A prototype national cattle evaluation for feed intake and efficiency of Angus cattle

Area of Science:

• Animal Genetics
• Quantitative Genetics
• Beef Cattle Production

Background:

• Advancements in feed intake measurement technology enable breed-wide genetic evaluations.
• Individual feed intake data is crucial for improving feed efficiency in cattle populations.

Purpose of the Study:

• Estimate genetic parameters for feed efficiency components in Angus cattle.
• Develop a prototype system for genetic evaluation of feed intake.
• Utilize indicator traits to enhance the accuracy of feed intake EPDs.

Main Methods:

• Accumulated individual feed intake, weaning weight, postweaning gain, and subcutaneous fat depth data.
• Standardized feed intake data (SFI) within contemporary groups.
• Estimated (co)variance components using a 4-trait animal model with ASREML.
• Calculated heritability and genetic correlations between traits.

Main Results:

• Heritability estimates for weaning weight, postweaning gain, subcutaneous fat depth, and standardized feed intake were 0.33, 0.31, 0.26, and 0.42, respectively.
• Positive genetic correlations were found between feed intake and weaning weight (0.40) and postweaning gain (0.55).
• Accuracy of feed intake EPDs ranged from 0.16 to 0.64, with a mean of 0.26; 9,075 animals exceeded 0.2 accuracy.

Conclusions:

• National cattle evaluations for feed intake are feasible using indicator traits.
• This methodology reduces selection bias and increases evaluation accuracy for feed intake.
• Facilitates the calculation of selection indexes that incorporate feed intake for improved breeding strategies.