Survey on the use of natural food and supplemental feed in commercial milkfish farms on Panay, Philippines
Abstract
This study evaluated the feed intake of the milkfish (Chanos chanos Forsskål) in commercial brackishwater ponds under different management regimes. Feed intake and growth were compared between a rather intensive culture management in a fish farm of 1 ha pond size and a semi-intensive one, with a total pond area of 30 ha. The data suggested a direct consumption of only 12 % of the supplemental feed in the intensive farm, leading to a wastage of high quality fish feed and a significantly lower specific and metabolic growth rate (P< 0.001) than in the semi-intensive system without any supplementation and only relying on abundant natural food through fertilization. These results suggest that a heavy reduction in, or even the abandonment of the use of, supplemental feed for milkfish culture would be more cost-effective.
Publisher
Stuttgart UniversitySubject
Type
Conference paperCollections
- Conference Proceedings [283]
Related items
Showing items related by title, author, creator and subject.
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Conference paper
A preliminary study on the purified test diet for young milkfish, Chanos chanos
- In Proceedings of the International Milkfish Workshop Conference, May 19-22, 1976, Tigbauan, Iloilo, Philippines, 1976 - Aquaculture Department, Southeast Asian Fisheries Development CenterIn studying the nutritional requirements of young milkfish experiments were conducted to develop a purified test diet. Mixtures of the purified constituents tested were: vitamin-free casein, vitamin-free gelatin, supplemented with L-tryptophan and L-cystine as the protein sources; shark liver oil and soybean oil as the far sources; and dextrin as the carbohydrate source. Mineral mixture and vitamin mixture were also added. The results showed that a test diet containing vitamin-free casein supplemented with L-tryptophan as the protein source, was best for the growth of young milkfish. Soybean oil was found to be a better source of fat. Vitamin mixture (4%) and mineral mixture (10%) were observed to promote growth in young milkfish. A purified test diet consisting of vitamin-free casein 60%, L-tryptophan 0.5%, soybean oil 10%, vitamin mixture 4%, mineral mixture 10%, carbohydrate and others 16% was thus suggested for young milkfish. -
Book chapter
Ration reduction, integrated multitrophic aquaculture (milkfish-seaweed-sea cucumber) and value-added products to improve incomes and reduce the ecological footprint of milkfish culture in the Philippines
- In Technical Reports: Investigations 2009-2011, 2012 - AquaFish Collaborative Research Support Program, Oregon State UniversityIn the Philippines, cage culture of milkfish in marine environments is increasing. The practice uses high stocking densities, with significantly greater inputs of artificial feeds which more often than not, have led to excessive feeding and consequently excessive nutrient loading in receiving waters, exacerbating problems with pollution. These could have contributed to occurrence of periodic fish kills in areas of marine milkfish culture clusters. In marine cage culture, about 80% of variable expenses are attributable to feed costs. Experiments were conducted to compare production characteristics of milkfish fed on alternate days versus those raised on daily feeding in marine cage culture. Fish were fed either daily or every other day using a reduced feed ration at 7.5% of fish biomass at the start of culture down to 3% of fish biomass towards harvest. We showed this ration level was as effective as the industry standard that begins at a rate of 10% average body weight. Morevover, we had previously found that milkfish reared in brackishwater ponds on an alternate day feeding scheme using the reduced ration level produced a 56% cost savings in feed with little impact on total yield relative to fish raised on a daily feeding protocol. In the present study, survival rates (~ 90%) were comparable between the control fish fed daily and groups fed on alternate days in marine cages. Similarly, total harvested biomass of fish in the alternate day and daily feeding groups was similar as was the harvest value, although fish on the alternate day feeding scheme grew slightly less. The amount of feed and the corresponding cost of feeds consumed were significantly lower in stocks that were fed on alternate days compared with those fed daily (P < 0.05). Feed conversion ratio (FCR) was lower in the alternate-day fed group (FCR = 2.46) relative to stocks fed daily (FCR = 3.59). Overall, the results demonstrate that feed costs can be reduced by around 32% in stocks fed on alternate days, which yields an estimated 20-25% improvement in production efficiency relative to raising animals on a daily feeding protocol. Hence, a significant costs savings with reduced impact of nutrient loading in the environment is likely to be realized for farmers who adopt an alternate day feeding scheme in raising milkfish in marine cages. -
Article
Utilization of mung bean, Vigna radiata (Linnaeus) as a novel protein source in practical-type diets for juvenile milkfish, Chanos chanos (Forsskal): Effects on growth, feed efficiency, body composition, and histology of gut and liver
-The Israeli Journal of Aquaculture-Bamidgeh , 2015 - Society of Israeli Aquaculture and Marine Biotechnology (SIAMB)A 15-week feeding trial was conducted to determine the optimum partial inclusion of mung bean protein in milkfish diet. Six isonitrogenous practical-type diets with mung bean included at 0%, 4%, 8%, 12%, 16%, and 20% of the diet equivalent to 0%, 3%, 7%, 10%, 13%, and 17% of the total dietary protein, respectively, were formulated. Milkfish with average body weight (ABW) of 8.5 ± 0.23g were distributed in eighteen tanks (6 treatments X 3 replications) with 10 fish each. The fish were fed the diets three times daily. Results showed that growth of milkfish was not adversely affected by the inclusion of mung bean protein at any dietary level. Feed conversion ratio (FCR) and protein efficiency ratio (PER) were significantly improved by the inclusion of mung bean at 20% of the diet. Nutrient compositions of the fish carcass were similar in all diets. Furthermore, no detrimental effects attributable to mung bean inclusion were seen in terms of protein retention, hepatosomatic index (HSI), and liver and midgut histology of the fish. Overall, mung bean is a promising protein source for milkfish and can be included up to 20% of the diet contributing as much as 17% of the total dietary protein without detrimental effects on growth, feed performance, PER, protein retention, HSI, and liver and intestinal histology.
