Table 6. Correlations between behavioral and cardiac parameters in the novel object test, grouped by breed and sex

Behavioral parameters	N	Heart rate			Heart rate variability
Behavioral parameters	N	BHR (bpm)	MHR (bpm)	Time to MHR (s)	SDNN (ms)	RMSSD (ms)	LF/HF
Behavioral score
Breed
Jeju crossbred	12	0.132	0.807^*	0.311	0.126	0.070	−0.462
Thoroughbreds	15	0.173	0.690^*	0.160	−0.644^*	−0.429	0.129
Warmbloods	12	0.361	0.646^*	0.168	−0.140	−0.146	0.569
Sex
Female	22	0.101	0.638^*	0.145	−0.248	−0.298	0.186
Gelding	17	−0.097	0.775^*	0.374	−0.470	−0.355	0.286
Escape duration (s)
Breed
Jeju crossbred	12	−0.130	−0.096	0.075	0.468	0.500	−0.261
Thoroughbreds	15	0.338	0.076	0.089	−0.699^*	−0.614^*	0.270
Warmbloods	12	−0.054	0.434	0.537	−0.430	−0.152	0.064
Sex
Female	22	−0.136	0.319	0.026	−0.451^*	−0.516^*	0.220
Gelding	17	0.192	−0.032	0.472	−0.029	0.271	0.087

p < 0.05.
N, the total number of horses used for a particular group; BHR, basal heart rate; bpm, beats per minute; MHR, maximum heart rate; SDNN, standard deviation of the beat-to-beat intervals; ms, milli seconds; RMSSD, root mean square of successive differences; LF/HF, the ratio of low frequency to high frequency components of continuous series of beats (power spectrum).