Abstract:Food enrichment experiments (wood-wool, sack and bamboo tube) were carried out on 8 Chimpanzees (Pan troglodytes) fed at Shanghai Zoo, and the orthogonal test was used to design the test factors and levels. We recorded feeding behavior using all-occurrence recording method before and after food enrichment. The results showed that the order of the factor on feeding behavior was wood-wool > sack > bamboo tube. The influence of different food enrichments on feeding behavior of adult male was not significant, while all the adult females decreased. The proportion of feeding behavior of young individuals decreased after enrichment. There was no significant effect on adult male and young individual in the three ways of enrichment. The optimal combination of enrichment for four adult female chimpanzees was wood-wool and sack (with or without bamboo tube), and the optimal combination for one sub adult female chimpanzee was wood-wool (with or without bamboo tube and sack). The effect of wood -wool on adult female's feeding behavior was very significant (P < 0.01), and the influence of bamboo tube on each individual’s behavior was not significant (P > 0.05), and the effect of sack on some individuals was not significant (P > 0.05) (Table 6).