Table 1.

Weight (g; mean ± SE) and use of nylon chew toy by male Sprague–Dawley rats during 4-wk gavage study

		No. of chew toys
Treatment group	Chew toy weight after week 4 (g)	Provided	Not used
Control	16.0 ± 1.6		10	3
Restraint only	17.9 ± 0.5		10	3
Dry gavage	15.6 ± 1.2		10	2
Gavage—single-housed	16.5 ± 1.0		10	3
Gavage—pair-housed	15.2 ± 1.5		9	1

Mean pretest chew toy weight was 20 g for all groups.