Nutritional And Protective Effects Of Different Dietary Fats Sources On Weaned Pigs Challenged With E.coli

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.