Mycotoxins- Contamination in Indian Feed and raw material

Abstract

Kemin India has conducted a detailed survey to understand the mycotoxin prevalence pattern in poultry feed and feed raw materials from various regions in India. The study was carried out from Jan 2010 to July 2010 and comprised of 400 samples. The study revealed that, 393 out of 400 samples tested were contaminated with one or more mycotoxin i.e. 98% of sample collected was contaminated with mycotoxin. Study has also revealed that all the major mycotoxins are prevalent in Indian Sub-continent including Fursarium Mycotoxin which is normally noticed in temperate countries like Europe, South America and New Zealand.

The European Food Safety Authority (EFSA) has drafted a maximum tolerance level for individual mycotoxin in poultry feed3. These safety levels were taken in to consideration for evaluating the degree of contamination of mycotoxins in the feed. The key findings of this study are, Aflatoxin continues to be the most prevalent mycotoxin - 40% of samples above the tolerance limit of 20 ppb, followed by ZEN, which was found to be higher than 250 ppb in 28% of samples and then T2 toxin at 100 ppb in 20% of samples. In this study Citrinin toxin was not found in any samples and Ochratoxin A was found only 6% of the samples.

Introduction

The three major fungi families which cause Mycotoxicosis in poultry are Aspergillus, Penicillium, and Fusarium. They produce mycotoxins namely Aflatoxin, Ochratoxin, Citrinin, T2 toxin, Zearalenone (ZEN) & Deoxyvalenol (DON, Vomitoxin) 1, 2. The severity of the toxins is characterized by their ability to induce a toxic response in human and animals when food or feed containing them is consumed4. There are more than 300 mycotoxins identified so far, and in that, above said 7 major mycotoxins are causing severe economic loss to the Poultry industry. In general Aspergillus and penicillum are believed to be prevalent in tropical countries like India.

Mycotoxin management is a major challenge in the poultry industry as it works toward improving bird performance and feed efficiency. For many years, Aflatoxin, Ochratoxin and T-2 Toxins were considered to be the most common mycotoxins in tropical countries like India, Bangladesh, Sri Lanka and Nepal. Recently, however, the prevalence of Fusariaum mycotoxins, such as DON (Vomitoxin), Fumonisin and Zeralenone, has become apparent, requiring new methods for mycotoxin management programs. Many studies have been conducted so far to understand the prevalent pattern of mycotoxins in South Asian region but there is no in-depth study conducted in Indian sub-continent.

Kemin conducted a survey to understand the contamination pattern of different mycotoxins in Indian Sub-continent and the samples were analysed by our Customer Laboratory Service (CLS) - a well-equipped laboratory located at Chennai, India to provide unique value added services to its customers. The data collected from the analysis has been compiled in this report to understand the prevalence of various mycotoxins and their ill effects on feed and food safety.

Maximum tolerance limit of mycotoxins

There is no safe level of mycotoxins11 however as per FDA the maximum permitted level of Aflatoxin is 20 ppb. For other mycotoxins EFSA has arrived at the maximum tolerance limit based on Individual mycotoxin contamination in the feed. The permissible levels are applicable only for single toxin contamination and not for multiple toxin contamination in feed. The multiple toxins, which are commonly noticed in animal feed has synergistic effects and cause more damage to poultry than an individual toxin.

Table 1: Maximum tolerance limit of different mycotoxins for Poultry - A proposal cited by EFSA(12)3, 12



Materials and Methods

The feed and raw material like Maize (30 samples), Soya (13 samples), and others like De-oiled Ground Nut Cake, De-oiled Rice Bran etc. were received from various geographical areas over the course of a six month period. The samples were analysed by Thin Layer Chromatography (TLC) and High pressure liquid chromatography (HPLC) methods for the presence of mycotoxins in comparison with the standard toxins obtained from Sigma Aldrich. The analysis was carried out by IUPAC (SOP) & AFAQCL method for Aflatoxin Ochratoxin, Citrinin and T2 toxins. DON (Vomitoxin) 15 and Zearalenone were analysed by HPLC procedure. (13, 15 & 16)

Result and Discussion

The Mycotoxin audit was conducted with 400 feed and raw material samples collected from all over the Indian sub-continent and data were analysed as per the below mentioned three major categories.
 Percentage of samples contaminated with one or the other Mycotoxins
 Region wise analyses were carried out to understand the presence of single or multiple mycotoxin
 Degree of contamination with respect to EFSA tolerance limit at different regions

Presence of Mycotoxins in feed samples and feed raw materials

In the total of 400 samples, the Feed and Raw material distribution was 285 and 115 respectively. In case of feed samples 98% of samples were found to be contaminated with one or more number of Mycotoxins. In the raw material samples 89% of samples were found to be contaminated with one or more Mycotoxins. In total 400 samples including raw materials 96% of samples were found to be contaminated with one or more Mycotoxins.

Graph 1: % of samples contaminated with one or the other mycotoxins



Presence of multiple toxins in feed and feed raw materials

The trend analysis was carried out to understand the number of Mycotoxins prevalent in the feed and raw material samples. As can be seen in the graph below it has been found that more 78% of feed and raw material samples in the Indian sub-continent were contaminated with more than one mycotoxin.

Graph 2: Presence of multiple toxins in feed and feed raw materials



Region wise Mycotoxin Prevalance

Feed and RM samples received from various regions for mycotoxin analysis is given below.

The percentage of feed and RM contaminated with mycotoxin found to be very high in Western Region - 94% followed by East -89% , than South -76% and then North 68%.

The Fusarium Mycotoxin contamination found to be higher in western region sample, In case of North, Aflatoxin was found to be the major mycotoxin. In Eastern region T2 toxin was predominant in majority of the samples and in South it is Aflatoxin along with ZEN mycotoxin which is majorly prevalent.

The different enviornmental and storage conditions could be the reason for the difference in the mycotoxin contamination levels, as well as for the presnce of different mycotoxins in different regions.

Graph 3: Mycotoxin prevalence in Western India



Graph 4: Mycotoxin prevalence in Northern India



Graph 5 Mycotoxin prevalence in Eastern India



Graph 6: Mycotoxin prevalence in Southern India




Degree of Mycotoxin contamination with respect to EFSA tolerance limit at different regions

Contamination level of individual mycotoxins which was higher than the safety limit is plotted below in Graphs 7 to 11 and the trend analysis was carried out.

The mycotoxin contaminaiton all over India is plotted in Graph 7. The data indicates that Aflatoxin continue to be the major Mycotoxin in India followed by Zearalenone (ZEN) contamination which was high in feed and raw material samples. The ZEN contamination level was plotted based on two levels, the tolerance limit at 250 ppb may impact the performance of the Poultry and more than 1000 ppb contamination will impact severe damage to the reproductive organs of the Animal. 8

The Trichothecene mycotoxin - T2 was found in more than 20% of the feed and raw material samples at higher limit of 100 ppb.

Graph 7: Samples above the maximum tolerance limits in India



Regionwise Mycotoxin Contaminants above the Permissible level

Fusarium Mycotoxins like ZEN and T2 toxins were found higher in the feed and raw material samples of Western Region. Particlularly ZEN Toxin contaminiation found to be in 70% of sample at higher level than the safe level and 15% of samples were above the tolerance limit of 1000 ppb.

Graph 8: Samples above the maximum tolerance limits in the Western region




The prevalance of different mycotoxins in Northern region were plotted in the below Graph 9. From the graph, it is very clear that Aflatoxin is continuing to be the major threat to the Poultry farmers in the North. On an average, 40% of samples were contaminated with Aflatoxin exceeding the tolerance limit of 20 ppb.


In the total of 124 feed and raw material which have higher contamination levels, 104 samples were in the range of 20 to 40 ppb and 20 samples were higher than 40 ppb. This may be because of poor storage and screening methods. The ZEN and T2 mycotoxins were also present in the samples collected from Northern part of Indian Sub-continent.


Graph 9: Samples above the maximum tolerance limits in the Northern region



In Eastern region the Trichothecene mycotoxin - T2 found to be very high in the feed and raw material samples. The high humidity conditions prevaling in the east may favor the growth of Fusarium fungi - Fusarium sporotrichioide.


Graph 10: Samples above the maximum tolerance limits in the Eatern region




The higher prevalence of Aflatoxin was observed in Southern Indian feed and raw material samples.

Graph 11: Samples were above the maximum tolerance limits in the Southern region



In general, samples from Western and Southern regions were found highly contaminated with DON (Vomitoxin) mycotoxins, with 46% of samples testing positive for Fusarium fungi toxin. More than 12% of samples were contaminated with more than 1000 ppb of Vomitoxin. An average of, 10% samples were contaminated with over 1000 ppb of DON in the entire Indian sub-continent feed and raw materials.

The presence of Ochratoxin was only to the extent of 6% in overall analyzed feed and raw material samples. The Citrinin toxin contamination was not observed in any of the 400 samples collected in this audit program.

Mycotoxin prevalence in Raw material samples

The Maize (29 samples), maize gluten (7 samples) and GN DOC (10 samples) samples were highly contaminated with Aflatoxin and Ochratoxin was present in maize and SF DOC samples. The Fusarium fungi mycotoxin like ZEN was present in most of the raw materials sampled, including: DORB, rice polish, soya doc, DDGS and maize. Soya, rice polish and maize samples were contaminated with T2 mycotoxin. Maize and maize gluten samples were contaminated with DON (Vomitoxin).

Mycotoxin prevalence above the critical limit on a monthly basis



Presence of Aflatoxin and Zearalenone is seen throughout all the six months whereas prevalence of T2 toxin is not seen after the month of April.

Conclusions

Mycotoxins are continue to remain as the major threat to the poultry farmers in Indian sub-continent. The present study revealed the contamination of different mycotoxins in Indian feed and raw material samples as single or in combination. Earlier it was understood that Indian tropical conditions may not have Fusarium mycotoxins contamination (ZEN, DON & Fumonisin). But the change in climate condition and prevalent of strong summer and strong winter would have encouraged the proliferation of Fusarium fungi and then the presence of Fusaraium mycotoxins in Indian raw materials and feeds The mycotoxin audit have revelaed that Aflatoxin continue to be a major mycotoxin in Indian subcontinent. The important finding in this survey is the presence of high level Fusarium mycotoxins in the Western, Eastern and Southern regions of Indian Subcontinet. This necessiate a comprehensive single solution which has got broad specturm mycotoxin binding efficacy against not only commonly know mycotoxin of Aflatoxin, Ochratoxin, Citrinin but also against ZEN, DON, and T2 toxins.


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