Presentation formulated with contributions from: Michael A. Ballou, PhD, US Foodservice Seminar 2009,

The American Farm Bureau “Addressing Misconceptions About Agriculture,” andThe American Meat Institute Fact Sheets

The Safety of Consuming Animal Products Produced

under Conventional SystemsANSC 3404

LEARNING OUTCOMES

• After attending the presentation the participant will know more about: (1) the need to adapt safe and sustainable technologies to feed the increasing global population and (2) the safety of current technologies used in the livestock industry.

• This presentation will focus on the current uses of growth promotants and antibiotics

For the first time in human history, the majority of people will have no contact with the source of their food….

…other than buying or eating it.

We know this population shift has occurred in the United States since the end of World War II.It will soon be true across the globe.

By 2050, the majority of the world’s population will be disconnected from the earth. In 1950, more than 75 percent of world’s

population was rural.By 2050, almost 75 percent of world’s population

will be urban.The average U.S. citizen is three or more

generations removed from the farm.Food is taken for granted.

Issue has no personal relevance.Sentimentality persists, but far less than in past.More questioning of farmers’ competency

The ignorant are very easily misled. We believe that we understand subjects that

we do not.We fear the wrong things.We don’t fear the right things.

The U.S. public has many misconceptions about agriculture.Many we are taught!Others come from superficial reporting by

media or through advertising.Once something is in print, it is repeated,

endlessly, as factual.

6

Population Growth256%

1798

1998

Malthus 1798 Prediction

Food Production 9%

An Inconvenient TruthThe world population is predicted to

continue increasingWorld population is growing at a rate of 1.7%

each yearTherefore by 2050 the population will have

nearly doubled

An Inconvenient TruthCentral question is……how are we going to feed

everyone?This is not a new question.

In 1798 Thomas Malthus published an essay on the Principle of Population that suggested population growth exceeded the growth of resourcesThis was at a time when population growth wasn’t growing quickly

by current standardsThomas predicted that famine, disease, and war would

ultimately be the causative force driving population stabilization.

This presentation will not discuss philosophies on how to control population growth, but will focus on the safety of current technologies that can feed, at least in the immediate future, an inevitable increase in the population.

16.9Ice Covered

15 Deserts

2.5Rock andTundra

5.2 Wetlands

33.2 DenseForests

4.7Urban Land

15.1Cropland

56.3Grazing

Land

World’s Agricultural LandApproximately 2/3 is permanent pasture,

range, or meadowOf which 60 % is unsuitable for producing

cropsThis land produces cellulosic roughages –

grass, and other vegetationDigestible by ruminant grazing animals (cattle,

sheep, goats, deer, and bison)Not digestible by humans

Diet of Cattle:Cattle graze and eat forages that humans

cannot digest due to the fiber content.Much of the grain milling and food processing

waste is turned into feeds that cattle can eat and convert into high quality protein.

Milling and Food Processing Waste:For every 100 pounds of human food

produced by processing crops, 37 pounds of waste products are produced.

These waste products can be turned into animal feed or will enter the waste stream to be disposed.

Diet of Cattle:50 – 70 percent of a beef animal’s feedlot

diet is human-inedible forages and feed.In U.S., 2.6 pounds of grain are used to

produce 1 pound of beef.Globally, 0.3 pound of grain is used to

produce 1 pound of beef.

An Inconvenient TruthHow are we going to feed the various populations

(1) Increase land devoted to food productionOr (2) Increase efficiency of yields

Most of earth’s productive land is already cultivated for food productionSome deforestation and use of rangeland will be

transitioned into cultivated landThe focus of this presentation will be on

technologies used to increase efficiencies of yields in livestock.

Central Goal: Adopt SAFE technologies that promote INCREASED

UTILIZATION of available resources in a SUSTAINABLE manner.

Growth Promotants

Growth PromotantsWhy use growth promotants in livestock?

Increase performance by 5 – 25%Increase efficiency of performance (kg feed

required for a kg of product produced) by 5 – 15%

Types of growth promotants currently used:Recombinant growth hormonesEstrogenic and Androgenic implantsβ-agonists (not discussed in this

presentation)

Growth Promotants - rBSTTypes of growth promotants currently used: - Recombinant growth hormones:

Commonly used in the dairy cattle industry under the name recombinant bovine somatotropin (rBST)

rBST is a Protein hormone that is naturally secreted from the pituitary of all cattle.

Using recombinant technology a synthetic form almost identical to the natural analog is produced (An extra amino acid at the terminal region of the protein – confers no biological activity)

Circulating rBST binds to receptors in the liver and increases the secretion of insulin-like growth factor-1 (IGF-1).

IGF-1 regulates many cell functions including stimulating cell growth and inhibiting programmed cell death

Growth Promotants - rBSTTypes of growth promotants currently used: - rBST:

The increase in IGF-1 decreases

mammary cell death and extends the lactation curve: (1) improving milk production & (2) improving feed

efficiency Days in milk

0 100 200 300 400

Milk

/ co

w /

day

(lbs)

10

20

30

40

50

60

70

80

No rBSTrBST - treated

Does rBST pose any health risk to humans?All milk contains small amounts (ppb) of BST

Cows treated with rBST also have very low levels of BST in milk and meat, comparable to naturally occurring concentrations

rBST is not active in humans because the protein is about 35% different than human somatotropin (Juskevich & Guyer, 1990)Therefore when rBST is injected into humans, even at

pharmacological doses, the rBST cannot bind to the somatotropin receptors in the liver.

Even if rBST was active in humans, since it is a protein it is digested in the gastrointestinal tract of humans to amino acidsRats are responsive to injections of rBST; however when

given pharmacological oral doses of rBST there is no growth response (Seaman et al., 1988).

Growth Promotants - rBST

Does rBST pose any health risk to humans?IGF-1 in meat and milk from rBST-treated

cattle are increased (30 – 60%). (Hammond et al., 1990)However, the amount of IGF-1 consumed in 1

glass of milk is equal to approximately 0.03% of the IGF-1 produced naturally in our bodies each day (Dale Bauman, Cornell University)Require 12,000 cups of milk per day to equal the

amount of IGF-1 produced in our bodies dailyAdditionally, IGF-1 is a protein, so oral IGF-1 is

digested in the small intestines to amino acids

Growth Promotants - rBST

The European Union, Japan, Australia, New Zealand, and Canada have not approved rBST for use.

Tillamook Cheese (Oregon) rBST free in 2005. Safeway (NE US) stopped buying milk from dairy farmers

that used rBST in Jan. 2007.California Dairies Inc (15 billion lbs annually or 8% of the

US milk produced) rBST free since Aug. 2007.Kroger has banned all rBST-derived milk products from

it’s stores.Starbucks all dairy is from rBST free animals in Jan. 2008Wal-Mart and Sam’s Club now sells milk from rBST free

animalsMostly citing consumer demand for hormone-free

milkEducation of safe technologies is needed

Growth Promotants - rBST

Does rBST pose any health risks to the cow?One meta-analysis suggested that rBST-treated

cattle are more likely to develop clinical mastitis and foot problems and less likely to conceive. (Dohoo et al., 2003)However in cows that conceived there was no

difference in number of days it took for them to conceive.

More data is needed to accurately assess the impact of rBST on health of cattle.Use immune, reproductive, and welfare parameters to

assess.If health is adversely affected the industry will need

to design preventative management strategies.

Growth Promotants - rBST

Growth Promotants – Estrogenic & Androgenic ImplantsTypes of growth promotants currently used: - Estrogenic and Androgenic Implants:

Commonly used in the beef cattle industryEstrogenic implants increase circulating

levels of somatotropin and IGF-1Androgenic implants increase circulating

levels of IGF-1

Growth Promotants – Estrogenic & Androgenic ImplantsDo Estrogenic or Androgenic implants

pose any health risk to humans?Estrogen and Androgen are lipid hormones

Unlike protein hormones (rBST and IGF-1) they are not digested in the gastrointestinal tract; therefore they can be absorbed intact.

Estrogen and Androgen produced in cattle are active in humans

Growth Promotants – Estrogenic & Androgenic ImplantsDo Estrogenic or Androgenic implants pose

any health risk to humans?Concentrations of estrogen and androgens

increase ~ 4 fold relative to untreated cattle (Daxenberger et al., 2001)4.3 vs 20 ng/500gObviously varies among tissue because lipid

hormones are stored with fat500 g = daily consumption of 300 g muscle,

50 g fat, 100 g of liver, and 50 g of kidney (Worldwide Regulatory Organization)

Growth Promotants – Estrogenic & Androgenic ImplantsDo Estrogenic or Androgenic implants pose

any health risk to humans?Is the increase in estrogen a risk to

humans?Assessment by the Food and Drug

Administration (FDA)Natural hormones regulated through

Allowable Incremental IncreaseNo harmful effects will occur if individuals

chronically ingest meat that contains an daily incremental increase of ≤ 1% of what is naturally produced in the segment of the population with the lowest daily production (ie: prepubertal boys).

Growth Promotants – Estrogenic & Androgenic ImplantsDo Estrogenic or Androgenic implants pose

any health risk to humans?Is the increase in estrogen a risk to

humans?Previous reports suggested serum

concentrations of ~ 8 pg/mL in prepubertal children based on RIA methods.

Recent bioassay suggested much lower concentrations, 1.4 and 3.5 pg/mL in prepubertal boys and girls, respectively. (Paris et al., 2002)Corresponds to 7 and 17.5 μg / d in prepubertal

boys and girls, respectively.

Growth Promotants – Estrogenic & Androgenic ImplantsDo Estrogenic or Androgenic implants pose any

health risk to humans?Is the increase in estrogen a risk to humans?

Using 7 µg / d naturally produced in prepubertal boysEqual to 7,000 ng

Hormone-treated beef having 20 ng / 500 gAmount of estrogen in a day’s serving of hormone-treated beef

is only 0.29% of the amount naturally produced in prepubertal boys0.11% for prepubertal girls0.014% for men and 0.0032% for women (calculations

based on data from Hartmann et al., 1998)Also most prepubertal boys and girls will not consume the 500

g / d as established by worldwide regulatory organizations Ie: ~ 75 g protein (> twice their protein requirement) and 50

g fat (450 kcal) from animal products / day

Growth Promotants – Estrogenic & Androgenic ImplantsDo Estrogenic or Androgenic implants pose

any health risk to humans?All implants are administered in the middle

third of the back side of the earThe ear is removed and discarded at harvest,

reducing any risk of estrogen or androgen from entering the food supply.Greater risk of your child eating your birth control

pills or hormone replacement therapies.

Growth Promotants – Estrogenic & Androgenic ImplantsEuropean Commission has agreed that both

naturally occurring and synthetic hormones are safe when used according to label directions in food producing animals.

FDA has concluded that there is essentially no difference between beef from animals raised using hormones and those raised without their use. The miniscule amount in beef is well below any level that would have a known effect on humans.

Conclusions on Growth Promotants

Increase growth and efficiency of nutrient utilizationIncreased utilization of available resources – land and

feed.Making them more “Green”?!

rBST treatment of cows posses absolutely NO risk for human health

More research is needed on the health risks to the cow when treated with rBST. Industry will have to respond if there is an effect.

Although the amount of estrogenic and androgenic hormones increases by ~ 4 fold in hormonally implanted cattle it posses no risk to the human population because consumptions is far less than naturally synthesized in the body.

Antibiotics

AntibioticsWhy use antibiotics and antimicrobials in

livestock industries?Used to treat bacterial infectionsAlso used to prevent bacterial infections

Disease due to bacterial infections decreases performance in animals due to the nutrient and energy costs of an immune response

If the growing phase is short this can have tremendous impacts on the efficiency and subsequent profitability of a producerBroiler chicken industry has almost completely bred out the

immune response because the cost of the response is too great relative to the pay off (extremely short growing period).

Prevent and control epidemic diseasesImprove animal welfare

AntibioticsDo meat and milk products from livestock contain

antibiotics?There is an extremely small chance: Most meat segments

will have < 0.5% chance of an animal with an antibiotic residue above safe tolerable limits.

Why is important to limit antibiotic contamination of food?Public health issue

Allergies to certain antibiotics (ie: penicillin)Toxicities to certain antibiotics (ie: nitrofurans & chloramphenicol)Would increase the likelihood of antibiotic resistance bacterial strains

emerging in the human populationsDairy industry issue

Many dairy products are fermented by specific bacteria added to the milk; antibiotics in milk could inhibit the growth of the added bacteria

AntibioticsHow does the FDA assure there is no antibiotics

in animal products for human consumption?FDA’s approval process for food animal antibiotics

FDA audited studies to ensure the meat, milk, and eggs from animals treated with a specific antibiotic are safe for human consumptionFree of antibiotics - Data used to determine withdrawl periods

Specifies the number of days required after the last antibiotic treatment before the animal can enter the food supply

They use large margins of safety for establishing withdrawl periods

As of 2003, determine relative risk of the antibiotic causing antibiotic resistance in the human population. (Guidance 152; FDA).

AntibioticsFDA approved studies to ensure the meat, milk, and

eggs from animals treated with a specific antibiotic are safe for human consumptionDetermine relative risk of the antibiotic causing

antibiotic resistance in the human population.Part 1: Determine the probability that a resistant bacteria will be

present as a result of the antibiotic.Part 2: Exposure – determines the likelihood that a human would

come in contact with the resistant bacteria.Part 3: Consequence – determines the health consequences if

ANY following human exposureIf the assessment indicates a high risk the FDA could

deny the application or put restrictions on its use.Even medium or low risk could have restrictions regarding its

use

AntibioticsFDA approved studies to ensure the meat,

milk, and eggs from animals treated with a specific antibiotic are safe for human consumptionIn addition, the FDA in cooperation with the

USDA and CDC monitor antimicrobial resistant foodborne pathogens in animal carcasses at slaughter, retail meats, and in human clinical cases to help provide insight into emerging resistance.Can be used to help make future decisions on

antibiotic use in livestock.

AntibioticsHow do we know that producers follow

the appropriate withdrawl times for each antibiotic.The FDA and USDA have coordinated

surveillance programs for meat and milk to help ensure that antibiotic residues found in the products are below safe tolerable limits.Monitoring Plan: designed to provide statistical

information regarding the prevalence and concentrations of residues. Identifies an emerging problemRecent data has indicated a problem in the veal calf

industry, which will now be addressed.

AntibioticsHow do we know that producers follow the

appropriate withdrawl times for each antibiotic.The FDA and USDA have coordinated surveillance

programs for meat and milk to help ensure that antibiotic residues found in the products are below safe tolerable limits.Surveillance: Investigates classes of animals suspect

because of a previous residue.Enforcement Testing: Samples collected by USDA in-

plant personnel on suspect animals because of previous residue or antemortem or postmortem evaluation (ie: does the animal appear sick).Unlike monitoring the goal here is to prevent violative

products from entering food supply

Conclusions on AntibioticsAntibiotics are used to prevent and treat bacterial infections

Improve growthPrevent and control epidemic diseasesImprove animal welfare

USDA & FDA determine the “safety” of a new and approved antibiotics.Since 2003, now consider the “risk” of causing antibiotic

resistance in human populationUSDA monitors and reports the incidence of violative

residuesIdentifies problem areas that need to be addressed

In house USDA personnel test all “suspect” carcasses for antibiotic residuesProducer history, or ante- or postmortem animal evaluation

Concluding RemarksPopulation growth is expected and if stabilization

doesn’t occur the population will nearly double by 2050.Resources: solar energy, land and water will limit how

much food can be producedTechnologies that improve utilization of resources in a

sustainable manner need to be implemented.Furthermore, the food produced using these technologies

needs to be safe for human consumption.Use of growth promotants and antibiotics in livestock have

little or no risk to human healthIn addition to the evaluating human health, the

environmental implications of each new and existing technology needs to be identified because sustainability = future.

Questions or Comments?