选用135头平均体重为(7.2±0.1)kg的杜×长×大三元杂交断奶仔猪，采用3×3两因子完全交叉试验设计，研究了日粮中添加3个中性蛋白酶水平(0、0.004%和0.008%)和3个酸性蛋白酶水平(0、0.004%和0.008%)对断奶仔猪生长性能的影响。试验共设9组，每组3个重复，每个重复5头猪。试验期为28 d，分为前期(1～14 d)和后期(15～28 d) 2个阶段。结果表明，中性和酸性蛋白酶对断奶仔猪的前期、后期和全期的平均日增重和料重比有显著影响(P＜0.05)；对腹泻率无显著影响(P＞0.05)。其中添加0.008%的中性蛋白酶和0.004%的酸性蛋白酶可显著提高断奶仔猪的平均日增重和平均日采食量，显著降低料重比(P＜0.05)，而单独在日粮中添加0.008%酸性蛋白酶时料重比最高(P<0.05)。由此可知，中性和酸性蛋白酶可一定程度上提高断奶仔猪生长性能，以添加0.008%的中性蛋白酶和0.004%的酸性蛋白酶效果最好，且两者存在互作效应。

In order to investigate the effects of neutral and acid protease on growth performance of weaned piglets, a feeding trial was conducted and 135 healthy Duroc×Landrace×Yorkshire crossbred weaned piglets with an average weight of (7.2±0.9) kg in a 3×3 crossing design trial were randomly assigned to 9 groups (3 replicates per group and 5 piglets per replicate). Supplemental levels of neutral protease were 0, 0.004% and 0.008%, respectively, and supplemental levels of acid protease were 0, 0.004% and 0.008%, respectively. The experiment lasted for 28 d, including early period (1～14 d) and later period (15～28 d). The results showed that neutral and acid protease had significant effects on average daily gain (ADG) and feed/gain (F/G) during early period, later period and the whole period, but no significant effects on diarrhea ratio (P＞0.05). Supplementation with 0.008% neutral protease and 0.004% acid protease simultaneously had significant increasing effects on ADG and average daily feed intake (ADFI) and decreasing effects on F/G (P＜0.05), but F/G was the highest when only 0.008% acid protease was added in feed. In conclusion, neutral and acid protease could improve the growth performance of weaned piglets to some degree, and supplementation with 0.008% neutral protease and 0.004% acid protease simultaneously was the best. And their interaction on growth performance was found.［Chinese Journal of Animal Nutrition, 2009，21(6):993-997］