Chapter 11- ANF and Toxins (Dec 6)

Question 1

organic poisons include

Answer 1

• selenium toxicity

- grass tetany (grass staggers)

Question 2

how do animals get selenium toxicity?

- what does it cause

Answer 2

some plants accumulate Se from high Se soils –> animal consumes high Se plants

• loss of hair
• blind staggers (impaired vision)
• sloughing of hooves (damage to connective tissues)
• paralysis, respiratory failure

Question 3

what causes grass tetany?

Answer 3

aka grass staggers

• rapidly growing lush pastures –> high in potassium

Question 4

mycotoxins=

Answer 4

toxins produced by molds that colonize crops

Question 5

T/F

lots of feeds have zero mycotoxins present

Answer 5

false

always SOME level

Question 6

what does mold growth require?

Answer 6

• available nutrients
• a certain moisture and temp
• oxygen

Question 7

what are the 4 most mycotoxin-producing species?

Answer 7

• penicillium species
• aspergillus species
• fusarium species
• claviceps species

Question 8

aflatoxin is considered a ___ mold, and grows best in __ conditions (__-__C)

Answer 8

storage

tropical
24-40

Question 9

corn, peanuts, and cottonseed meal are particularly susceptible to

Answer 9

aflatoxins

Question 10

what do aflatoxins do?

Answer 10

toxicity causes jaundice, damage of the liver

• has high affinity for nucleic acids, so interferes with protein synthesis
• immunosuppressent
• carcinogenic (can cause liver tumors)

Question 11

why do aflatoxins pose food safety concerns for humans?

Answer 11

animals metabolize the toxins, but metabolites may still be toxic

Question 12

the mycotoxin “fusarium” is a ___ mold that grows in ___ climates

Answer 12

storage

temperate (warn/ cool cycle)

Question 13

zearalenone =

Answer 13

a type of fusarium

• estrogen-like compound, interacts with estrogen receptor –> causes hypoestrogenism and infertility
• swine most susceptible

Question 14

trichothecenes =

Answer 14

a type of fusarium

• inhibit translation during protein synthesis
• causes hemorrhages, nervous disorders

Question 15

ochratoxin is produced in ___ climates

Answer 15

cooler

as low as 4C

Question 16

ochratoxin has a high affinity for ___ involved in __ and ___ metabolism

Answer 16

enzymes

CHO
protein

Question 17

how do ochratoxins affect swine? ruminants?

Answer 17

swine: kidney degradation
ruminants: rumen microbes detoxify, toxicity is rare

Question 18

how does ergot work?

Answer 18

fungus develops in seed ovary, and replaces seed (very common in rye)

Question 19

what are the 3 types of ergotism?

Answer 19

1. gangrenous
   - vasoconstriction due to smooth muscle contraction
   (no blood flow to extremities_
   - abortion
   - gangrene (death of body tissue)
2. convulsive (neurotoxic effect)
   - St. Anthony’s fire: phantom pain in extremities
3. hallucinogenic

Question 20

what are 2 medicinal used of ergot?

Answer 20

1. reduce hemorrhages following childbirth

2. control of migraines

Question 21

can ergoty grain still be fed to animals?

Answer 21

yes, clean it, dilute it, and avoid feeding it to pregnant animals
limit to 0.1% of the diet

Question 22

explain the link between ergot and witch trials

Answer 22

witch trials followed cool, wet seasons –> linked to consumption of ergot in bread etc (hallucinating)

Question 23

In the middle ages, ergotism led to the emergence of __ as the most important cereal grain. Why?

Answer 23

wheat

• rye was most common, but it was affected by ergot – wheat less susceptible