Abstract: The objective of this study was to accurately determine the appropriate amount and period of adding soybean protein hydrolysate in the diet of weaned piglets. A total of 48 （half male and half female） 14-day-old, healthy and just weaned three-way crossbred piglets （Duroc×Landrace×Yorkshire） with similar weight were selected in this study. The experimental piglets were randomly assigned into the following three groups group Ⅰ was served as a control, in which no dietary supplementation of soybean protein hydrolysate was made; group Ⅱ and group Ⅲ were used as experimental groups, in which 3.0% and 4.0% of soybean protein hydrolysate were supplemented in the basal diet, respectively. The pretrial period was 7 days, and the formal trial period lasted for 28 days. The results showed that in the first three weeks of the experiment, the average week weight and average daily gain of piglets in group Ⅱ and group Ⅲ were significantly （P<0.05） higher than those in group Ⅰ; in the first week of the experiment, the average daily feed intake of group Ⅱ and group Ⅲ was significantly （P<0.05） higher than that in group Ⅰ; in the first two weeks of the experiment, group Ⅱ and group Ⅲ had significantly （P<0.05) lower feed to gain ratio compared with group Ⅰ; in the first three weeks of the experiment, group Ⅱ and group Ⅲ had significantly （P<0.05） lower diarrhea rate in each week than group Ⅰ; significantly （P<0.05） better performance in utilizations of dietary dry matter and crude protein were observed in group Ⅱ and group Ⅲ compared to group Ⅰ. The combined data suggest that the dietary supplementation of soybean protein hydrolysate can effectively improve the production performance and the utilization rate of nutrients in weaned piglets. The 3.0% of soybean protein hydrolysate is recommended to be supplemented in basal diet of weaned piglets from 15 to 42 days of age.

Key words: soybean protein hydrolysate, weaned piglets, production performance, nutrients, utilization rate