Exam 3 Advanced Beef Production Chapter 16 & 17: Water & Energy

What nutrient is needed to regulate body temperature, digestion, metabolism, and excretion?

Water

What factors can increase water intake?

stage of production

ambient temperature

dry matter intake

salt comsumption

breed

amount of physical activity

T/F: situations that restrict water intake below the level required by the animal will reduce feed intake and performance.

true

_____ refers to the total amount of these salts dissolved in water and is measured as total dissolved solids.

Salinity

T/F: a certain amount of energy is required for maintenance of life without any production or change in body energy stores.

true

what measure of energy expresses the requirement as a percentage of the diet assuming a certain level of intake, or alternatively as the total number of pounds required per day?

TDN

What system recognizes that once the maintenance requirement has been met, the remaining energy in the diet is available for production functions.

Net Energy System (NE)

what are energy requirements expressed as?

Megacalories (Mcal)

T/F: as body weight increases, the energy required for maintenance increases by a power of o.75, and is referred to as the metabolic body weight.

True

What is the critical temperature for a wet or summer coat?

59F

what is the critical temperature for a dry, fall coat?

45F

what is the critical temperature for a dry, winter coat?

32F

what is the critical temperature for a dry, heavy winter coat?

18F

what does the effective ambient temperature consider?

Wind

humidity

solar radiation

air temperature

what is the lowest temperature in the thermo-neutral zone?

lower critical temperature

what is an index of the heating or cooling power of the environment?

Effective Ambient temperature

T/F: if the effective ambient temperature is below the lower critical temperature, additional energy is required for maintenance.

True

what is the difference between the effective ambient temperature and the lower critical temperature?

degree of coldness

A general rule of thumb is that the maintenance requirement is increased ___ percent for each degree F that the effective ambient temperature is below the lower critical temperature.

1%

Until a cow reaches approximately _____ months of age, there is an additional energy requirement for growth.

48

T/F: The level of milk production peaks at 60 days and then gradually declines until weaning.

True

What are the maintenance requirements for bos indicus breeds?

90%

what are the maintenance requirements for bos indicus crosses with british and continental?

95%

what is the is a safe measurement of salt in water before it affects health and performance of cattle?

1,000 ppm

what levels of nitrate in water are safe for cattle?

0-44 ppm

45-132 ppm if diet is low in nitrates

T/F: Energy is the most limiting nutrient in grazing cow diets although it is not a nutrient.

True

Why does the TDN and Net energy work well for beef cows? And why is the NE good for growing or finishing?

good use of maintenance in cows and measures the access after maintenance.

What is the Nem formula?

(kg of BW)^0.75 x 0.77

What factors influence energy requirements?

1. body weight

2. weather

3. age

4. lactation

5. pregnancy

6. breed

7. bus