Feed efficiency and surplus feed intake among Norwegian Red dairy cows

Area of Science:

• Animal Science
• Agricultural Economics
• Environmental Science

Background:

• Feed costs and greenhouse gas emissions are major concerns in livestock production.
• Improving feed efficiency is crucial for economic and environmental sustainability in the livestock sector.

Purpose of the Study:

• To estimate feed efficiency in Norwegian Red dairy cows using a stochastic feed requirement frontier (SFRF).
• To decompose feed efficiency into time-invariant and time-variant components.
• To identify sources of variation in feed intake and their relation to feed efficiency.

Main Methods:

• Utilized intake and performance data from 48 early- to mid-lactation Norwegian Red dairy cows over 54 days.
• Applied the stochastic feed requirement frontier (SFRF) model to predict minimum feed intake requirements.
• Calculated feed efficiency scores and surplus feed intake (SFI) for individual cows.

Main Results:

• The average feed efficiency score was 89.7% and remained time-invariant during the study period.
• Surplus feed intake (SFI) averaged 10.3% of observed intake (13.3 kg DM/wk), with significant differences between efficient and inefficient cows.
• Cow-specific feed intake variation was largely driven by feed efficiency (82.1%), with remaining variation attributed to other unobserved factors and statistical noise.

Conclusions:

• The SFRF model provides a robust method for estimating feed efficiency in dairy cows.
• Feed efficiency has a significant time-invariant component, suggesting heritable traits that can be targeted in breeding programs.
• Understanding feed efficiency variation is essential for enhancing sustainable livestock production and developing effective breeding strategies.