Effects Of Dietary Vitamin C And Vitamin B₆ On The Metabolism Responses And Shell Biomineralization Of Juvenile Abalone Haliotis Discus Hannai Ino

A series of experiments were conducted to elucidate effects of dietary vitamin C and vitamin B₆ on the metabolism responses and shell biomineralization of juvenile abalone Haliotis discus hannai Ino. The current studies include the followings: (1) Immune response to dietary vitamin C of juvenile abalone Haliotis discus hannai Ino. (2) The effect of dietary vitamin C on lipid metabolism of juvenile abalone Haliotis discus hannai Ino. (3) Effects of dietary pyridoxine (vitamin B₆) on the protein metabolism of juvenile abalone Haliotis discus hannai Ino. (4) Immune responses to dietary pyridoxine of juvemle abalone Haliotis discus hannai Ino. (5) The effect of dietary pyridoxine (vitamin B₆) on lipid metabolism in juvenile abalone Haliotis discus hannai Ino. (6) The effect of dietary vitamin C on the contents of elements and crystals in the shell of juvenile abalone Haliotis discus hannai Ino. (7) The effect of dietary pyridoxine (vitamin B₆) on the contents of elements and crystals in the shell of juvenile abalone Haliotis discus hannai Ino.(1) A 240-day feeding experiment was conducted to investigate the immune responses to dietary vitamin C of juvenile abalone Haliotis discus hannai Ino. Juvenile abalone (initial weight: 0.929±0.001g; initial shell length: 1.743±0.008cm) were fed to satiation with one of 3 semi-purified diets containing 0, 100, 10000 mg/kg equivalent vitamin C. The results showed that there were no significant effects of dietary vitamin C on the weight gain rate (WGR), the daily increment in shell length (DISL) and survival rate both at 120 and 240 days (P>0.05). The activity of acid phosphatase (ACP) and alkaline phosphatase (AKP) significantly increased in viscera and soft body of abalone fed diets without vitamin C after 120-day feeding. Lysozyme activity in viscera and soft body significantly increased with the dietary vitamin C supplements (P<0.05). Phenoloxidase (PO) activity was significantly higher in the soft body and muscle in 100mg/kg treatmentthan those with 0 and lOOOOmg/kg at 120d (PO.05) and the PO activity was significantly higher in 1 OOmg/kg and 1 OOOOmg/kg treatments compared with the treatment of Omg/kg supplementation at 240d (PO.05). The superoxide dismutase (SOD), glutathione peroxidase (GPX), glutathione-sulfate-transferase (GST) and glutathione reductase (GR) activitiy in viscera was significantly higher in treatment of 1 OOOOmg/kg compared with the other two at 240d (PO.05). Dietary vitamin C significantly influenced the activity of catalase (CAT), SOD, GPX, GST, GR in soft body of abalone and it was highest in treatment of 1 OOmg/kg at 120d (PO.05); CAT and SOD activity was higher in soft body of abalone fed diet with vitamin C supplementation 1 OOmg/kg and 1 OOOOmg/kg )than those without vitamin C at 240d (PO.05), CAT and SOD activitiy in was significantly higher in treatment of 1 OOmg/kg compared with the other two at 240d (PO.05). The enzymes activity involved in immunity was significantly decreased in muscle in treatment without vitamin C at 120d and 240d (PO.05).(2) A feeding experiment was conducted to investigate the the effect of dietary vitamin C on the lipid metabolism of juvenile abalone Haliotis discus hannai Ino.Three semi-purified diets were formulated to contain 0, 100, lOOOOmg vitamin C kg"1. Each diet was fed to three replicate groups of abalone (initial weight: 0.929±0.001g; initial shell length: 1.743±0.008cm) in a re-circulated water system for 240 days. The results showed that dietary vitamin C did not significantly influence the weight gain rate (WGR), the daily increment in shell length (DISL) and survival rate both at 120 and 240 days (P>0.05). The content of some kinds of fatty acids in soft body was significantly influenced by dietary vitamin C (PO.05): when juvenile abalone were fed diet deficient in vitamin C, content of fatty acid 14:0, 16:0 and 18:0 increased significantly at 120d (PO.05); content of fatty acids 16:1, 18:ln-9 and 18:2n-6 was significantly higher in treantment of 1 OOmg/kg and 1 OOOOmg/kg than those in treatment of Omg/kg at 120d (PO.05). The content of 14:0 and 16:0 in soft body increased significantly in Omg/kg treatment than the other two at 240d (PO.05), and the content of 18:2n-6 in treatment of lOOmg and 1 OOOOmg/kg was significant higher than that of Omg/kg (PO.05), and the content of fatty acid 22:6n-3 was higher in treantment of 1 OOOOmg/kg than that ofOmg/kg (PO.05). Dietary vitamin C did not significantly influence the content of fatty acid 18:3, 20:4n-6 and 20:5n-3 in soft body at 120d and 240d (PO.05). These results suggest that dietary vitamin C can decrease the level of saturated fatty acid and maintain the level of poly unsaturated fatty acid to prevent lipid peroxidation.(3) A 240-day growth experiment was conducted in a re-circulated water system to investigate the effect of dietary pyridoxine on the protein metabolism in abalone Haliotis discus hannai Ino. Juvenile abalone (initial weight: 0.834±0.002g; initial shell length: 1.668±0.003cm) were fed to satiation with one of 3 semi-purified diets containing 0, 40, 4000 mg pyridoxine kg"1. Results showed that there was an increase trend of the weight gain rate (WGR), the daily increment in shell length (DISL) and the survival rate (SR) of abalone during the 240 days with the increase of pyridoxine in diet, and were significantly higher than that in treatment without pyridoxine supplements (PO.05). The level of PLP increased significantly with the increase of diet pyridoxine (PO.05). The contents of protein in abalone tissues were not significantly affected by different levels of pyridoxine. The activity of alanine aminotransferase(ALT) increased significantly in muscle and viscera. Dietary pyridoxine significantly increased the activity of aspartate aminotransferase(AST) both in viscera and muscle. There were no significant effects of dietary pyridoxine on the contents of amino acid in viscera. The contents of Asp, Thr, Ser and Tau in the muscle of abalone with pyridoxine supplement of 4000 mg/kg were significantly higher than those in the treatments with 0 or 40 mg/kg dietary pyridoxine supplements (P<0.05); The contents of Gly, Ala, Val, Met in the muscle of abalone with pyridoxine supplement were significantly higher than those in the treatments without dietary pyridoxine supplements (P<0.05).(4) A 240-day feeding experiment was conducted to investigate the immune response to dietary pyridoxine of juvenile abalone Haliotis discus hannai Ino. Juvenile abalone(initial weight: 0.834±0.002g; initial shell length: 1.668±0.003cm) were fed to satiation with one of 3 semi-purified diets containing 0, 40, 4000 mg pyridoxine kg"1. The results showed that there was no significant difference between the weight gain rate (WGR), the daily increment in shell length (DISL) and survival rate (SR) at 120d(P>0.05), but as time extended , WGR, DISL and SR were higher in treatments of pyridoxine supplementation ( 40mg/kg and 4000mg/kg ) than that in treatment of Omg/kg at 240d (P<0.05). When juvenile abalone were fed diet deficient in pyridoxine, the activity of acid phosphatase(ACP), lysozyme, glutathione-sulfate-transferase(GST) and catalase(CAT) in viscera was higher compared with treatment of pyridoxine supplementation(40mg/kg and 4000mg/kg ) at 120d(P<0.05); while the activity of enzymes mentioned above in soft body and muscle was higher in treatment of 4000mg/kg than the other two(P<0.05); alkaline phosphate(AKP), phenoloxidase(PO), superoxide dismutase(SOD) activity in muscle significantly increased as dietary vitamin C increased and the activity of these enzymes was higher in treatment of 4000mg/kg than that of the other two at 120d (P<0.05). Dietary pyridoxine(40mg/kg and 4000mg/kg) significantly enhanced glutathione peroxidase(GPX) activity at 120d (PO.05). There was no significant difference of glutathione reductase(GR) activity in viscera and soft body between the three treatments at 120d(P>0.05). ACP, AKP, PO, SOD, GST activity in viscera and PO activity in soft body increased significantly when abalone were fed diet without pyridoxine at 240d; dietary pyridoxine (40mg/kg and 4000mg/kg ) significantly enhanced the activity of ACP, AKP, lysozyme, CAT, SOD, GPX, GST and GR in soft body and muscle at 240d (i><0.05).(5) A feeding experiment was conducted to investigate the the effect of dietary pyridoxine on the lipid metabolism of juvenile abalone Haliotis discus hannai Ino. Three semi-purified diets were formulated to contain 0, 40, 4000mg pyridoxine kg"1. Each diet was fed to three replicate groups of abalone (initial weight: 0.834±0.002g; initial shell length: 1.668±0.003cm) in a re-circulated water system for 240 days. The results showed that there was no significant difference between the weight gain rate(WGR), the daily increment in shell length(DISL) and survival rate(SR) at 120d(.P>0.05), but as time extended, WGR, DISL and SR were higher in treatment of pyridoxine supplementation ( 40mg/kg and 4000mg/kg ) than those in treatment of Omg/kg at 240d (PO.05). The content of lipid in soft body was higher in treatment of 4000mg/kg than the other two(0mg/kg and 40mg/kg) at 120d and 240d(P<0.05). Dietary pyridoxine(40mg/kg and4000mg/kg)significantly decreased the content of fatty acid 18:2n-6 in soft body at 120d, content of fatty acid 14:0, 18:ln-9 and 18:0 was lower in treatment of 40mg/kg than that in the other two(0mg/kg and 4000mg/kg) at 120d CPO.05); while the content of 16:1, 18:3n-3, 20:5n-3, 20:4n-6 and 22:6n-3 was higher in treatment of 40mg/kg than that in the other two at 120d (PO.05). After 240-day feeding, the content of 16:1, 18:ln-9, 18:ln-7 and 18:2n-6 increased significantly in treatment of 40mg/kg(P<0.05); and the content of 16:0, 16:1, 18:ln-9 and 18:2n-6 was significantly lower in treatment of 4000mg/kg than that of 40mg/kg(P<0.05); while content of 20:4n-6 and the value of 22:4n-6/18:2n-6 were higher in treatment of 4000mg/kg than that of 40mg/kg(P<0.05). These results suggest that feeding diet deficient in pyridoxine to abalone will disturb the lipid metabolism , increase the content of saturated fatty acid and decrease the content of unsaturated fatty acids.(6) A 240-day feeding experiment was conducted to investigate the effect of dietary vitamin C on shell compositon of elements and crystals of juvenile abalone Haliotis discus hannai Ino. Juvenile abalone (initial weight: 0.929±0.001g; initial shell length: 1.743±0.008cm) were fed to satiation with one of 3 semi-purified diets containing 0, 100, 10000 mg/kg equivalent ascorbic acid(vitamin C). The results showed that dietary vitamin C can significantly increase the content of Mg and Fe in abalone shell(P<0.05), but didn't significantly influence the content of Ca, Cu, Sr(P>0.05). There was no significant difference of crystal composition in shell between the three treatments (Omg/kg ,100mg/kg and lOOOOmg/kg) (PO.05). AKP activity was significantly higher in viscera, soft body and muscle of abalone fed diet with vitamin C(100mg/kg and lOOOOmg/kg )than that fed diet without vitamin C(P<0.05).(7) A feeding experiment was conducted to investigate the the effect of dietary pyridoxine on shell compositon of elements and crystals of juvenile abalone Haliotis discus hannai Ino. Three semi-purified diets were formulated to contain 0, 40, 4000mg pyridoxine kg"1. Each diet was fed to three replicate groups of abalone (initial weight: 0.834±0.002g; initial shell length: 1.668±0.003cm) in a re-circulated water system for 240 days. The results showed that the contents of Ca, Mg, Fe and Cu in abalone shellincreased significantly as the level of dietary pyridoxine increasedfT^O.OS) while the content of Sr was not significantly influnced by dietary pyridoxine(P>0.05). The ratio of calcite and aragonite was higher in shell of abalone fed diet with pyridoxine (40mg/kg and 4000mg/kg) than that without pyridoxine(0mg/kg)(P<0.05). Dietary pyridoxine significantly enhanced AKP activity in soft body and muscle of abalone(/><0.05).