試驗選用總共132頭豬（初重= 7.23kg）在21日齡斷奶并喂食了7天無抗生素飼料，根據體重分成33圈，每圈4頭豬（去勢公豬或小母豬）。每種日糧飼喂11個圈。 日糧為玉米豆粕型基礎日糧、復合酶制劑A組（每公斤日糧提供木聚糖酶4000U，β-葡聚糖酶3500U，淀粉酶A 1500U）和復合酶制劑B組（淀粉酶B 150U，其它酶制劑同A組）。所有日糧中添加植酸酶1000 U/kg。
復合酶B組顯著提高了階段一和階段二的日增重（P＜0.05）。全期來看，復合酶B將日增重從262提高到313g，平均采食量從419提高到504g（P＜0.05）。復合酶A組將日增重提高至290g（P＜0.05），但是對采食量沒有顯著影響。復合酶制劑A和B對總能全腸道表觀消化率無影響，但是將粗脂肪消化率從30%提高至36%、37%。復合酶制劑A不影響糞便評分，但是復合酶制劑B有降低糞便評分的趨勢（P=0.09），說明其有降低腹瀉的趨勢。硬壁菌門是糞便中細菌最豐富的門（其相對豐度為58％至72％）。 擬桿菌和放線菌是糞便細菌的第二大和第三大門。 兩種復合酶均不影響糞便細菌組成。
Growth performance, nutrient digestibility, and fecal microbial composition of weaned pigs fed multi-enzyme supplemented diets
A study determined the effects of supplementing corn-based diets for weaned pigs with multi-enzymes on growth performance, apparent total tract digestibility (ATTD) of nutrients, fecal score, and fecal microbial composition. A total of 132 pigs (initial body weight = 7.23 kg) that had been weaned at 21 d of age and fed a drug-free nursery diet for 7 d were housed in 33 pens of 4 barrows or gilts, blocked by body weight and gender, and fed 3 experimental diets at 11 pens per diet. The diets were corn-based diet without or with multi-enzyme A or B. Multi-enzyme A supplied 4,000 U of xylanase, 150 U of β-glucanase, 3,500 U of protease, and 1,500 U of amylase per kilogram of diet. Multi-enzyme B was the same as multi-enzyme A except that it supplied amylase at 150 U/kg, and that its source of amylase was different from that of multi-enzyme A. All diets contained phytase at 1,000 U/kg. The diets were fed for 35 d in 2 phases; phase 1 for the first 14 d and phase 2 for the last 21 d of the trial. Fecal score was determined daily during the first 7 d of the trial. Fecal samples were collected from rectum of 1 pig per pen on days 2, 7, 14, and 35 of the trial for determining bacterial composition. Also, fresh fecal samples were collected from each pen on days 41 and 42 to determine ATTD of nutrients. Multi-enzyme B increased (P < 0.05) average daily gain (ADG) for phases 1 and 2. For the overall study period, multi-enzyme B increased (P < 0.05) ADG from 262 to 313 g, and average daily feed intake (ADFI) from 419 to 504 g. Multi-enzyme A increased (P < 0.05) overall ADG from 262 to 290 g, but did not affect ADFI. Multi-enzyme A or B did not affect ATTD of gross energy, but increased (P < 0.05) the ATTD of ether extract from 30% to 36% or 37%, respectively. Multi-enzyme A did not affect fecal score; however, multi-enzyme B tended to decrease (P = 0.09) fecal score, implying that it tended to decrease diarrhea. Firmicutes were the most abundant phylum of fecal bacteria (its relative abundance ranged from 58% to 72%). Bacteroidetes and Actinobacteria were the 2nd and 3rd most abundant phyla of fecal bacteria. Neither multi-enzyme affected fecal bacterial composition. In conclusion, the addition of multi-enzyme A or B to phytase-supplemented corn-based diet for weaned pigs can improve their growth performance and fat digestibility. However, multi-enzyme B was more effective than multi-enzyme A in terms of improving the growth performance of weaned pigs fed corn-based diet.