饲粮豆粕水平与β-甘露聚糖酶对断奶仔猪血清半乳甘露聚糖含量、生化指标及肠道氨基酸转运载体基因表达的影响

摘要

According to the analysis of α-galactomannan(α-GM), β-galactomannan(β-GM)and galacto-mannan(GM)contents in 22 kinds of feed ingredients, this study evaluated the effect of β-mannanase (β-MN)on the contents of α-GM, β-GM and GM in serum, serum biochemical indices, and the gene rela-tive expression of solute carrier family 7 member 1(SLC7A1),solute carrier family 7 member 11(SLC7A11) and solute carrier family 38 member 2(SLC38A2)of weaner piglets. Twenty-four healthy dualistic hybrid weaner piglets with similar body weight were randomly divided into 4 groups(groupsⅠ,Ⅱ,ⅢandⅣ)with 6 replicates per group and 1 pig per replicate in a 2×2 factorial design. Piglets in groupⅠfed the 22% soybean meal(SBM)level diet, piglets in group Ⅱ fed the 22% SBM level diet supplemented with 0.02% β-MN, piglets in groupⅢfed the 37% SBM level diet,and the others in groupⅣfed the 37% SBM level diet supple-mented with 0.02% β-MN. The experiment lasted for 30 days. At day 30,10 mL blood samples from carotid artery, mesenteric vein and portal vein were collected from 24 piglets for serum α-GM, β-GM and GM con-tents determination,respectively;10 mL blood from precaval vein used for serum biochemical indices analysis. The proximal jejunum and distal ileum samples were collected for analysis gene relative expression of SLC7A1, SLC7A11 and SLC38A2. The results showed that compared with groupⅠ,the average daily feed intake(AD-FI)and SLC7A1 gene relative expression in ileum of weaner piglets in group Ⅲ were significantly decreased (P<0.05), the average daily intake of α-GM content, the content of β-GM in carotid artery serum, the con-tents of β-GM and GM in mesenteric vein serum,the alanine aminotransferase,glutamic oxaloacetic transami-naseand activities and urea nitrogen content in precaval vein serum of weaner piglets in group Ⅲ were signifi-cantly increased(P<0.05); the content of α-GM in mesenteric vein serum,the contents of α-GM and GM in portal vein serum of weaner piglets in group Ⅱ were significantly decreased(P<0.05), the contents of glu-cose, calcium and high density lipoprotein in precaval vein serum were significantly increased(P<0.05). Compared withⅢgroup,the content of GM in portal vein serum of weaner piglets in groupⅣwas significant-ly decreased(P<0.05), the gene relative expressions of SLC7A1, SLC7A11 and SLC38A2 in jejunum were significantly increased(P<0.05). These findings suggest that with the average daily intake of α-GM content increase, the ADFI is decreased; the contents of α-GM, β-GM, and GM in carotid artery, mesenteric vein, and hepatic portal vein serum are increased by the dietary α-GM,β-GM and GM contents increase. When diet-ary α-GM, β-GM and GM increase, β-MN can decrease the content of GM in portal vein serum and increase the gene relative expression of SLC7A1,SLC7A11 and SLC38A2 in jejunum.%本试验在分析了22种饲料原料中 α-半乳甘露聚糖(α-GM)、β-半乳甘露聚糖(β-GM)和半乳甘露聚糖(GM)含量的基础上,研究了饲粮豆粕水平与β-甘露聚糖酶(β-MN)对断奶仔猪血清 α-GM、β-GM、GM 含量,血清生化指标,以及肠道溶质载体家族7成员1 (SLC7A1)、溶质载体家族7成员11(SLC7A11)、溶质载体家族38成员2(SLC38A2)基因相对表达量的影响.试验采用2×2因子设计,将24头初始体重接近的健康二元杂交断奶仔猪随机分为4组(Ⅰ、Ⅱ、Ⅲ、Ⅳ组),每组6个重复,每个重复1头猪.Ⅰ组饲喂22%豆粕水平饲粮,Ⅱ组饲喂22%豆粕水平并添加0.02% β-MN的饲粮,Ⅲ组饲喂37%豆粕水平饲粮,Ⅳ组饲喂37%豆粕水平并添加0.02% β-MN的饲粮.试验期为30 d.在第30天对24头仔猪进行颈动脉、肠系膜静脉以及肝门静脉采血10 mL,检测血清中 α-GM、β-GM 和 GM 含量;对前腔静脉采血10 mL,检测血清生化指标;并取空肠前端和回肠后端,检测SLC7A1、SLC7A11、SLC38A2基因相对表达量.结果表明:与Ⅰ组相比,Ⅲ组断奶仔猪平均日采食量(ADFI)和回肠SLC7A1基因相对表达量均显著降低(P<0.05),Ⅲ组断奶仔猪平均日采食α-GM含量,颈动脉血清β-GM含量,肠系膜静脉血清β-GM、GM含量,前腔静脉血清谷丙转氨酶、谷草转氨酶活性和尿素氮含量均显著升高(P<0.05);Ⅱ组断奶仔猪肠系膜静脉血清α-GM含量及肝门静脉血清α-GM和GM含量均显著降低(P<0.05),前腔静脉血清葡萄糖、钙和高密度脂蛋白含量均显著升高(P<0.05).与Ⅲ组相比,Ⅳ组断奶仔猪肝门静脉血清GM含量显著降低(P<0.05),空肠SLC7A1、SLC7A11和SLC38A2基因相对表达量均显著升高(P<0.05).由此可见,仔猪平均日采食α-GM的含量升高,可降低仔猪ADFI;肝门静脉、颈动脉和肠系膜静脉血清α-GM、β-GM和GM含量随饲粮α-GM、β-GM和GM含量的增加而增加.饲粮α-GM、β-GM和GM含量增加时,添加β-MN可降低肝门静脉血清GM含量,上调空肠SLC7A1、SLC7A11和SLC38A2基因相对表达量.