Method for raising animals

Abstract

According to the invention, it was found that a feedstuff containing an Aurantiochytrium biomass brings about a significant increase in growth in fish.

Claims

1. A fish feedstuff comprising an Aurantiochytrium or Schizochytrium biomass in an amount of 7 to 20% by weight of the feedstuff, fish oil in an amount of 4 to 11% by weight of the feedstuff and fish meal in an amount of 5 to 25% by weight of the feedstuff, wherein, when fish are fed a diet of said feedstuff, the fish exhibit an increase in body weight and growth.

2. The feedstuff of claim 1, wherein the biomass comprises cells from the species Aurantiochytrium limacinum.

3. The feedstuff of claim 2, wherein the cells are from the strain Aurantiochytrium limacinum SR21.

4. The feedstuff of claim 1, wherein said feedstuff has a total protein content of 40 to 50% by weight of the feedstuff and a total fat content of 22 to 28% by weight of the feedstuff.

5. The feedstuff of claim 1, wherein said feedstuff contains omega-3 fatty acids in a total amount of 2.0 to 4.0% by weight of the feedstuff.

6. The feedstuff of claim 5, wherein said fish meal is present in an amount of 10-20% by weight of the feedstuff.

7. The feedstuff of claim 1, wherein said fish meal is present in an amount of 12-18% by weight of the feedstuff.

8. The feedstuff of claim 1, wherein said fish oil is present in an amount of 4 to 8% by weight of the feedstuff.

9. The feedstuff of claim 1, wherein said fish oil is present in an amount of 4 to 6% by weight of the feedstuff.

10. The feedstuff of claim 7, wherein said fish oil is present in an amount of 4 to 6% by weight of the feedstuff.

11. The feedstuff of claim 9, wherein the biomass is present at 7-11% by weight of the feedstuff.

12. The feedstuff of claim 1, wherein the biomass is present at 7-11% by weight of the feedstuff.

13. The feedstuff of claim 1, wherein: a) said biomass is present at 7-11% by weight of the feedstuff; b) said fish meal is present in an amount of 10-20% by weight of the feedstuff; c) said fish oil is present in an amount of 4 to 8% by weight of the feedstuff.

14. The feedstuff of claim 13, wherein said feedstuff has a total protein content of 40 to 50% by weight of the feedstuff, a total fat content of 22 to 28% by weight of the feedstuff and a total omega-3 fatty acid content of 2.0 to 4.0% by weight of the feedstuff.

15. A method for farming fish, comprising feeding said fish the feedstuff of claim 1.

16. The method of claim 15, wherein the feedstuff has a total protein content of 40 to 50% by weight of the feedstuff and a total fat content of 22 to 28% by weight of the feedstuff.

17. The method of claim 15, wherein the feedstuff contains omega-3 fatty acids in a total amount of 2.0 to 4.0% by weight of the feedstuff.

18. The method of claim 15, wherein the feedstuff comprises: a) 7-11% biomass by weight of the feedstuff; b) 10-20% fish meal by weight of the feedstuff; c) 4 to 8% fish oil by weight of the feedstuff.

19. The method of claim 15, wherein the increase in body weight and growth exhibited by fish when fed a diet of the feedstuff is greater than when the fish are fed a diet of the feedstuff which comprises said fish oil but not Aurantiochytrium or Schizochytrium biomass or which comprises said Aurantiochytrium or Schizochytrium biomass but not said fish oil, and wherein these feedstuffs all have the same fat content.

Description

WORKING EXAMPLES

Example 1

Producing the Biomass

Example 1

Producing Biomass by Fermentation of Aurantiochytrium limacinum SR21 in a Medium Having a High Sulphate Content and Subsequent Drying of the Biomass

(1) The cells were cultured for about 75 h in a feed process using a steel fermenter having a fermenter volume of 2 litres with a total starting mass of 712 g and an attained total final mass of 1.3-1.5 kg. During the process, a glucose solution (570 g/kg glucose) was metered in (fed-batch process)

(2) The composition of the starting medium was as follows:

(3) Medium 1:20 g/kg glucose; 4 g/kg yeast extract; 16 g/kg sodium sulphate; 2 g/kg ammonium sulphate; 2.46 g/kg magnesium sulphate (heptahydrate); 0.45 g/kg potassium chloride; 4.5 g/kg potassium dihydrogen phosphate; 0.1 g/kg thiamine (HCl); 5 g/kg trace element solution.

(4) The composition of the trace element solution was as follows: 35 g/kg hydrochloric acid (37%); 1.86 g/kg manganese chloride (tetrahydrate); 1.82 g/kg zinc sulphate (heptahydrate); 0.818 g/kg sodium EDTA; 0.29 g/kg boric acid; 0.24 g/kg sodium molybdate (dihydrate); 4.58 g/kg calcium chloride (dihydrate); 17.33 g/kg iron sulphate (heptahydrate); 0.15 g/kg copper chloride (dihydrate).

(5) Culturing was carried out under the following conditions: Culture temperature 28° C.; aeration rate 0.5 vvm, stirrer speed 600-1950 rpm, control of pH in the growth phase at 4.5 using ammonia water (25% v/v).

(6) After the culturing process, the fermentation broths were heated to 60° C. for 20 minutes in order to prevent further cellular activity.

(7) This was followed by a two-stage drying of the biomass: Firstly, the fermentation broth was concentrated by evaporation to a dry mass of about 20% by weight. This was followed by spray drying of the concentrated fermentation broth using a Production Minor™ spray dryer (GEA NIRO) at a drying air inlet temperature of 340° C. By means of spray drying, a powder having a dry mass of more than 95% by weight was thus obtained.

(8) The sulphate content of the biomass obtained was determined by determining the sulphur content of the biomass in accordance with DIN ISO 11885. To this end, an aliquot of the biomass was firstly disrupted under pressure at 240° C. with nitric acid and hydrogen peroxide. The sulphur content ascertained was 11 g/kg of biomass, corresponding to a sulphate content of 33 g/kg of biomass.

Example 2

Producing the Feedstuff

(9) Feedstuffs each containing 42.5% by weight of total protein and 24% by weight of total lipid, based on the dry mass, and having a pellet size of 3 mm were produced by extrusion.

(10) Three different feedstuff formulations in total were produced (Diet 1, 2 and 3). The control formulation “Diet 1” contained 11.0% by weight of fish oil. In the formulation “Diet 2”, the fish oil was partly (about 50%) replaced by Aurantiochytrium biomass, this being done by adding 9.1% by weight of biomass and, for that reason, reducing the amount of fish oil to 5.5% by weight. In the formulation “Diet 3”, the fish oil was completely replaced by Aurantiochytrium biomass, this being done by adding 16% by weight of biomass and, at the same time, increasing the amount of rape oil from 8.2% to 9.9% by weight. Differences in the total weight were balanced out by the amount of wheat added.

(11) The individual components of the feedstuff are shown in the table below.

(12) TABLE-US-00001 TABLE 1 Formulations used for farming Components (g kg.sup.−1) Diet 1 Diet 2 Diet 3 Aurantiochytrium biomass 0.0 91.6 160.0 SPC 229.0 229.0 229.0 Fish meal 150.0 150.0 150.0 Wheat 147.6 111.0 80.5 Fish oil 110.0 55.0 0.0 Wheat gluten 100.0 100.0 100.0 Pea protein concentrate 100.0 100.0 100.0 Rape oil 82.0 82.0 99.1 Monosodium phosphate 20.0 20.0 20.0 Vitamin mixture 20.0 20.0 20.0 Soya lecithin 10.0 10.0 10.0 L-Lysine (50% by weight) 10.0 10.0 10.0 Betafine 9.4 9.4 9.4 Mineral mixture 5.2 5.2 5.2 L-Histidine (98% by 4.2 4.2 4.2 weight) DL-Methionine (99% by 2.0 2.0 2.0 weight) Carop. Pink (10% by 0.50 0.50 0.50 weight) Yttrium oxide 0.10 0.10 0.10

(13) The individual components were—with the exception of the oils—mixed intimately with each other and then an extrudate was produced using a twin-screw extruder (Wenger TX 52, Wenger, USA) through use of an outlet nozzle having a diameter of 2 mm. The extrudates were dried for about 1 hour in a carousel dryer (Paul Klöckner, Verfahrenstechnik GmbH, Germany) at 65° C. to a water content of 7 to 8% by weight. The extrudates were then dried overnight at room temperature before the oils were applied by vacuum coating (Dinnissen, Sevenum, the Netherlands).

Example 3

Feeding Experiments

(14) The feeding experiments were carried out by feeding each of these formulations for a total of 12 weeks to each of three tanks containing smolts having a mean weight of 83.6 g and a total salmon weight of 4 kg per tank.

(15) Over this period, the total salmon weight per tank increased from 4 kg to 15-17 kg per tank. In this connection, the fish consumed 8 to 11 kg of feed per tank, corresponding to a feed conversion rate (FCR) of 0.8 to 0.9 kg of feed per kg of fish.

(16) The results of the feeding experiments are shown in the table below.

(17) TABLE-US-00002 TABLE 2 Diet-dependent fish weight gain Diet Final weight [g] 1 331 2 362 3 339

(18) Altogether, it was established that it was possible to achieve an increase in salmon growth both in the case of complete and in the case of partial replacement of the fish oil by the Aurantiochytrium biomass.

(19) Interestingly, partial replacement of the fish oil by the Aurantiochytrium biomass achieved a higher salmon growth than complete replacement by the Aurantiochytrium biomass.

(20) In this connection, it was established that the fish fed with the control formulation Diet 1, having a mean final weight of 331 g, had a distinctly lower final weight than the fish fed with the formulations Diet 1 or 2. In this connection, the fish fed with the formulation Diet 2 performed the best: they achieved a distinctly increased mean final weight of 362 g.

Example 4

Fatty Acid Utilization by the Fish

(21) Fatty acid utilization was ascertained by lipid detection using the Bligh & Dryer extraction method and subsequent fatty acid analysis in accordance with AOCS Ce 1b-89. Both muscle samples and total salmon samples were analysed. In this connection, the results shown in the tables below were obtained (displayed in each table is the amount of ascertained fats at the start and end of the diet in grams, based in each case on 100 g of total fat).

(22) TABLE-US-00003 TABLE 3 Diet-dependent fatty acid profile of salmon muscle samples Diet PUFAs Omega-3 fatty acids DHA Start 41.6 32.7 22.1 1 31.8 19.0 10.1 2 35.3 21.7 14.2 3 38.0 22.8 16.4

(23) TABLE-US-00004 TABLE 4 Diet-dependent fatty acid profile of total salmon samples Diet PUFAs Omega-3 fatty acids DHA Start 32.5 22.4 12.5 1 29.9 17.2 9.0 2 32.6 18.8 11.5 3 35.2 19.6 13.1

(24) It can be observed that it was already possible to achieve a distinct increase in the content of PUFAs, omega-3 fatty acids and DHA in the case of partial replacement of the fish oil by the Aurantiochytrium biomass. In the case of complete replacement of the fish oil by the Aurantiochytrium biomass, the increase in the content of PUFAs was accordingly higher.

Example 6

Determining the Fat Content in Salmon Liver

(25) Each of 3 smolts were fed for 9 weeks in each case with the different formulations Diet 1, 2 and 3 and the livers of the salmons were subsequently removed for determination of the fat content. Fat was extracted according to the method by Folch (1957; J. Biol. Chem., 226 (1), 497-509). Fat content was then determined by a gravimetric method.

(26) It became apparent that it was possible to significantly reduce the fat content in the liver from 8% by weight to 4-5% by weight by virtue of the presence of the biomass in comparison with feeding without the biomass.

(27) Fat deposition in the liver is considered to be a sign of an imbalance in food metabolism and, in particular, also an indication of oxidative stress. The distinct reduction in the proportion of fat in the liver is thus a clear indication of the reduction of stress and thus of the improvement in the physical condition of the salmon.