| The mechanism of dietary-induced fatty liver of Palmipedes remains puzzling (Hermier et al., 2003). Firstly, the nutritional values of four varieties of early paddy brown rice, Jinyou402, Jinyoul52, Ezao6 and 9530, planted widely in Hubei Province were evaluated in this dissertation. Secondly, compared to maize and wheat diets, the effects of brown rice overfeeding diet of Jinyou402 on performance of fatty liver of Landes Geese and Mule Ducks were demonstrated. At last, using singular factor design, different levels of soybean salad oil, choline and carnitine were supplemented to brown rice-based overfeeding diets of Jinyou 402, and the effects of them on fatty liver performance, lipid metabolism, fatty liver composition, fat storage and distributing in fatty liver tissue and hepatocytes in overfed Landes Geese were investigated, respectively. The results summarized as follows:1. Evaluation of Nutritional Values of brown rice of Jinyou402, Jinyoul52, Ezao6 and 9530Objective: to evaluate the nutritional values of early paddy brown rice, Jinyou402, Jinyoul52, Ezao6 and 9530, planted widely in Hubei Province.Methods: Using Sibbald true metabolizable energy (TME) method and high performance liquid chromatography (HPLC), the contents and metabolizabilities of crude protein (CP), gross energy (GE) and amino acid in brown rice of these four varieties were analyzed and compared with high quality maize Ludan50, quality protein maize (QPM) Jinyu34, two varieties of high quality fodder early paddy (FEP) brown rice Xiangzaoxian24 and Weiyou56, and one middle paddy brown rice Jinyou63, respectively. Results: (1) The GE contents in these four varieties of brown rice were all higher than 18 MJ/kg except 9530, and the CP contents were all beyond lOOg/kg dry matter (DM). (2) The true metabolizabilities (TM) of CP in these four varieties were all higher than those in maize Ludan50 and Jinyu34, and higher than (p<0.05) or close to (p>0.05) those in brown rice of Xiangzaoxian24, Weiyou56 and Jinyou63. (3) Except for 9530, the true metabolizable energy (TME) in these four varieties were all higher than those in maize and Jinyou63 (p<0.05). (4) the essential amino acid index (EAAI) of these four varieties were all higher than those of Ludan50 , Jinyu34 and Weiyou56 , and the contents and TM of amino acid were all higher than those of maize. (5) The contents and TM of amino acid in these four varieties were all higher than those in two varieties of maize (p<0.05), andthe TM of essential amino acid were close to Weiyou56, Jinyou63 and Xiangzaoxian24.Conclusions: The four varieties of early paddy, Jinyou402, Jinyou152, Ezao6 and 9530 are all high quality FEP.2. Effects of brown rice on fatty liver performance of Landes Geese and Mule DucksObjective: To evaluate the effect of brown rice as main overfeeding ingredient on fatty liver performance of Landes Geese and Mule Ducks.Methods: Compared to corn and wheat, Landes Geese and Mule Ducks were overfed with brown rice of Jinyou 402. After overfeeding, the carcass traits of geese and ducks were measured and their serum biochemical parameters and fatty liver composition in each treatment were assayed, respectively.Results: To Landes Geese: (1) After 2 week overfeeding, besides body weight and body weight gain increased significantly, the fatty liver weights were increased dramatically from 94.67 g to 246.70g, 554.67 g and 754.00 g in wheat treatment, corn treatment and rice treatment, respectively, and the liver weight was greater in brown rice group than those in the other groups (p<0.05). The fat accumulation in adipose tissues reached up to or close to 2 folds of initial weight in all treatments. (2) Although TG, total cholesteryl esters (TCHO) and very low density lipoprotein (VLDL) contents in serum increased sharply after overfeeding except glucose (GLU) , there were no difference among these parameters in all three treatments. (3) Compared to before overfeeding, triacylglycerols (TG) in geese fatty liver increased dramatically and predominated (from 9.08% to close to or more than 90% of hepatic lipids), whereas phospholipid (PL) and TCHO decreased sharply in all treatments (p<0.05). The percentages of hepatic lipid and PL in hepatic lipids were higher in brown rice treatment than that in corn treatment, and that of TCHO was lower (p<0.05). The percentage of TG was higher in brown rice treatment and corn treatment than that in wheat treatment, while PL and TCHO were lower.To Mule Ducks: After 2 week overfeeding, the fatty liver weights were increased dramatically from 69.70 g to 186.90g, 312.60g and 356.30 g, and the other results were similar to those in Landes Geese.Conclusions: Brown rice diet induces the greatest fatty liver among the three treatments, and brown rice is one of high quality overfeeding ingredients instead of corn.3. Effects of supplementary soybean salad oil, or choline or carnitine in brown rice-based diets with different levels on fatty liver weight gain and fat accumulation in adipose tissue of Landes GeeseObjective: To study effects of supplementary soybean salad oil, or choline or carnitine with different levels on fatty liver weight gain and fat accumulation in adipose tissue in overfed Landes Geese, respectively.Methods: Using singular factor design, soybean salad oil with four levels (0, 2%, 4% and 6%), both of choline and carnitine with four levels (0, 0.05%, 0.1% and 0.2%) were supplemented in brown rice-based overfeeding diets of Jinyou 402, respectively. After overfeeding, carcass traits of Landes Geese in each treatment were measured after overfeeding, respectively.Results: Among choline or carnitine treatments, there were no differences in geese fatty liver weight in each level, respectively. However, fatty liver weight was significantrlower in the treatment with 6% oil than that in the other oil treatments. Body weight gain, abdominal fat weight, percentage of abdominal fat, skin and subcutaneous fat weight, percentage of skin and subcutaneous fat in overfed Landes Geese were no significant differences among each level of oil, or choline or carnitine treatments, respectively.Conclusions: Optimal amount of soybean salad oil addition in the brown rice-based overfeeding diets should be less than 2%, and there were no differences in geese fatty liver performance among all of choline or carnitine treatments, respectively.4. Study on mechanism of lipid metabolism in blood and lipid storage in liver of overfed Landes GeeseObjective: To study changes of lipid metabolism in blood and lipid storage in liver of overfed Landes Geese in response to different levels of supplementary soybean salad oil, or choline or carnitine in brown rice-based diets, respectively.Methods: According to the design of part 3 above. Pancreatic hormonal, critical enzyme and biochemical parameters in serum and compositions in fatty liver in each treatment were assayed after overfeeding.Results: (1) blood lipid metabolism: In each level of oil, or choline or carnitine treatments, VLDL, TG, TCHO, glucagons (Glu), insulin (INS), lipoprotein lipase (LPL) and lipase (LPS) in serum of overfed geese increased dramatically when compared to before overfeeding, respectively, and there were no differences in these parameters among all levels of each treatment after overfeeding, respectively. (2) Lipids storage in fatty liver: Before overfeeding, PL predominated in hepatic lipids (85.9%) and TG was in very lowamount. However, it is similar in all levels of each treatment, TG reached up to 10 folds of initial amount and became the chief lipid (90% in hepatic lipids) in overfed geese, and there were all no significant differences in contents of TG, PL and TCHO in hepatic lipids, respectively.Conclusions: Because the overfed geese were never deprived of carbohydrate-rich diet, the intensive lipogenesis in liver, especially for TG, was increasing and the pathways of lipid metabolism appeared to be overwhelmed, and the regulation of hormonal and enzyme on capability of lipid transfer in geese became limited, which induced TG to remain dramatic accumulation in the liver. Landes geese adapted well to these abnormal changes, and the strong metabolic adaptability might result in the fact that the effects of supplementary oil, or choline or carnitine in diets on geese blood lipid metabolism and liver lipid storage were not different significantly during whole overfeeding period.5. Study on dynamics of lipid deposition and distribution in fatty liver tissue of Landes geese during overfeeding periodObjective: To study on changes of lipid deposition and distribution in fatty liver tissue of Landes Geese in response to different levels of supplementary soybean salad oil, or choline or carnitine in brown rice-based diets during overfeeding period.Methods: According to the design of part 3 above. In the 1st, 2nd, 3rd, 4th, 5th, 6th, 7th, 8th, 9th, 11th, 14th day of overfeeding, one geese in each group of oil, or choline or carnitine treatments were killed and their liver were picked out within 5 minutes, respectively. Using Hematoxylin and eosin (HE) stain, all histological slides of their livers were observed and analyzed by histological image system, respectively.Results: Among each level of oil or choline or carnitine treatments, there were no differences in the changes of liver tissue and hepatocytes of geese. The progress of lipid deposition as follows: Initially, lipid droplet distributed along the area of liver vein diffusely. Gradually, lipid droplet stored and distributed evenly in whole liver tissue and hepatoc}tes, and the size of hepatocytes increased rapidly. Although huge lipid was stored in liver rapidly, the hepatocellular structure remained integrated and there were no inflammatory cell infiltration and necrotic focus in liver tissue during whole overfeeding period. These changes maybe improved the hepatocellular capacity for huge fat accumulation.Conclusions: Making use of the changes of fat distribution in hepatic tissue and strong capacity of hepatocytes for fat accumulation, Landes geese adapted well to huge storage of fat in liver during whole overfeeding period. The changes and patterns of lipiddeposition and distribution in liver tissue and hepatocytes were not different in each level of supplementary oil, or choline or carnitine treatments, respectively.6. Study on progress of ultra-structural changes in liver tissue of Landes Geese during overfeeding periodObjective: To study on progress of hepatocellular lipid distribution and ultra-structural changes of Landes Geese in response to different levels of supplementary soybean salad oil, or choline or carnitine in brown rice-based diets during overfeeding period, respectively.Methods: According to the design in part 3 and the preparation for liver samples in part 5 above. Electron-micrography and ultra-structural analysis for lipid deposition and distribution in hepatic tissue was performed when preparation of electron microscopical slides was completed.Results: Among all treatments, the hepatocellular ultra-structural changes and lipid droplet distribution were similar. The progress of hepatocellular lipid deposition and distribution from initial overfeeding period to middle period as follows: Initially, it showed that there were phenomena of resistance for lipid droplet deposition in hepatocytes with stacks of heparin and swelling of mitochondrion temporarily. Then the hepatocellular capability of lipogenesis and lipid accumulation was increasing and the lipid droplets located evenly in the middle of hepatocytes. Although lipid accumulation in hepatic stellate cell (HSC) was increasing, there was no proliferation of HSC and Kupffer cell (KC) in whole hepatic tissue.Conclusions: The ultra-structural changes of Landes Geese's liver tissue in all treatments were similar. From initial overfeeding period to middle period, the mechanism of structural alterations in liver tissue and the changes of organelle in hepatocytes improve the adaptability of huge fat storage in liver of Landes Geese. |
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