microbial contribution to nutrition

Question 1

What do microbes use as fuel?

Answer 1

all macronutrients
mostly carbohydrates, mostly fiber (cellulose)

Question 2

end products of fermentation of fiber

Answer 2

volitile fatty acids/short chain fatty acids
* acetate
* propionate
* butyrate

Question 3

acetate use

Answer 3

energy and fat
greatest product from fermentation

Question 4

propionate use

Answer 4

glucose and lactose
BG regulation

Question 5

butyrate use

Answer 5

eterocyte fuel

Question 6

What percent of daily energy comes from products of microbial fermentation (VFAs)?
cattle, horses, dogs/cats

Answer 6

cattle- up to 80%
horses- up to 50%
cats/dogs <5%

Question 7

Where do ruminants get most of their protein?

Answer 7

microbes
microbes eat most protein that the ruminant eats
microbial protein is absorbed in the small intestine

Question 8

What happens to microbial protein in hindgut fermenters?

Answer 8

lost in feces

Question 9

Why can you feed a herbivore too much fat? How much can you feed?

Answer 9

overwhelms gut microbes
foregut: no more than 8% of total dry matter
hindgut: <15% (greater because absorbed in small intestine prior to fermentation)

Question 10

what vitamins do microbes contribute?

Answer 10

cobalamin (B12), biotin, vitamin K (menaquinone)

Question 11

non structural carbohydrates

Answer 11

simple sugars, starches, and fructan (soluable fiber)
rapidly fermented by gut microbes

Question 12

what happens if you feed too much non structural carbohydrates?

Answer 12

lots of rapid fermentation
creates lots of VFAs and decreases pH of fermentation chamber
* can cause death of gram - bacteria (release endotoxin),
* proliferation of gram + bacteria (vasoactive amines, mucosal damage)
* increased production of thiaminase producing bacteria (thiamine deficiency, polioencephalomalacia)

increase gas production

Question 13

Why is too much starch a problem for hindgut fermenters when it should be digested and abdorbed?

Answer 13

if too much, small intestine cannot process all of the starch and it gets passed into the cecum/colon
less sensitve than foregut fermenters but still causes a problem if too much

Question 14

How to positively influence gut microbial population?

Answer 14

feed a proper diet!
prebiotics
transfaunation (give micobes from a healthy animal)
fecal enemas (fecal transplant)
probiotics (some are a waste of $$)