Nutrition Exam #1

Which region of the ruminant GI tract is water not absorbed from? a. rumen b. small colon c. large colon d. omasum

A

Which ruminal VFA would be in highest in concentration after a meal of mostly grass hay? a. Acetate b. Propionate c. Butyrate d. Lactate

A

Which statement about a horse's GI tract is most correct? a. Though a horse is a post-gastric fermentor, most of it's energy source is from digestion and absorption of simple carbs and fat in the small intestine. b. Feeding high levels of grain is safe because a horse is a non-ruminant c. The horse derives most of it's energy from VFAs produced from cecal and large colon fermentation of structural carbs d. Horses begin the digestion of proteins in the mouth

A

As the amount of degradable carbohydrates in a ration increases you would see a change in the acetate:propionate ratio. a. What is the change in acetate:propionate ratio? b. Why does this occur?

A. Propionate would increase and acetate would be lowered as the amount of degradable carbohydrates increases B. Shift in microbial populations

Which feedstuff when fermented in the rumen will result in the greatest amount of lactic acid production? a. Alfalfa haylage b. Corn silige c. Cereal rye balage d. finely chopped grass haylage

B

Insulin is released by cells of the pancreas in response to: a. Low energy levels in the animal b. Low glucose levels in the blood c. A higher than optimal blood glucose level in the circulation d. High energy consumption

C

Lipids that are liquid at room temperature are: a. long chain FA b. saturated c. unsaturated d. over 10 carbons in length

C

Rumen microbes alter the chemical structure of a long chain unsaturated FAs how? a. break down the FA into shorter, saturated chains b. dehydrogenate and hydrolyze the FAs c. biohydrogenate and hydrolyze the FAs d. oxidize the FAs

C

The type of lipids common to membranes are: a. triglycerides b. sterols c. phospholipids d. lipoproteins

C

This partner hormone in the homeostatic regulation of blood glucose is released in response to lower blood glucose levels, stimulating both glycogenolysis and gluconeogenesis. a. epinephrine b. cortisol c. glucagon d. glucocorticoid

C

Urea from the saliva of a cow is used: a. by the cow to synthesize amino acids b. to buffer the rumen fluid so that fermentation can be maximized c. only by the microorganisms for amino acid synthesis d. can be utilized by both by the cow and the microbes

C

Water consumption varies during the different stages of production for a ewe. Would a ewe's water intake be greater, the same, or less, for a ewe lactating during the winter months compared to a summer lactation? a. greater b. same c. less

C

What is the purpose of urea in the saliva of a ruminant? a. route for disposing excess N by the animal b. provides a N source for amination of carbon chains in the liver of the animal c. provides a N source for protein synthesis by the rumen microorganisms d. buffers the rumen content

C

How are cellulytic microorganisms able to ferment cellulose, but a cow can not?

Cellulytic microorganisms have cellulase, while a cow does not.

Feeding diets that contain unsaturated fats in the form of oilseeds are less toxic to the microbes because release of the FAs into the rumen fluid is slow. TRUE or FALSE

False

The microbial population in the gut has a profound effect on dietary proteins in both ruminants and nonruminants. TRUE or FALSE

False

There are two oxidative processes responsible for most of the energy (ATP) produced from fat in the pig. What are the names of those processes?

TCA cycle and beta oxidation

The primary purpose for Na bicarb in the saliva of a ruminant is to help provide pH stability in the rumen so that proper fermentation can occur. TRUE or FALSE

True

Animals fed a diet of 60% concentrate will have greater total VFA concentration than those fed 40% concentrate diets. TRUE or FALSE

True

Gluconeogenesis is the primary source of glucose in the ruminant. The precursor for glucose is primarily propionate, but lactate can also be a pre-source of glucose. TRUE or FALSE

True

Protein requirements for cows are actually the ??? reaching the SI.

deanimated amino acids

Elevated ketone levels (ketosis) are cause when: a. Acetyl-CoA is unable to be metabolized through the TCA cycle because of a lack of carbohydrate in a diet b. Fat metabolism is generating less acetyl-CoA c. Carbohydrate metabolism generates propionate rather than acetate d. Glucose is being converted to pyruvate at an accelerated rate

A

If your goal is to feed a diet that will have various carbohydrates available for microbial fermentation over a longer period of time you should consider using these feeds in a diet: a. Whole shelled corn, corn silage and dry hay b. Ground corn, high moisture corn, corn silage, haylage, dry hay c. High moisture corn, corn silage, dry hay d. Ground corn, rolled barley, haylage, dry hay

A

Some of the diversity in the rumen microbial population is due to: a. types and concentrations of nutrients b. the presence of CO2 and methane in the rumen c. a lack of oxygen in the rumen environment d. buffers from the saliva

A

The TCA cycle's primary functions is to: a. metabolize pyruvate to acetylCoA and CO2 b. generate additional ADPs for use in energy requiring processes c. metabolize glucose for the tissues of the body d. produce high energy compounds that are used to generate ATPs in the electron transport system

A

The tissues where the majority of lipid metabolism takes place is the: a. liver, mammary tissue, adipose tissue b. liver, adipose tissue, muscle c. liver, brain, muscle d. adipose tissue, muscle

A

Transport of lipids from the intestinal mucosal cell is: a. with a mixed micelle through the lymph system b. with high density lipoproteins (HDL) through the blood c. chylomicron through the lymph system d. through the bloodstream

A

What is a high quality protein? a. highly digestible in the rumen b. provides high quality of amino acids c. provides excess essential amino acids d. digestible proteins.

A

When urea is broken down in the rumen, it results in what nitrogen compound(s)? a. two ammonia molecules b. three ammonia molecules c. two nitrogens d. amino acids

A

Ruminants have evolved to be able to utilize the fibrous fractions of plants as a source of energy. a. What are the primary fibrous or structural carbohydrates found in grasses? b. How are the ruminants able to utilize these plant carbohydrates as an energy source when a pig is unable use them? c. Which structural carbohydrate is most degradable?

A. Cellulose, hemicullulose B. Ruminants themselves cannot utilize these carbohydrates because they lack cellulase and hemicellulase, but the microbes in their rumens contain both, allowing them to digest the carbohydrates. Since pigs are non ruminants, they don't have the microbes or the cellulase/hemicellulase to digest them C. Hemicellulose

If you look at the average butter fat % in a group of cows, and it appears to be lower than expected, you could have a problem with the diet. a. Identify the two most impactful dietary issues. b. Explain how those dietary issues in (a.) could affect BF production

A. Fatty livers and ketosis B. Fatty liver - cows have less energy to divert to milk production, Ketosis- cows are mobilizing fat stores for energy, which means feeds are being less utilized, thus lowering butterfat percentage

A group of young grazing cattle have unlimited access to grass pasture. The manager added a mineral option containing Rumensin. a. What would be the likely effect on rumen microbial fermentation end products produced? b. Why would we normally see changes in the rumen fermentation even when grass pasture remains the primary carbohydrate source. c. Why do ruminants being fed high forage diets show improvement in feed efficiency when fed an ionophor?

A. Increased the levels of propionate while decreasing production of a stage and butyrate. B. acetate levels do not change, but the propionate levels increases C. Ruminants fed a high forage diet typically have higher levels of acetate, which does not produce as much energy as propionate. Feeding an ionophore will produce higher levels of propionate.

A late gestation ewe is receiving 1st cutting grass hay and exhibiting mild signs of pregnancy disease/toxemia. a. What is the metabolic problem seen in a ewe with pregnancy disease? b. Why does feeding 1 pound of corn grain normally eliminate the symptoms of this metabolic disease?

A. Ketosis B. The one pound of corn grain provides the ewe with enough energy to keep her out of the negatives when she lambs. This is common in ewes who have multiples because they don't have enough room to eat enough roughage to provide the energy they need. Feeding the corn grain allows more starches to be ingested, even if the amount of feed isn't huge.

What do these abbreviations actually stand for: a. LAA b. PUFA c. NEFA d. EAA e. UIP

A. Limiting amino acids B. Polyunsaturated fatty acids C. Nonessential fatty acids D. Essential amino acids E. Undegraded intake protein

A cow's saliva contains water, mucin, sodium bicarb, urea, and phosphates. a. What is the purpose of the sodium bicarb? b. What is the purpose of the urea?

A. Na Bicarb is used to moderate the pH in the rumen B. Urea is used as a source of protein for protein biosynthesis, mainly by microorganisms for amino acid synthesis

A group of mixed heifer and steer feeder calves are transported from southern Missouri to Ohio (14 hours on the road). Prior to leaving Missouri for the one day trip the steers had access to a free choice supply first cutting fescue grass hay. a. If glucose is being metabolized to generate ATP energy, what is the sequence of metabolic pathways used in the process? b. If you assume that the calves will continue to have a glucose based energy metabolism, what are the three most likely sources of that glucose used to generate energy in the calves during at least a portion of trip to Ohio.

A. Stage 1- Gycolysis, stage 2- TCA cycle, stage 3- electron transport system B. propionate, amino acids (gluconeogenesis), and glycogen (glycogenolysis)

A pig consumes a typical "meal" of ground corn and soybean meal. a. What would be the primary carbohydrate being digested in this ration? b. What is the function of insulin in the pig following a meal?

A. Starch B. Insulin responds to high blood glucose levels and stimulates uptake by the adipose tissue, thus resulting in a lower blood glucose level.

The primary VFA produced by microorganisms in the rumen is what?

Acetate

Name the 4 products typically produced by microbial fermentation of carbohydrates in the rumen and utilized in some way by the ruminant animal itself

Acetate, propionate, butyrate, lactate

A group of lactating ewes were each being fed a ration containing about 4 pounds of a grain mix (corn, oats, protein supplement) and 6 pounds of 2nd cutting grass/alfalfa hay. The producer went in to feed them one morning and found that they had got the gate to their pen open and had gotten into the bagged creep feed stored on the barn floor. All of the ewes seemed normal in the morning at the time of feeding and were fed only the hay, but at the evening feeding most of the ewes had diarrhea and several refused both the grain and hay. a. What disease are the ewes suffering from? b. Describe the events occurring in the ewes' rumens that have lead them to the point where they are reluctant to eat.

Acidosis, after engorging on grain, the VFA's in the rumen increases, causing the pH and free glucose in the rumen to drop, followed by an increase in S. Bovis and lactic acid. The lactic acid is continued to be produced, and eventually there is too much to be processed. This results in it being absorbed through the rumen wall, causing lactic acid in the blood to increase and blood pH to decrease

What is the general mode of action for an ionophore in a ruminant diet? Explain why a dairyman should consider adding an ionophore to both the close-up dry and the just fresh lactation diets.

An ionophore will allow the cow to produce more propionate, which is the more effective energy source than acetate or butyrate. A dairyman might consider using an ionophore in fresh lacataion and close up dry diets to keep his cows out of a negative energy balance. This will keep cows from becoming ketotic or getting fatty livers, as well as keep them at peak production

The main purpose of bicarb in the saliva of the pig is: a. provide a buffer for the content of the stomach b. maintain an optimal pH for the amylase in the mouth c. activate the pepsinogen produced in the stomach d .help initiate the digestion of cellulose in the mouth

B

We use the terms structural carbohydrate and non-degradable carbohydrate to mean a similar type of compound. Those carbohydrates are: a. Cellulose, hemicellulose, and lignin b. Cellulose, starch, and glycogen c. all long chains of glucose molecules bonded together d. Cellulose and hemicellulose

B

What area of the GI tract of a non-ruminant will most digestion take place? a. stomach b. duodenum c. jejunum d. ileum e. large colon

B

How is the ruminant able to moderate the pH of the rumen following a feeding?

Bicarb in the saliva

What is the primary function of bile salts in the GI tract of the pig?

Bile salts will emulsify fats, thus increasing surface area and allowing more lipase to attach

You have a group of steers being fed a high grain diet. They have been on this diet for several weeks. Several of the steers are showing signs of expanded abdomens and are laboring to breath. What is the name of this health issue? What is the simple explanation for the cause?

Bloating. The steers are either not belching or they are producing too much gas and cannot expel it fast enough.

A ruminant relies on fermentation of structural carbohydrates by a diverse microbial population: a. because digestion becomes a faster and more thorough process with the microorganisms b. because the microorganisms are unable to utilize most of the fermentation products c. because the ruminant does not posses the proper enzymes to digest structural carbohydrates d. because the ruminant relies mostly on degradable carbohydrates as their energy source

C

An example of a common essential amino acid that is deficient in most corn based diets is: a. Methionone b. Leucine c. Lysine d. Glycine

C

Cellulytic organisms: a. utilize nonstructural plant carbohydrates as their primary carbon source b. collectively ferment cellulose and pectins c. ferment dietary cellulose and produce significant amounts of acetic acid in the process d. are able to ferment lignin in addition to cellulose and hemicellulose

C

Glycogenolysis would most likely take place when: a. insulin stimulates the uptake of glucose after a meal b. an animal requires more glycogen in the liver c. when an animal has depleted it's blood glucose during a short term fast d. if an animal has consumed a large quantity of glycogen

C

Which answer is incorrect? a. Animals in the mid-west consume the most water during summer months because they lose significantly more body water through sweating and respiring. b. High intake of dietary minerals like Na and Cl will normally increase water consumption c. Digestion is reduced in animals with diarrhea because passage rates decrease d. Spring pasture contains more than 60% water and therefore provides a significant portion of their water requirements

C

Which feed will contribute to faster production lactic acid in the rumen? a. Whole shelled corn b. cracked corn c. ground corn d. oats

C

What ruminal pH range is most beneficial for the cellulytic bacteria to function properly? a. 5.5-7.0 b. 5.5-6.5 c. 5.0-6.0 d. 6.0-7.0

D

An example of a disaccharide is: a. glucose b. galactose c. maltose d. lactose

D

Fats that are solid at room temperature are: a. polyunsaturated b. short chain and saturated c. Long chain and unsaturated d. Long chain and saturated

D

One example of gluconeogenesis is: a. the production of glycogen from glucose b. the production of glucose from acetic acid c. the production of glycogen from propionate d. the production of glucose from specific amino acids

D

Rumen inert fats: a. are easier digested than saturated fats b. reduce the level of modification by the rumen microbes c. are saturated fats d. are hydrolyzed but not biohydrogenated by rumen microbes

D

The characteristic of FAs in adipose tissue of a pig: a. is mostly dependent on fat metabolism in the tissue b. can be influenced by the synthesis of FAs in the liver c. can be altered by high levels of insulin d. is influenced by dietary FAs absorbed from the SI

D

The difference between deamination and transamination in the animal is that transamination occurs a. during the protein catabolism process in the animal b. during the synthesis of essential amino acids in the animal c. if a N source is needed for protein synthesis by the rumen microorganisms d. when there is a transfer of an amino group from one amino acid to a keto acid during amino acid synthesis in the animal

D

The essential amino acid requirements a. are met by the dietary proteins for ruminants b. are met by microbial and dietary protein sources for the pig c. can be supplied in part by synthesis in the animal's body d. are met by the dietary proteins for a nonruminant

D

The primary function of glycolysis is to: a. generate lactate from glucose for entry into the Krebs Cycle b. increase circulating levels of glucose from glycogen c. store excess glucose in the form of glycogen d. convert one glucose molecule into two pyruvate molecules for the TCA cycle

D

The recommended limits to added unsaturated fats is .5 pound because: a. They are difficult to mix in a ration b. microbes need to hydrolyze them at a fast rate c. the animal rarely needs more than .5 pound d. more than .5 may overwhelm the microbial population's ability to biohydrogenate them

D

Triglyceride (TG) absorption: a. requires the they be converted to short chain FAs and glycerol to cross the mucosal membrane b. occurs in the duodenum with the help of emulsifiers and pancreatic lipase c. can occur in the rumen only if lipolytic bacteria are present and active d. involves the disassembling of the TGs, movement across the mucosal membrane and reassembling the TGs in the intestinal mucosal cells

D

What activates pepsin in the stomach? a. mucin b. HCl c. proteins d. amylase

D

When a ruminant is fed a diet that contains a significant about of grain and the pH drops following a meal, what typically happens to the ruminal fiber digestion by the cellulytic bacteria? a. the microbes have adjusted to the drop in pH so that fermention of fiber doesn't really change b. fermentation increases measurably until the pH rises, then slow to a normal rate c. rate of fiber digestion by the microbes increases slightly to compensate for the reduced activity d. cellulytic organisms will slow their fermentation process for a short period until the pH recovers to a more optimal level

D

When grain makes up a large portion of a ruminant's diet: a. Large amounts of Na bicarb from the saliva will help to maintain the pH in the desirable range for the cellulose fermenting microbes. b. Lactic acid producers flourish because of the higher pH in the rumen c. Propionate and lactate production increases significantly causing the pH to rise d. Propionate and lactate production increases causing the pH to drop rapidly

D

Which polysaccharide contains other sugars in addition to glucose? a. starch b. cellulose c. glycogen d. hemicellulose

D

You manage a group of feedlot cattle. The waterline has broken to the automatic waterers, preventing the cattle to drink for a day. Would you expect the DMI to increase or decrease during this time?

Decrease

After a meal, does the pH in the rumen increase or decrease?

Decrease

Why are there recommended limits for adding dietary oils to a ruminant diet? Why is there often times a difference in rumen microbial stability when oils are fed in the free form versus being fed as part of a whole oilseed?

Dietary oils contain PUFA's, which in high levels are toxic to rumen microbes. There is often a difference in microbial stability when oils are fed free form vs. wholeseed because the oils will breakdown faster, allowing an excess of PUFA's that the microbes that are capable of biohydrogenation will not be able to keep up with. Whole oil seed digests much slower, allowing those microbes to properly biohydrogenate the PUFA's before they reach toxic levels

Briefly describe in three steps in the process of triglyceride absorption in the gut of a pig.

Fats mix with bile and other intestinal secretions. Bile salts emulsify the fat, allowing a larger surface area for lipases to attach. Lipases attach to produce beta monoglycerides and free FA

A dairy cow calves normally but within a few weeks goes off feed and does not respond to normal ketosis treatments. She eventually shows a yellowing of the eyes and mucus membranes and subsequently dies. When the cow is necropsied, you find that the internal fat depots are yellowish in color as well. Diagnose the cow's problem or disease, explain how the condition developed, and explain what could have been done to reduce the risk of having this disease occur.

Fatty liver. The condition developed because the cow was in a negative energy balance. Her body was mobilizing the fat from her adipose tissue rather than any fat from the feed. This causes the body to be breaking down more fat than the liver can handle, so it starts to fail, hence the yellowing of the eyes, mucus membranes, and internal fat deposits. Both feeding protected choline and giving the cow a proper dry period are both ways this problem would have been prevented.

A steer's diet is made up of grass hay, ground corn, urea, minerals and vitamins has a calculated % fat of 3.4%. What feed provides most of the lipid?

Grass hay

Rumen fermentation can be affected if there are high dietary levels of PUFAs. Why do high levels of PUFAs cause a rumen disturbance? Under normal conditions in the rumen, lower levels of PUFAs seem to have little impact on the overall fermentation. How are the rumen microorganisms able to accommodate the lower levels of PUFAs ?

High levels of PUFA's can cause a rumen disturbance because they are toxic to microbes. The microorganisms are able to accommodate the lower levels of PUFA's because some of them are capable of biohydrogenation.

Under what dietary situation would a nutritionist consider using a "rumen inert" fats in a high producing dairy cow ration?

If the ration is 7-8% fat, a nutritionist would want to use rumen inert fats

What are two main functions of insulin in a pig?

Insulin responds to high blood glucose and stimulates glucose uptake by the muscle and adipose tissue, thus lowering the levels of glucose in the blood

Under what conditions would fatty livers in dairy cows be most commonly seen? What is one possible feed ingredient that could help mobilize the accumulated fats from the livers of a lactating cows?

It is commonly seen in dairy cattle with a negative energy balance and is caused by excessive fat mobilization from the adipose tissue. Feeding protected choline would help mobilize these fats

What are the two EAAs that are often times limiting in both rapidly growing pigs and high milk producing dairy cows.

Methionine and lysine

The function of Na bicarb in the saliva of non ruminants is to do what?

Moderate the pH of the rumen

An animal that is in an energy deficit would be deficient in ATP or the ability to generate ATP? YES or NO

No

What does the abbreviation NEFA refer to? Under what circumstances would you typically see higher amounts of NEFA in a cow's blood?

Nonessential fatty acids. Higher amounts of NEFA's would occur in a cows blood when depot stores are being mobilized

What would be one difference and one similarity between a ruminant and a non-ruminant when comparing starch digestion in their respective GI tracts?

Nonruminants digest starch in the SI, ruminants digest starch in the rumen, but both turn that starch into glucose

What is meant by the term post-gastric fermenter? Give an example of an animal considered a post-gastric fermenter.

Primary fermentation occurs in the cecum, after most digestion takes place. Horses are an example

The portion of the CP in a ruminant's diet that is broken down by the microbes is the:

RDP or DIP

What is the primary factor determining when rumen content will move out of the rumen-reticulum and into the omasum compartment of the ruminant stomach?

Size of the feed particles. Smaller particles will move out of the rumen while larger particles will stay to digest further

What is the primary factor determining when rumen content will move out of the rumen-reticulum and into the omasum compartment of the ruminant stomach?

Size of the particles. Smaller particles will move into the omasum, while larger particles will remain in the rumen-reticulum until they can be broken down further.

In the pig, where does the most digestion take place?

Small intestine

What is the explanation for urea found in ruminant saliva?

Source of nitrogen for protein biosynthesis

A ewe is fed a diet containing alfalfa hay, cracked corn, oats, soybean meal, mineral premix, and molasses. List 3 major carbohydrates being supplied in this diet.

Starch, cellulose, hemicellulose

Why does a neonatal calves fed milk and grain diets have greater rumen development than calves fed milk alone?

The bacteria a calf needs in the rumen will come from feeds given to the calf

We know that starch and cellulose are long chains of glucose. What is so different between those two molecules that we would see nearly complete digestion of the starch but very little digestion of the cellulose in the GI tract of a pig? Why are ruminants able to utilize the cellulose in forages as their primary energy source?

The linkages between the monomers in starch and cellulose differ. A pig would not have cellulase to cleave the bonds of cellulose, therefore they would not be able to digest anything but the glucose bonds. Ruminants have microbes in their guts that do possess cellulase, giving them the ability to digest cellulose.

A group of 9 month old calves have been recently weaned and fed a diet consisting of good quality grass hay. Without any adjustment or transitional period they are given a diet in which half of the DM is grass hay and the other half is a ground corn/SBM mix with the appropriate vitamins and minerals. Explain what would happen to the rumen pH within the first hour or so following a meal. What is the primary cause for a change in the rumen pH? What common rumen bacteria plays a significant role in the production of lactic acid in the rumen? What is the likely outcome, from a health perspective, for most calves who have been part of a scenario like the one described?

The pH of the rumen would decrease due to acid production by the rumen microbes during starch fermentation. S. Bovine (an amylolytic bacteria) is the comment bacteria that plays a role in lactic acid production. The outcome most calves in this scenario would face would likely be lactic acidosis, varying in how extreme based on how much grain the calves ingested.

What is the primary metabolic concern for cattle being fed high grain diets? How would Bovatec help to minimize this problem?

acidosis; lactic acid decreases