Free amino acid content in three species of earthworms, cosmopolitan tiger worms, Eisenia foetida, African earthworms, Eudrilus eugeniae, and Indian blue worms, Perionyx excavatus, are studied by Reinecke et al. (1991). Leucine and arginine are most abundant among essential amino acids in all three species. Crude protein content are 66,13 % in E. foetida, 58,38 % in E. eugeniae, 61,63 % in P. excavatus and 61,00 % in fishmeal, for comparison. The amino acid profile in four species of earthworms namely E. eugeniae, Hyperiodrilus africanus, Alma millsoni and Libyodrilus violaceus, in comparison with E. foetida, is studied by Dedeke et al. (2010). Arginine is most abundant in four African species and one of the abundant essential amino acids (after leucine and lysine) in E. foetida. Glutamic and aspartic acids, among non-essential amino acids, are most abundant than arginine and leucine in all five species, achieving 16,4 g per100g crude protein in E. foetida.

Lysine and methionine, that are limited amino acids in most feedstuffs, are present in all species of earthworms (Dedeke et al., 2010).

Earthworm Meal

Earthworm meal (Lumbricus rubellus) has become one of the natural materials that can be used as feed additive. The study of Istiqomah et al. (2009) is carried out (1) to evaluate the amino acid profile of earthworm and earthworm meal, (2) to calculate the value of essential amino acid index of both materials. It is shown that essential amino acid of earthworm is dominated by histidine (0,63 % of dry matter basis), meanwhile the earthworm meal is dominated by isoleucine (1,98 %). The non-essential amino acid of earthworm and earthworm meal is dominated by glutamic acid (1,52 % and 3,60 % of dry matter basis, respectively). The value of essential amino acid index obtained from earthworm meal is higher (58,67,%) than those from earthworm (21,23 %). It is concluded that powdering method of earthworm by using formic acid addition has higher amino acid balance than earthworm.

According to data by Istiqomah et al. (2009) and other authors, earthworm meal of L. rubellus contains 65,63 % crude protein, earthworm meal of L. terestris contains 32,60 % crude protein, earthworm meal of P. excavatus contains 57,20 % crude protein and have complete amino acids. Dynes (2003) gives the similar results on crude protein in earthworm meal of Eisenia andrei and E. foetida.

Silage

Earthworms (E. foetida and L. rubellus) have been ensiled with sorghum and molasses in the following proportions: 1) 60% earthworms, 40% sorghum; 2) 60% earthworms, 40% sorghum, adjusting pH to 4,0 with HCl; 3) 60% earthworms, 20% sorghum, 20% molasses; 4) 60% earthworms, 20% sorghum, 20% molasses, adjusting pH to 4,0 with HCl (Ortega Cerrilla et al., 1996). These four mixtures have been allowed to ferment for 15 days at 18^o C. No essential differences are in the percentage of moisture, ether extract, crude fiber and crude protein for treatments 1, 2, 3 and 4, respectively, hence Ortega Cerrilla et al. (1996) conclude that it is possible to preserve earthworms E. foetida and L. rubellus by ensiling, adding carbohydrates like sorghum or molasses, and that an addition of acids to have an adequate fermentation is optional.

Vermicomposts

Basically, vermicomposts contains cow, horse and other manure, agricultural waste, tree leaves and other vegetable byproducts, processed by earthworms, together with the earthworms themselves. Vermicomposts are effectively used in aquaculture where they play dual role (e.g., Chakrabarty et al., 2010; Rafael et al., 2012; Sutar et al., 2012). Firstly, particles of vermicomposts are eaten by fish. Secondly, vermicomposts fertilize the nursery ponds increasing the forage base of juvenile fish due to the intensive development of phytoplankton and zooplankton.

In additon, vermicomposts can be used together with unfermented or fermented agricultural byproducts such as straw, grain chaff, brans and more. For example, it is shown in experiments with the fingerlings of Nile tilapia (Oreochromis niloticus) (Rafael et al., 2012) that combinations of fermented rice bran and vermicompost (20-25 %) (processed by E. eugeniae) give the better growth of fish in comparison with feeding with unfermented rice bran only or fermented rice bran alone.

Basic References

Chakrabarty D., Das S.K., Das M.K., Bag M.P. 2010. Assessment of vermicompost as direct application manure in fish farming ponds. Turkish Journal of Fisheries and Aquatic Sciences 10, 47-52

Dedeke G.A., Owa S.O., Olurin K.B. 2010. Amino acid profile of four earthworms species from Nigeria. Agriculture ans Biology Journal of North America 1, 97-102

Dynes, R. A., 2003. Earthworms: technology information to enable the development of earthworm production. Australian Government, Rural Industries Research and Development Corporation Publication No. 03-085, Canberra

Istiqomah L., Sofyan A., Damayanti E., Julendra H. 2009. Amino acid profile of earthworm and earthworm meal (Lumbricus rubellus) for animal feedstuff. Journal of the Indonesian Tropical Animal Agriculture 34, 253-257

Ortega Cerrilla M.E, Reyes Ortigoza A.L, Mendoza Martínez G. 1996. Chemical composition of earthworm (Eisenia fetida and Lumbricus rubellus) silages. Archivos Latinoamericanos de Nutrición 46, 325-328

Rafael D., Guerrero III, Guerrero L.A. 2012. The use of fermented rice bran and vermicompost as supplemental feeds for Nile tilapia (Oreochromis niloticus) fingerlings in aquaria. Journal of Recent Trends in Biosciences, India 2, 1-2

Reinecke A.J., Hayes J.P., Cilliers S.C. 1991. Protein quality of three different species of earthrvorms. South African Journal of Animal Science 21, 99-193

Sutar V.B., Chavan B.R., Bonde V.R., Balamani C.H. 2012. Efficacy of farm yard manure and vermicompost on growth and servival of Catla catla, Labeo rochita and Macrobrachium rosenbergii in rearing pond. DAV International Journal of Science 1, 128-131