Lecture 11

Question 1

what is a feed additive?

Answer 1

any feed ingredient that is not a:
hay
silage
pasture (fresh forage)
energy feed
protein feed
vitamin supplement
mineral supplement

Question 2

“No preservatives or additives” suggest what negative connotations?

Answer 2

feed additives are unhealthy or unnatural

feed additives are either antibiotics or hormones

Question 3

examples of feed additives

Answer 3

-rumen additives
-buffers and neutralizers
-antioxidants
-preservatives
-humectants
-pellet binding agents
-flow agents
enzymes
-probiotics
-flavoring agents
-therapeutic microbials
non-therapeutic microbials

Question 4

Rumen additives are fed specifically to do what?

Answer 4

alter rumen fermentation

increase feed efficiency

Question 5

What is an ionophore

Answer 5

a special class of antibiotic that causes affected bacterial cell walls to become permeable to cations (K, Na)

Question 6

Examples of rumen additives

Answer 6

Rumensin (monensin)

bovatec (lasalocid)

Question 7

Why are buffers and neutralizers added to feeds?

Answer 7

to reduce fluctuation in rumen pH

supplements natural buffering in saliva

Question 8

Examples of buffers/neutralizers

Answer 8

sodium bicarbonate, magnesium oxide, sodium sequicarbonate, potassium carbonate

Question 9

why are antioxidants added to feeds

Answer 9

to prevent rancidity and oxidation of fats, particularly unsaturated fats

Question 10

examples of antioxidants

Answer 10

butylated hydroxytoluene (BHT)

ethoxyquin

vitamin E

Question 11

why are chemical preservatives added to feed?

Answer 11

to prevent mold and bacterial degradation of feedstuffs

Question 12

examples of chemical peservatives

Answer 12

ascorbic acid
propionic acid, calcium propionate
sodium metabisulfite

Question 13

why are humectants added to feeds?

Answer 13

to hold moisture

Question 14

examples of humectants

Answer 14

glycerol
propylene glycol
glyceryl triacetate
sugar polyols (sorbitol, xylitol, maltitol)

Question 15

why are pellet binding/flow agents added to feeds

Answer 15

to improve the pelleting characteristics of mixed feeds

Question 16

examples of pellet binding additives

Answer 16

bentonite
lignosulfonate
molasses

Question 17

why are flow agents added to feeds

Answer 17

used to improve mechanical handling

Question 18

examples of flow agents

Answer 18

calcium carbonate

bentonite

Question 19

why are probiotics added to feed

Answer 19

to stimulate the GI environment and promote healthy intestinal flora

Question 20

why are coloring agents added to feed

Answer 20

to alter the color of feed or animal skin

helps the food not look like shit

Question 21

why are feed flavors added to feed

Answer 21

natural/synthetic compounds are added to alter the taste and/or smell

Question 22

what are the targets for adding feed flavors

Answer 22

the animal fed

the customer purchasing the feed

Question 23

therapeutic antimicrobials are added to feeds to_____

Answer 23

treat/prevent a specific disease

Question 24

what would one add to prevent ketosis in cattle?

Answer 24

propylene glycol

Question 25

are hormones allowed in chickens

Answer 25

NERP

Question 26

are there technically any hormones in feed?

Answer 26

NOPE, but there are a few

Question 27

Recombinant bovine somatotropin (posilac) has been approved for 20 yrs in lactating dairy cows to enhance what?

Answer 27

milk production

Question 28

how is posilac administered?

Answer 28

subcutaneous injection every 2 weeks

Question 29

What do beta-agonists do?

Answer 29

• increase lean muscle growth

- reduce fat deposition

Question 30

what are non-therapeutic antimicrobials?

Answer 30

antibiotics added to poultry and swine feed to increase growth rate and feed efficiency

Question 31

Effects of Non-therapeutic antimicrobials

Answer 31

• increase ADG 5-10%
• increase feed efficiency
• stimulate feed intake

Question 32

What are possible methods behind the mechanisms of non-therapeutic antimicrobials?

Answer 32

• inhibition of pathogens
• inhibition of GI microbes-toxins
• nutrient sparing effects
• inhibit nutrient by GI microbes
• increase feed and water intake
• increase nutrient absorption

Question 33

what are some problems with feeding antimicrobials?

Answer 33

contamination of animal products due to:

• withdrawal times not followed
• improper use on farm
• cross contamination of feeds during manufacturing
• inadequate cleanout of feeders
• improper dosage fed

ANTIBIOTIC RESISTANCE

• occurs in three forms
• Transformation (DNA uptake from environment)
• conjugation (plasmids, transpossons)
• transduction (bacteriophage)

Question 34

how does conjugation work?

Answer 34

donor bacteria links to recipient cell via conjugating pilus. Passes the plasmid across the pilus and gives it to the recipient cell

Question 35

how does transduction work?

Answer 35

a virus infects a bacteria and uses it to produce daughter viruses. One virus contains the plasmid from the old cell, which when passed on to the next bacteria can be used to confer that resistance that it encoded for

Question 36

What is the “Danish Experience?”

Answer 36

life without non-therapeutic antimicrobials

Question 37

When did the Danish Experience begin? what did they do?

Answer 37

2000; Danish Parliament banned the use of antimicrobials for growth promotion, much like the EU ban of 2006

Question 38

What is the DANMAP

Answer 38

Danish Integrated Antimicrobial Resistance Monitoring and Research Programme

Question 39

What does DANMAP do?

Answer 39

monitors antibiotic use in both animals and humans

monitors antibiotic resistant strains in animals, animal food products, and humans

Question 40

the results of the Danish Experience thus far shows an_________ in prescribed antimicrobials in both animals and humans

Answer 40

increase