5:15 PM - 6:45 PM
[ACG38-P01] Possibility of using unused marine plant resources as insect feed
Crickets are being actively studied as a new protein source to replace conventional livestock. However, commercial cricket production currently uses poultry feed, which is resource-intensive and competes with human food resources, posing a sustainability challenge. Therefore, it is important to use unused resources as feed that do not compete with other uses, and feeding trials using crop stover, beer yeast, and other agricultural and industrial residues have been conducted extensively in terrestrial areas. On the other hand, the floating seaweeds that have detached from the rocks and macrophytes that have grown abnormally under eutrophic conditions are unutilized resources and become a source of nutrients and carbon emissions and negatively affect the coastal landscape if left unattended. Since the collection and treatment of drifted seagrass requires significant costs, it is necessary to propose a profitable utilization of the collected seagrass to improve its economic sustainability. This study aims to evaluate the feasibility of using unutilized marine resources such as seaweeds and seagrass as feed for crickets based on their growth performance when fed to crickets in comparison with poultry feed.
Zostera marina was used as the seagrass, Ulva spp. as the macroalgae, and Gryllus bimaculatus as the crickets. A forage diet, a single diet of Z. marina and aosa, and a 25% and 50% mixture of Z. marina and aosa with the forage diet were prepared, and experimental plots were created with each diet and 50 juvenile G. bimaculatus were raised within 24 hours of birth. Larval survival and body weight were measured every 7 days, and if adults developed, they were removed each time and the number of days they hatched and adult body weight were recorded. The final growth performance was evaluated using the Yield Per Day (YPD) value, which was obtained by dividing the weight of adults obtained by the number of days of hatching and summing the values for all adults in the experimental area. In addition, the nutritional composition (moisture, crude protein, crude fat, crude fiber, and crude ash) of the chicken feed, green algae, and Z. marina was analyzed to examine the factors contributing to the results obtained in the feeding test.
When compared to a single diet, both Z. marina and Ulva showed significantly lower survival rates and YPD values than poultry diets. The survival rate and YPD were significantly lower in the 50% Ulva feed mixture than in the poultry feed mixture, while there was no significant difference between the other feed mixtures and the poultry feed mixture. Since there was no significant difference in protein content between Z. marina and Ulva, it is possible that differences in protein, fiber and ash content in both samples caused differences in growth performance.
Zostera marina was used as the seagrass, Ulva spp. as the macroalgae, and Gryllus bimaculatus as the crickets. A forage diet, a single diet of Z. marina and aosa, and a 25% and 50% mixture of Z. marina and aosa with the forage diet were prepared, and experimental plots were created with each diet and 50 juvenile G. bimaculatus were raised within 24 hours of birth. Larval survival and body weight were measured every 7 days, and if adults developed, they were removed each time and the number of days they hatched and adult body weight were recorded. The final growth performance was evaluated using the Yield Per Day (YPD) value, which was obtained by dividing the weight of adults obtained by the number of days of hatching and summing the values for all adults in the experimental area. In addition, the nutritional composition (moisture, crude protein, crude fat, crude fiber, and crude ash) of the chicken feed, green algae, and Z. marina was analyzed to examine the factors contributing to the results obtained in the feeding test.
When compared to a single diet, both Z. marina and Ulva showed significantly lower survival rates and YPD values than poultry diets. The survival rate and YPD were significantly lower in the 50% Ulva feed mixture than in the poultry feed mixture, while there was no significant difference between the other feed mixtures and the poultry feed mixture. Since there was no significant difference in protein content between Z. marina and Ulva, it is possible that differences in protein, fiber and ash content in both samples caused differences in growth performance.