饲粮精粗比对犊牛肠道小肽转运蛋白mRNA表达的影响

Effects of Dietary Concentrate to Forage Ratio on Intestinal Peptide Transporter mRNA Expressions of Calves

本试验旨在研究不同精粗比颗粒料对犊牛肠道黏膜小肽转运蛋白Pep T1、Pep T2、PHT1和PHT2 mRNA表达的影响。选择日龄、体重相近的中国荷斯坦公犊牛6头,分为2个处理,每个处理3头,各处理精粗比分别为75∶25(Ⅰ)和65∶35(Ⅱ),预试期14 d,正试期56 d。结果表明:1)十二指肠和空肠Pep T1 mRNA表达丰度极显著高于回肠、盲肠和结肠(P<0.01);处理Ⅰ犊牛十二指肠和空肠Pep T1 mRNA表达丰度极显著高于处理Ⅱ(P<0.01);2)与Pep T1 mRNA相比,Pep T2 mRNA在犊牛肠道中表达丰度较低;处理Ⅰ十二指肠和结肠Pep T2 mRNA表达丰度极显著高于处理Ⅱ(P<0.01);3)处理Ⅰ盲肠PHT1 mRNA表达丰度极显著低于处理Ⅱ(P<0.01),处理Ⅰ犊牛回肠和结肠PHT1 mRNA表达丰度显著高于处理Ⅱ(P<0.05);4)处理Ⅰ犊牛盲肠PHT2 mRNA表达丰度极显著低于处理Ⅱ(P<0.01),处理Ⅰ犊牛十二指肠和结肠PHT2mRNA表达丰度极显著高于处理Ⅱ(P<0.01)。以上结果说明,与精粗比为65∶35的饲粮相比,精粗比为75∶25的饲粮更能够促进犊牛肠道中Pep T1、Pep T2、PHT1和PHT2 mRNA的表达。

This experiment was conducted to observe the effects of concentrate to forage ratio in pellet diet on the mRNA expressions of peptide transporters（ Pep T1,Pep T2,PHT1 and PHT2） in intestinal mucosa of calves. Six Holstein bull calves with similar days of age and body weight were divided into 2 treatments with 3 calves per treatment. Calves were fed pellet diets with concentrate to forage ratio of 75 ∶25（ Ⅰ） and 65 ∶35（ Ⅱ）,respectively. The preliminary trial period was 14 d and the experimental period was 56 d. The results showed as follows： 1） the expression abundance of Pep T1 mRNA in duodenum and jejunum was significantly higher than that in ileum,cecum and colon（ P〈0. 01）,and duodenum and jejunum in treatment Ⅰ were significantly higher than those in treatment Ⅱ（ P〈0. 01）. 2） The expression abundance of Pep T2 mRNA intestine was little compared with that of Pep T1 mRNA. The expression abundance of Pep T2 mRNA in duodenum and colon in treatment Ⅰwas significantly higher than that in treatment Ⅱ（ P〈0. 01）. 3） The expression abundance of PHT1 mRNA in cecum in treatment Ⅰ was significantly lower than that in treatment Ⅱ（ P〈0. 01）,and ileum and colon in treatment Ⅰ were significantly higher than those in treatment Ⅱ（ P〈0. 05）. 4） The expression abundance of PHT2 mRNA in cecum in treatment Ⅰ was significantly lower than that in treatment Ⅱ（ P〈0. 01）,and duodenum and colon in treatment Ⅰ were significantly higher than those in treatment Ⅱ（ P〈0. 01）. The results showthat compared with 65∶35,concentrate to forage ratio of 75∶25 can promote the expressions of Pep T1,Pep T2,PHT1 and PHT2 mRNA.