Initial Contaminant Levels in
Swine Feed Ingredients

Karen B. Ekelman, PhD

Presented To:
Animal Feed Safety System 
Public Meeting
Gaithersburg, Maryland
May 22, 2007 

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Initial Contaminant Levels in Swine
Feed Ingredients - Outline

• Introduction
• Feed Contaminants Program Data 
   -  Pesticides   -   Microbes
   -  Elements  -     Dioxins
   -  Mycotoxins -  PCBs
• Initial contaminant levels in ingredients for starter, grower and finisher swine feeds

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Initial Contaminant Levels in Swine Feed Ingredients

1. Introduction 

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Ingredients: Initial Contaminant Levels

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Ingredients: Initial Contaminant Levels

• Challenge #1: Lack of data!
  • For chemicals – Feed Contaminants Program, published data, expert opinion
    • Data are particularly limited for elements
  • For microbes – Feed Contaminants Program, published data, expert opinion
    • Little or no data on levels of microbes in many feed ingredients and feeds
    • Data on % of feeds and feed ingredients containing microbes are generally limited to Salmonella and E. coli O157:H7; much less data are available for other microbes of interest

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Ingredients: Initial Contaminant Levels

• Challenge #2:  Data are not always available for the ingredient!
  • For example - Soybean meal
    • Microbes – Plant products and byproducts
    • Mycotoxins – Soybeans and soybean byproducts
    • Pesticides – Soybeans and soybean byproducts
    • Dioxins, PCBs – Soybean meal
  • For example – Spray-dried blood cells vs. Choice white grease
    • Microbes – Animal products and byproducts
    • Mycotoxins – Animal products and byproducts
    • Pesticides – Animal products and byproducts
    • Dioxins, PCBs – Animal fats

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Initial Contaminant Levels in Swine Feed Ingredients

2. FDA CVM Feed Contaminants Program Data 

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Feed Contaminants Program (FCP)

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Feed Contaminants Program (FCP)

• Pesticides
  • Malathion, chlorpyrifos-methyl, pirimiphos-methyl, methoxychlor, diazinon
• Elements
  • Cadmium, lead, mercury
• Mycotoxins
  • Aflatoxins, fumonisins, deoxynivalenol, zearalenone, ochratoxin A
• Microbes
  • Salmonella enterica, E. coli O157:H7
    Dioxins and PCBs
     

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Feed Contaminants Program – Pesticides

• FDA conducts routine, annual surveillance for levels of pesticides in animal feeds
  • Feed ingredients and mixed feeds
  • From 1989 - 2005, approximately 500 – 600 samples per year; since then, approximately 200 per year
  • Data for AFSS swine feed model example are from 2000 - 2006
  • Routine surveillance results are summarized each year by district and food commodity but not by individual pesticides; these annual reports will soon be available on CVM’s web page

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Feed Contaminants Program – Pesticides

Domestic Surveillance Feed Samples With Pesticides, 1992 to 2002

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Feed Contaminants Programs – Pesticides

Means Pesticides Levels For Domestic Feeds Samples, 1992 - 2003 

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Feed Contaminants Program – Elements (Heavy Metals)

• Very limited surveillance of elements in feed and feed ingredients
• Some samples are collected in response to investigations (e.g., 2003 pet food investigation)
• Data used for the AFSS swine feed example are from 2000 – present (2007)
• Some data are available for:
  • Cadmium  
  • Selenium  
  • Nickel
  • Lead   
  • Copper   
  • Iron
  • Arsenic  
  • Zinc   
  • Mercury
  • Chromium 

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Feed Contaminants Program – Mycotoxins

• Routine, annual surveillance for levels of 5 mycotoxins in animal feeds
  • Aflatoxins, fumonisins, deoxynivalenol, zearalenone, and ochratoxin A
  • Approximately 200 – 250 samples of feed ingredients and mixed feeds per year since 1994
  • For AFSS swine feed example, will use data from 1994 - 2004
  • Results are summarized annually by district, food commodity and mycotoxin and will soon be available on CVM’s web page; a publication is also planned. 

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Feed Contaminants Program – Mycotoxins

• Results: FY05 256 samples (229 domestic, 27 import)
  • 4 samples exceeded guidance, 7 samples were positive with no official guidance

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Feed Contaminant Program - Mycotoxins

• Distillers dried grains with solubles (DDGS) collected as part of routine surveillance sampling, 1999 – 2004, and as part of a special assignment during FY 2007 where 40 total samples are scheduled for collection.

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Feed Contaminants Program – Microbes

• Routine, annual surveillance of feed and feed ingredients for Salmonella and E. coli O157:H7
  • About 200 samples collected per year, 1999 – present; data used for swine feed model example are from 1999 – 2003
  • Plant- and animal-origin feed ingredients, mixed feeds, pet foods and pet treats
  • Results reported as positive or negative; # of microbes per gram of sample is not determined
  • Each Salmonella isolate is characterized by serotype, genetic fingerprint, and antimicrobial susceptibility pattern
  • Results are summarized each year and will soon be available on CVM’s web page

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Feed Contaminants Program – Microbes

• Routine surveillance results are summarized each year and will soon be available on CVM’s web page

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Feed Contaminants Program – Microbes

• Special surveillance assignments
  • Heat-treated and non-heat-treated swine feed (FY 05)
  • Direct-human-contact feeds (pet foods/treats) (FY 06)

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Feed Contaminants Program - Dioxins and PCBs

• Special assignments almost every year since 1998, approximately 1000 total samples
• Goal has been to obtain information about the background levels in feeds and feed ingredients
• Sample collection and analysis also in response to specific dioxin-related issues (ball clay, zinc oxide, etc.)
• Expensive sample collection and analysis by the GC-MS “gold” standard method compared to biological methods (e.g., CALUX)
• Results reported as PPT TEQs (parts per trillion toxicity equivalents) for 10 dioxin and 7 furan congeners; recently, results also reported for 3 dioxin-like PCB congeners
• Congener patterns can help trace sources of contamination
• Results will be posted on CVM’s web page; several publications are also planned.

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Feed Contaminants Program - Dioxins and PCBs

• 1998 – anti-caking agents (ball clay)
• 2000 – animal fats, fish meal, meat and bone meal, deodorizer distillates, molasses
• 2001 – milk products, wood products, minerals, complete  feed, vitamins, oilseed meals
• 2002 – minerals, forage, grains
• 2003 – minerals (in response to 2 contamination incidents)
• 2004 – animal and plant fats and oils used in animal feeds
  and in clays used to bleach/filter these fats/oils
• 2005 – rendered mammalian and poultry fats, yellow grease
  and filtering and bleaching agents
• 2006 – anti-caking agents, feed ingredients or bedding containing wood or wood products, and feed ingredients contacting or containing soil

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Feed Contaminants Program - Dioxins and PCBs

• Results:  Levels of dioxins in grains, grain by-products, and forages were consistently low and significantly below the EU limit for these products (0.75 ppt TEQ)

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Feed Contaminants Program - Dioxins and PCBs

• Results:  Levels of dioxins in fish meal and fish oil samples were low and below the EU limit for dioxins in these products (1.25 ppt TEQ D/F for fish meal, 6 ppt TEQ D/F for fish oil), except for menhaden fish meal and fish oil. 

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Ingredients: Initial Contaminant Levels

• Data may be available for some or all of the following:
  • Specified ingredients
  • Starting materials for ingredients
    • Modifying contaminant levels for processing steps associated with a specific ingredient will be presented by Drs. Benjamin and Okelo
  • Complete feed (mixed feeds, feed supplements, etc.)
    • Information on how to use contaminant levels in feed to check or validate some aspects of the risk ranking model will be discussed by Dr. Hooberman 

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Ingredients: Initial Contaminant Levels

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Initial Contaminant Levels in Swine Feed Ingredients

3. Contaminant Levels in Ingredients for Starter, Grower and Finisher Swine Feeds 

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Point Estimates vs. Distribution Measures

• Examples today use point estimates of data, usually the mean
• Model will use all available data, not just means:
  • Median vs. mean; range
  • Sample distributions and estimated population distributions
    • May incorporate “static” representations of the distributions
    • May use some method of random, iterative sampling from the distribution (e.g. Monte Carlo)

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Starter Swine Feed – Example

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Grower Swine Feed - Example

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Finisher Swine Feed - Example

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Initial Contaminant Levels in Swine Feed Ingredients – Next Steps

• Adjust initial contaminant levels in swine feed ingredients derived from Feed Contaminants Program data for information available in the published scientific literature
  • Except for mycotoxins, little of the data available in the public literature is specifically for feed ingredients/feeds
• Where data are not available, or where data from different sources do not agree, use expert opinion to fill in the gaps or resolve discrepancies
  • Problem – Expert opinion is not data
  • Can determine how sensitive the risk ranking model results are to assumptions used (e.g., expert opinion); this can help identify the most critical data needed to improve the model’s results 

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Next Presentations – Estimated levels of contaminants in swine feed

• Estimate levels of contaminants in feed ingredients for which no data are available (e.g. spray-dried blood), based on how processing of the starting material (e.g. animal products and byproducts) is know or predicted to affect the level of contaminants in the ingredient
• Estimate levels of contaminants in swine feeds, based on ingredients used  and  on how feed processing is know or predicted to affect levels of contaminants.
   

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Initial Contaminant Levels in Swine Feed Ingredients

• Questions?