Table 4. Means ± SD of behavioral and cardiac parameters, calculated for breed and sex

	N	Behavior		Heart rate			Heart rate variability
	N	Behavioral score	Escape duration (s)	BHR (bpm)	MHR (bpm)	Time to MHR (s)	SDNN (ms)	RMSSD (ms)	LF/HF
Breed
Jeju crossbred	12	2.75 ± 1.01^a	98.58 ± 48.23^a	44.42 ± 5.79^a	132.42 ± 13.31^a	37.00 ± 12.96^a	86.98 ± 33.11^a	68.50 ± 21.18^a	1.76 ± 0.79^a
Thoroughbred	15	3.73 ± 0.93^b	118.27 ± 75.36^a	40.27 ± 4.19^ab	146.07 ± 23.74^a	40.87 ± 19.81^a	66.79 ± 21.72^a	49.12 ± 16.81^b	4.24 ± 3.94^a
Warmblood	12	3.58 ± 0.95^ab	118.33 ± 52.82^a	39.42 ± 4.86^b	137.58 ± 15.54^a	57.67 ± 31.92^a	66.78 ± 19.35^a	50.48 ± 13.45^ab	3.88 ± 3.62^a
Sex
Female	22	3.45 ± 1.08^a	109.05 ± 62.49^a	41.95 ± 5.24^a	141.50 ± 16.62^a	41.82 ± 18.24^a	69.28 ± 29.66^a	52.60 ± 20.51^a	3.72 ± 3.91^a
Gelding	17	3.29 ± 1.02^a	116.35 ± 61.07^a	40.41 ± 5.41^a	136.35 ± 22.28^a	48.76 ± 29.99^a	77.81 ± 21.78^a	59.25 ± 17.24^a	2.90 ± 2.42^a

Different letters within breed or sex group in a single column indicate significance at p < 0.05.
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).