Final

Question 1

we eliminate all of the potential factors that can influence heat production, then we can obtain a minimum energy expenditure associated with maintenance of life, and it is called

Answer 1

Basal metabolism

Question 2

When we think about the “maintenance need” for protein or N, a couple of very obvious important terms would pop into your head such as________________ and other biologically active N compounds (ex Histamine & carnitine).

Answer 2

enzymes and peptide hormones

Question 3

Most minerals can easily form____________ thus their absorption rate is generally very low. Exceptions are Na, Cl, & K.

Answer 3

salts or other insoluble compounds

Question 4

The sense of ____ is important for pigs where as _____ is important for poultry.

Answer 4

smell

vision

Question 5

4) Obviously the major difference between fat and water soluble vitamins is solubility but another major difference would be

Answer 5

fat sol stored in fat, water vit constantly replenished.

Question 6

5) It seems that “gastrin” is the focal point of regulating gastric secretion and _____________are primarily factors involved in controlling gastrin secretion, thus the activity of the stomach.

Answer 6

histamine and secretin

Question 7

Unlike pigs) Chickens do not have a “stomach” per se, and they use their

Answer 7

crop for food storage, proventriculous for enzyme secretion, and gizzard for grinding respectively.

Question 8

7) What are gizzard teeth?

Answer 8

Well they are uniquely associated with the fowl and consisted of a protein-polysaccharide complex known as koilin which form rods that can protrude through the lining of the luminal surface.

Question 9

8) Obviously, ____________ are very important in energy metabolism, and it seems that plasma glucose is the major factor controlling their secretion.

Answer 9

glucagon and insulin

Question 10

9) Well, as we mentioned, horses seem to have a lot of digestive/nutritional related problems such as

Answer 10

colic and stomach rupture(disorders).

Question 11

1) Under _________, C-skeletons cannot be oxidized to CO2. Consequently, the end products of rumen fermentation are mostly VFAs.

Answer 11

anaerobic conditions

Question 12

10) Having ________ is important for young ruminants so that milk can flow directly into the omasum/abomasums which results in better utilization of milk.

Answer 12

reticular groove

Question 13

11) As we mentioned, animals may be “marginally” deficient or excess in certain nutrients but we may not realize that all simply because

Answer 13

they show no clear signs or symptoms.

Question 14

12) It seems that “mineral metabolism” is a bit different from metabolism of most other nutrients such as protein, simply because

Answer 14

minerals aren’t broken down

Question 15

13) In practice, “fattening or finishing” is an integral part of “growing” animals for the commercial meat production. But, as we mentioned, it is not part of “growth” because

Answer 15

growth involves protein, minerals and water, and fat is energy storage.

Question 16

14) It would be important for us to have some ideas on “interactions” of minerals for two important reasons:

Answer 16

avoid undesirable reactions & secondary deficiencies.

Question 17

15) We did talk about estimating nutrient digestibility just briefly. And, we use the term, “apparent” rather than saying “digestibility or true digestibility” simply because

Answer 17

it does not consider metabolic fecal nutrient.

Question 18

16) As we mentioned, laying hens and lactating sows mobilize a lot of “Ca and P from bones” which can lead to leg problems! The best way to alleviate such problems seems to be

Answer 18

Supplement Ca & P during gestation.

Question 19

17) For most species, “esophagus” is simply a passage way for food/feed but it does have some implications for “horses” because

Answer 19

their smooth muscle is one way peristaltic contractions; cannot vomit or burp.

Question 20

18) In the small intestine, “2 sets of glands” are primarily responsible for digestive secretions. The 1st one is _______ or duodenal glands which can secrete viscous mucous. The second is_______ or intestinal glands which secrete mucous and enzymes.

Answer 20

Brunner’s gland

crypts of lieberkuhn

Question 21

19) Briefly we talked about changes in pH as ingesta/digesta move thru gastrointestinal tract and the pH changes seem to be important for

Answer 21

reducing microbial growth/load and keeping at optimum pH for enzymes to work properly

Question 22

_______which account for 40-50% of total dry weight of most plans, cannot be utilized efficiently by us & most other nonruminant species simply because:

Answer 22

cellulose

don’t have enzyme to break B-1.4 linkage; only microbes do

Question 23

21) When we are dealing with ruminant species we often hear the term ketosis. Ok, what is exactly ketosis and how does it happen

Answer 23

Buildup of ketone bodies observed in blood/tissues from lack of propionate or oxalate.

Question 24

22) Obviously, there are some advantages in having “rumen” but everything is not perfect. Some disadvantages are

Answer 24

lots of time/energy/work spent chewing, lots of energy used in fermentation, inefficient protein synthesis, rely on microbes, and wasted energy via methane and CO2.

Question 25

We had some discussion on “indispensible and dispensable” nutrients in class. Perhaps we should not say a “nonessential amino acid” but perhaps we can use the term “nonessential” if we include the term “dietary”. I.e. “dietary nonessential amino acid”.

Answer 25

T

Question 26

We had some discussion on indis and dis. Now we can say a ‘nonessential amino acid’ without any problem, but we should not say a ‘nonessential mineral’ because metabolically all minerals are essential.

Answer 26

F

Question 27

When we consider protein synthesis; we have to remember that the process is not exact. That is many mistakes can take place during the translation process thus increasing energy expenditure greatly as well as protein or amino acid needs.

Answer 27

T

Question 28

Females seem to have no special needs for energy or nutrients before breeding but if they are not consuming sufficient energy or nutrients during last 1/3 gestation, we can definitely expect adverse effects on their reproductive performance.

Answer 28

F

Question 29

A balance test may not be a good way to estimate mineral requirements simply because the balance can be affected by many other factors…other than dietary concentration or intake of mineral in question that is.

Answer 29

T

Question 30

To estimate protein needs we have to consider urinary N, fecal N, and hair/nail growth

Answer 30

T

Question 31

A main advantage of using radioactive indicator in studying mineral metabolism? Well we are not really increasing the content of particular element in feed or physiological concentration of the element thus we are not disturbing the animal’s normal metabolism

Answer 31

T

Question 32

Throughout history, people had to deal with many serious diseases/disorders, and we now know some are caused by deficiency of some vitamins. Ex. Beriberi thru Thiamin and pellagra thru Niacin.

Answer 32

T

Question 33

• Although a borderline deficiency of vitamin is common, unaware bc no clear signs. Especially true for fat-soluble vitamins.

Answer 33

F

Question 34

One reason that chickens have high heart rate has to do with # of erythrocytes, which seems to be less than half of many mammals!

Answer 34

T

Question 35

Pigs have a poorly developed “olfactory mechanism” and having unheated mouth, thus no release of volatile compounds may have something to do with poor smell. (Chickens actually do have poor developed olfactory mechanism).

Answer 35

F

Question 36

in terms of ‘prehension’ chickens don’t have good mechanism, horses use lips, cattle use tongue to consume feed.

Answer 36

T

Question 37

• It seems that pig’s saliva contains ptyalin or amylase but not in chickens, horses, ruminants, cats or dogs.

Answer 37

T

Question 38

As we mentioned, regardless of species, majority of nutrients are digested and absorbed at upper portion of small intestine, especially at the ileum(answer jejunum), even though some nutrients can be absorbed at the lower portion, ex B12 at the colon.

Answer 38

F

Question 39

The “duodenum” is primary a mixing site for all nutrients in digesta. That is, bile, pancreatic secretions, ect. Would be mixed with digesta in the duodenum, but not as much digestion or absorption would take place in this part of small intestine.

Answer 39

F

Question 40

• In chickens, two long ‘ceca’ are primary fermentation sites; cannot utilize fiber efficiently perhaps bc the entrance to each cecum is somehow restricted thus only small particles and fluids can enter the ceca.

Answer 40

T

Question 41

It seems that chicken’s lymphatic system is poorly developed, which has some implications bc unlike other species, they’d have to absorb long-chain FA directly into portal circulation system…somehow.

Answer 41

T

Question 42

“Somatostatin” is a hormone originally identified as an inhibitor of growth hormone, & it may be involved in day-to-day regulation of nutrition thru it effects on the action of insulin and glucagon.

Answer 42

T

Question 43

Pepsin is mostly responsible for intestinal digestion of protein, and it (actually there seem to be 4 diff types in pigs & humans) has 2 pH optima, 2, and 3.5.

Answer 43

F

Question 44

We often hear the terms ‘ruminal acidosis and bloat” Well simply, acidosis caused by too much lactic acid; bloat is excessive accumulation of these gases.

Answer 44

T

Question 45

Although most carbs would be fermented by rumen microbes, small amt of carbs can escape. “Escaped” soluble carbs cannot be digested/absorbed efficiently by the host animal’s digestive enzymes.

Answer 45

T

Question 46

Two most likely limitations for ‘microbial protein synthesis’ seem to be availability of energy and ammonia but under practical conditions, ammonia is the limiting factor because carbs are readily fermented in the rumen to produce a lot of VFA!

Answer 46

F

Question 47

It seems that most VFA are absorbed from forestomach wall and absorption rate might be greater if ruminal pH is reduced and chain length increased.

Answer 47

T

Question 48

Although ruminant species can have a functional rumen by 8 wks, we can say that they are essentially ‘nonruminant’ during first couple months after birth.

Answer 48

T

Question 49

It’s amazing that each milliliter of rumen content contains 10-50 billion bacteria, 1 million protozoa and variable number of yeasts and fungi.

Answer 49

T

Question 50

Maintenance energy needs estimated by measuring fasting heat production(define). Also, we mentioned fasting metabolic rate is not adequate to satisfy maintenance energy need under practical conditions. Why?

Answer 50

Heat production: the conversion of energy/nutrients to work is not 100% efficient, energy that’s not converted to work is released as heat. – Fasting metabolic rate is not adequate to satisfy ME needs bc it does not consider all factors such as energy needed to eat, activity, & other needs. Animals are active.

Question 51

Brush-border enzymes such as lactase, sucrose, peptidase. What’s unique about intestinal enzymes when comparing to pancreatic enzymes? What is meant by villi and microvilli and are they factors that influence the status of them?

Answer 51

These enzymes are shed; pancreatic enzymes are secreted. Microvilli are tiny projections from intestinal wall contains brush boarder, increases the SA  better absorption of nutrients. pH, water, and microbes influence & high turnover rate.

Question 52

We determined energy/protein digestibility of corn in pigs and chickens of 3 cities. What kind of conclusion or inferences can we make by looking at this data?

Answer 52

Most energy is released at end of digestion at rectum/cloaca; this is where breakdown of nutrients and VFA’s occurs and protein is stored in duodenum.

Question 53

Horses have advantages of ruminant and nonruminants. Do they really though? Elaborate

Answer 53

Their hindgut ferments and uses cellulose and VFAs like ruminants’ large intestine, similar small intestine to non ruminants. Designed to utilize forages but are commonly fed grain and concentrates that can’t be used efficiently either. Can reduce problems by small, frequent feeding throughout day. Can synthesis vitamins, proteins, AA like ruminants & can ferment nutrients directly like nonruminants.

Question 54

When discussing rumen fermentation of dietary protein, concluded that VFA’s most impt. Why?

Answer 54

Crude protein is broken down to AA  ketoacids +ammonia  used by bacteria to make microbial protein. Ammonia also used in cycle that involves VFAs.

Question 55

Usually include most ‘vitmains’ in pig/poultry diets much more than req. You think rational? Req vs allowance affect this?

Answer 55

Vitamins are relatively inexpensive and are nontoxic unless very high levels. Impt to avoid secondary deficiency that has no symptoms. Want to satisfy all needs. Vitamin antagonists can interefere with vitamin activities. Reqiurement is the minimum amt to prevent deficiency and to satisfy the average population. Allowance is amt that satisfies population, not just avg. yes want to satisfy population and optimize performance. Non ruminants can synthesis most vitamins and must come from diet. Ruminants can synthesize vitamins and require forage to do so; less vitamin supp needed.