单 位：
浙江大学动物科学学院;中国农业科学院饲料研究所
摘 要：
本试验旨在研究益生菌(PRO)和纤维寡糖(COS)对热应激肉鸡营养物质消化、肠黏膜氨基酸转运载体mRNA表达和氮排放的影响。将900羽21日龄罗斯(Ross)308肉鸡分为5个组:热中性(TN)组、热应激(HS)组、益生菌(HS+0.15%PRO)组、纤维寡糖(HS+0.15%COS)组、合生素(HS+SYN,SYN=0.15%PRO+0.15%COS)组。热中性组鸡舍温度22℃;其余各组鸡舍为循环热应激,温度08:00—18:00为33℃,18:00—次日08:00为22℃。饲养试验期为21 d。结果如下:1)与热中性组相比,热应激组肉鸡平均日增重和平均日采食量分别显著降低10.65%(P<0.05)和8.04%(P<0.05),单独添加益生素或者纤维寡糖对肉鸡平均日增重、平均日采食量和料重比均无显著影响(P>0.05);热应激组粗蛋白质和粗纤维表观消化率显著下降(P<0.05);热应激组氮摄入量和氮沉积量显著降低(P<0.05),氮排泄量和排泄率及排泄物氨态氮和尿酸含量显著提高(P<0.05);热应激组排泄物脲酶活性和鸡舍氨气浓度显著提高(P<0.05);热应激组肠黏膜基础氨基酸运载体(rBAT)、y+L氨基酸运载体-2(y+LAT2)、阳离子氨基酸运载体-1(CAT1)和阳离子氨基酸运载体-4(CAT4)mRNA表达量显著降低(P<0.05)。2)与热应激组相比,益生菌组和纤维寡糖组粗蛋白质表观消化率显著升高(P<0.05),氮排泄量和氮排泄率显著降低(P<0.05),氮沉积量显著升高(P<0.05);益生菌组排泄物氨态氮含量显著降低(P<0.05);纤维寡糖组鸡舍氨气浓度、排泄物脲酶活性显著降低(P<0.05)。3)与热应激组相比,合生素组粗蛋白质和粗纤维表观消化率显著升高(P<0.05),氮排泄量、氮排泄率显著降低(P<0.05),氮沉积量显著升高(P<0.05),鸡舍氨气浓度、排泄物氨态氮含量和脲酶活性显著降低(P<0.05),肠黏膜rBAT mRNA表达量显著升高(P<0.05)。结果提示,热应激使肉鸡营养物质消化率下降和氮排放升高,益生菌和纤维寡糖不同程度地改善了热应激引起的上述不良影响,两者组合添加效果优于单独添加。
译 名：
Effects of Probiotics and Cello-Oligosaccharide on Nutrient Digestion,mRNA Expression of Intestinal Mucosa Amino Acid Transporters and Nitrogen Emission of Broilers under Heat Stress
作 者：
HONG Qihua;SONG Juan;HU Caihong;SHI Bo;DIAO Qiyu;Animal Science College,Zhejiang University;Feed Research Institute,Chinese Academy of Agricultural Sciences;
关键词：
cello-oligosaccharide;;probiotic;;heat stress;;nitrogen emission;;broiler
摘 要：
This experiment was conducted to study the effects of probiotics( PRO) and cello-oligosaccharide( COS) on nutrient digestion,mRNA expression of intestinal mucosa amino acid transporters and nitrogen emission of broilers under heat stress. Nine hundred 21-day-old Ross 308 broilers w ere randomly allocated to 5groups: thermoneutralzone( HN) group,heat stress( HS) group,probiotics( HS+0.15%PRO) group,cellooligosaccharide( HS+0.15%COS) group and synbiotics( HS +SYN,SYN = 0.15%PRO +0.15%COS) group.Birds w ere either raised in a thermoneutral zone( 22 ℃) in HN group,and the others w ere subjected to cyclic heat stress by exposing to 33 ℃ from 08: 00 to 18: 00 and 22 ℃ from 18: 00 to next day 08: 00. Raising experiment period w as 21 days. The results show ed as follow s: 1) compared w ith birds kept in HN group,average daily gain and average daily feed intake of broilers subjected to heat stress w ere significantly reduced 10.65%( P<0.05) and 8.04%( P<0.05),respectively. Average daily gain,average daily feed intake and feed to gain ratio of broilers subjected to heat stress w ith diet added probiotics or cello-oligosaccharide individually w ere not significantly different( P>0.05). Apparent digestibility of crude protein and crude fiber in HS group w as significantly decreased( P<0.05),nitrogen intake and nitrogen retention w ere significantly decreased( P<0.05),nitrogen excretion and nitrogen excretion rate w ere significantly increased( P<0.05),ammonia nitrogen,uric acid contents in excreta and ammonia concentration in chicken house w ere significantly increased( P<0.05),the activity of urease in excreta w as significantly increased( P<0.05),and mRNA expression of the basic amino acid transporter( rBAT),y+L amino acid transporter-2( y+LAT2),cationic amino acid transporter-1( CAT1) and cationic amino acid transporter-4( CAT4) in intestinal mucosa was significantly down-regulated( P<0.05). 2) Compared with HS group,apparent digestibility of crude protein was significantly increased in HS+PRO and HS+COS groups( P<0.05),nitrogen excretion and nitrogen excretion rate in HS+PRO and HS+COS groups w ere significantly reduced( P<0.05),w hile nitrogen retention w as significantly increased( P<0.05). Compared w ith HS group,excreta ammonia nitrogen content in HS+PRO group w as significantly low-ered( P<0.05),and ammonia concentration in chicken house and activity of urease in excreta of HS +COS group w ere significantly reduced( P<0.05). 3) As compared w ith HS group,apparent digestibility of crude protein and crude fiber w ere significantly increased( P<0.05) in HS+SYN group. Nitrogen excretion and nitrogen excretion rate in HS+SYN group w ere significantly reduced( P<0.05),w hile nitrogen retention w as significantly increased( P<0.05). Ammonia nitrogen concentration in chicken house,excreta ammonia nitrogen content and urease activity of HS+SYN group w ere significantly reduced( P<0.05). and mRNA expression of rBAT in intestinal mucosa in HS+SYN group w as significantly up-regulated( P<0.05). The results indicate that heat stress decrease nutrient digestion and increase nitrogen emission of broilers,and dietary addition of probiotics and cello-oligosaccharide are effective in partially ameliorating these changes. The combination of probiotics and cello-oligosaccharide is superior to individually addition.
