| Popis: |
The objective of this research was to develop a quality fish feed that could be produced from simple plant material by way of microbial processing. Silaged grass clippings, applied to shallow ponds, produced floating mats of microbial biomass containing 26% protein and 43% carbohydrate in 7–10 days. The final silage-microbe mat (SMM) showed increases of over 300% in biomass and 100% in protein content over the silage feedstock. Productivity and microbial succession patterns were similar in laboratory ponds and tropical field ponds located in the Dominican Republic. In laboratory experiments SMM-fed tilapia, Oreochromis niloticus, showed significant growth increases over controls (fed commercial catfish fish feed), if they were allowed to graze the SMM together with the gelatinous detrital deposited during SMM culture. SMM produced little fish growth if it was harvested and fed separately in clean-bottom ponds without detrital buildup. These data show that the microbial mat produced from processed grass clippings can produce a nutritious natural fish food in the pond. The detrital trophic level in the sediment (stimulated by SMM culture), is a critical component in this diet. |
