Feed Additives

Question 1

Feed Additives

Answer 1

Feed additives are non-nutritive substances added to feeds to improve the efficiency of feed utilization and feed acceptance, or to be beneficial to the health or metabolism of the animal in some way

Question 2

3 Types of Feed Additives

Answer 2

1. Additives that influence feed stability, feed manufacturing, and properties of feeds
2. Additives that modify animal growth, feed efficiency, metabolism and performance
3. Additives that modify animal health

Question 3

Additives that influence feed stability, feed manufacturing, and properties of feeds

Answer 3

• anti fungals
• antioxidants
• pellet binders

Question 4

Additives that modify animal growth, feed efficiency, metabolism and performance

Answer 4

1. Feed flavors
2. Digestion modifiers
3. Metabolism modifiers
4. Growth promotants

Question 5

Additives that modify animal health

Answer 5

1. Worming agents

2. Coccidiostats - prevent growth of protozoa in the GI tract

Question 6

Antifungals

Answer 6

agents used to prevent fungal (mold) growth in stored feed ingredients. Molds reduce palatability and can produce mycotoxins. Aflatoxin and Fusarium are among those of most concern

Question 7

Mold growth in stored feeds can be prevented by:

Answer 7

• adequate drying (moisture content of 12% or less)
• storage under dry conditions
• use of mold inhibitors (antifungals)

Question 8

Antioxidants

Answer 8

polyunsaturated fats can react with oxygen and fall apart, leading to the creation of new compounds that are unpalatable and may be toxic. This process is referred to as oxidative rancidity

Question 9

Vitamins __, __, and __ may also be destroyed as a result of oxidative rancidity

Answer 9

A, D and E

Question 10

Examples of antioxidants that can be added to feeds at ~0.25 lb/ton are:

Answer 10

butyated hydroytoluene

ethoxyquin

Question 11

two naturally occuring antioxidants in feeds are:

Answer 11

vitamin E

vitamin C

Question 12

Pellet binders

Answer 12

pelleting increases the density of feed resulting in increased feed intake and improved growth and feed efficiency
A disadvantage is added cost, which may add 10% or more to the cost of the feed

Question 13

Two commonly used pellet binders are:

Answer 13

bentonites- clay minerals that are probably the most widely used binders
lignin sulfonate- a by-product of the wood processing industry. xylose

Question 14

Feed flavors are used to increase:

Answer 14

• acceptance of diets with low palatability
• increase the intake of palatable diets
• increase the intake of diets during periods of stress

Question 15

digestion modifiers include:

Answer 15

• enzymes
• buffers
• ion-exchange compounds
• ionophores and methane inhibitors
• isoacids
• probiotics

Question 16

Enzymes

Answer 16

the main purpose of enzyme addition to feed appears to be for digestion of substances that the animal is incapable of digesting

Question 17

Primary enzymes that have been used as feed additives

Answer 17

• phytase for non-ruminants, because it degrades phytic acid

- beta glucanase for swine and poultry, because it increases digestion of beta glucans. Barley and oats

Question 18

Buffers

Answer 18

salts of a weak acid or base that resists a pH change. Buffers are used most commonly in high concentrate diets fed to cattle to counteract acid production resulting from fermentation of carbohydrates in the rumen

Question 19

ion exchange compounds

Answer 19

the principle ion-exchange compounds used in feeding are zeolites, which are clay minerals that gain and lose water reversibly

Question 20

zeolites have been reported to have beneficial effects on

Answer 20

• growth
• feed efficiency
• reducing ammonia in the air of poultry and swine confinement facilities

Question 21

ionophores and methane inhibitors

Answer 21

a class of antibiotics that are used as feed additives for cattle because they improve:

• feed conversion efficiency
• daily gain

Question 22

isoacids

Answer 22

also referred to as branched chain volatile fatty acids which include isobutyrate, isovalerate, and 2-methylbutyrate

Question 23

probiotics

Answer 23

referred to as direct-fed microbials
are live microbial feed supplements that can benefit the host animal, possibly by altering gastrointestinal tract microflora

Question 24

the most commonly found DFMs are::

Answer 24

bacteria: lactobacillus acidophilus

yeast (fungi): saccharomyces cerevisae or aspergillus oryzae

Question 25

two examples of hormones that modify metabolism are:

Answer 25

ralgro (estrogenic)- increases growth and feed efficiency in ruminants - implanted in ear
bovine somatotropin (BST)- increases milk yield in dairy cows- administered by injection

Question 26

beta-adrenergic agents (repartitioning agents)

Answer 26

norepinephrine analogs that stimulate B-adrenergic receptors causing repartitioning of nutrients from fat —> protein
this causes an increase in muscle mass and decrease in body fat

Question 27

antibiotics

Answer 27

natural metabolites of fungi that inhibit growth of bacteria, altering gastrointestinal tract microflora

Question 28

antibiotics alter gastrointestinal tract microflora and possibly:

Answer 28

• suppress microbes responsible for mild infections
• reduce microbial production of growth-depressing toxins
• reduce microbial destruction of essential nutrients in the GI tract