Table 2.

Soft tissue thickness, cranial thickness, total tissue thickness, and cross-sectional brain area of cadaver heads from mature sows and boars¹ (BW < 200 kg) assigned to three penetrating captive bolt (PCB) placements² and sectioned by band saw following the plane of bolt entry

Sex	Dependent variable	PCB placement
		FRONTAL			TEMPORAL			BEHIND EAR
		n	LS means	SE	n	LS means	SE	n	LS means	SE
SOWS
	Soft tissue thickness, mm	10	7.30b	0.51	10	49.30a	3.01	10	47.80a	3.22
	Cranial thickness, mm	10	42.11a	2.95	10	13.52b	2.22	10	39.97a	2.18
	Total tissue thickness, mm	10	49.41c	2.74	10	62.83b	1.83	10	84.76a	3.67
	Cross-sectional brain area, mm2	8	4,229.38a	83.71	10	1,334.48c	217.47	10	2,465.38b	58.90
BOARS
	Soft tissue thickness, mm	8	10.64b	1.12	8	52.63a	3.55	11	61.24a	6.20
	Cranial thickness, mm	8	44.09a	3.60	8	18.09c	3.04	11	31.57ab	3.31
	Total tissue thickness, mm	8	54.73c	3.23	8	70.72b	3.60	11	92.81a	5.50
	Cross-sectional brain area, mm2	8	4,217.99a	69.21	10	1,155.24c	84.26	11	2,274.47b	175.54

¹Comparisons between sexes were not conducted because it is unknown how morphological changes in head conformation change as sows and boars continue to grow heavier than the sows and boars that provided the heads for this study.

²Placements: FRONTAL—Medial bolt entry approximately 3.5 cm superior to the optic orbits at midline perpendicular with the external surface of the head; TEMPORAL—Bolt entry at the depression located between the right eye and right ear.

BEHIND EAR—Bolt entry directly caudal to the pinna of the ear on the same plane as the eyes and targeting the middle of the opposite eye.

^a,b,cSuperscripts that differ within a row identify significant differences between means within dependent variables across placements (P ≤ 0.05).