Test duration for growth, feed intake, and feed efficiency in beef cattle using the GrowSafe System

Area of Science:

• Animal Science
• Agricultural Science
• Genetics and Genomics

Background:

• Accurate measurement of feed efficiency is crucial for beef cattle production.
• Optimizing test duration and accounting for missing data can improve efficiency and reduce costs.

Purpose of the Study:

• To determine the optimal test duration for measuring feed efficiency and related traits in beef cattle.
• To assess the impact of missing data on the accuracy of these measurements.

Main Methods:

• Utilized data from 456 steers with weekly feed intake and body weight measurements over 91 days.
• Analyzed phenotypic variances and correlations across shortened test durations (7-84 days) compared to a 91-day test.
• Employed mixed-effects models with repeated measures in SAS to fit the data.

Main Results:

• Optimal test durations were identified as 63 days for average daily gain (ADG) and residual feed intake (RFI), 35 days for dry matter intake (DMI), and 42 days for feed conversion ratio.
• Test accuracy remained high even with up to 30% of records randomly removed after the initial 35 days.

Conclusions:

• Test durations for key feed efficiency traits in beef cattle can be significantly shortened without compromising accuracy.
• These findings offer practical implications for optimizing performance testing protocols in beef cattle operations.