Protein utilization, hormone treatment and nutrient metabolism as they apply to culture of abalone Haliotis kamtschatkana

• Main Author: Taylor, Barbara Elan
• Format: Others
• Language: English
• Published: 2009
• Online Access: http://hdl.handle.net/2429/8611

Development of formulated diets for use in abalone culture demands knowledge of the animal's nutritional requirements, growth, and metabolism. This thesis addresses some important aspects of these issues with regard to the abalone Haliotis kamtschatkana. Protein requirement was investigated from the standpoint of how protein utilization is affected by dietary protein content, amino acid balance, and protein sparing, together with the possible amelioration of the last through enzymatic adaptation to diet. Focus on protein utilization stems from the fact that protein is a costly dietary ingredient and is an essential nutrient for protein growth. With respect to abalone growth, I assessed the efficacy of administering vertebrate growth hormones which enhance growth in other cultured aquatic animals. I also investigated metabolism of cells isolated from the abalone digestive gland (a primary site of metabolic conversions) from the standpoints of seasonal variation in metabolic activity, and relationships between digestive gland and gonad activity during the reproductive cycle. My data show that optimal utilization of dietary protein in Haliotis kamtschatkana occurs when diets are formulated with about 20 % dry mass of protein, and with carbohydrates, rather than fats, comprising the energy source since enzymatic adaptation to diet does not alter protein-sparing effects. With respect to growth, I found no enhancement from treatment with recombinant bovine or porcine somatotropin, or somatostatin (vertebrate growth hormones). Furthermore, I found that metabolism in these animals is seasonal and possibly inter-related with the competitive needs of reproduction and somatic growth. These findings contribute to the general understanding of abalone biology and provide information useful for culture of abalone. === Science, Faculty of === Zoology, Department of === Graduate