Special feed for mullet, silver drum and gold drum bred in northwest saline-alkali land and preparation method

Abstract

This invention relates to the field of aquatic compound feed technology, specifically to a special feed for mullet, silver carp, and golden carp cultured in saline-alkali land in Northwest China. The feed is characterized by being composed of the following raw materials by weight percentage: 10%–14% alfalfa meal, 16%–22% soybean meal, 16%–22% corn meal, 5%–7% molasses, 1%–3% yeast powder, 2%–5% lactic acid bacteria preparation, 2%–5% premixed feed for aquatic life in saline-alkali land in Northwest China, 1%–4% fish oil, and 1%–5% vegetable oil. This invention solves the problems of low survival rate, high feed conversion ratio, easy antagonistic inactivation of probiotics, fish oil oxidation, poor water resistance of pellets, and insufficient regional adaptability of traditional feeds. Compared with commercially available ordinary marine fish feeds, the survival rate of juvenile fish is increased by 15% to 30%, the feed conversion ratio is reduced by 10% to 20%, the Vibrio inhibition rate is ≥80%, the power consumption per ton of feed is reduced by 25% to 35%, and the raw material cost is reduced by 30% to 45%. It is suitable for large-scale aquaculture in saline-alkali land in Northwest China and has important value for improving the quality and efficiency of fisheries, ecological restoration, and rural revitalization.

Description

Technical Field

[0001] This invention relates to the field of aquatic compound feed technology, specifically to a special feed for mullet, silver mullet, and golden mullet suitable for aquaculture in saline-alkali land in Northwest China, and its preparation method. Background Technology

[0002] Saline-alkali waters in Northwest China are generally characterized by pH levels of 8.0–9.5, large salinity fluctuations (5–25), long periods of low temperatures, mineral imbalances (low K⁺ / Na⁺ ratio), and a high risk of Vibrio outbreaks. Direct application of conventional marine fish feeds presents significant drawbacks. (1) Nutritional mismatch: unreasonable protein gradient, electrolyte imbalance, and high crude fiber content lead to low survival rate of juvenile fish (usually less than 60%) and slow growth; (2) Poor digestion and absorption: Under saline-alkali conditions, the activity of digestive enzymes in fish decreases by 30% to 50%, and ordinary feed is prone to causing enteritis, bloating, and high feed conversion ratio (usually >1.8); (3) Insufficient microecological regulation: Simple mixed probiotics are prone to antagonism, and high-temperature granulation (>80℃) leads to inactivation, which cannot effectively inhibit Vibrio and protect the intestines; (4) The process is uneconomical: 200 mesh ultrafine grinding has high energy consumption (about 80-100 kWh per ton of electricity) and poor water resistance of particles (<2 hours), which is not suitable for large-scale production in Northwest China; (5) Lack of regional specificity: Existing feeds are not systematically designed in conjunction with Northwest alfalfa resources, low-temperature fermentation, and salt-alkali stress resistance requirements.

[0003] Although there are technologies related to saline-alkali aquaculture feed and microecological preparations, the following technical biases are prevalent: it is believed that euryhaline fish such as mullet and silver carp have strong tolerance to saline-alkali stress and do not require a complex anti-stress nutrition system; it is believed that alfalfa meal has a high crude fiber content (≥25%) and is not suitable as a main raw material for aquatic feed, let alone for fermentation; it is believed that multi-strain fermentation can be carried out by synchronous inoculation and does not require time control. These problems need to be solved by a special feed and preparation method for mullet, silver carp, and golden carp that is suitable for aquaculture in the saline-alkali land of Northwest China. Summary of the Invention

[0004] The purpose of this invention is to provide a special feed and preparation method for mullet, silver mullet, and golden mullet suitable for aquaculture in saline-alkali land in Northwest China, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a special feed for mullet, silver carp, and golden carp suitable for aquaculture in saline-alkali land in Northwest China, characterized in that it is composed of the following raw materials by weight percentage: 10%–14% alfalfa meal, 16%–22% soybean meal, 16%–22% corn meal, 5%–7% molasses, 1%–3% yeast powder, 2%–5% lactic acid bacteria preparation, 2%–5% special aquatic premix for saline-alkali land in Northwest China, 1%–4% fish oil, and 1%–5% vegetable oil.

[0006] As a preferred technical solution of the present invention, the following steps are included: S1. Accurately weigh all the ingredients according to the recipe, roast all the corn flour in the recipe until it emits a fragrance, and then grind it for later use. S2. Mix the weighed alfalfa powder and soybean powder evenly in a fermentation container, slowly add warm water while stirring, and adjust the moisture content of the mixture to 35% to 50%. Then add an appropriate amount of photosynthetic bacteria liquid to the mixture, stir thoroughly, and carry out aerobic fermentation at a temperature of 25 to 35°C for 20 to 28 hours. During this period, it is necessary to stir appropriately to ensure oxygen supply. S3. After the first stage of fermentation is completed, add the yeast powder of the formula to the material, stir it thoroughly again, compact the material slightly to reduce oxygen contact and create a micro-anaerobic environment, and continue fermentation for 14 to 22 hours at 25 to 35°C. S4. Add the prescribed amount of lactic acid bacteria preparation, stir evenly, transfer the material to a completely sealable fermentation container, compact and seal it strictly to create an absolutely anaerobic environment, and carry out anaerobic fermentation for 14 to 22 hours at the same temperature range of 25 to 35°C. S5. Take out the material that has completed anaerobic fermentation, spread it out, and dry it at a low temperature of ≤60℃ until the moisture content of the material is ≤12%. Crush the dried fermented material to a fineness of 60-100 mesh to obtain "fermentation base material". S6. Put the crushed fermentation base material, pretreated roasted corn flour, special aquatic premix for saline-alkali land in Northwest China and molasses into the mixer and mix them thoroughly. Then, send the mixed dry powder into the conditioner and introduce steam for conditioning. Strictly control the conditioning temperature to ≤60℃ to avoid high temperature damage to the heat-sensitive active substances in the fermentation products. The conditioning time is determined according to the equipment conditions to make the material mature and the moisture content uniform. S7. Feed the conditioned material into a ring die pellet mill and press it into shape. Select a ring die aperture of 1.5mm or 2.0mm according to the mouth diameter of the target fish. After the pellet feed is cooled, use special equipment to evenly spray fish oil and vegetable oil onto the surface of the pellets. It is best to cool the coated pellets for the final step, then screen them to remove powder, and then weigh and package them.

[0007] As a preferred technical solution of the present invention, the special aquatic premix for saline-alkali land in Northwest China contains the following per kilogram: 25g potassium, 12g magnesium, 15g betaine, 10g vitamin C phosphate, 5g β-glucan, 3g vitamin E, 2g zinc, and 0.2g selenium, with zeolite powder as the carrier. The premix is ​​specifically designed for high saline-alkali water bodies in Northwest China. Based on this premix, when the potassium content in the feed is 0.38% to 0.42%, the serum osmotic pressure of juvenile mullet is reduced by ≥25% compared with the control group with potassium content of 0.2% or 0.6%.

[0008] As a preferred technical solution of the present invention, the feed is divided into the following three functional stages: the juvenile fish feed contains 33.0% to 38.0% crude protein and has a particle size of 1.5 mm, which is suitable for the seedling stage with a body length of 3 to 8 cm; the adult fish feed contains ≥31.0% crude protein and has a particle size of 2.0 mm, which is suitable for the growth stage with a body length of 8 to 15 cm; and the overwintering fattening feed contains ≥30.0% crude protein and has a particle size of 2.0 mm, which is suitable for fattening before overwintering.

[0009] As a preferred embodiment of the present invention, the core indicators of the finished product are: crude fat 7.0%–8.5%, crude fiber ≤6.5%, potassium 0.38%–0.42%, DHA+EPA ≥1.2%, saline-alkali water stability ≥3 hours, pH 5.0–7.0, and effective viable bacteria (lactic acid bacteria) ≥1×10⁻⁶. 8 CFU / g.

[0010] As a preferred technical solution of the present invention, the feeding amount is 2% to 3% of the fish's body weight per day, divided into 2 to 3 feedings; compared with commercially available ordinary marine fish feed, the survival rate of juvenile fish is increased by 15% to 30%, the feed conversion ratio is reduced by 10% to 20%, the intestinal Vibrio load is reduced by more than 80%, and the power consumption per ton of feed is reduced by 25% to 35%; under the same breeding conditions, the weight gain rate of the complete program group is significantly higher than that of the "no three-stage fermentation group" and the "no special premixed feed group".

[0011] As a preferred technical solution of the present invention, in step S2, photosynthetic bacteria decompose crude fiber to produce vitamins and growth factors, and begin to degrade anti-nutritional factors. In step S3, yeast proliferates to produce microbial protein, B vitamins and aromatic substances, improving feed nutrition and flavor, and further softening fiber structure. In step S4, the fermentation product meets the following standards: pH value: 4.0-5.0, lactic acid content: ≥2.0%, and the total fermentation time is controlled within 48-72 hours. It can produce a large amount of acid, significantly reduce pH value, inhibit harmful bacteria, form natural acidifiers and strong palatability enhancers, and at the same time generate live lactic acid bacteria and metabolites.

[0012] As a preferred technical solution of the present invention, the peak viable cell counts of the three fermentation stages in steps S2 and S3 appear sequentially at 24h, 42h, and 60h, and the lactic acid content reaches ≥2.0% at the end of the third stage, which is significantly higher than the lactic acid content of the simultaneous mixed fermentation of the three strains.

[0013] Compared with the prior art, the present invention has the following beneficial effects: This invention relates to a specialized feed and preparation method for mullet, silver carp, and golden carp suitable for aquaculture in the saline-alkali lands of Northwest China. This invention solves the problems of low survival rate, high feed conversion ratio, easy antagonistic inactivation of probiotics, fish oil oxidation, poor water resistance of pellets, and insufficient regional adaptability of traditional feeds. Compared with commercially available ordinary marine fish feeds, it increases the survival rate of juvenile fish by 15%–30%, reduces the feed conversion ratio by 10%–20%, achieves a Vibrio inhibition rate of ≥80%, reduces power consumption per ton of feed by 25%–35%, and reduces raw material costs by 30%–45%. It is suitable for large-scale aquaculture in the saline-alkali lands of Northwest China and has significant value for improving the quality and efficiency of fisheries, ecological restoration, and rural revitalization. This invention relates to a special feed and preparation method for mullet, silver mullet, and golden mullet farmed in saline-alkali land in Northwest China. The invention employs a three-stage sequential directional fermentation process: avoiding antagonistic microbial communities, sequentially degrading fiber, producing vitamins, and producing lactic acid to lower the pH to 4.0-5.0, significantly inhibiting Vibrio, and simultaneously improving crude protein digestibility. Compared with synchronous mixed fermentation, the lactic acid content is increased by more than 100%, and the crude fiber degradation rate is increased by 75%. This invention relates to a special feed and preparation method for mullet, silver mullet, and golden mullet farmed in saline-alkali land in Northwest China. The invention features low-temperature drying at ≤60℃ to protect live bacteria and heat-sensitive nutrients, solving the problem of probiotic inactivation caused by traditional high-temperature granulation. Moderate grinding to 60-100 mesh reduces energy consumption by 25%-35%, while ensuring palatability and granule water resistance for ≥3 hours. This invention relates to a special feed and preparation method for mullet, silver carp, and golden carp farmed in the saline-alkali land of Northwest China. The fish oil post-coating process of this invention avoids fish oil oxidation caused by tempering at 70-85℃, improves fatty acid retention rate and storage stability, strengthens the potassium and magnesium ratio in the electrolyte balance system, simulates the ion composition of saline-alkali water in Northwest China, significantly improves the fish's tolerance to saline-alkali osmotic pressure and survival rate, and uses localized alfalfa from Northwest China to reduce raw material costs, increase the content of carotenoids and natural active substances, and enhance the fish's stress resistance. Detailed Implementation Example

[0014] Example 1 includes the following formula: 100kg alfalfa hay powder, 220kg soybean powder, 160kg corn powder, 50kg molasses, 20kg yeast powder, 30kg lactic acid bacteria, 30kg premix, 30kg fish oil, and 20kg soybean oil. 140kg alfalfa meal, 180kg soybean meal, 180kg corn meal, 60kg molasses, 20kg yeast powder, 30kg lactic acid bacteria, 30kg premix, 20kg fish oil, and 30kg soybean oil; 120kg alfalfa hay powder, 160kg soybean powder, 220kg corn powder, 70kg molasses, 20kg yeast powder, 30kg lactic acid bacteria, 30kg premix, 20kg fish oil, and 40kg soybean oil.

[0015] This embodiment includes the following steps: S1. Accurately weigh all the ingredients according to the recipe, roast all the corn flour in the recipe until it emits a fragrance, and then grind it for later use. S2. Mix the weighed alfalfa powder and soybean powder evenly in a fermentation container, slowly add warm water while stirring, and adjust the moisture content of the mixture to 35% to 50%. Then add an appropriate amount of photosynthetic bacteria liquid to the mixture, stir thoroughly, and carry out aerobic fermentation at a temperature of 25 to 35°C for 20 to 28 hours. During this period, it is necessary to stir appropriately to ensure oxygen supply. S3. After the first stage of fermentation is completed, add the yeast powder of the formula to the material, stir it thoroughly again, compact the material slightly to reduce oxygen contact and create a micro-anaerobic environment, and continue fermentation for 14 to 22 hours at 25 to 35°C. S4. Add the prescribed amount of lactic acid bacteria preparation, stir evenly, transfer the material to a completely sealable fermentation container, compact and seal it strictly to create an absolutely anaerobic environment, and carry out anaerobic fermentation for 14 to 22 hours at the same temperature range of 25 to 35°C. S5. Take out the material that has completed anaerobic fermentation, spread it out, and dry it at a low temperature of ≤60℃ until the moisture content of the material is ≤12%. Crush the dried fermented material to a fineness of 60-100 mesh to obtain "fermentation base material". S6. Put the crushed fermentation base material, pretreated roasted corn flour, special aquatic premix for saline-alkali land in Northwest China and molasses into the mixer and mix them thoroughly. Then, send the mixed dry powder into the conditioner and introduce steam for conditioning. Strictly control the conditioning temperature to ≤60℃ to avoid high temperature damage to the heat-sensitive active substances in the fermentation products. The conditioning time is determined according to the equipment conditions to make the material mature and the moisture content uniform. S7. Feed the conditioned material into a ring die pellet mill and press it into shape. Select a ring die aperture of 1.5mm or 2.0mm according to the mouth diameter of the target fish. After the pellet feed is cooled, use special equipment to evenly spray fish oil and vegetable oil onto the surface of the pellets. It is best to cool the coated pellets for the final step, then screen them to remove powder, and then weigh and package them. Example

[0016] Example 2 further illustrates Example 1, including a premixed aquatic feed specifically designed for saline-alkali lands in Northwest China containing: 25 g potassium, 12 g magnesium, 15 g betaine, 10 g vitamin C phosphate, 5 g β-glucan, 3 g vitamin E, 2 g zinc, and 0.2 g selenium per kilogram, with zeolite powder as the carrier. This premix is ​​specifically designed for the high salinity and alkalinity of Northwest China. Furthermore, based on this premix, when the potassium content in the feed is 0.38%–0.42%, the serum osmotic pressure of juvenile mullet is reduced by ≥25% compared to the control group with potassium content of 0.2% or 0.6%. The feed is divided into the following three functional stages: juvenile fish feed contains 33.0% to 38.0% crude protein and has a particle size of 1.5 mm, suitable for the seedling stage with a body length of 3 to 8 cm; adult fish feed contains ≥31.0% crude protein and has a particle size of 2.0 mm, suitable for the growth stage with a body length of 8 to 15 cm; and overwintering fattening feed contains ≥30.0% crude protein and has a particle size of 2.0 mm, suitable for fattening before overwintering.

[0017] The core indicators of the finished product are as follows: crude fat 7.0%–8.5%, crude fiber ≤6.5%, potassium 0.38%–0.42%, DHA+EPA ≥1.2%, saline-alkali water stability ≥3 hours, pH 5.0–7.0, and effective viable bacteria (lactic acid bacteria) ≥1×10⁻⁶. 8 CFU / g.

[0018] The feeding amount is 2% to 3% of the fish's body weight per day, divided into 2 to 3 feedings. Compared with commercially available ordinary marine fish feed, the survival rate of juvenile fish is increased by 15% to 30%, the feed conversion ratio is reduced by 10% to 20%, the intestinal Vibrio load is reduced by more than 80%, and the power consumption per ton of feed is reduced by 25% to 35%. Under the same breeding conditions, the weight gain rate of the complete program group is significantly higher than that of the "no three-stage fermentation group" and the "no special premixed feed group".

[0019] In step S2, photosynthetic bacteria decompose crude fiber to produce vitamins and growth factors, and begin to degrade anti-nutritional factors. In step S3, yeast proliferates, producing microbial protein, B vitamins, and aromatic substances to improve feed nutrition and flavor, and further soften the fiber structure. In step S4, the fermentation products meet the following standards: pH value: 4.0-5.0, lactic acid content: ≥2.0%, and the total fermentation time is controlled within 48-72 hours. This process can produce a large amount of acid, significantly reduce the pH value, inhibit harmful bacteria, form a natural acidifier and a strong palatability enhancer, and simultaneously generate live lactic acid bacteria and metabolites.

[0020] Among them, the peak viable cell counts of the three fermentation stages in steps S2 and S3 appeared at 24h, 42h and 60h respectively, and the lactic acid content reached ≥2.0% at the end of the third stage, which was significantly higher than the lactic acid content of the three strains in the simultaneous mixed fermentation.

[0021] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A special feed for mullet, silver mullet, and golden mullet suitable for aquaculture in saline-alkali lands of Northwest China, characterized in that, It is composed of the following raw materials by weight percentage: 10%–14% alfalfa meal, 16%–22% soybean meal, 16%–22% corn meal, 5%–7% molasses, 1%–3% yeast powder, 2%–5% lactic acid bacteria preparation, 2%–5% special aquatic premix for saline-alkali land in Northwest China, 1%–4% fish oil, and 1%–5% vegetable oil.

2. The method for preparing a special feed for mullet, silver mullet, and golden mullet adapted for aquaculture in saline-alkali land in Northwest China, as described in claim 1, is characterized in that... Includes the following steps: S1. Accurately weigh all the ingredients according to the recipe, roast all the corn flour in the recipe until it emits a fragrance, and then grind it for later use. S2. Mix the weighed alfalfa powder and soybean powder evenly in a fermentation container, slowly add warm water while stirring, and adjust the moisture content of the mixture to 35% to 50%. Then add an appropriate amount of photosynthetic bacteria liquid to the mixture, stir thoroughly, and carry out aerobic fermentation at a temperature of 25 to 35°C for 20 to 28 hours. During this period, it is necessary to stir appropriately to ensure oxygen supply. S3. After the first stage of fermentation is completed, add the yeast powder of the formula to the material, stir it thoroughly again, compact the material slightly to reduce oxygen contact and create a micro-anaerobic environment, and continue fermentation for 14 to 22 hours at 25 to 35°C. S4. Add the prescribed amount of lactic acid bacteria preparation, stir evenly, transfer the material to a completely sealable fermentation container, compact and seal it strictly to create an absolutely anaerobic environment, and carry out anaerobic fermentation for 14 to 22 hours at the same temperature range of 25 to 35°C. S5. Take out the material that has completed anaerobic fermentation, spread it out, and dry it at a low temperature of ≤60℃ until the moisture content of the material is ≤12%. Crush the dried fermented material to a fineness of 60-100 mesh to obtain "fermentation base material". S6. Put the crushed fermentation base material, pretreated roasted corn flour, special aquatic premix for saline-alkali land in Northwest China and molasses into the mixer and mix them thoroughly. Then, send the mixed dry powder into the conditioner and introduce steam for conditioning. Strictly control the conditioning temperature to ≤60℃ to avoid high temperature damage to the heat-sensitive active substances in the fermentation products. The conditioning time is determined according to the equipment conditions to make the material mature and the moisture content uniform. S7. Feed the conditioned material into a ring die pellet mill and press it into shape. Select a ring die aperture of 1.5mm or 2.0mm according to the mouth diameter of the target fish. After the pellet feed is cooled, use special equipment to evenly spray fish oil and vegetable oil onto the surface of the pellets. It is best to cool the coated pellets for the final step, then screen them to remove powder, and then weigh and package them.

3. The method for preparing a special feed for mullet, silver mullet, and golden mullet adapted for aquaculture in saline-alkali land in Northwest China, as described in claim 2, is characterized in that... The Northwest Saline-Alkali Land Special Aquatic Premix contains the following per kilogram: 25 g potassium, 12 g magnesium, 15 g betaine, 10 g vitamin C phosphate, 5 g β-glucan, 3 g vitamin E, 2 g zinc, and 0.2 g selenium. The carrier is zeolite powder. The premix is ​​specifically designed for the high salinity and alkalinity of Northwest China. Based on this premix, when the potassium content in the feed is 0.38%–0.42%, the serum osmotic pressure of juvenile mullet is reduced by ≥25% compared to the control group with potassium content of 0.2% or 0.6%.

4. The method for preparing a special feed for mullet, silver mullet, and golden mullet adapted for aquaculture in saline-alkali land in Northwest China, as described in claim 2, is characterized in that... The feed is divided into the following three functional stages: juvenile fish feed with crude protein of 33.0% to 38.0% and particle size of 1.5 mm, suitable for the seedling stage with a body length of 3 to 8 cm; adult fish feed with crude protein of ≥31.0% and particle size of 2.0 mm, suitable for the growth stage with a body length of 8 to 15 cm; and overwintering fattening feed with crude protein of ≥30.0% and particle size of 2.0 mm, suitable for fattening before overwintering.

5. The method for preparing a special feed for mullet, silver mullet, and golden mullet adapted for aquaculture in saline-alkali land in Northwest China, as described in claim 2, is characterized in that... The core indicators of the finished product are: crude fat 7.0%–8.5%, crude fiber ≤6.5%, potassium 0.38%–0.42%, DHA+EPA ≥1.2%, saline-alkali water stability ≥3 hours, pH 5.0–7.0, and effective viable bacteria (lactic acid bacteria) ≥1×10⁻⁶. 8 CFU / g.

6. The method for preparing a special feed for mullet, silver mullet, and golden mullet adapted for aquaculture in saline-alkali land in Northwest China, as described in claim 2, is characterized in that... The feeding amount is 2% to 3% of the fish's body weight per day, divided into 2 to 3 feedings. Compared with commercially available ordinary marine fish feed, the survival rate of juvenile fish is increased by 15% to 30%, the feed conversion ratio is reduced by 10% to 20%, the intestinal Vibrio load is reduced by more than 80%, and the power consumption per ton of feed is reduced by 25% to 35%. Under the same breeding conditions, the weight gain rate of the complete program group is significantly higher than that of the "no three-stage fermentation group" and the "no special premixed feed group".

7. The method for preparing a special feed for mullet, silver mullet, and golden mullet adapted for aquaculture in saline-alkali land in Northwest China, as described in claim 2, is characterized in that... In step S2, photosynthetic bacteria decompose crude fiber to produce vitamins and growth factors, and begin to degrade anti-nutritional factors. In step S3, yeast proliferates, producing microbial protein, B vitamins, and aromatic substances, improving feed nutrition and flavor, and further softening the fiber structure. In step S4, the fermentation products meet the following standards: pH value: 4.0-5.0, lactic acid content: ≥2.0%, and the total fermentation time is controlled within 48-72 hours. This process can produce a large amount of acid, significantly reduce the pH value, inhibit harmful bacteria, form a natural acidifier and a strong palatability enhancer, and simultaneously generate live lactic acid bacteria and metabolites.

8. The method for preparing a special feed for mullet, silver mullet, and golden mullet adapted for aquaculture in saline-alkali land in Northwest China, as described in claim 2, is characterized in that... The peak viable cell counts in the three fermentation stages of steps S2 and S3 occurred at 24h, 42h, and 60h respectively, and the lactic acid content reached ≥2.0% at the end of the third stage, which was significantly higher than the lactic acid content of the three strains in the simultaneous mixed fermentation.