Compilations and updates on residual feed intake in sheep

Area of Science:

• Animal Science
• Agricultural Science
• Genetics

Background:

• Global food demand and climate change necessitate advancements in animal production efficiency.
• Feed costs represent over 70% of sheep farm expenses, highlighting the economic importance of feed efficiency.
• Residual Feed Intake (RFI) is a widely accepted metric for feed efficiency in genetic selection.

Purpose of the Study:

• To review updated literature on Residual Feed Intake (RFI) in sheep.
• To explore the relationship between RFI estimates and performance, molecular markers, and greenhouse gas production.
• To discuss the technical and physiological basis of metabolic efficiency in sheep.

Main Methods:

• Literature review of scientific publications on RFI in sheep.
• Analysis of studies correlating RFI with performance traits, carcass quality, and enteric gas production.
• Examination of research on molecular markers associated with feed efficiency.

Main Results:

• Animals with negative RFI (RFI-) are more feed-efficient than those with positive RFI (RFI+).
• RFI is independent of growth traits, making it a robust measure for genetic selection compared to feed conversion ratio.
• RFI influences key production variables including animal performance, carcass quality, and greenhouse gas emissions.

Conclusions:

• RFI is a critical trait for improving sheep production efficiency and farm profitability.
• Understanding the physiological basis of RFI can aid in developing targeted selection strategies.
• Further research into molecular markers associated with RFI can accelerate genetic improvement in sheep.