Abstract: Seventy healthy mice were randomly divided into 7 groups,each group was 10. The oral feeding 0 mg/kg cholecystokinin (CCK) control group,0 mg/kg empty microcapsules group,1 mg/kg CCK-IgY-LD microcapsules group,5 mg/kg CCK-IgY-HD microcapsules group and injection 0 mg/kg control group,1 mg/kg CCK-IgY-LD injection group, 3 mg/kg CCK-IgY-HD injection group,the experiment period lasted for 40 days. The D value of ovine CCK-IgY,the feed intake and body weight in mice via both forms of treatments were measured, the effect of both forms of treatment was compared each other. The results showed that in whole experimental period,the feed intake and weight gain in group 3 were extremely significantly higher than that in group 4 (P<0.01), but it had no significant difference with the group 1 (P>0.05). With the increase of CCK-IgY injection dose, the D value was also increased, and the D value of group 7 was extremely sinificantly higher than the control group (P<0.01). CCK-IgY microencapsulated group didn't had reached the expected effect. Oral feeding and injection of CCK-IgY could stimulate the corresponding immune response in mice. The CCK-IgY injected intra-abdominally to mice presented obvious growth-promoting effect, but the effect of microencapsulated CCK-IgY orally fed to mice showed be further studied.

Key words: CCK-IgY; microencapsulation; body weight; feed intake; mice