Final

Question 1

How are somatotropin(growth hormone) and IGF-1 involved in regulation of body growth?

Answer 1

1. Somatotropin induces the growth of bones and muscles
2. IGF-1 functions include; bone elongation, muscle growth, reducing negative energy balance, wound healing, regulating apoptosis ( programmed cell death)

Question 2

What are “catecholamimes” and how do they control body growth?

Answer 2

1. Synthesized by adrenal gland and are important for growth
2. Fight or flight hormones
   • epinephrine (Adrenalin)
   • norepinephrine (noradrenaline)

Question 3

How are glucocorticoids involved in regulation of body growth?

Answer 3

1. Improve gluconeogenesis
   • increase mobilization of lipids and proteins from body reserves
   • decrease glucose use of peripheral tissues
   • inhibit GH release

Question 4

What are major hormones associated with mammogenesis, lactogenesis and galactopoiesis?

Answer 4

1. estrogen

2.

Question 5

What factors do influence the palatability of feed?

Answer 5

• appearance
• odor
• taste
• texture
• temperature
• other sensory properties of feed

Question 6

What hormones/peptides of small intestine control feed intake in short term?

Answer 6

• gastrin
• CCK
• secretin
• GLP-1
• PYY

Question 7

What hormone controls the feed intake in long term? What is its source?

Answer 7

1. Leptin

2. Released from adipose tissues

Question 8

What is “chemeostatic regulation of appetite” and how is it explained for ruminants?

Answer 8

1. The food intake is related inversely with blood glucose concentration in most non ruminants.
2. In ruminants, blood glucose has little impact on feed intake. Blood propionate levels may be negatively related with feed intake.

Question 9

How the caloric density of feed and physical limitations of the GI tract control feed intake?

Answer 9

1.

Question 10

What factors do influence the energy demands and feed consumption of animals?

Answer 10

• body weight
• species, class and individuality of the animal
• production of stage and level of production
• environmental factors

Question 11

How do the following affect the feed consumption of animals?

•Body weight (BW)

Answer 11

• The energy needs of adult animals is related with their metabolic size: BW0.75
• The energy need and feed consumption of animals is related more to body lean mass than to total body weight.

Question 12

How do the following affect the feed consumption of animals?

•Type and level of production

Answer 12

The feed intake of animals is increased during growth, lactation
and pregnancy

Question 13

How do the following affect the feed consumption of animals?

•Environmental factors

Answer 13

• High temperature and high humidity reduce feed intake.

* Most infectious diseases, metabolic diseases (e.g. ketosis) and stressors (e.g. noise) decrease the intake.

Question 14

How are energy, protein, vitamins and mineral requirements expressed in animals?

Answer 14

• Metabolizable energy (poultry, dogs and cats), digestible energy (hordes and rabbits), TDN and NE (goats/beef cattle)
• Protein requirements are mostly given in digestible protein (DP).
~In ruminants, crude protein (CP) is often used.
~MP in ruminants: the true protein absorbed by the intestine = microbial protein + UIP
• Vitamins A, D and E are expressed in international unites (IU).
• For mineral requirements:
o P values are given based on protein intake
o Ca values are determined base on P needs and body size
o other mineral requirements are given based on metabolic size

Question 15

What is the difference between crude protein and metabolizable protein(MP) in ruminants?

Answer 15

1. In ruminants, crude protein (CP) is often used.
   • CP = dietary intake protein (DIP) + undegraded intake protein (UIP)
2. The use of metabolizable protein (MP) in ruminants was introduced by NRC (1996).
   • MP in ruminants: the true protein absorbed by the intestine = microbial protein + UIP

Question 16

How are the energy needs of animals determined? What are the limitations of each?

Answer 16

1. Energy needs of animals determined by:
   •calorimetric studies
   ~ Limitation of calorimetric studies:
   not accurate values of energy expenditure for grazing animals due to:
   ➢higher activity
   ➢environmental factors such as temperature, radiation, wind and humidity
   •feeding experiments in practical conditions
   ~ animal’s energy gain or loss determination
   is challenging

Question 17

What are inaccuracies in feeding standards reported by the NRC?

Answer 17

• management and feeding methods that may influence the animal requirements
• increased intake in severe weather
• stressors such as diseases, parasitism, injury or surgery that may change the allowance
• beneficial effects of additives or feed preparatory methods

Question 18

What is the importance of colostrum in young mammals? When is the best time to offer it? Why?

Answer 18

1. Colostrum is a good source of globulins and proteins, antibodies, vitamins and minerals.
2. In few hours after birth
3. The GI tract is permeable to globulins and other proteins of colostrum

Question 19

What is compensatory growth?

Answer 19

1. Energy restriction/subnormal growth can be followed by faster weight gain than normal if animals are fed with adequate rations.

Question 20

What nutrients need to be increased in the diet of animals doing work?

Answer 20

• Carbohydrates are more important than fats as energy sources for work.
• The work may increase the Na and Cl requirements, if sweating occurs.
• Dietary P should be increased during work as it is a key nutrient for many energy- yielding reactions.
• Thiamin, niacin and riboflavin that are particularly involved in energy metabolism should be increased during the work

Question 21

At what stage of pregnancy are the nutrient requirements the highest?

Answer 21

1. Third

Question 22

What are the outcomes of moderate and severe malnutrition during pregnancy?

Answer 22

1. Moderate
•body gives priority to fetus
•withdrawn of mother’s body reserves
2. Severe 
•body gives a partial priority to fetus
•detrimental effects on fetus: malformed fetus or resorption of the fetus, abortion, birth of dead, weak, or undersized young
•long-term effects on the mother

Question 23

What nutrients must be increased in the diets of animals during lactation?

Answer 23

• The requirements for all nutrients including fat, protein, carbohydrate, Ca and P are increased during lactation

Question 24

What factors do influence the nutrient requirements in animals?

Answer 24

• genetics
• nutritional individuality
• breed and species differences
• environmental factors

Question 25

What factors must be considered for including feed stuff in the diet?

Answer 25

* cost * palatability * digestibility and bioavailability of the energy and nutrients * nutrient concentration and balance * level of toxins and nutrient inhibitors * handling and milling properties

Question 26

What are the nutritional advantages of grasses for grazing animals?

Answer 26

* palatability * grows in most environments * nutrients for production and reproduction

Question 27

How legumes are compared to grasses in terms of nutrient content?

Answer 27

* Legumes have higher protein than grasses. * The leaves of legumes are rich in protein and their stems are rich in cellulose and lignin. * Compared to grasses, legumes have more Ca, Mg, S and Cu and less Mn and Zn. * Legumes are more palatable than grasses, but feeding them needs adaptation (bitter taste).

Question 28

Why is alfalfa the most common legume used as hay in the U.S.?

Answer 28

* high yield * it’s persistence as a perennial crop * it’s high palatability and high nutrient content

Question 29

What’s the best water content of plants for haymaking and how drying is done?

Answer 29

1. The water content of plant materials should be reduced to <15% to allow storage with no spoilage. 2. • Rapid drying is essential for making high-quality hay. • Traditional drying: circulating air through the hay after barn storage. • Modern drying: cutting herbage at pre-bloom stage, drying at high temperature in a short time, ground and sometimes pelleted. • To save the carotene and xanthophyll, the hay can be stored using inert gasses (e.g. N2

Question 30

What are the main sources of straw/chaff and what is their use in animal nutrition?

Answer 30

1. The main source is from small cereal grains-wheat, barley, rye, rice, and oats 2. Straws can be used as a dilute in high concentrations

Question 31

How is silage produced and what is it’s advantage in animal nutrition?

Answer 31

1. Silage is produced by controlled fermentation of high-moisture forages in an anaerobic condition 2. Silage is palatable and produces excellent results with high-producing lactating cows

Question 32

What is corn protein called? What are it’s limiting amino acids (AA’s) for animals?

Answer 32

1. Zein | 2. Lysine and tryptophan

Question 33

What are limiting AA’s of sorghum for animals nutrition?

Answer 33

Lysine | Threonine

Question 34

How the nutritional value of barley and oat is compared to corn?

Answer 34

Barley • It has more protein with higher levels of lysine, tryptophan, methionine, and cystine than corn. Oats • Its protein content and AA balance is relatively higher than corn.

Question 35

Why are fats added to the diets of animals?

Answer 35

* source of energy * increasing palatability * reducing dustiness * reducing bloat in ruminants * lubrication value on milling machinery

Question 36

What is the acceptable range of dietary fats for mono gastrics and ruminants?

Answer 36

* 5-10% fat is generally added to diets of pigs and poultry, with higher than 10% resulting in sharp decrease in feed intake * Ruminants can tolerate less amount of dietary fat (optimal: 2-4%; maximum 7%).

Question 37

What factors do influence the quality of meat meal during its production?

Answer 37

* its dilution with bone and connective tissues | * methods/temperature used for processing

Question 38

What is the limiting AA of blood meal?

Answer 38

1. Isoleucine

Question 39

What are the nutritional values of fish meal for animals?

Answer 39

* They are great sources of proteins and AA’s (rich in lysine), ranking close to milk proteins. * They are good sources of B-vitamins and most of the mineral elements.

Question 40

What factors do influence the quality of fish meal during its production?

Answer 40

1. The quality of fish meal can be affected by: •partial decomposition before processing ooverheating during processing •excess oil and rancidity •inadequate drying and mold growth

Question 41

What are the nutritional advantages/disadvantages of using cottonseed meal for animals?

Answer 41

• Its limiting AA’s are cystine, methionine, and lysine. • It is palatable for ruminants, but is low in Ca and carotene. • it contains a yellow pigment, gossypol: relatively toxic for nonruminants poor egg quality (green egg yolks) oit contains sterculic acid: can cause egg whites to turn pink

Question 42

What are the nutritional advantages/disadvantages of using soybean meal for animals?

Answer 42

• It is highly digestible and palatable and has a high-energy. • Its limiting amino acids for swine and poultry are methionine and lysine. 2. Similar to other oilseeds, soybeans have some toxic and inhibitory compounds: •goitrogenic material •toxic antigens for young preruminants •trypsin inhibitors • genistin (growth-promoting properties)

Question 43

What method is commonly used for measuring the dry matter (DM) of feeds and what are the challenges?

Answer 43

1. moisture meters 2. • Determining the DM in the following materials is challenging: • plants that contain high concentration of volatile fatty acids • plants that contain higher amounts of essential oils, terpenes and other volatile substances • silages or other fermented products that contain large amounts of volatile fatty acids (acetic, propionic, butyric) and ammonia • some sugars that decompose, and partially insoluble proteins at temperatures above 70°C

Question 44

What method is used to measure the crude proteins (CP) of feeds and what are the pros and cons?

Answer 44

1. Kjeldahl method 2. pros: 1) accurate, 2) repeatable cons: 1) time consuming, 2) use of hazardous chemicals, 3) does not distinguish one form of N from another

Question 45

What method is used to measure the fat content of feed and what are the pros and cons?

Answer 45

1. EE is the fraction of a feedstuff that has a high caloric value. • The EE method has some pros and cons: opros: a valid approach for materials made up primarily of fats and fatty acid esters ocons: less meaningful if the extract contains large amount of plant waxes, essential oils, resins, or similar compounds

Question 46

What components of plants cells are extracted using crude fiber (CF), NDF and ADF methods?

Answer 46

Cellulose | Hemicellulose