Minerals Vitamins and Supplements, and Sampling Analysis, Carbohydrates Flashcards
3 main uses of feed additives
stimulate growth of animals
improve feed efficiency
improve general health
what are antibiotics used for?
reduce incidence of subclinical bacterial infections
at what level are antibiotics added to feed?
sub-theraputic
what is therapeutic use of antibiotics
administration at much higher levels to combat established infection
why is the use of antibiotics controversial?
it can create antibiotic resistance
what do antibiotics improve?
growth rate
feed efficiency
antibiotics are used to help control:
respiratory infections
foot rot
liver abscess
diarrhea
what is bioavailability?
portion of the total mineral in feed that is absorbed
what are “safety factors”
when the bioavailability of minerals is unknown, the concentration fed is adjusted upward
minerals have poor _______ & ________
palatability and different bioavailability values
what are the two most used liquid feeds?
molasses and oils
what are ionophores obtained from?
Streptomyces bacteria
what are ionophores used for?
prevent coccidiosis
improve feed efficiency in growing or lactating ruminants
what animal are ionophores toxic to?
Horses
Ionophores mechanism of action (how do they work?)
- Gram + bacteria cells pump out K+ which is a source of base
- causes cytoplasm to become acidic
- bacteria use all available ATP to pump out the acid
- cells die
Ionophores mechanism of action (how do they work?)
- Gram + bacteria cells pump out K+ which is a source of base
- causes cytoplasm to become acidic
- bacteria use all available ATP to pump out the acid
- cells die
benefits of feeding liquid supplements
^increase ration density/palatability
^more uniform nutrient distribution
LESS animal sorting & feed wastage
examples of feed additives
buffers
antioxidants
hormones
antibiotics & chemotherapeutic agents
What happens to horses who may recover from low levels of ionophore poisoning?
can develop chronic heart failure resulting in exercise intolerance, poor performance, and death
why are ionophores good for rumen metabolism?
increase propionate production
increase feed efficiency (more propionate = more glucose = more energy produced for animal)
decease methane production (propionate is a H sink)
amino acid sparing effect (less ammonia)
Gram Negative bacteria produce more ______ & Gram Positive bacteria produce more _____
- PROPIONATE
- ACETATE
Gram Negative bacteria produce more ______ & Gram Positive bacteria produce more _____
- PROPIONATE
- ACETATE
for dairy cows, an increase in propionate means an increase in _______
milk production
what does phytase do?
breaks down phytic acid in feedstuffs, releases trapped phosphorus
What is “force feeding” minerals?
using salt to improve palatability
T/F: Feed additives meet the known nutrient requirements of animals
False, they do not meet any known nutrient requirements
Why is it important to know the nutrient content of feedstuffs?
it is key for balancing rations
Grains have _____ nutrient composition
Grains have LESS VARIABLE nutrient composition
Forages have _____ nutrient composition
Forages have MORE VARIABLE nutrient composition
What do growing, working, and lactating animals need?
concentrate
What does the proximate analysis system measure (6)
Nitrogen-free extract
Ash
crude fiber
crude protein
crude fat/ether extract
moisture/dry matter
Why would adding phytase decrease the amount of P in feces?
phytase breaks down phytate which makes P more available for the animal to use and less that gets excreted as waste.
T/F: Crude fiber is a poor analytical method for measuring fiber concentration in feedstuffs. Explain
T. crude fiber errors occur because this process makes lignin and structural carbs soluble in the solution and underestimates the true fiber content
T/F: Crude fat/ether extract usually overestimates the concentration of fat present in feed stuffs. Explain.
T. It overestimates the amount of fat in the feed because it counts anything that is soluble by ether to be a fat
T/F: NFE is a better approach than NFC to estimate amount of non-structural carbs. Explain.
F. NFC uses NDF which is a more reliable method of fiber estimation
What would you recommend to reduce the N bound interference when analyzing feedstuffs for NDF?
add sodium sulfite to remove N-bound fiber
steps of energy partition (dietary energy)
Gross Energy
- Fecal energy
Digestible energy
- Urinary & Gaseous energy
Metabolizable Energy
- heat
Net Energy
- Maintenance energy
- Productive energy
What is the mechanism of 3NOP?
3NOP is a feed additive that inhibits the enzyme responsible for methane production by microbes
The energy system used to determine the energy requirements for horses
digestible energy
The energy system used to determine the energy requirements for swine
metabolizable energy
What is the monosaccharide resulting from the hydrolysis of alpha 1,4 glycosidic linkage
glucose
Metabolic steps in the utilization of glucose in animal tissues
Glycolysis → pyruvate → Krebs cycle → generate additional ATP & e- transporters
Name of the hormone responsible for glucose uptake by cells
insulin
Name the hormone responsible for mobilizing glucose from tissues
glucagon
Why are the NFC concentrations of fiber overestimated?
Because the estimation uses NDF and doesn’t account for pectin losses
The energy system used for determining energy requirements for chickens is
metabolizable energy
What effect on enteric methane emissions do ionophores have?
gram negative bacteria produce more acetate so the increase in propionate means there is low levels of acetate so the microbes that can produce methane are decreased because they don’t have hydrogen
