Effects of Dietary Soybean Meal Level and β-Mannanase on Serum Galactomannan Content, Biochemical Indices and Intestinal Amino Acid Transporters Gene Expression of Weaner Piglets
ZHU Xiaotong1, ZHANG Fangliang1, YIN Jie2,3, LI Yuying2,3, HAN Hui2,3, BIN Shiyu1, LI Tiejun2,3,4, YIN Yulong2,3,4
1. College of Life Science, Guangxi Normal University, Guilin 541006, China;
2. Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences;National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production, Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Changsha 410125, China;
3. University of Chinese Academy of Sciences, Beijing 100039, China;
4. Hunan Co-Innovation Center of Animal Production Safety, Changsha 410128, China
Abstract：According to the analysis of α-galactomannan (α-GM), β-galactomannan (β-GM) and galactomannan (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 relative 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 (groups Ⅰ, Ⅱ, Ⅲ and Ⅳ) with 6 replicates per group and 1 pig per replicate in a 2×2 factorial design. Piglets in group Ⅰ fed 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 group Ⅲ fed the 37% SBM level diet, and the others in group Ⅳ fed the 37% SBM level diet supplemented 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 contents 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 group Ⅰ, the average daily feed intake (ADFI) 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 contents of β-GM and GM in mesenteric vein serum, the alanine aminotransferase, glutamic oxaloacetic transaminaseand activities and urea nitrogen content in precaval vein serum of weaner piglets in group Ⅲ were significantly 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 glucose, calcium and high density lipoprotein in precaval vein serum were significantly increased (P<0.05). Compared with Ⅲ group, the content of GM in portal vein serum of weaner piglets in group Ⅳ was significantly 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 dietary 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.
