Necrotic enteritis (NE) is an acute infection caused by the gram-positive microorganism Clostridium perfringens, which causes severe necrosis of the intestinal mucosa. It is one of the most important avian pathologies worldwide, because it has a high prevalence and causes severe losses in poultry production.

The disease usually begins with an increase in the mortality rate and also with the appearance of dehydrated birds and worsened productive parameters. Necropsy allows a reliable diagnosis for this pathology, since there are intestines with foci of necrosis distributed in the mucosa of the small intestine that can be observed from the outside and from the lumen. This pathology can also affect the liver due to the toxins produced by Clostridium perfringens.

It mainly affects birds between 2 and 5 weeks of age, although it can also affect hens near the beginning of the laying period or in the laying peak. In addition, this pathology is mainly associated with coccidiosis.

This disease originates when the predisposing factors allow a higher proliferation, adherence and production of toxins by Clostridium perfringens.

There are risky situations that favour the growth of Clostridium, such as stress or transport of the hens to the laying farm. Other factors are dietary, such as changes in diet, the addition of non-starchy polysaccharides or high levels of protein in feed. Environmental management is very important as a risk factor, as well as concomitant diseases. Among these ones, coccidiosis is the most studied interaction. The different species of Eimeria produce intestinal damage and stimulate the mucus production in the intestine, which favours the proliferation of Clostridium perfringens.

But necrotic enteritis does not always require the previous course of coccidiosis, this disease may be the result of many other predisposing factors.

Approaches for the treatment of necrotic enteritis

It is convenient to prevent necrotic enteritis instead of waiting to treat it when an outbreak appears. The effort should be directed as follows:

• Control the damage of the intestinal epithelium and control the presence of coccidia.
• Avoiding the multiplication of toxigenic strains of Clostridium perfringens by the use of quality feed, by the addition of enzymes in the formulation, the maintenance of a balanced intestinal microbial flora and by helping to restore or maintain intestinal health.
• Avoiding the use of antibiotics, because, taking into account that the disease and the production of toxins progress very fast, it is usually too late to treat with antibiotics, since there is irreversible intestinal damage. In addition, antibiotics leave residues in meat and eggs, and also generate resistances.
• Using pronutrients that strengthen and maintain animal health, condition the intestinal mucosa and avoid the proliferation of Clostridium perfringens. They have a positive impact on intestinal health and also on productive and economic performance.
• Administer immunostimulants that strengthen the immune response.
• Adding feed optimizers to the diet, to maintain or improve feed quality and utilization.
• Control damage caused by mycotoxins, which can trigger malabsorption and, therefore, undigested feed available for Clostridium perfringens.

How to naturally fight necrotic enteritis

Alquermold Natural is a natural antimicrobial with bactericidal and fungicidal activity. The active principle of Alquermold Natural is the cimenol ring, which has synergistic activity with citric acid. It controls the pathogenic intestinal flora and serves as a preservative of raw materials and compound feed.

The cimenol ring is found in plant extracts such as Thymus vulgaris, Origanum majorana, Origanum vulgare, Mentha piperita, Ocimum basilicum or Salvia officinalis and is active against bacteria, fungi and yeasts. In bacteria, the cimenol ring causes an immediate release of cellular contents to the medium, due to the perforation of the bacterial membrane. In fungi and yeasts, in addition to perforating the cell membrane, the cimenol ring inhibits the biosynthesis of ergosterol, which is the most important sterol in the fungal cell membrane. The cimenol ring and the citric acid contained in Alquermold Natural have a synergistic action. Citric acid interferes with the cellular metabolism and facilitates the entry of the cimenol ring into pathogenic cells and it perforates the cell membrane.

Thanks to its bactericidal and fungicidal activity, the cimenol ring is used to control the pathogenic flora in the intestine, such as Salmonella, E. coli, Clostridium spp. or Staphylococcus spp.

Since it has specific microbicidal activity against pathogenic bacteria, it favours the growth of other beneficial ones.

Therefore, it presents the following important advantages:

• Immediate and long-term efficacy as a microbicide. It is the best alternative to organic acids as a preservative
• It is a better alternative to the antibiotics used to reduce intestinal pathogens

Effect of Alquermold Natural in broilers challenged with Clostridium Perfringens

In an in vivo trial conducted in an experimental farm of the Universidad Científica del Sur (Lima, Peru) in September 2017, the bactericidal effects of Alquermold Natural on the productive parameters and the CFU counting of Clostridium perfringens in the intestine were evaluated, as well as other parameters, in broilers artificially challenged with these bacteria.

The trial had a total of 504 Cobb 500 broilers, raised from day 1 to 42 (slaughter) and distributed in batches with 126 animals each. Each batch was had 7 replicates, with a total of 28 experimental units with 18 broilers each.

The batches were distributed as follows:

• T1 or Negative control: standard basal diet.
• T2 or Positive control: standard basal diet + challenge with Clostridium perfringens in drinking water on days 19, 20 and 21 of age with 10⁸ CFU/bird.
• T3 or Alquermold Natural as a preventative: standard basal diet + natural preservative continuously at 0.5 kg/Tm + challenge with Clostridium perfringens in drinking water on days 19, 20 and 21 age with 10⁸ CFU/bird.
• T4 or Alquermold Natural as a treatment: standard basal diet + challenge with Clostridium perfringens in drinking water on days 19, 20 and 21 of age with 10⁸ CFU/bird + inclusion of 1 ml preservative/liter of drinking water, for 7 days, from the detection of symptoms of necrotic enteritis.

The results are shown below:

Productive parameters

Pesos semanales (imagen izquierda) e índice de conversión (imagen derecha) a lo largo del ensayo. T-1: Control; T-2: Control + Desafío; T-3= Anillo cimenol (prevención) + Desafío; T-4: Desafío + Anillo cimenol + tratamiento (tras la aparición de signos)

In T1 (basal diet, non-infected) normal parameters were observed, while there was a remarkable decrease in the productive parameters in T2 (infected non-treated) after challenge with Clostridium perfringens.

T3 (Alquermold Natural as a preventative) significantly improved the weight of the birds and the feed conversion rate, as bserved in the tables, and also the weight gain and feed consumption were improved. T4, where Alquermold Natural liquid was used as treatment, improved the parameters compared to T2, although it did not reach the results of T3.

Mortality was lower in T3 (Alquermold Natural as preventative) than in the other groups. In T4 (Alquermold Natural as a treatment) mortality was lower than in T2 (infected and non-treated), which means that the product applied as treatment in an enteritis outbreak is effective in reducing the mortality.

After the challenge with Clostridium perfringens, animals in T3 (Alquermold Natural as a preventative) did not decrease their performance, since the animals obtained better weight and FCR than T1 (uninfected birds). Additionally, animals in T3 weighed 292 more grams and got a 12.3% FCR on day 42 compared with T2 (infected).

On the other hand, animals in T4 (Alquermold Natural as treatment) after challenge with Clostridium perfringens, improved daily weight gain. In fact, theyweighed 138.9 grams more on day 42 and improved the feed conversion rate by 8.7%, compared with T2 (infected).

Uniformity and carcass yield

The batches with Alquermold Natural, both as prevention and treatment (T3 and T4, respectively) obtained even greater uniformity than batch T1 (non-infected), reaching, in the case of T3 (Alquermold Natural as preventative), 86% uniformity. Likewise, T3 obtained the highest carcass yield (78.21%) and the lowest percentage of abdominal fat.

Microbiological analysis (Sulphite-reducing Clostridium)

Regarding the microbiological count, T3 (Alquermold Natural as a preventative) showed the lowest CFU counting in duodenum and caecum after infection. Treatment with Alquermold Natural (T4) also reduced CFU in the duodenum and caecum compared to batch T2 (infected without treatment).

Histopathology

T2 (infected non-treated) showed more animals with compatible lesions of necrotic enteritis, and these were more severe (atrophy, necrosis, ulcerations).

In T3 and T4, both with Alquermold Natural, animals showed fewer lesions than in T2, and they were less intense. Specifically, T3 (Alquermold Natural as a preventive), was the batch that showed fewer and milder injuries. The largest mucosal length was also observed in this batch in intestinal morphometry tests.

Conclusions

Alquermold Natural, natural preservative based on cimenol ring, can be used to prevent necrotic enteritis in broilers with good results. Also, it can be used as a treatment against necrotic enteritis when an outbreak has already been established. This natural preservative based on ring cimenol obtains better results used as a preventative for necrotic enteritis than as a treatment.

Main picture: Brett Jordan