Proteins Flashcards
what are conditionally essential AA? what is an example?
AAs that sometimes need to be supplied in the diet
EX: arginine needed by pregnant mares
what percent of body mass is protein? where is most of it found
15%
found mostly in muscle
functions of protein
provide structure
nutrient transport
metabolic function regulation
immune system
pH buffer
what do parietal cells release to help digest protein
HCL
what do chief cells release to help digest protein
pepsinogen(converted to pepsin by HCl)
what pancreatic enzymes digest protein in the small intestine
trypsinogen
chymotrypsinogen
procarboxypeptidase
why is it important for the horse to get colostrum within the first 24 hours of life
foals can absorb the immunoglobins in colostrum whole for the first 24 hours of life
why is urea supplementation not beneficial to the horse
its broken down in the hindgut and not accessible to the horse
what percent of protein is nitrogen
16%
what is the purpose of transaminating an AA
to turn it into a ketoacid depending on the horses needs
what is the purpose of deaminating an AA
removing amino group for energy
main fates of absorbed AAs
-tissue protein synthesis
-enzymes, hormones, metabolites
-transamination
-deamination
what is leibig’s barrel
a visual representation of limiting amino acids
-without enough of the limiting AA, the other AA quantities dont matter in regards to how much protein you can make
relationship between intake and digestibility
-apparent dietary CP intake increases digestibility
-true, low to moderate CP intake has no change on digestibility, high intake decreases digestibility
how to calculate apparent vs. true affect of intake on digestibility
Apparent: dietary N intake - fecal N output
True: dietary N intake - (fecal N output - endogenous N losses)
places for endogenous N losses
dead cells
MCP
problem with using growth and nitrogen retention to determine AA requirements
-takes many horses, and significant time
-can only be tested on growing horses
problem with testing AA concentrations in blood to determine requirements
concentrations increase linearly without plateau
what is the issue with using plasma urea nitrogen to determine AA requirements
doesn’t account for non protein nitrogen that can come from dead cells of MCP
factors impacting AA requirements
sex
age
stage of life
exercise level
what factor has the greatest impact on protein requirement
stage of life
what horse type has the highest protein requirement? the lowest?
highest: nursing foals/weanlings
lowest: mature, idle
effects of protein deficiency
-decreased growth in young horses
-decreased performance/production
-poor hair/hoof growth
-anorexia
why does protein deficiency lead to anorexia
high urea circulating in blood tricks horse into thinking it doesn’t need to eat
T/F increased urination from excess protein can put strain on the kidney/liver
FALSE. it may exacerbate already present issues, but will not cause issues
consequences of feeding excess protein
-deamination to use C skeleton for energy
-excess urination/ammonia in urine
-expensive
