Requirements for maintanence

What does maintenance mean in livestock nutrition?

Approximately constant liveweight over time, or an energy balance of zero.

What is the cattle maintenance ME equation in the lecture?

Mem = 0.53 x Empty Bw 0.67

• \(ME_m\) = maintenance metabolisable energy (MJ/day)

• \(EmptyBW\) = empty bodyweight (kg)

The lecture estimates:

\[ EmptyBW=0.92 x liveweight \]

What are the sheep maintenance equations in the lecture?

• Sheep under 1 year: \(ME_m=0.25 x EmptyBW^{0.75}\)

• Sheep over 1 year: \(ME_m=0.23 x EmptyBW^{0.75}\)

These equations use empty bodyweight in kg and give the lecture's maintenance energy estimate. Check the original slide's units when applying them in a calculation.

How is total ME requirement divided?

ME total = MEm + MEp

Maintenance energy (\(ME_m\)) supports basic bodily functions; production energy (\(ME_p\)) supports outputs such as growth or pregnancy.

Maintenance ME plus production ME.

Why can maintenance energy requirements differ between animals?

They are affected by body composition and the proportion of active metabolic tissues. The lecture notes that animals selected for greater growth or milk production can have higher maintenance costs.

How can prolonged maintenance change tissue weights?

Visceral tissues can shrink, reducing the amount of metabolically active tissue and therefore lowering energy requirements.

How much can grazing increase maintenance requirements?

The lecture gives approximately 10–25%, depending on grazing activity and walking.