HK1002425B - Long-life feedstuff for aquatic animals - Google Patents

Description

The invention relates to a long-term freshwater and seawater stable feed for aquatic animals, in particular fish, shrimp and invertebrates, which can also be used as a weekend holiday feed for ornamental fish.

The Commission has already taken a number of steps to ensure that the Community's fisheries policy is implemented in a way which is compatible with the objectives of the common fisheries policy and with the objectives of the common fisheries policy.

DE 19 58 253 is known to incorporate conventional fish feed basic mixtures into a gel of a hydrocolloid such as gelatine or agar agar. This gel or foam gel can be fed directly or dried for longer storage. However, comparative tests have shown that such a feed has an open porous surface and does not meet the requirements of a holiday feed, since it decomposes after only a few hours in water.

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The purpose of the invention is therefore to provide an industrially manufactured, durable, long-term feed for aquatic animals, in particular fish, shrimp and invertebrates, usable in fresh and marine water, which provides a continuous supply of nutrients for a prolonged period of time, particularly for warm and cold water fish in aquarium water during the weekend and holiday seasons, without using any additives not authorised by law in all places, but without compromising the quality of the aquarium water by other additives.

Surprisingly, it has now been found that the use of vegetable gum, preferably agar-agar, avoids the use of cement, calcium sulphate and/or latex and that these feed preparations even have significantly improved additional properties compared to the feed described in DE 37 07 032.

The subject of the invention is therefore a long-term stable, insoluble, soluble and non-water-chemically stressful extruded long-term feed for aquatic animals, in particular fish, shrimp and invertebrates in fresh and marine waters, also suitable as a weekend and holiday feed for warm and cold-water fish in fresh and marine waters, which has a smooth surface, a residual moisture content of 1 - 20% and contains 1 - 50% agar.

The novel long-life feed for ornamental fish is characterised by the elimination of natural rubber and cement, the use of feed additives compliant with feed law, the production using optimized extrusion parameters, increased production performance, improved optical and physical properties, increased water resistance and reduced water stress.

In addition, a reduction in the moisture content of the feedingstuffs of the invention has other positive properties in terms of water resistance and, in particular, binding properties.

The formula of the long-term feed is composed of many different raw materials. Favorable for the water stability of the sticks as well as the permanent cohesion of the particles are plant gum, preferably Agar Agar, a gelling agent made from seaweed, belonging to the group of hydrocolloids. Agar is a dried, hydrophilic colloidal substance made of giant molecules that have a linear, thread-like structure and are mainly made of galactose.

The long-life feed of the invention is conveniently prepared by means of a cooking extruder from the usual feed premixtures and vegetable gum and, where appropriate, from the usual vitamins, minerals, colours, flavourings, attractants and preservatives.

Preferably a feed mixture of 15 to 35% bolus alba, 15 to 35% wheat glue, 5 to 25% alfalfa flour, 5 to 20% casein, 5 to 20% krill, 1 to 10% soya oil, 1 to 10% milk protein, 1 to 10% agar and, where appropriate, vitamin and mineral mixtures, common colours and/or flavourings and preservatives, by means of a double-slotted cooking extruder at a slotted rate of 50 to 300 rpm and a temperature in the medium intake range of 40 to 160°C and in the nozzle of 40 to 180°C, with the addition of 10 to 50 l of water and/or 1 to 30 D of agar per hour, at a flow rate of 80 kg/500 kg/50 kg.In particular, a mixture of 22.2% bolus alba, 22.0% wheat glue, 14.5% alfalfa flour, 12.1% casein, 9.7% krill, 4.8% soya oil, 4.0% milk protein and 2.9% agar agar is preferably used, which is extruded, where appropriate, with vitamin and mineral mixtures, common colours and/or flavourings and/or attractants and/or preservatives at an extrusion rate of 100 revolutions/minute and a temperature in the 80°C extraction range and 85°C in the nozzle head, with the addition of 31 litres of water per hour to 20-25 mm long stick extrudate with a diameter of 6-8 mm.

The analytical composition of the long-life feed according to the invention is 20 - 60% crude protein, 2 - 20% crude fat, 20 - 40% crude ash and 10 - 30% HCl insoluble ash at a moisture content of 1 - 20%. In the preferred form, the feed contains 38% protein, 6% crude fat, 32% crude ash and 17% HCl insoluble ash at a residual moisture content of 3%.

The most common preservatives are ethoxyquin, calcium propionate or citric acid.

The resulting feed sticks are uniformly shaped compared to the known feedingstuff, have a smooth surface and good interfaces, i.e. the visual appearance is significantly improved, and they are very well waterproof and show no melting on the surface of the water surface even after a longer stay, unlike known feedingstuff. When introduced into the water, the feed immediately softens and boils to about twice the size, but retains its geometrical shape and does not break down. The known feedingstuff 07 37 032 DE is not broken down in its geometric form, but then decomposes in a relatively small but stable manner after a relatively short time in water.

When feeding the sticks according to the invention, the water content in the aquarium is significantly lower than in the known recipes. No increased ammonium levels are measurable and nitrite levels are greatly reduced. With an average fish population of 18 fish in a 30 l aquarium, according to the usual feeding tests, 1-2 sticks according to the invention are sufficient for about a week. With a biologically correct active filter system with foam cartridges, these feeding tests achieved only 0,2 mg/l nitrite and 0,05 mg/l ammonia as maximum concentrations of pollutants. This results in a concentration of 0,5 mg/l nitrite and 0,2 mg/l ammonia in comparison with the feeding according to 37 0732 DE 0 0 holidays.

The feedingstuffs of the invention are relatively large in relation to the relatively small ornamental fish. The feedingstuff offered cannot therefore be eaten whole, but the fish bites off small pieces of it as required. This makes it possible to stock up on feedingstuffs for several days in the aquarium. Due to this special method of partial feeding, the feedingstuff must immediately become soft and spring up in the water, but must not decompose.

Claims (6)

1. A feed for aquatic animals, especially for fish, shrimps and invertebrates, which feed is stable for a long time, is insoluble, swellable and does not load the water chemistry in fresh and sea water and can also be used as a weekend or holiday feed for warm and cold water ornamental fish, characterized in that it has a smooth surface and contains 1 - 50% by weight of agar-agar by a moisture content of 1 - 20% by weight.
2. Feed according to claim 1, charcterized in that it contains 1 - 10% by weight of agar-agar.
3. Feed according to claim 1 or 2, it contains 2.9% by weight of agar-agar by a moisture content of 3% by weight.
4. Process for the production of a fish feed according to claims 1 to 3, wherein a mixture of 15 to 35% by weight of bolus alba, 15 to 35% by weight wheat gum, 5 to 25% by weight lucerne green flour, 5 to 20% by weight casein, 5 to 20% by weight krill, 1 to 10% by weight soya oil, 1 to 10% by weight milk protein, 1 to 10% by weight agar-agar and vitamin and mineral material pre-mixtures, conventional colouring materials and/or aroma and luring materials and preserving agents is extruded with the use of a twin-screw boiling extruder at an extruder screw speed of rotation of 50 to 300 r.p.m. and at a temperature in the meal introduction region of 40 to 160°C and in the nozzle head of 40 to 180°C with the addition of 10 to 50 litres of water and/or of 1 to 30 kg of steam per hour at a throughput capacity of 80 to 1500 kg/hour to give extrudates of 5 to 50 mm length, with a stick diameter of 2 to 20 mm and a moisture content of 1 - 20% by weight.
5. Process for the production of fish feed according to claim 7, wherein a mixture of 22.2% by weight bolus alba, 22.0% by weight wheat gum, 14.5% by weight lucerne green meal, 12.1% by weight casein, 9.7% by weight krill, 4.8% by weight soya oil, 4.0% by weight milk protein, 2.9% by weight agar-agar and vitamin and mineral material pre-mixtures, conventional colouring materials and/or aroma or luring materials and/or preserving agents is extruded with the help of a twin-screw boiling extruder at an extruder screw speed of rotation of 100 r.p.m. and at a temperature in the meal introduction region of 80°C and in the nozzle head of 85°C with the addition of 31 litres of water per hour to give extrudates of 20 to 24 mm length, with a stick diameter of 6 to 8 mm and a moisture content of 3% by weight.
6. The use of a feed according to any of claims 1 to 5 as weekend and holiday feed for cold and warm water fish in fresh and sea water which feed is stable for a long period of tine.