Nutrition Exam 3

What is the standard unit for energy defined as the energy required to displace 1 newton by 1 meter?

Joule

How many joules are in one calorie?

4.184 joules

What unit of power is equivalent to 1 Joule per second?

Watt

How many Joules per second are in one Horsepower?

746 J/sec

According to the First Law of Thermodynamics, if energy isn't in the diet, where must it come from?

Body reserves

What device is used to measure Gross Energy (GE) in feed?

Bomb calorimeter

Which energy system is the basis for high-precision feeding models?

Net Energy

What is the term for heat produced during digestion and metabolism?

Heat increment

Which nutrient often has a higher heat increment cost?

Protein

What state is reached when metabolizable energy intake equals energy expenditure?

Energy maintenance

What occurs when an animal is in a positive energy balance?

Weight gain

What occurs when an animal is in a negative energy balance?

Weight loss

Which of the following are included in maintenance energy expenditure?

Basal metabolism, posture, and minimal activity

In which stage of lactation is negative energy balance most common in dairy cows?

Early lactation

During gestation, when does energy demand increase most significantly?

Late gestation

What is a risk of over-conditioning during gestation?

Dystocia

What do ruminants primarily rely on as fermentation products for energy?

VFAs

What do monogastrics primarily rely on for energy via absorption?

Glucose

Which of the following are Volatile Fatty Acids (VFAs) produced in the rumen?

Acetate, propionate, and butyrate

In ruminants, what gas represents both an energy loss and a climate impact?

Methane

Which method measures energy expenditure by monitoring O₂ consumption and CO₂ production?

Indirect calorimetry

What does the Respiratory Quotient (RQ) help nutritionists infer?

Fuel use

What factor regulates intake in ruminants based on physical space?

Rumen fill

What is typically the largest cost in animal production?

Feed

What metabolic disorder is associated with negative energy balance in early lactation?

Ketosis

What disorder can be caused by a rapid diet change?

Acidosis

What disorder results from energy deficits in late gestation?

Pregnancy toxemia

How many calories are in one kilocalorie (kcal)?

1,000 calories

How many calories are in one megacalorie (Mcal)?

1,000,000 calories

What is a calorie?

The amount of heat required to increase the temperature of one gram of water by one degree Celsius

Order the energy steps from the total energy in feed to the energy available for maintenance and production:

1. Gross Energy

2. Digestible Energy

3. Metabolizable Energy

4. Net Energy

What are the primary loss components of DE, ME, and NE?

DE - Fecal energy

ME - Urine and gas energy

NE - Heat increment

What is the energy expended per second by a 55 lb Australian Shepherd compared to?

75-Watt light bulb

A lactating dairy cow expends energy equivalent to how many 100-Watt light bulbs?

20

What is the definition of work in the context of energy?

Force x distance

What type of energy is defined as the potential energy in food?

Chemical energy

Which factors influence maintenance energy requirements?

Temperature, species, and physiological state

What happens to maintenance needs during cold stress?

They increase

Heat stress typically reduces feed intake in animals. T/F?

TRUE

Gross Energy (GE) is equal to the amount of energy an animal can actually use. T/F?

FALSE

Energy can be created if the diet is sufficiently high in nutrients. T/F?

FALSE

Which step in the energy flow framework sets the ceiling for animal performance?

Intake

What is the net ATP yield per glucose molecule during glycolysis?

2 ATP

What is the primary absorbed fuel used for glucose synthesis in ruminants?

Propionate

What is glycolysis?

The metabolic pathway that converts glucose to pyruvate in the cytosol

In aerobic conditions, what is the fate of pyruvate?

Acetyl-CoA

In anaerobic conditions, what is the fate of pyruvate?

Lactate

Which cycle oxidizes acetyl-CoA to produce CO2, NADH, and FADH2?

TCA cycle

Approximately how much total ATP is produced per glucose molecule in aerobic respiration?

30 ATP

How much ATP is generated from one NADH molecule in oxidative phosphorylation?

2.5 ATP

How much ATP is generated from one FADH2 molecule in oxidative phosphorylation?

1.5 ATP

What does NDF influence in ruminants?

Rumen fill and intake

Higher fiber content in a diet often increases the energy density. T/F?

FALSE

Order the flow of energy through an animal from start to finish:

1. Intake

2. Digestion

3. Absorption

4. Metabolism

What are the primary products of carbohydrate fermentation in ruminants?

VFAs

The efficiency of energy use for different functions is represented by ?

K factors

Efficiency 'k' factors vary based on which animal functions?

1. Maintenance

2. Growth

3. Lactation

4. Fat gain

Why is protein considered a 'costly' energy source?

Metabolically messy and expensive

Net Energy (NE) systems are more precise than Metabolizable Energy (ME) systems. T/F?

TRUE

What is the primary source of heat from metabolism?

Basal metabolism and activity

How are VFAs absorbed in ruminants?

Through the rumen wall

What determines the direction of pyruvate's fate?

Oxygen and tissue state

Monogastrics have significant fermentation before absorption compared to ruminants. T/F?

FALSE

Which feed analysis system better predicts digestion than crude fiber?

Detergent system

Inefficiency in oxidative phosphorylation results in the production of heat. T/F?

TRUE

Define what each energy term does:

Intake - Sets the performance ceiling

Digestion - Determines what is absorbed

Metabolism - Partitions to ATP or storage

Methane - Ruminant energy loss

Which tissues or products specifically require glucose in the ruminant?

Brain, red blood cells, and lactose

What is the primary purpose of the electron transport chain?

Produce ATP

Define what each feed analysis component does:

NDF - Predicts rumen fill

ADF - Predicts digestion

Crude Fiber - Limited proximate measure

Propionate - Glucose precursor

What is the end result of energy flow in an animal?

Heat, work, storage, or product

Energy flow is a system of transformation, not just a list of pathways. T/F?

TRUE

Why can two animals consuming diets with similar total energy show different performance

outcomes?

Because total energy intake doesn’t equal usable energy

What is the primary risk of rapid starch loads in horses?

Colic and laminitis

What happens to fat during Negative Energy Balance (NEB)?

Body mobilizes fat

In Negative Energy Balance, the mobilization of fat leads to a rise in ?

NEFA

What causes the drop in rumen pH during acidosis?

Rapidly fermentable carbohydrates

Which of the following are signs of Ketosis?

Reduced appetite, production drop, and lethargy

Match the species to its specific energy-related risk:

Dairy cow - Ketosis

Pig - Excess fat gain

Horse - Laminitis

Small ruminant - Pregnancy toxemia

The highest-risk windows for energy disorders are ?

Transition periods

What is the consequence of NDF being too high or poorly digestible?

Energy shortfall

Methane mitigation is considered a strategy for improving energy efficiency. T/F?

TRUE

Order the progression of Negative Energy Balance (NEB) leading to Ketosis:

1. Demands exceeds intake

2. Body mobilizes fat

3. NEFA levels rise

4. Ketone production increases

What is the primary goal of using buffers or rumen modifiers?

Stabilize fermentation

In pigs, what causes excess fat gain despite high energy intake?

Insufficient AA supply

The strategy for feeding horses to minimize risk is ?

Forage-first

What is the result of excess fat mobilization into the liver?

Reduced metabolic capacity

Which energy system is commonly used for poultry formulation?

Metabolizable Energy (ME)

In poultry, energy density strongly influences intake. T/F?

TRUE

What is the purpose of a Total Mixed Ration (TMR)?

Consistency and reduced sorting

What is the recommended management focus for transition periods?

Gradual change and monitoring

What systemic issue does starch overload cause in horse hooves?

Systemic inflammation

What happens to rumen microbes during acidosis?

Microbial shifts

Why does intake often lag behind demand in transition periods?

Physiology and diet changes

What is the primary goal of matching energy supply to demand?

Optimize efficiency

Which of the following are shared traits of fat-soluble vitamins?

1. Absorbed with lipids

2. Stored in liver/adipose

3. Excess

What is the plant precursor form of Vitamin A?

β-carotene

Which protein synthesis requires Vitamin A for vision?

Rhodopsin

Vitamin A is stored in the liver in the form of ?

Retinyl esters

What is a primary clinical sign of Vitamin A deficiency regarding vision?

Night blindness

Vitamin A acts as an energy source for the body.

FALSE