ANSC 3270 Exam
what is a nutritionist driven by? - Answer -need to precisely match nutrient supply w/requirements at
least cost, improve efficiency of production, assure environmental sustainability, and maximize net
income, assuming a functional and healthy gut w/stable and normal microflora
limitations of young gut biology - Answer -inadequate endogenous enzyme secretion
reduced absorptive capacity
inadequate HCl acid secretion
inadequate food and water intake
why is digestion/absorption not perfect/complete? - Answer -limitations of young gut biology
inherent digestive inefficiency
what feed compounds cause digestive inefficiency and what are the implications? - Answer -phytate
fibre and resistant starch bc it's an anti-nutrient and encapsulates other nutrients (?)
inhibitors and toxins
ex. chronic enteritis is related to high protein consumption
implications: increase endogenous loss, lower net nutrient absorption
what is the proximal gut?
,describe its microbiota? - Answer -crop and small intestine
gram+ faculatative anaerobes
colonization resistance
compete for nutrients
growth-depressing bacterial catabolites
what is the distal gut?
describe its bacteria - Answer -ceca, colon, cloaca
gram- anaerobes
colonization resistance
VFA energy production
growth-depressing bacterial catabolites
what effect do undigested/unabsorbed nutrients in the gut have? - Answer -stimulate overgrowth of
deleterious/pathogenic microflora in the gut
this reduces fat digestion through deconjugation and dehydroxylation, so the animal absorbs less energy
and toxic products are produced, both of which contribute to lack of growth
how does gut health status influence nutrient utilization? - Answer -when nutrients are absorbed, they
go to the plasma nutrition pool
pathogens cause the animal to eat less, so there are fewer available nutrient and increase excretion and
maintenance energy requirements, ultimately resulting in less total energy for the animal to use for
growth, and may even cause them to break down tissues in order to get enough energy to fight disease
what impact does gut microbial dysfunction have on efficient nutrient digestion and absorption? -
Answer -causes pathogenic bloom
increases enteric disease risk and gut wall damage
causes increased competition for nutrients, gut maintenance and immunity due to the nutrient diversion
increases tissue catabolism
elements of gut health - Answer -effective digestion and absorption of feed
,asbsence of gut illness
normal and stable intestinal microbiota
effective immune status
how does gut health affect performance? - Answer -germ-free: increases efficiency of nutrient
utilization, but low barrier function
acute pathogen load: sick and inflamed w/poor digestion and high nutrient requirements
want to be in sweet spot b/w the two extremes
how do antibiotics get us to the sweet spot for growth promotion? - Answer -antibiotics prevent
bacterial colonization, which reduces gut microbial use of nutrients and enhances uptake/use of
nutrients through SI wall
also reduces sub-clinical infect, growth-depressing gut microbial metabolites, and immunologic stress
antimicrobials and amino acids - Answer -antibiotics decrease bacteria, allowing the animal to absorb
and create more amino acids, especially threonine, which is important for mucus production, which is
used to fight bacteria
also helpful bc adding AAs to diet is v expensive
5 challenges to finding effective alternatives to antimicrobial growth promoters? - Answer -i) intestinal
microbiota is abundant, diverse, and dynamic, hard to define what ideal is
ii) highly influenced by gut environment ex. stuff flows very fast through SI, may not help there if it flow
out too fast
iii) influenced by life events such as weaning stress (rapid decrease in lactobacilli and increase in E.coli,
inflammatory response (IL-1), reduced barrier function)
iv) influenced by management ex. better in highly sanitized environments, lower stocking density, and
affected by sex and genetics
v) changes w/age - can make developing a probiotic hard bc gut microbiota will change so much as they
age, may want to establish adult gut biota early on
*hard to predict what will work, lots of trial and error*
reduced barrier function - Answer -bacteria causes damage/adhesions to gut wall, causing it to be more
permeable/"leaky"
, this reduces nutrient absorption
gut health sweet spot - Answer -controlled by complex interactions b/w gut health, environment, and
diet
can find and manage it w/out antibiotics, but difficult bc managed by so many factors and there are so
many options
strategies for alternatives to antibiotics - improving digestion - Answer -stimulate functional gut
development - can be done using functional ingredients and nutrients, probiotics, and changing feed
structure
complement endogenous enzymes - add feed enzymes
seed, feed, and weed protocol - Answer -seed w/favourable microflora - probiotics, feed microbes such
as lactobacilli
feed favourable microflora - prebiotics, feed enzymes
weed out pathogens - organic acids, essential oils, feed enzymes
strategies for alternatives to antibiotics - maintain gut integrity - Answer -improve barrier function -
probiotics, betaine
repair gut wall - butyrate, betaine, EGF
why should we be concerned about domestic and companion animal respiratory disorders - Answer -
73% of emerging diseases are considered to be zoonotic diseases, many target resp system
endemic resp diseases have major health and welfare impact on domestic and companion animals,
which negatively affects productivity and profit
also zoonosis concern
dead-end infections - Answer -human contracts infects it rarely spreads it ex. West Nile Virus, Lyme
disease
two types of zoonotic pathogens/infections - Answer -dead-end infection - cause infection w/out
adapting to humans ex. West Nile Virus, Lyme disease