Abstract: The experiment was conducted to study the effects of the level of protein in dietary on growth performances and blood biochemical indices in Hainan pigs. A total of 36 Hainan pigs with the weight of (15.88±1.82)kg were randomly allocated to three treatments, treatment one group (CP 16.5%), treatment two group (CP 18.5%) and treatment three group (CP 18.5%), each treatment group had three replicates and 4 pigs per replicate. The experiment lasted 40 days. The results showed that there were no significant effects of the level of protein in dietary on growth performances in Hainan pigs (P>0.05), but when the level of protein in diatary was 18.5%, the growth performances of Hainan pigs was the best. The concentrations of total protein and globulin in blood significantly influenced by the levels of protein in diets(P<0.05), as dietary protein level increased, Hainan pig blood total protein and globulin concentrations were elevated. In conclusion, Hainan pig’s optimal dietary protein level was 18.5%.

Key words: protein; Hainan pigs; growth performances; biochemical indices