Technical note: evaluation of data loggers for measuring lying behavior in dairy calves.

Area of Science:

• Animal Behavior
• Agricultural Technology
• Livestock Management

Background:

• Lying behavior is a key indicator of cow and calf welfare and environmental interaction.
• Behavioral recording using data loggers is efficient but requires validation for specific applications.
• Previous validation of the Hobo Pendant G data logger focused on cows, not calves.

Purpose of the Study:

• To assess the accuracy of the Hobo Pendant G data logger for measuring total lying time and lying bout frequency in dairy calves.
• To determine optimal logger attachment sites and recording intervals for accurate data collection.
• To evaluate the logger's performance against direct observation as a reference standard.

Main Methods:

• Two experiments were conducted with dairy calves, involving 2-hour and 24-hour observation periods.
• The study tested the effects of different recording intervals (30-s and 60-s), logger attachment to various legs, and data filtering techniques.
• Direct observation served as the reference for validating logger accuracy.

Main Results:

• An excellent correlation was observed between 30-s and 60-s recording intervals.
• The highest accuracy for total lying time and bout frequency was achieved when the logger was attached to a hind leg with a 60-s sampling interval.
• With a 60-s interval and removal of short, erroneous readings, predictability, sensitivity, and specificity exceeded 97%.

Conclusions:

• The Hobo Pendant G data logger accurately measures total lying time and bout frequency in dairy calves.
• Optimal performance is achieved with a sampling interval of 60 seconds or less, logger attachment to the right hind leg, and processing that accounts for short lying/standing events.
• This validated logger offers a reliable tool for monitoring calf behavior and welfare.