This article explains the lecture given by Dr. Manuel Rosemberg of the Scientific University of the South, “Científica” (Lima, Peru), in the XXXI International Symposium of Biovet in Tarragona (Spain), during the third session dedicated to pronutrients, which took place on the 28^th May 2018.

With the title, “Alquermold Natural, treatment and prevention of necrotic enteritis”, the conference addressed the use as a preventive and as a treatment of this preservative of botanical source in broilers challenged experimentally with Clostridium perfringens, evaluating the productive parameters, the bacterial burden and intestine lesions. The veterinarian of the team of Biovet S.A, Dr. Antón Tallero, has made the adaptation of the article.

Introduction

The bacterium Gram + and spore-forming, Clostridium perfringens, is the causative agent of gas gangrene in humans, enterotoxemia in ruminants and necrotic enteritis in birds. It can be classified into five different types (A, B, C, D and E) depending on the potency and lethality of the toxins they produce.

Necrotic enteritis is an acute enterotoxemia that can affect chickens and turkeys. Clinical disease is usually very brief and, often, the only signs are severe depression followed rapidly by a sudden increase in flock mortality.

The enterotoxemia that causes clinical disease occurs more frequently after a change in the intestinal microflora or a condition that causes damage to the intestinal mucosa (eg, coccidiosis, mycotoxicosis, salmonellosis, ascarid larvae).

This disease has gained special importance in recent years within the poultry sector, mainly due to the restriction of antibiotic treatments and growth promoters (AGPs), so it has been necessary to find alternatives for its prevention.

Biovet S.A. has isolated and patented a molecule of botanical source called cimenol ring, which can prevent the growth of Clostridium perfringens in feed and raw materials, as well as acting as an intestinal biocide.

To demonstrate its effectiveness, a study was developed at the “Científica” University in Peru, led by Dr. Manuel Rosemberg. This consists of the use of Alquermold Natural, a natural preservative of Biovet S.A. containing cimenol ring and citric acid, in a broiler farm challenged experimentally with Clostridium perfringens.

Objective

To evaluate the effects of the bactericide Alquermold Natural on the productive parameters, bacterial burden and intestine lesions of broiler chickens experimentally challenged with Clostridium perfringens.

Experimental design

The test was carried out in a total of 504 Cobb 500 variety broilers, distributed in 4 treatments (126 animals / lot) through the “Completely Randomized Design” protocol. Each lot had 7 repetitions, giving a total of 28 experimental units, with 18 broilers in each experimental unit. The trial, which began on September 13th, 2017, lasted a total of 42 days, from birth to slaughter of the animals.

The lots were as indicated below:

• T-1 or Negative Control: standard basal diet.
• T-2 or Positive Control: standard basal diet + challenge with Clostridium perfringens in drinking water at 19, 20 and 21 days of age with 10⁸ CFU / bird.
• T-3 or natural preservative with Alquermold Natural as a prevention: standard commercial basal diet + natural preservative continuously at 0.5 kg / Tm + challenge to Clostridium perfringens in drinking water at 19, 20 and 21 days of age with 10⁸ CFU / bird.
• T-4 or natural preservative with Alquermold Natural as a treatment: standard commercial basal diet + challenge to Clostridium perfringens in drinking water at 19, 20 and 21 days of age with 10⁸ CFU / bird + inclusion of 1 ml preservative / liter of drinking water, for 7 days, from the detection of necrotic enteritis symptoms.

For the processing and analysis of data, tests of normality, homogeneity of variance, ANOVA and a Tukey comparison test were carried out. The General Linear Model (GLM) procedure of SAS, version 9.1 (SAS Institute, 2003) was used.

Results

Weight by ages

Effect of Alquermold Natural (AMN) on live weight, administered as a preventive and treatment in broilers from 1 to 42 days of age challenged with Clostridium perfringens.

Weight gain

Effect of Alquermold Natural on weight gain, administered as a preventive and treatment in broilers from 1 to 42 days of age challenged with Clostridium perfringens.

Feed intake

Effect of Alquermold Natural on feed intake, administered as a preventive and treatment in broilers from 1 to 42 days of age challenged with Clostridium perfringens.

Feed Conversion Rate (FCR)

Effect of Alquermold Natural on the Conversion Index administered as a preventive and treatment in broilers from 1 to 42 days of age challenged with Clostridium perfringens.

Mortality and / or slaughtered

Effect of Alquermold Natural on mortality, administered as a preventive and treatment in broilers from 1 to 42 days of age challenged with Clostridium perfringens.

Uniformity

The presented uniformity indicates the weight of all the birds belonging to the respective treatments. Birds were weighed individually.

Effect of Alquermold Natural on uniformity, administered as a preventive and treatment in broilers from 1 to 42 days of age challenged with Clostridium perfringens.

In the table it is observed that T-4 did not recover the uniformity after the infection.

Carcass performance

Effect of Alquermold Natural on carcass performance, administered as a preventive and treatment in broilers from 1 to 42 days of age challenged with Clostridium perfringens.

In the table it is observed that T-3 obtained the best weight of the carcass, in addition, those responsible for the trial indicated that the broilers of T-3 had lower percentage of abdominal fat, with observable differences at first sight.

On the other hand, T-4 did not recover the performance of the carcass after infection.

Microbiological analysis

h.1. Sampling and quantification of sulfate-reducing Clostridium in the duodenum in the different stages of the trial: preinfection, 3 days post-infection and 1-week post-infection.

h.2. Sampling and quantification sulfate-reducing Clostridium in the caecum at the different stages of the trial: preinfection, 3 days after infection and 1 week after infection.

Histopathological study

Both in the duodenum and in the rest of the studied sections (jejunum, ileum, caecum and colon), T-3 shows a smaller number of samples with lesions in lots T-2 and T-4. In addition, the lesions in the lots with natural preservative were of less intensity than in T-2, since T-2 presented atrophy and necrosis, while in T-3 and T-4 the atrophy was mild and had mucus.

In the histological image above, we can differentiate how the T-1 group consists of a duodenum with normal appearance, and how the T-2 group shows regenerative hyperplasia of the duodenal mucosa.

In this new histological image, we can compare the appearance of a normal jejunum (T-3) and another that is atrophied (T-2).

In the image above, we observe different states of the caecum, which in group T-3 is contracted, and in group T-2 we see it dilated and atrophied.

In this last image, the difference between the appearance of a normal colon (T-3) and a colon with mild atrophy (T-4) is visible.

Intestine morphometry

As we can see in the graph above, in the group T-2 is where the length of the mucosa decreases the most, while in the group T-3 and T-4 it is higher despite the infection, especially in T-3.

Macroscopic lesions

Conclusions

1) Productive parameters (weight gain, feed conversion rate and mortality)

In the T-1 lot (basal diet) normal parameters were observed in the farm.

There was a notable decrease in the productive parameters in the T-2 treatment after the challenge with Clostridium perfringens.

T-3 treatment (AMN as a preventive) significantly improved bird weight, weight gain, feed intake and conversion rate.

Mortality was lower in T-3 (AMN as preventive) than in the other treatments. In T-4 (treatment) it was lower than in T-2 (infected and untreated).

After the challenge with Clostridium perfringens, the T-3 animals did not alter their productive response.

• The animals of lot T-3 weighed 292 grams more on day 42 and improved the conversion rate by 12.3%, compared to T-2 (infected)

After the challenge with Clostridium perfringens, the T-4 animals that received AMN in drinking water, improved the daily weight gain.

• Animals from lot T-4 weighed 138.9 grams more at 42 days and improved the conversion rate by 8.7%, compared to T-2 (infected)

2) Uniformity

The treatment and prevention with Alquermold Natural (T-3 and T-4) allows the recovery of the uniformity of the animals.

3) Carcass performance

Lot T-3 has the highest carcass yield and the lowest % of abdominal fat. While the lot T-4 does not improve the performance to the carcass after the infection.

4) Microbiological analysis (sulfate-reducing Clostridium)

Lot T-3 shows the lowest duodenum and caecal bacteria count after infection. While treatment with Alquermold Natural (T-4) reduces the load on the duodenum and the caecum.

5) Histopathology

• Lot T-2 presents more animals with lesions, and these are more severe (atrophy, necrosis, ulcerations)
• T-3 and T-4 have fewer injuries than T-2, and of less severity.
• T-3 (AMN as a preventive) is the batch that presents fewer injuries and of lower intensity.

6) Intestinal morphometry

• The total length of the mucosa is smaller in T-2 (infected)
• T-3 and T-4 obtain a length of the mucosa greater than T-2, despite the infection.
• T-3 obtains a length of the upper mucosa even to the control batch T-1.

A greater length of the mucous means greater surface of absorption and, therefore, better use of the diet.

Recommendations

1) Alquermold Natural can be used to prevent necrotic enteritis in broilers with good results.

2) It can be used as treatment for necrotic enteritis, when the outbreak has already been established.

3) This natural preservative has better results used as a preventive for necrotic enteritis rather than as a treatment.