Preliminary Study of Using High Level of Ulva Meal as a Feed Ingredient for Nursery Stage of Cultured Golden Rabbitfish, Siganus guttatus Asda Laining (a*), SRH Mulyaningrum (a), MC Undu (b), Lideman (c), Ramadhan (a)
(a) Research Institute for Coastal Aquaculture and Fisheries Extension, Ministry of Marine Affairs and Fisheries, Jl. Makmur Dg. Sitakka No.129, Maros 90512, South Sulawesi, Indonesia
*asdalaining[at]yahoo.com
(b) Polytechnic of Marine and Fisheries of Jembrana, Ministry of Marine Affairs and Fisheries, Desa Pengambengan, Kecamatan Negara, Kabupaten Jembrana, Bali, Indonesia
(c) Brackishwater Aquaculture Development Center, Ministry of Marine Affairs and Fisheries, Kecamatan Galesong Selatan, Kabupaten Takalar, South Sulawesi, Indonesia
Abstract
A 15-weeks feeding trial was conducted to evaluate the effect of utilizing a high level of seaweed Ulva meal as a dietary feed ingredient for the nursery stage of cultured golden rabbitfish, Siganus guttatus on the growth and biochemical composition of the fish body. Two tested diets as the treatment were evaluated with four replicates. One diet was formulated with a high level of Ulva meal at a rate of 30% combined with a high level of soybean as the protein source whilst another diet used fish meal as the major protein source (FP). Cultured rabbitfish (3rd generation) with a mean initial body weight of 5.4 g and length of 6.3 cm were stocked into 8 of 120 L fiberglass tanks with a density of 20 fishes per tank. Fish were fed to satiation 4 times a day at 0700, 1000, 1300, and 1600. Sampling to monitor the fish growth was performed every 3 weeks for 15 weeks. The growth rate showed a linear pattern in both FP and PP diets. Fish fed the PP diet grew faster than those fed with FP diet. Weight gain of fish fed PP diet was 453% higher compared to those fed with FM (343%). A similar trend was observed on SGR where fish fed the PP diet had a higher SGR of 1.40 %/d compared to the PF diet (1.22%/d). Feed consumption of fish fed the PP diet tended to be higher approximately 49.8 g than fish fed FP diet (30.7 g) further resulting in a lower FCR of the FM diet at the rate of 1.3 compared to 1.6 for the PP diet. Survival of the fish fed FP and PP diets were 92.5 and 100%, respectively. Fish fed the FM diet contained a higher ash content compared to those fed with the PP diet (14.9 vs 10.1%). In contrast, fish fed the PP diet had a slightly higher fiber content of 8.5% compared to the FP diet (7.6%). Inclusion of Ulva meal at 30% combined with a high level of soybean meal as a protein source in a low fishmeal diet produced better growth performances of rabbitfish during the nursery stage in floating pond cages.
Keywords: low fishmeal diet, high plant-supplemented diet, herbivorous, seaweed
