Validation of a radio frequency identification system for monitoring the feeding patterns of feedlot cattle?

The feed bunk attendance patterns of six crossbred beef heifers (averaging 481+/-22 kg) and six crossbred beef steers (averaging 471+/-44 kg) being fed an 80% steam-rolled barley grain:15% barley silage and 5% supplement diet were monitored for 52 days using a radio frequency (RF) system (GrowSafe(R) Systems Ltd., Airdrie, AB). The system was validated by three methods: (1) comparing the duration and frequency of feeding visits recorded by the RF system against those calculated from video surveillance data; (2) comparing the bunk attendance data provided by two separate RF transponders carried by a single animal; and (3) documenting the relationship between bunk attendance and actual feeding time. When one considered the ability of the RF system to monitor the presence or absence of an animal, total daily error in the RF system was 6% as compared to the videotaped data. Incidence of errors due to RF interference and false antennae readings were 2.4 and 3.6%, respectively. The RF system was concluded to be a highly effective tool for documenting bunk attendance. Feeding durations documented by animals bearing two transponders were highly correlated, averaging 88.4+/-1.5 and 84.5+/-1.5 min day(-1) (R-2 = 0.96). Frequency of bunk visits was also highly correlated (R2 = 0.96). Approximately 84% of total bunk attendance time was spent consuming feed; 16% was spent on non-feeding activity. On average, the cattle made 29+/-11.8 visits day(-1), with 55.8% of visits associated with feeding activity and 44.2% with non-feeding activity. These observations suggest that attendance duration may be a better indicator of an animal's feed intake than frequency of attendance at the bunk. Future studies with GrowSafe(R) or other RF systems that do not automatically record feed intake should incorporate a correction factor to relate attendance to feeding time. Factors were identified that could introduce errors with the GrowSafe(R) system. These include non-grounded, metal material (connected in a loop configuration), particularly when associated with the feed bunk area. Crown Copyright (C) 1999 Published by Elsevier Science B.V.