Increasing Thai Catfish's Immunity (Pangasius hypophthalmus Fowler) Using Ascorbic Acid

<p>ABSTRACT</p><p>An experiment to determine Thai catfish's (Pangasius hypophthalmus Fowler) immunity was carried out using different levels of ascorbic acid (0, 1.000, 2.000 and 3.000 mg/kg feed). Fish of 15-20 g in weight were kept in aquaria for 6 weeks with density of 15 fish/aquaria. Feed was given at 5-10 % of total biomass with frequency of three times a day. The blood sampling was taken every week and the challenge test with Aeromonas hydrophila (106cells/mm3) injection intramuscular was done on the 30th day. The result of this experiment shown that feed with ascorbic acid of 2.000 mg/kg was elevated the cellular responses such as: leucocyte total (34.850 cels/mm3), differential of leucocyte (lymphocyte: 72,2%, monocyte: 8,0%, neutrophyl: 7,8%), phagocytic index (13%) and humoral response (titre antibody: 0.829 serum aglutination unit), which at the same time proves high level of survival rate against the artificial injection using A. hydrophila. Key words : Ascorbic acid, fish immunity, Thai catfish, Pangasius hypophthalmus. ABSTRAK Suatu penelitian telah dilakukan di laboratorium dengan menggunakan ikan jambal Siam (Pangasius hypophthalmus Fowler) untuk melihat tingkat kekebalan ikan dengan menambahkan vitamin C pada pakan (0, 1.000, 2.000 dan 3.000 mg/kg pakan). Ikan jambal Siam ukuran 15-20 g dipelihara dalam aquarium selama 6 minggu dengan kepadatan 15 ekor/wadah. Pemberian pakan dilakukan 3 kali sehari sebanyak 5-10% dari bobot biomasa, pengambilan contoh darah dilakukan setiap minggu dan uji tantang dilakukan pada hari ke-30 dengan bakteri Aeromonas hydrophila (106 sel/mm3) secara intramuskular. Hasil penelitian menunjukkan bahwa penambahan vitamin C sebanyak 2.000 mg/kg pakan menyebabkan meningkatnya respon seluler antara lain: total lekosit (34.850 sel/mm3), jenis lekosit (limfosit: 72,2%, monosit: 8,0%, netrofil: 7,7% dan trombosit: 17,6%) indeks fagositik 13% dan respon humoral (titer antibodi: 0,829 unit serum aglutinasi). Kelangsungan hidup ikan jambal Siam dengan respon seluler demikian mencapai 100%. Kata kunci : Vitamin C, imunitas ikan, ikan jambal Siam, Pangasius hypophthalmus.</p>

Concentrations of vitamin C in milk of sows and in plasma of piglets

Colostrum or milk samples from 10 sows and blood plasma samples from 68 piglets were taken between 0 and 28 d after farrowing and analyzed for ascorbic acid and dehydroascorbic acid by high-performance liquid chromatography with electro-chemical detector. Ascorbic acid content of colostrum (265.0 μm mL−1) was more than twice that of subsequently produced milk (100.0 μg mL−1) at 7 d of age. Ascorbic acid content of blood plasma of piglets at birth after uptake of colostrum was 13.1 μg mL−1, which slowly declined during the first 28 d of age to 3.2 μg mL−1. The dehydroascorbic acid concentration in the plasma of piglets ranged from 3.0 μg mL−1 to 3.9 μg mL−1from 7 d to 28 d of age. There was a significant positive correlation between piglet plasma ascorbic acid and maternal milk ascorbic acid concentration. Key words: Ascorbic acid, dehydroascorbic acid, colostrum

Effect of Graded Levels of Supplemental Ascorbic Acid in Practical Diets Fed to Rainbow Trout (Salmo gairdneri)

Deficiency symptoms, including anorexia, lethargy, lying prostrate at the bottom of the tank, scoliosis, and lordosis, were noted 20 wk after the start of the experiment in rainbow trout (Salmo gairdneri) held at 15 °C and fed a diet with no supplemental ascorbic acid. The apparent requirement was 40 mg/kg of supplemental ascorbic acid; however, the amount added to trout diets should be in excess of this level due to processing and storage losses and other factors. The ascorbic acid requirement for rainbow trout appears to vary with the age and rate of growth of the trout in that the requirement is higher in young fish. Ascorbic acid was noted to function in the iron metabolism of rainbow trout. Liver and spleen iron levels were correlated with the ascorbic acid level in the diet and suggest either a redistribution of iron stores due to impaired release of iron from reticuloendothelial stores or an increase in the efficiency of intestinal iron absorption. Scorbutic trout developed a gradual but progressive anemia. Key words: ascorbic acid, rainbow trout, vitamin requirement, iron, mineral metabolism, anemia

Evaluation of the Ascorbic Acid Status of Rainbow Trout (Salmo gairdneri)

Due to the instability of supplemental ascorbic acid in practical trout diets and the increased metabolism of this vitamin in trout ingesting enviromental toxicants, a method of assessing the adequacy of dietary ascorbic acid and the ascorbic acid status of the trout is required. Two groups of trout grown on ascorbic acid deficient diets produced deficiency symptoms within 16–20 wk. Liver ascorbic acid concentrations in the two groups declined to levels below 20 μg/g when deficiency symptoms appeared. Groups of trout grown on diets containing supplemental ascorbic acid to provide near or in excess of the National Research Council–National Academy of Science requirement for this vitamin after processing showed substantially higher liver ascorbic acid concentrations than the deficient fish. This indicates that the liver ascorbic acid concentration can be used as an index of the ascorbic acid status of the trout and that levels 20 μg/g or lower are marginal and immediate supplementation is required. Key words: ascorbic acid, rainbow trout, nutritional requirements