The purpose of this research project was to evaluate the Nedap Smarttag Neck 2.0 (Nedap Identification Systems, Groenlo, the Netherlands) for dairy cow behavior measuring accuracy. The behaviors measured were time inactive, ruminating, feeding, and miscellaneous activity or movement. Fifty lactating Holstein dairy cows were randomly selected from the University of Kentucky’s Coldstream Dairy Research Herd and fitted with the technology. The same observer observed each cow on a separate day for a total of 4 h, including 2 h after the morning milking (0800 h) and 2 h after the evening milking (2000 h). The observer recorded the time behaviors occurred using a synchronized watch (CASIO, CASIO America, Inc., Dover, NJ). The hour, minute, and second of the day each behavior occurred was compared with corresponding technology measurements. Concordance correlation coefficients (CCC; epiR package; R Foundation for Statistical Computing, Vienna, Austria) and Pearson correlation coefficients (r; CORR procedure; SAS Institute Inc., Cary, NC) were used to calculate association between visual observations and technology-recorded behaviors. Results are shown in Table 1. Visually recorded inactive time and rumination time were moderately correlated with technology data. Visually recorded feeding behaviors were strongly correlated with technology data but visually recorded miscellaneous activity behaviors were poorly correlated. The Nedap Smarttag Neck 2.0 accurately monitored activity, feeding, and ruminating behaviors and would be effective in monitoring these behaviors in a commercial farm setting. Table 1. Results of a validation study between technology or visual observation measured behaviors in Holstein dairy cattle

Variable	Pearson correlation (r)	Pearson correlation P-value	Bias correction(Cb)	Location shift (V)	Scale shift (μ)	CCC
Ruminating	0.86	< 0.01	0.97	−0.12	1.22	0.83
Inactive	0.87	< 0.01	0.98	−0.16	0.85	0.85
Eating	0.90	< 0.01	0.99	0.06	0.92	0.89
Other	−0.18	0.43	0.46	1.26	2.35	−0.08