NUTR 3000 - The Role of MIcrobes

Dysbiosis is a

microbial imbalance

Microbial diversity is affect by what general factors?

age

diet

stress

diseases

antibiotics

dysbiosis

A greater amount of microbial ___________________ is linked with health

diversity

Microbial diversity increases with

age

Where are SCFA produced in cows, horses and chickens

rumen (cow)

ceca (horses, chicken)

higher acetate is associated with higher

milk fat and marbling

What structure do calves have that cows dont

reticular groove (bypasses the rumen because they only have milk and have no need for microbial fermentation)

What SCFA is associated with a healthy gut. What does it due?

butyrate

develops intestinal wall

papillae growth

Butyrate is reduced when animals are fed

low quality forage that is high in fibre and low in starch

Prepartum magnesium butyrate increases

calving ease

colostrum yield

early lactation performance

Butyrate can be supplemented with

calcium butyrate and magnesium butyrate

how does butyrate help develop a healthy gut

-makes a thick rumen wall and stimulates papillae growth

-develops the intestinal wall

What is Necrotic enteritis

acute clostridial infection of Clostridium perfringens

Necrotic enteritis can be contracted from

clostridium perfringens found in water, soil, dust, feed, manure, used litter

Necrotic enteritis is more common when

raised on litter as a group

Necrotic enteritis is so expensive because

it arises usually right before slaughter, after you've invested in all their growth

zoopharmacognosy

animals self medicate with certain foods in order to adjust gut pH, supplement missing nutrients, or eat anti-parasitics

EX; fruit flies ingest alcohol to stop parasites

Three general types of microbes

beneficial, commensal, pathogenic

Microbial diversity in an animal can be due to

age, diet, stress, disease, antibiotics, dysbiosis (autoimmune disease, metabolic disorder)

What increases risk of necrotic enteritis

wet litter

ventilation

leaky waterers

gut damage (parasite, antinutrients, etc)

high Na (drink more, leak more, wet litter)

etc

What is the primary VFA produced in the rumen

acetate

What does acetate do for cattle

increase energy

increase milk and milk fat

increase marbling in older cattle

The SCFAs

acetate, propionate, butyrate

Signs of necrotic enteritis

depression

closed eyes

ruffled feathers

loss of appetite

dark diarrhea

sudden death

Which form of necrotic enteritis is harder to identify

sub-clinical (mild) is more difficult because the only symptom is sudden death

clinical (severe) easier because visible symptoms

Internal signs of necrotic enteritis

Intestinal signs

-ballooned intestine

-friable (fragile and breakable)

-diarrhea

-lesions, ulcers, spots

-in the later stages, tan and yellow membrane on the lumen looking like a flannel

Clostridium perfringens grows in what conditions

anaerobic

Clostridium perfringens is ______________ forming

spore

spores recist

heat

acid

drying

T/F: c perfringens are also found in healthy guts

true, in low amounts

C perfringens are ___________________ bacteria

opportunistic

Intestinal distress makes it easier for CP to infect. Distressees include

intestinal infection (coccidiosis)

intestinal parasites (round worms)

mycotoxins (reduced immunity)

illness (reduced immunity); include chicken anemia virus, Marek's disease, gumboro diseases, Eimeria infection

Nutritional causes of infection

-high levels of non-starch polysaccharides (NSP) (ie, barley)

-high fish meal

-high protein (poor AA balance)

-mycotoxins

-particle size

-trypsin inhibitor (antinutrient)

The main NSP used to make jam

pectin

NSPs are an

antinutrient

CP proliferates faster on _____________ ______________ feed

highly ground (and slower on coarse ground food)

Trypsin destroys

CP toxins

how does a high fibre diet impact passage rate

low passage rate giving fermentation time

Grains in a cattle diet give what SCFA

propionate

what does propionate give

-low fibre

-reduced milk fat

-marbling

-requires energy, must be converted to glucose

High levels of NSP are found in

wheat, barley, oats, rye

NSP increases the ___________ of intestinal contents

viscosity

increasing digesta viscosity increases

growth of facultative anaerobes like gram pos bacteria and enterobacteria

High NSP decreases what two things?

passage rate and nutrient digestibility

CP is gram +/-?

+

Does CP have a thick or thin peptidoglycan wall

thick

What does is the effect of CP being gram positive

-it is protected from antibiotics and other agents

-more easily increasingly becoming antibiotic resistant

How can high dietary fish meal cause infection

it alters beneficial bacteria populations (lactobacillus), which increases Irritable Bowel disease and its associated bacteria

bacteria associated with irritable bowel disease

ruminococcaeceae, lachnospriacea, clostridiales

How to prevent fish meal from causing infection

include probiotics

High fish meal is found in what kinds of diets

starter diets

How does high protein cause infection

it imbalances AA profiles. If you are not using them, you are leaving AAs available for someone else to use (microbes). It is a substrate for intestinal microflora in lower dig tract

-reduce disgetibility in upper digestive tract

-fermentation products increase pH

What are the effects of a high protein diet

-reduces digestibility in the upper digestive tract

-fermentation products increase pH

-substrate for intestinal microflora in the lower part of the digestive tract

The increased pH from fermentation of high protein diets encourages

proliferation of clostridium spp

How do mycotoxins cause infection

they cause intestinal damage that increases permeability of intestinal epithelium

Example of a common mycotoxin

deoxynivalenol (DON)

mycotoxins grow on

grow on grain and produce chemical byproducts that posion consumers of grain

mycotoxins arise from

old, wet, feed

antibiotic treatments

bacitracin

penicillin

lincomycin

toxins cannot be treated with

antibiotics

What kind of antibiotics are we trying to phase out

sub-therapeutic levels (prophylactic)

Cocciodiostats (ionophores) are alternatives to

antibiotics

T/F: No drug tolerances emerge from coccidiostat use

false, some drug tolerance emerging

How to coccidiostats work?

they transfer ions across a cell membrane. increasing the ion permeability

Nutritional treatments that serve as antibiotic alternatives are

probiotics

prebiotics

organic acids

probiotics work by

COMPETITIVE EXCLUSION

Probiotics are similar to the

microflora of healthy chicken gut

Treatment methods (multi-tiered)

management

minimizing stress

dry litter

feed storage

vaccination

vermin

mortalities (cannibalism risk)

Examples of probiotics

live bacteria and yeasts

Examples of prebiotics

lactose

mannooligosaccharides

fructo-oligosaccharides

Organic acids examples

bismuth citrate

formic acid

acetic acid

prpionic acit

butyric acid

As silage is made, what beneficial bacteria increases

lactobacillus

Things that can cause wet litter