Feedipedia
Animal feed resources information system
Feedipedia
Feedipedia

Fish silage

IMPORTANT INFORMATION: This datasheet is pending revision and updating; its contents are currently derived from FAO's Animal Feed Resources Information System (1991-2002) and from Bo Göhl's Tropical Feeds (1976-1982).

Datasheet

Description
Click on the "Nutritional aspects" tab for recommendations for ruminants, pigs, poultry, rabbits, horses, fish and crustaceans
Common names 

Fish silage, fishery waste

Species 
Description 

The ensiling of fishery waste can be an easy and economical methods of preserving fishery waste, so that it can be fed at a later time. This can be especially useful when only small amounts of fishery waste is available. Production of fish silage is a viable alternative to fish meal, especially in location where small amount of fishery waste or by-catch is produced (Abdullah, 1983). It is well suited for handling small quantities of fish wastes.

Quality of substrate used to prepare the fish silage is directly related to the quality of the resultant fish silage.

Processes 

Several different methods can be used to produce fish silage: 1) adding inorganic or organic acids to lower the pH to a point where it is stable; 2) addition of inorganic or organic acids to lower the pH to a point at which intrinsic enzymes will liquefy (which are normally most active around pH 4 and at temperatures between 35 to 40 o C) the the protein, prior to adding additional acid to stabilize the pH to a level that is suitable for storage); and 3) adding carbohydrates and allow fermentation to occur, so that enough acid is produced to stabilize the silage. Various acid stabilization methods will be described in later sections. The resultant liquefied product can then be screened to remove bones and reduce the ash content. Mold inhibitors are often added to control surface mold growth.

Enzymes present in the fish waste will digest and liquefy the protein associated with the fish waste (Cetinkaya et al., 1995). Organic or inorganic acids can be used lower the pH of the fish silage to a pH that is stable for storage (Cetinkaya et al., 1995). Fish silage was prepared by boiling fishery waste and then adding enzymes to digest the material and then the pH was adjusted by adding acid (Naret, 1996). Acidifying fish silage by adding an equivalent percentage of either H3PO4, formic acid and acetic acid were evaluated, H3PO4 resulted in the lowest pH and lowest NH3-N content in the silage (Jovic et al., 1998). Formic acid resulted in the highest content of NH3-N (Jovic et al., 1998). Formic acid (4%) treated fish silage was found to be superior to acetic or lactic acid preserved silages (Olivo et al., 1998).

Nutritional aspects
Potential constraints 

If silage is prepared from partially decomposed materials then the histamine levels in the fish silage will reflect what was present initially. Histamine levels can be a problem if the fish waste is allow to decompose prior to being ensiling.

Ruminants 

Fish silage fed to sheep has high digestibility for DM, CP and phosphorus (Samuels et al., 1991).

Pigs 

Formic acid was added at the rate of 2.5 % (w/w) to prepare fish silage made from fish waste (heads, guts, remains after deboning) was found to increase growth and feed conversion when compared to fish meal when fed to swine (Treviño et al., 1982). Tilapia fish silage prepared with 4 % formic acid was found to be comparable to imported Peruvian Fish Meal when compared in growing / finishing swine (Olivo et al., 1998).

Poultry 

Broilers

Dried fish silage replaced soybean meal no difference in gain or feed conversion was observed in broilers (Ramlal et al., 1991).

Laying hens

Replacement of 50 % of the fish meal in layer diets was not shown to affect egg flavor or quality (Kuprasert et al., 1987).

Ducks

When fish silage replaced fish meal performance in ducks was reduced, but when the silage was dried its performance was similar (Rahardjo et al., 1984). Thiamine seems to not be present in adequate amounts in fish silage to support normal growth in ducks (Rahardjo et al., 1984). Sun drying of fish silage that has been combined with rice bran or wheat bran were found to be viable options, but deoiling it was a problem (Ganegoda et al., 1982).

Fish 

Fish silage was found to give better growth than fish meal when fed to carp (Djajasewaka, 1986). Nutrient digestibility in fish silage is high (Cetinkaya et al., 1995).

Nutritional tables
Tables of chemical composition and nutritional value 

Avg: average or predicted value; SD: standard deviation; Min: minimum value; Max: maximum value; Nb: number of values (samples) used

IMPORTANT INFORMATION: This datasheet is pending revision and updating; its contents are currently derived from FAO's Animal Feed Resources Information System (1991-2002) and from Bo Göhl's Tropical Feeds (1976-1982).

Main analysis Unit Avg SD Min Max Nb
Dry matter % as fed 26.7 4.5 22.3 33.8 6
Crude protein % DM 56.0 8.7 43.5 69.1 6
Ether extract % DM 30.9 11.5 15.3 44.0 6
Ash % DM 10.3 2.9 6.7 14.0 6
Gross energy MJ/kg DM 25.6 2.8 21.2 26.7 3 *
 
Minerals Unit Avg SD Min Max Nb
Calcium g/kg DM 33.8 30.4 37.1 2
Phosphorus g/kg DM 21.5 19.3 23.6 2
Potassium g/kg DM 12.6 12.2 12.9 2
Sodium g/kg DM 6.6 6.1 7.1 2
Magnesium g/kg DM 1.6 1.6 1.6 2
 
Amino acids Unit Avg SD Min Max Nb
Alanine % protein 8.4 1
Arginine % protein 8.5 1
Aspartic acid % protein 12.4 1
Cystine % protein 1.0 1
Glutamic acid % protein 18.6 1
Glycine % protein 8.4 1
Histidine % protein 2.6 1
Isoleucine % protein 5.6 1
Leucine % protein 9.8 1
Lysine % protein 11.7 1
Methionine % protein 3.1 1
Phenylalanine % protein 4.4 1
Proline % protein 4.8 1
Serine % protein 3.9 1
Threonine % protein 4.5 1
Tyrosine % protein 3.4 1
Valine % protein 5.8 1

The asterisk * indicates that the average value was obtained by an equation.

References

Green et al., 1988; Offer et al., 1987; Tatterson, 1982

Last updated on 24/10/2012 00:44:11

Main analysis Unit Avg SD Min Max Nb
Dry matter % as fed 39.5 16.0 21.1 49.8 3
Crude protein % DM 45.8 22.5 28.2 71.1 3
Ether extract % DM 4.3 1.9 2.4 6.2 3
Ash % DM 13.8 5.3 10.2 19.9 3
Gross energy MJ/kg DM 18.5 *
 
Amino acids Unit Avg SD Min Max Nb
Alanine % protein 8.1 1
Arginine % protein 7.6 1
Aspartic acid % protein 9.9 1
Cystine % protein 0.8 1
Glutamic acid % protein 14.5 1
Glycine % protein 9.1 1
Histidine % protein 2.7 1
Isoleucine % protein 4.2 1
Leucine % protein 6.8 1
Lysine % protein 7.1 1
Methionine % protein 2.7 1
Phenylalanine % protein 3.4 1
Serine % protein 5.5 1
Threonine % protein 4.6 1
Tyrosine % protein 3.1 1
Valine % protein 4.9 1

The asterisk * indicates that the average value was obtained by an equation.

References

Göhl, 1970; Tatterson, 1982

Last updated on 24/10/2012 00:44:12

References
References 
Datasheet citation 

DATASHEET UNDER CONSTRUCTION. DO NOT QUOTE. http://www.feedipedia.org/node/203 Last updated on October 9, 2011, 16:34

Image credits