ANSC 301 EXAM 3

Will animals that are not fed well reproduce optimally or at all?

NO--> only healthy animals reproduce; optimum reproduction requires optimum nutrition

What is required before an animal will become fertile?

requires sufficient body weight and energy reserves

lactation is most energetically demanding stage

What predicts age at puberty?

1. body growth 2. increase in fat reserves

BODY FAT SET POINT

Well fed animals grow faster and reach puberty earlier

What hormone signals energy status that allows reproductive cycles to start?

LEPTIN

coming from adipose tissue, telling the body how much energy it has

What hormones does increased leptin change in the brain?

increased GnRH (which then affects LH and FSH)

How does this control population size in wild rodents?

cycles (of fertility/ infertility) based of nutrient/food availability

Why would there generally be a negative relationship between fertility and milk production in dairy cows?

they were not selecting for fertility

high producing cows in early lactation have neg energy balance (i.e. they lose weight)

delay estrous (fertility) until put weight back on (FED WEEL)

What maternal tissues contribute to the requirement for pregnancy?

1. uterus & placenta, fetus

2. mammary requirement

What two factors are important to know to determine the impact of a pregnancy on the mother/dam?

ratio fetal weight/maternal weight

gestational length

in mice: LARGE burden, short gestation

in elephants: small burden, long gestation

What period of gestation are nutrient requirements the highest? Why?

last trimester (GROWTH OF FETUS)

lactation

Is under or over-feeding an issue in early pregnancy?

BOTH ; can cause embryo mortality

feed at or a little above maintenance for a month after breeding

Why do we not want to over feed during late gestation?

synthesize and deposit fat very efficiently with progesterone

If an animal is underfed during late gestation who gets higher priority for the nutrients- mom or fetus?

prioritize FETUS

What is fetal programming and the "Barker Hypothesis"? What is the biological explanation?

in utero undernutrition:

-decreases weight, increases age at first conception, and decreases litter size

-high fat diet in male rats increased insulin resistance in adult offspring

biological explanation: epigenetics

Nutritional Epigenetics

impact DNA methylation through Maternal Diet Supplementation

--> impacts generations to come

GROWTH

What is a key tissue that helps keep young animals warm?

How is the mitochondria and the electron transport chain involved?

Is this mechanism present in adults?

Brown Adipose Tissue (in kidneys and neck) regulates thermoneutral zone-->

ABUNDANT MITOCHONDRIA and thus ETC w/

"uncoupling protein 1"--> HEAT

utilizes own fatty acids

nutrients convert to 100% HEAT (rather than 33%)

Yes! "uncoupling protein 1" present in cells in deep muscle in adults

Most of the ATP synthesized from oxidation of glucose comes from?

NADH in the ETC

Where will a newborn animal get its blood glucose?

dietary source lactose

gluconeogenesis

liver glycogen mobilization

blood NEFA incr. after birth

Milk fat IMP

Is protein deposition high or low in a young animal? How does milk support this?

HIGH bc rapid rates of lean growth and tissue protein synthesis

MILK PROTEIN is rich in EAA (high quality protein)

What does a normal growth curve look like? What does the curve look like for bone, muscle and fat?

growth curve has rapid growth early in life that slows over time

bone, muscle, fat

diff between breed, genetics, gender, energy and protein intake

What do proteins contain that make them unique? What is true protein vs non-protein N?

Proteins contain NITROGEN

true protein: AA

non-proteinN: everything that has nitrogen but not AA

AA that can be used to make glucose are:

glucogenic

AA that cannot be used to make glucose

ketogenic

Does the concentration of proteins change much over development?

NO!

Largest depot of protein in the body

BODY FLUIDS (plasma has ALBUMIN)

What tissue has the highest rate of protein synthesis, gut or muscle?

gut--> rapid loss of cells (high turnover)

liver--> degradation

How would you increase protein deposition even if protein degradation was increased?

increase synthesis

syn-degrad=depos

What optical form of amino acids are found in normal feeds?

L-isomers (levo-rotational)

Why do synthetic amino acids differ in their ability to meet an amino acid requirement?

L is only used for life forms

synthesized ones...

methionine: efficient in conversio of Dform to L form

lysine: PROB not efficiently converted

What is transamination? What is formed?

making a diff amino acid

transfer of the amino group of one AA to the C-skeleton of a keto-acid =

AA synthesis

What is a glucogenic amino acid? Ketogenic AA? Essential and non-essential AA?

glucogenic- can make glucose

ketogenic- cannot make glucose

essential- needed in diet

nonessential- synthesized naturally

What is used and what is produced during deamination?

amino group --> keto acid and ammonia

What needs to be detoxified after deamination? What cycles do this?

ammonia--> UREA

uric acid cycle

What are the benefits of the Uric Acid cycle?

detoxifies ammonia

co2+ammonia+energy-->urea

When is amino acid catabolism increased?

-dietary protein intake exceeds requirements

-composition of absorbed AA is unbalanced

-gluconeogenesis from AA is increased

What does muscle do with AA after a meal? During a fast?

stores as glycogen

A protein requirement is actually a requirement for?

amino acid requirement for tissues

Would two proteins that differ in their amino acid profiles have the same effect on growth?

maybe...

What is biological value?

def. how good is this protein at providing AA that this animal needs?

Nretention/Nabsorbtion

If a protein has a less ideal amino acid profile, will it have a high or low biological value?

LOW

Is biological value of a protein the same for an animal growing vs lactating?

NO

What do we mean by an ideal protein?

how much AA is the protein providing based on the requirement

--> you want NOTHING under 100%

If one amino acid is provided at 50% of requirement, but all others are adequate, what would you expect for performance/growth?

DEATH

diet provides only 50% growth rate

Does one feed have an ideal amino acid profile? Rank plant proteins, microbial proteins, and animal proteins.

microbial proteins(GOLDEN in ANIMAL NUTRITION) >animal proteins>plant proteins

What are two feeds called that when mixed together have an amino acid profile better than either alone?

complementary feeds

How are proteins broken down? What do we absorb?

PROTEIN -->pepsin (stomach)/ trypsin,chymotrypsin (pancreas--> PEPTIDES--> peptidase (pancreas & SI)--> AA and DI/TRIPEPTIDES

absorb: in carbs, glucose

in proteins di/tripeptides

What is an AA antagonism, toxicity, and imbalance

antagonism: growth depression from an exxcess on one AA that CAN BE reversed by adding a second

toxicity: growth depression from an excess of one AA that CANNOT be reversed by adding a second

imbalance: deficit of one or several AA that can cause depression in growth of production and CAN BE reserves by small amts of AA

What happens if we have a slight or severe protein deficiency?

slight: reduced growth rate, INCREASED fat, low milk prod., poor feed efficiency

severe: reduced growth rate, weight loss, scruffy hair, etc.

What happens if we have too much dietary protein?

high feed costs, normal growth, enlarged kidneys, excess water intake

Why does feeding too much energy have an energetic cost to the animal?

synthesis of urea

What are the environmental emissions from feeding excess protein?

contribute N pollution to water

ammonia emission (urease in feces creates ammonia)

What is the main contributor to ammonia emissions in the US?

livestock

What is the environmental risk of underfeeding dietary protein?

Animals are deficient and it takes more animals to meet demand for the product they are producing

D methionine

is efficiently converted to L methionine

D lysine

slightly toxic

LACTATION

Is the dairy cow the most extreme example of lactation?

NO ocean living animals

What is unique about the kangaroo?

nursing two Joey's at once and will make different milk composition for newborn vs. older

What is unique about the Northern Elephant Seal? How does their milk composition differ from a cow?

does not eat during lactation

30 day lactation

Milk: 44% fat & 12% protein

loses 42% of body weight

transfering to pups as quiclkly as possible so she can eat

To determine amount of a nutrient required for milk synthesis (say Ca) we need to know milk yield and ?

milk nutrient (Ca) concentration

which has most influence on milk composition

nutrient requirement of offspring

Does milk composition match growth rate and requirement of the offspring? What are some examples?

YES

protein composition

Whale 42% fat

Porpoise 49% fat

human and donkey

How do we classify sugars?

number of Sugars

monosaccharide

disaccaride

trisaccaride

polysaccaride (starch, cellulose)

What happens to glucose requirement during lactation? Where does the cow get this glucose?

high glucose demand

(BUT low absorp in rum)

gluconeogenesis!!

What is the link between milk protein and milk lactose? Do all animals have the same amount of casein (the protein that makes cheese)?

diffrenced in caseins!

What happens to energy requirements during lactation? Where does the energy come from?

homerhesis

LIPID catabolism : LIPID STORES make up for deficits in E supply

lipolysis

transport of NEFA to other tissues

fatty

When we release fatty acids from adipose tissue how are they transported in blood? Are they quickly or slowly used?

NEFA transported in blood bound to plasma albumin

turnover is RAPID

Plasma NEFA is directly related to

rate of fatty acid mobilization

Where and how do we complete oxidize fatty acids? What cells are not able to do this?

uptake increases as plasma conc. increases

beta-oxidation

can't: brain, RBCs, testes

What limits fatty acid oxidation in the TCA cycle?

low OAA

What are the key steps of beta-oxidation?

takes fatty acids and makes acetyl CoA

When are we not able to completely oxidize acetyl-coA coming from beta-oxidation? What do we do with the acetyl-CoA? What tissue does this occur in?

low OAA (stolen when animal fasting for gluconeogenesis) inhibits TCA

acetyl CoAs MAKES KETONES

(IN LIVER)

When an animal has high ketones, what can we smell on their breath?

sweet-smelling breath

due to not enzymatic breakdown

If the liver is taking up more fatty acids than it can export as vLDL, oxidize completely, or make ketones our of, what does it do with them?

stores it (BAD) liver failure

What can ketones be used for by other tissues in the body?

use ketones in blood of cows bc VFAs are converted to ketones

Where can we look for ketones to determine if an animal is ketotic?

URINE, milk

blood?

What are four things that can contribute to metabolic diseases?

1. Failure to adapt to a new physiological state (i.e. start of lactation)

2. Very low intake

3. Hormone deficiency/imbalance

4. Obesity

What is a primary metabolic disease? A secondary metabolic disease? Do we have to treat the secondary? What happens if we only treat the secondary?

1: symptoms directly related to primary dysfunction

2: symptoms INDIRECTLY related to primary dysfunction

diagnose and treat both primary and secondary in order for recovery

What causes lactation ketosis, pregnancy toxemia?

lactation ketosis--> can't keep up demand for lactation

preg tox -->

What happens in Feline Hepatic Lipidosis? What increases the risk? What is the short and long-term treatment?

def. -NEFA mobilization from adipose tissue

-excessive uptake of NEFA by liver

-limited ability of liver to oxidize or export fatty acids as TAG in VLDLleads to fat accum.

OBESITY

low intake, acute stress

restore E intake

tube feeding

SLOWLY reduce weight of obese

minimize stress

LIPIDS IN LACTATION

What is a common description of lipids?

structure (lipid bilayers)

signaling

storage

What are the two sources of fatty acids in milk fat? What do we need to make these?

de novo (made in mammary gland from glucose and acetate)

preforms (from diet and body stores)

Which lipids have the highest energy density?

fatty acids

Which have very little nutritional value?

non-glycerol based

Which lipid do we make to store energy?

In concentrates

triglycerides

Which lipid do mostly find in forages? Are they as energy dense as triglycerides?

glycolipids

NO less ebergy dense

What do we use phospholipids for in cells? Are they as energy dense as triglycerides?

MEMbranes

NO!

What are some examples of steroid derived compounds?

cholesterol, vitamin F, hormones

How can fatty acids be different from each other? Are these important to their metabolism?

characterized by # of carbons, number of double bonds, location/orientation of double bonds

YESSSS

Where do we find trans fatty acids? Are they all bad?

industrial processed oils, ruminant fat

industrial = bad

ruminant fat (made from microbes) = likely healthy!

palmitic acid

16:0 Palm Oil

stearic acid

18:0

oleic acid

18:1 cis-9

Olive Oil / Canola Oil

vaccenic acid

18:1 trans-11

linoleic acid (Omega-6)

18:2 Corn/ Soybean

a-linoleic acid (Omega 3)

18:3 Cannola/ Flax

arachidonic acid

20:4

EPA and DHA

very long chain Omega 3s in fish oil and algeas