Animal Nutrition

K.LaunchbaughUSDA-ARS

BLM Photo K.Launchbaugh

Animal Nutrient Requirements Maintenance = Basal Metabolism +

Minimum Movement + Foraging On a yearly basis requires greatest amount of

energy by the animal. Depends on species - Cow > Sheep > Deer Domestic vs Native - Most wildlife species have

the ability to vary their basal metabolic rate with season.

Animal Nutrient Requirements Maintenance

Depends on Age - Young > Old

For example basal metabolic rate of sheep: birth = 132 kcal/m3

15 weeks = 68 kcal/m3

6 years = 52 kcal/m3

Animal Nutrient Requirements Growth - important energy demand in young

animals and pregnant females Reproduction –

energy need in last trimester of pregnancy for females

important for males during breeding season

Animal Nutrient Requirements Lactation - greatest energy requirement of

mature females above maintenance. Requires 45% greater energy supply than

maintenance.

Changes in Demand over YearE

nerg

y &

Nut

rien

t Req

uire

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ts

Yearly Change in Demand for PregnantFemale Range Herbivore (i.e., Cow, sheep, elk , deer)

Winter Spring Summer Fall

Last Trim

ester

Birth &

Lactation Weaning

Maintenance

Animal Nutrient Requirements Level of activity

15% greater energy required for standing compared to lying down.

40-46% more energy needed for range animals than stall-fed animals.

Animal Nutrient Requirements Environmental conditions affect the amount of

energy needed by animals Cold environments require more energy for

maintenance. Hot environments require more water for perspiration.