliminate, on average, 98.5% of Clostridium, E. coli and Salmonella, and more than 86% of Aspergillus, compared to the reduction produced by organic acids (97% against bacteria and 84% in Aspergillus) and organic acids combined with formaldehyde (97.5% and 85.5% reduction, respectively). Thus, the effect of Alquermold Natural was superior to those of the products compared, despite they were used at two-fold and four-fold dosage.

3.2. ALQUERMOLD NATURAL COMPARED TO ORGANIC ACIDS – IN VIVO

In broilers, an improvement in weight (+14 g/bird) was observed when supplemented with Alquermold Natural, with a similar conversion and survival rate compared to a group receiving two additives based on organic acids. Both the Alquermold Natural group and the organic acids group achieved the same efficiency index (439 pts.). This demonstrates that Alquermold Natural can replace two chemical additives simultaneously, obtaining similar productive results at a lower dosage.

 4. Conclusions

Many infectious diseases of the digestive tract, which impair the animal performance, have their origin in feed. Organic acids, mold inhibitors and acidifiers have been used to control the growth of such microorganisms, although these products may have several disadvantages, including a short-term action, corrosivity and narrow spectrum of action.

Alquermold Natural, thanks to the synergistic effect of cimenol ring and citric acid, demonstrated to be an effective natural solution with antimicrobial properties, which works as a feed preservative to control the entry and growth of pathogens in the digestive tract by completely eliminating pathogenic fungi and bacteria.

Results obtained in vitro and in vivo, showing better results of this product at lower dosage, corroborate that Alquermold Natural is a great solution to replace other preservatives, easing feed formulation and management using only one product and at low inclusion rate.

In addition, the product offers safe features thanks to its natural origin, as it is not corrosive and cannot harm animals, nor workers nor machinery, no resistances may appear and there is no withdrawal period required because no residues are left in products.