Effects of environmental factors on cribbing activity by horses

Quantitative measurements of cribbing were made and the environmental influences on the behavior were examined. Licking the substrate preceded cribbing; the horses licked a median of 1.7 times before each cribbing event while eating grain and 1.1 times before each cribbing event while eating hay. They spent 23% of their time cribbing in bouts separated from other bouts by 30 s. Exercise influenced cribbing rate (P < 0.013) with a non-significant trend to increase cribbing rate after the longest (20 min) exercise periods. When not exercised the horses cribbed 25.3 ± 3.8% of the 24-h day; after 20 min exercise they cribbed 30.6 ± 3.5% of the 24-h day. A stall toy that increased oral activity lowered cribbing rate slightly. The horses cribbed significantly more frequently when fed a sweetened grain diet (29.8 ± 7.4% of the day) than when fed oats (16 ± 4.1%). Although no treatment abolished cribbing in these adult horses, modifying diet and increasing foraging behavior with a toy the horse could only lick lowered the time spent cribbing.