【作者】 刘忠臣；

【导师】 陈代文；

【作者基本信息】 四川农业大学 ， 动物营养与饲料科学， 2011， 博士

【摘要】 试验一不同来源脂肪对断奶仔猪生长及血液生化指标的影响本试验通过饲喂不同来源脂肪的日粮,研究脂肪来源对断奶仔猪生长及血液指标的影响。采用单因子试验设计,选用48头28±1日龄断奶杜x长x大仔猪,分别饲养在48个猪栏中,随机分为3个处理组,每个处理组16个重复,每个重复1头猪。3组仔猪分别饲喂10%椰子油、鱼油、猪油纯和日粮。试验期21d。试验结果表明,与鱼油和猪油组相比,椰子油极显著增加仔猪1-3W ADG (p<0.01),极显著降低1-3W F/G (P<0.01);鱼油降低第21d仔猪血清甘油三酯(P<0.01)、总胆固醇(P<0.01)、血糖(P<0.05)、胰高血糖素(P<0.01)。与10%猪油组相比,10%鱼油显著降低仔猪血清皮质醇浓度13.54%(P<0.05),显著降低血清IL-1β水平19.21%(P<0.05)；与10%椰子油相比,鱼油显著降低血清TNF-α水平12.32%(P<0.05)。试验结果表明,不同来源脂肪具有不同的营养生理效应,椰子油的促生长效果优于鱼油和猪油；但鱼油降低仔猪血脂、血糖、血清皮质醇及细胞因子水平。试验二不同来源脂肪对E. coli攻毒仔猪的保护效应研究本试验通过研究脂肪来源和E. coli攻毒对仔猪生产性能、糖脂代谢、脂肪酶活性、肠道发育及肠道菌群的影响,探讨不同脂肪来源对E. coli攻毒对仔猪的保护效果。采用2(E. coli攻毒和对照)×3(三种脂肪来源)因子试验设计,即试验一的48头仔猪第在21d称重采血后,每个处理选12头共36头猪(公母各半)进入试验二,12头仔猪中随机选6头接近该组平均体重的猪实施E. coli攻毒,另外6头作为对照。试验第7d所有仔猪称重、采血后屠宰。结果表明：E. coli攻毒影响仔猪生长及代谢,表现为降低ADG、ADFI,相应的增加F/G；显著增加血清总胆固醇水平,血清胰高血糖素有增加趋势(P=0.107)；血清IL-1β显著升高,IgG和IgA则显著降低；仔猪胰腺脂肪酶活性显著降低；显著降低空肠绒毛高度和粘膜厚度；降低盲肠内容物C14:1、C16:0、C16:1、C18:3、CLA, C20:0、C20:1、C20:2、C20:5n3、C22:1、C22:4n6、C24:1、MUFA及PUFA含量；增加盲肠内容物大肠杆菌数量,降低乳酸杆菌、双歧杆菌数量及乳酸杆菌/大肠杆菌、双歧杆菌/大肠杆菌的比值。日粮不同来源脂肪影响E. coli攻毒仔猪生长、代谢及肠道菌群平衡。椰子油和鱼油增加仔猪ADG,血清IgG,降低F/G、IL-1β;鱼油降低血清甘油三酯、总胆固醇及胰岛素水平；椰子油增加空肠绒毛高度、绒毛高度/隐窝深度及粘膜厚度；猪油增加盲肠内容物SFA和MUFA含量,鱼油增加盲肠内容物PUFA含量；椰子油降低盲肠内容物中大肠杆菌数量,增加乳酸杆菌、双歧杆菌数量及乳酸杆菌/大肠杆菌、双歧杆菌/大肠杆菌的比值,鱼油次之,猪油组最差。结论：E. coli攻毒降低仔猪生产性能、改变糖脂代谢水平及细胞因子和免疫球蛋白分泌、影响肠道形态、降低盲肠内容物多种脂肪酸含量、扰乱肠道菌群平衡,脂肪来源特别是椰子油和鱼油可通过调控仔猪生长、代谢、肠道发育及菌群平衡等途径降低E. coli攻毒对仔猪的影响程度。试验三不同来源脂肪对E. co I i攻毒仔猪的保护机制研究本试验通过研究不同来源脂肪对E. coli攻毒仔猪小肠脂肪酸结合蛋白mRNA表达,空肠和肝脏炎症因子PPAR-γ、IL-1β、IL-6、TNF-amRNA表达,以及回肠、盲肠TLR受体mRNA表达的影响,探讨脂肪来源对E. coli攻毒仔猪保护作用的可能机理。试验设计同试验二。结果表明：E. coli.攻毒降低仔猪十二指肠FABP1、空肠TNF-α和PPAR-γ、肝脏IL-6和PPAR-γ、盲肠TLR-4 mRNA表达；增加空肠FABP1和FABP1空肠IL-1β和IL-6、肝脏IL-1β和TNF-α、回肠TLR-2和TLR-4 mRNA表达。日粮不同脂肪来源影响E. coli攻毒仔猪脂肪酸结合蛋白、炎症因子及TLR受体mRNA表达。相对于10%猪油组,椰子油和鱼油有增加十二指肠FABP1、空肠FABP1和FABP2 mRNA表达,降低空肠IL-1β和IL-6、回肠和盲肠TLR-2及TLR-4 mRNA表达的趋势。相对于10%鱼油和10%猪油组,椰子油降低肝脏IL-6和TNF-α、回肠和盲肠TLR-2及TLR-4 mRNA表达,增加空肠PPAR-γ、肝脏PPAR-γ和IL-1βmRNA表达。结论：E. coli攻毒可影响仔猪脂肪酸结合蛋白表达、炎症因子及TLR受体mRNA表达；脂肪来源通过调控上述基因表达,从脂肪酸吸收、炎症过程及肠道屏障途发挥对E. coli攻毒仔猪的保护效应。本研究表明,不同来源脂肪具有不同的营养生理效应；E coli攻毒降低仔猪生产性能、改变糖脂代谢水平和免疫球蛋分泌、影响肠道形态、降低盲肠内容物多种脂肪酸含量、扰乱肠道菌群平衡,影响脂肪酸结合蛋白、TLR受体mRNA表达,以及细胞因子的表达和分泌；脂肪对仔猪脂肪代谢、肠道结构和微生物菌群结构和炎症反应具有调节作用,对E. coli攻毒具有保护作用,并表现出脂肪来源的差异性。更多还原

【Abstract】 Exp.1 Effects of different dietary fat sources on growth performance and blood biochemical index of weaned pigsThis study was designed to evaluate the effects of dietary fat sources on growth performance and biochemical index in weaned pigs. According to a single factorial arrangement, a total of 48 Duroc×Landrance×Yorkshire (DLY) weaned pigs were randomly assigned to one of three dietary groups of 16 animals each. The three dietary groups were purified diet supplemented with 10% either coconut oil, fish oil, or lard. The experiment had two stages and lasted for 21d. Results showed that:From 1 to 3 w, the ADG and F/G of coconut oil group was significant higher the lower, respectively, than that of fish oil and lard group. On day 21, the serum triglyceride (P< 0.01), total cholesterol (P< 0.01), blood sugar (P< 0.05), glucagons (P< 0.01) in piglets of fish oil group were reduced. The serum cortisol concentration and IL-1βlevels in pigs of 10% fish-oil group were significantly reduced, compared to 10% lard group. The serum TNF-αlevel in fish oil group was decreased 12.32%(P < 0.05), comparing result of 10% coconut oil group.These results suggested that different dietary fats had different nutritional and physiological effects, and cocunut oil had better growth performance of weaned pigs than fish oil and lard. But fish oil could reduce serum glucose, lipid, cortisol, and cytokine levels.Exp.2 The protective effects of different dietary fat sources on E. coli-administrated pigsThe study was conducted to evaluate the protective effects of different dietary fat sources on growth performance, lipid metabolism, activity of lipase, intestinal development and intestinal flora of pigs challenged with E. coli. Blood samples were collected from all pigs on d 21 in Exp.1. After blood collection,12 pigs (6 female and 6 male) of each dietary groups in Exp.1 were assigned into Exp.2. The three dietary groups were the same as described in Exp.I. Six piglets (three female and three male) of each group received E. coli challenge, and the others received sterile normal saline at the same dose. Results showed that:Pigs received E. coli challenge had lower ADG and ADFI but higher F/G. The serum total cholesterol and IL-1βlevels were increased, while the surum IgG and IgA, activity of lipase, villi height and mucous thickness in jejunum, and fatty acids (C14:1, C16:0, C16:1, C18:3, CLA, C20:0, C20:, C20:2, C20:5n3, C22:1, C22:4n6, C24:1, MUFA and PUFA) in cecum were decreased in E. coli-challenged pigs. There was a tendency toward elevated surum glucagon. E. coli-administrated pigs aslo had lower Lactobacillus and Bifidobacterium population, the ratio of Lactobacillus to E. coli, and the ratio of bifidobacterium to E. coli. Results also showed that different dietary fat sources influenced growth performance, metabolism and the intestinal folra balance of pigs challenged with E. coli. Coconut oil and fish oil increased ADG and serum IgG level, and reduced F/G and serum IL-1βlevel. Fish oil reduced serum triglyceride, total cholesterol and insulin levels. Coconut oil increased willi height, villi height/crypt depth, and mucous thickness. Lard increased MUFA and PUFA content in cecum. Coconut oil reduced E. coli population and increased Lactobacillus and Bifidobacterium population, and the ratios of Lactobacillus/E. coli and Bifidobacterium/E. coli, and lard group was the worst.These results suggested that E. coli challenge suppressed growth, changed glucose and lipid metabolism. influenced intestinal morphology and cytokine and immunoglobulin secretion, decreased fatty acid content in cecum, and disrupted the belance of intestinal flora.Dietary fat, especially coconut oil and fish oil protected pigs against E. coli infection by regulating growth, metabolism, intestinal develpoment, and the balance of intestinal flora.Exp.3 The mechanism of protective effects of different dietary fat sources on E. coli-administrated pigsThe purpose of this experiment was to investigate the possible mechanism of protective effects of different dietary fat sources on E. coli-administrated pigs by detecting the mRNA level of FABPs in small intestines, the mRNA level of inflammatory factors, such as PPAR-y, IL-1β, IL-6 and TNF-a, in jejunum and liver, and the Toll-like receptor (TLR) mRNA level in ileum and caecum. Experimental design was the same as Exp.2. The results showed that:E. coli challenge suppressed the mRNA expression levels of FABP1 in duodenum, TNF-a and PPAR-y in jejunum, IL-6 and PPAR-y in liver, and TLR-4 in cecum. E. coli challenge also increased the mRNA expression levels of FABP1, FABP2, IL-1βand IL-6 in jujunum, IL-1βand TLR-4 in ileum. Different dietary fat sources influenced the mRNA expression levels of related genes as mentioned in E. coli-administrated pig. Compared to lard group, coconut oil and fish oil increased the mRNA levels of FABP1 in duodenum, FABP1 and FABP2 in jujunum, and suppressed the mRNA levels of IL-1βand IL-6 in jejunum, TLR-2 and TLR-4 in ileum and cecum. Compared to fish oil and lard groups, coconut oil decreased the mRNA expression levels of IL-6 and TNF-a in liver, TLR-2 and TLR-4 in ileum and cecum, and increased the mRNA expression levels of PPAR-y in jujunum and liver, and IL-1βin liver.These results suggested that E. coli challenge influenced the mRNA expression levels of FABPs, cytokines and TLRs in intestinal tract and cytokines in liver. Ditary fat especially cocunut oil and fish oil played protective role by regulating the mRNA expression levels of FABPs, inflammatory factor and TLK genes in E. coli-challenged pigs.In conclusion, Oue results showed that different dietary fats had different nutritional and physiological effects and E. coli challenge decreased growth performance, changed glucose and lipid metabolism, influenced intestinal morphology and cytokine and immunoglobulin secretion, decreased fatty acid content in cecum, disrupted the balance of intestinal flora, influenced FABPs and TLRs mRNA abundance. Dietary fats had a regulatory role in lipid metabolism, intestinal structure, intestinal flora and inflammatory response. Different dietary fats also had different protective effects on pigs challenged with E. coli.更多还原