Dietary zinc and calcium requirements of channel catfish fry and effects of zinc and calcium on immunocompetence /
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| Other Authors: | , , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1989.
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| Subjects: | |
| Online Access: | Link to OAKTrust copy |
| Abstract: | The paucity of information regarding the specific nutrient requirements of channel catfish, Ictalurus punctatus, for growth and the effects of these nutrients upon immune functions may be hindering the productivity of catfish aqua-culture. Therefore, minimum dietary zinc (Zn) and calcium (Ca) requirements for growth of channel catfish fry were determined. Purified egg-white diets containing 0, 20, 40 or 80 mg Zn/kg diet and 0, 0.5, 1.0 or 2.0% calcium were fed to swim-up fry in soft (<1 mg/L as CaCO₃) and hard (>100 mg/L as CaCO₃) water for six to eight weeks. Growth, whole-body has, zinc and calcium content, survival, mortality due to handling stress and spinal deformities were determined. The minimum dietary zinc requirement for channel catfish fry grown in hard water was determined to be 20 mg Zn/kg diet; whereas, fry grown in soft water had a requirement higher than 20 but less than 40 mg Zn/kg diet. The minimum dietary calcium requirement for fry grown in hard water was determined to be 0.5%; whereas, fry grown in soft water had a requirement higher than 0.5% but less than 1.0%. Calcium derived solely from dietary or environmental sources was not sufficient for optimum growth and health of fry. Catfish grown in soft water had reduced whole-body ash, whole-body calcium and survival.The effects of Zn and Ca upon immunocompetence of channel catfish fingerlings were determined after feeding fish purified egg-white diets without supplemental zinc, calcium or both, as well as diets with each mineral supplemented at established and in excess of requirement levels for ten weeks. Immunocompetence of fish on the various diets was determined by measuring the difference between basal and antigen-stimulated serum immunoglobulin M levels, whole-blood neutrophil count and survival of immunized and non-immunized fish after an LD₅₀ injection of live Aeromonas hydrophila. Nutritional parameters indicated that various degrees of Zn and Ca nutritional status existed when immune functions were tested. Diet affected resistance of non-immunized fish to the bacterial LD₅₀ injection; zinc deficiency and calcium excess improved resistance. No other measured parameter was affected by diet. |
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| Item Description: | Typescript (photocopy). Vita. "Major subject: Wildlife and fisheries sciences." |
| Physical Description: | xi, 80 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references. |