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Mycotoxins in livestock systems in developing countries

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Presentation by Johanna Lindahl and Delia Grace at the World Mycotoxin Forum, Belfast, Northern Ireland, 14–16 October 2018.

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Mycotoxins in livestock systems in developing countries

  1. 1. Mycotoxins in livestock systems in developing countries Johanna Lindahl1,2,3 & Delia Grace1 1International Livestock Research Institute, Nairobi, Kenya; 2Uppsala University, Uppsala, Sweden 3Swedish University of Agricultural Sciences, Uppsala, Sweden World Mycotoxin Forum, Belfast, Northern Ireland, 14–16 October 2018
  2. 2. Presentation outline • Mycotoxins and livestock in low and middle- income countries (LMIC) • Our work in Africa • What do we do about it? • Mitigation strategies at different levels in Kenya
  3. 3. Aflatoxins are a global issue
  4. 4. CGIAR are global institutes International Center for Tropical Agriculture (CIAT) International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) International Institute of Tropical Agriculture (IITA) International Livestock Research Institute (ILRI) International Maize and Wheat Improvement Center (CIMMYT) International Food Policy Research Institute (IFPRI)
  5. 5. Why focus on aflatoxins in Kenya? • Kenya outbreak 2004-2005 125 known fatal cases • 884 women sampled in Eastern Province • All had aflatoxin in the blood • Exposure levels higher in poor people
  6. 6. Why bother about aflatoxins and animals? • Animals are susceptible to aflatoxins: some more, some less 1. Animal suffering- an animal welfare issue 2. Reduced animal productivity 3. Aflatoxins in animal-source foods
  7. 7. Health effects observed • Liver damage • Gastrointestinal dysfunction, decreased appetite • Immunosuppression • Decreased reproductive function, decreased growth, and decreased production • Can we see these effects in low-producing animals? • Little research in Africa in literature search • Varying effects in all studies
  8. 8. Highly susceptible: oral LD50 (<1 mg per kg body weight) Rabbits, ducks, cats, swine, rainbow trout Moderately susceptible: oral LD50 (1-2 mg per kg body weight) Dogs, horses, calves, turkeys, guinea pigs, sheep, baboon Relatively resistant: oral LD50 (5-10 mg kg body weight) Chickens, rats, macaque monkeys, mouse, hamsters One teaspoon of aflatoxin is enough to kill 2,500 rabbits
  9. 9. Safe levels? • ≤50 in young poultry • ≤100 in adult poultry • ≤50 in weaned pigs • ≤200 in finishing pigs • <100 in calves • <300 in cattle • <100 in Nile tilapia However depending on other factors!
  10. 10. Interactions Mycotoxin Main fungi Impact on animal health Aflatoxins Aspergillus spp All livestock susceptible to different degrees. Acute toxicity, hepatotoxic and nephrotoxic. Carcinogenic and mutagenic. Growth impairment. Immunosuppression. Ochratoxin A Aspergillus spp, Penicillum spp Nephrotoxic Immunosuppression Possibly carcinogenic Fumonisins Fusarium spp Toxic to liver and central nervous system Possibly carcinogenic Zearalenone Fusarium spp Swine highly sensitive, cattle less sensitive. Endocrine disruption. Estrogenic effects, reduced reproduction, feminisation, malformations. Trichotecenes Fusarium spp Gastrointestinal disturbance. Reduced feed intake. Ill-thrift. Immunosuppression.
  11. 11. Animal source food • Aflatoxins are transferred to animal products • 1-7% of aflatoxins in feed is metabolized and transferred to milk • Much lower transfer to meat and eggs • Reduced if stop feeding
  12. 12. Farmer Consumer Economic flow Aflatoxin flow Human exposure Feed produce r AB1 AB1 AB1-> AM1 AM1 Corn/feed produced at farm Corn/feed purchased Milk produced at farm AB1 AM1 Treatments Feed seller Farmer Veterinary services Milk retailer Agricultural services Consumer
  13. 13. Aflatoxins in Kenya dairy Qualitative study- understanding behaviour • Women greater role in deciding what to feed cattle • Common to feed mouldy food to livestock • Women more likely to report taste of maize as an indicator of moulds • Men and women share more decision making than literature suggests • Men and women disagree which gender has responsibility
  14. 14. Kenya- dairy value chain • Feed collected from 5 countiesa – From farmers: 0.02 ppb to 9,661ppb – Samples exceeding 5ppb • 25% to 100% of the feed in farms • 85.7% to 100% of the feed from feed retailers • 20% to 100% of the feeds from feed manufacturers • Milk samples: Up to 6999ppt a Mugangai et al. 2016
  15. 15. One year survey 0 50 100 150 200 250 300 1 2 3 4 5 6 7 8 9 10 11 12 dagoretti Westlands 24 samples per month Dagoretti: low-income area Westlands: High-income area
  16. 16. One year survey 0 200 400 600 800 1000 1200 Pasteurized Boiled Pasteurized Raw UHT Pasteurized Lala Milk Yoghurt Average of ppt Max of ppt
  17. 17. Producer Number Mean price KES/litre (range) Mean aflatoxin M1 levels (ng/kg) Standard deviation Min Max Geometric mean Farmers 75 65 (45-110) 116.5 153.3 <LOD 1069.5 65.6 a Company A 74 155 (80-610) 57.0 43.9 7.6 272.3 46.4 Company B 12 101 (90-120) 296.9 206.1 59.0 743.3 226.9 Company C 51 128 (60-233) 37.2 33.9 <LOD 166.1 22.7 b Company D 37 125 (86-233) 38.9 33.5 <LOD 156.1 23.7 b Others 42 176 (76-660) 111.3 169.9 7.3 1078.5 68.0 a Table 2. Aflatoxin M1 levels in milk samples of different origins purchased in Nairobi, Kenya Geometric means with the same superscript were not significantly different LOD: Limit of detection (2 ng/kg)
  18. 18. Kenya- urban milk • Milk collected from informal milk retailers – 58% knew about aflatoxin, but only 6% thought milk was not totally safe after boiling – Milk samples: mean AFM1 was 128.7 ppt, up to 1675 ppt. 55% of samples exceeded 50 ppt and 6% 500 ppt – Women consume 1 litre per day! Kiruni et al. 2016, Afr J Food, Nutr Ag Dev
  19. 19. Kenya- urban milk • Child exposure study • Korogocho & Dagoretti • 41% of children were stunted • 98% of foods contained aflatoxin • 100% of milk contained AFM1 • AFM1 exposure associated with decreased Height for Age score Kiarie et al. 2016, Afr J Food, Nutr Ag Dev 27% 59% 14% moderate stunted Normal severe stunted
  20. 20. Urban consumers Completed and results Willingness to pay study: 600 consumers • Dagoretti: • 55% know of aflatoxin (45% of these believe it can be transferred to milk) • 53% think aflatoxin is a serious threat. • CBD and Westlands: • 80% know of aflatoxin (51% of these believe it can be transferred to milk) • 32% think aflatoxin is a serious threat • All income willing to pay a premium aflatoxin assured milk
  21. 21. Ethiopia dairy value chain • Milk – 26% exceeded 500 ppt – Max 4980 ppt • Feed – 90% above 10 ppb – Max 419 ppb • Feeding noug cake increased AFM1 levels in milk
  22. 22. Senegal- dairy value chain • Feed and milk- under analysis – Feed: highest levels in concentrate 305 ppb – Milk: Mean 205 ppt, max 1000 ppt
  23. 23. Uganda pigs Feed Mean ppb Max ppb Commercial feeds 27 64 Cottonseed 65 134 Maize bran 57 118 Silage 22 48 Silverfish 15 23 34 out of 728 urine samples > 20 ppb
  24. 24. Vietnam pigs • 1920 pigs screened for aflatoxins in urine at slaughter • 54% positive • AFB1 in maize: 29% above 5 ppb, max 35 ppb • Low knowledge, most maize for animal feed • Where does the aflatoxin come from?
  25. 25. Mitigation options • Aflatoxins can be mitigated all along the dairy value chain Costs Implementation Side effects
  26. 26. Farmer Consumer 1. Stop aflatoxin production Aflatoxin flow Human exposure AB1 AB1 AB1-> AM1 AM1 Corn/feed produced at farm Corn/feed purchased Milk produced at farm AB1 AM1
  27. 27. On the field- storage • Improved varieties- more resistant crops • Bio control: AflaSafe™, AflaGuard™ • Improved drying • Improved storage • Good Agricultural Practices, GAP Reduces aflatoxins for both humans and animals Costly?
  28. 28. Farmer Consumer 2. Stopping the bad feed Aflatoxin flow Human exposure AB1 AB1 AB1-> AM1 AM1 Corn/feed produced at farm Corn/feed purchased Milk produced at farm AB1 AM1
  29. 29. Objectives of feed standards 1. Protect humans from harmful aflatoxins in animal source foods 2. Safeguard the benefits people derive from livestock 3. Protect value chain actors from bad products 4. Encourage fair trade, and economic growth through promoting standards and credibility
  30. 30. 2. Stopping the bad feed • Feed regulations Implementation What do you do with illegal feed? Costs? • Market incentives Poor people? Not sustainable
  31. 31. Farmer Consumer 3. Within the cow Aflatoxin flow Human exposure AB1 AB1 AB1-> AM1 AM1 Corn/feed produced at farm Corn/feed purchased Milk produced at farm AB1 AM1 Binder
  32. 32. Standards for Anti-Mycotoxin Additives (AMAs) in Feeds Clays (aluminosilicates) • Most effective binder but different clays vary in effectiveness. Up to 90% reduction. Yeast/bacterial cell wall extracts • Provide other useful nutrients, but evidence on effectiveness is mixed Other binders • Some are promising but less evidence of effectiveness
  33. 33. The case for binders • Multiple benefits: 1. Increase animal productivity 2. Reduce aflatoxins in animal-source foods 3. Create safe “sink” for aflatoxin 4. Improved animal welfare • Food safety/security tradeoff  win-win opportunity • Current trial will provide evidence on effectiveness
  34. 34. Reducing aflatoxins in milk using binders • Baseline survey to collect data on: – Levels of aflatoxins in milk – Feeding practices – Farmer awareness – Farmer willingness to use mitigation methods – Farmer willingness to pay for binders or other mitigation methods
  35. 35. Study sites • Urban/Peri-urban – Kasarani – Kisumu • 20 trial farms and 10 control farms recruited in each site – Given Novasil as a feed additive
  36. 36. Follow up • Regular follow up and endline survey of farmers • Preliminary results: • High dosing of binder reduces aflatoxin • Farmers perceive improved production • Compliance? • Concerns with adulteration
  37. 37. Farmer Consumer 4. In the milk? Aflatoxin flow Human exposure AB1 AB1 AB1-> AM1 AM1 Corn/feed produced at farm Corn/feed purchased Milk produced at farm AB1 AM1
  38. 38. 4. In the milk • Biological control?? Research still ongoing Pasteurization not working
  39. 39. Farmer Consumer 5. Stopping consumption of contaminated milk Aflatoxin flow Human exposure AB1 AB1 AB1-> AM1 AM1 Corn/feed produced at farm Corn/feed purchased Milk produced at farm AB1 AM1
  40. 40. 5. Stopping consumption • Legislation • Awareness and market incentives Implementation What do you do with illegal milk? Costs? Poor consumers?
  41. 41. The challenge Change: To: Food safety Food security Improved food security Improved food safety Better health
  42. 42. Take home messages • Livestock is affected by aflatoxins, and so are animal- sourced food • Livestock feed sector + binders can suck contaminated grain out of human food chain • Potential for regulation to cause harm (burden on agricultural sector, concentrating contaminated among poorest) • Need to research what works in each country
  43. 43. Conclusions There is no silver bullet to eradicate aflatoxins Animals may be both part of the problem and part of the solution
  44. 44. The Kenya work is financed by the Ministry of Foreign Affairs, Finland in partnership with the International Food Policy Research Institute (IFPRI), Luke Finland and the Biosciences in eastern and central Africa–International Livestock Research Institute (BecA-ILRI) hub It contributes to the CGIAR Research Program on Agriculture for Nutrition and Health Acknowledgements
  45. 45. The presentation has a Creative Commons licence. You are free to re-use or distribute this work, provided credit is given to ILRI. better lives through livestock ilri.org

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