Feed for improving heat stress resistance of channel catfish, fermented feed and preparation method thereof

Abstract

The invention provides a feed for improving heat stress resistance of channel catfish, a fermented feed and a preparation method of the fermented feed, and belongs to the technical field of fish feeds. The feed for improving the heat stress resistance of channel catfish provided by the invention comprises the following raw materials: fish meal, chicken meal, soybean meal, rapeseed meal, flour, rice bran, rice bran meal, monocalcium phosphate, soybean oil, lysine, methionine, VC phosphate, choline chloride, a vitamin premix feed, a trace mineral element premix feed and a Chinese herbal medicine compound, the Chinese herbal medicine compound consists of pogostemon cablin, turmeric, oriental wormwood, mangnolia officinalis and poria cocos. The feed and the fermented feed provided by the invention have the advantages of heat stress resistance, high digestion and utilization rate and liver and intestine protection, and can effectively reduce the morbidity of channel catfish in a high-temperature period and improve the survival rate and culture benefits when the feed is used at the water temperature exceeding 32 DEG C. In addition, the feed and the fermented feed are high in operability, the cost is in a controllable range, and the economical efficiency is high.

Description

Technical Field

[0001] The invention belongs to the technical field of fish feed, and in particular relates to a feed for improving the heat stress resistance of channel catfish, a fermented feed and a preparation method thereof. Background Art

[0002] Ictalurus punctatus belongs to the order Siluriformes, family Ictaluridae, genus Ictalurus. It is native to North America and is also known as channel catfish. It is also called pliers fish because of its large and deeply forked tail, which resembles a pair of pliers. It is a well-known freshwater farmed fish and one of the freshwater economic species.

[0003] Channel catfish is a cold-blooded animal, and its body temperature changes with the change of external temperature. Temperature not only affects many physical and chemical factors in the water body, such as ammonia nitrogen content and dissolved oxygen, but also controls the metabolic reaction rate of channel catfish, affecting its physiological and biochemical processes. The growth, survival, feeding, development and reproduction of channel catfish are all affected and restricted by temperature factors. Suitable temperature can promote the growth and development of channel catfish, while temperature exceeding its own limit will have a negative impact, such as inhibiting the feeding, growth, feed efficiency, physiological function, immune response and oxidation status of channel catfish. In recent years, continuous high temperature weather has frequently occurred in various places. High temperature will not only cause stress to channel catfish, but also cause diseases and metabolic disorders in fish. When the water temperature exceeds 32℃, the feeding, survival rate and growth rate of channel catfish decrease. Therefore, improving the ability to resist heat stress is an important manifestation of the survival ability of channel catfish in the face of changes in environmental water temperature. Therefore, there is an urgent need to develop a feed that can improve the channel catfish's ability to resist heat stress, so as to alleviate the negative impact of heat stress on the channel catfish. Summary of the invention

[0004] In view of this, the object of the present invention is to provide a feed and a fermented feed for improving the ability of channel catfish to resist high temperature stress, which can effectively reduce the incidence of channel catfish during high temperature periods when the water temperature exceeds 32°C, thereby improving the survival rate and breeding efficiency.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a feed for improving the heat stress resistance of channel catfish, comprising the following raw materials in parts by weight:

[0007] 5-15 parts of fish meal, 3-8 parts of chicken meal, 20-35 parts of soybean meal, 5-15 parts of rapeseed meal, 20-30 parts of flour, 3-8 parts of rice bran, 3-8 parts of rice bran meal, 1.5-2.5 parts of calcium dihydrogen phosphate, 3.0-5.0 parts of soybean oil, 0.1 parts of lysine, 0.1 parts of methionine, 0.02-0.15 parts of VC phosphate, 0.1-0.3 parts of choline chloride, 0.2-0.3 parts of vitamin premix feed, 2-3 parts of trace mineral element premix feed, 1-5 parts of Chinese herbal medicine compound;

[0008] The Chinese herbal medicine compound consists of patchouli, turmeric, capillaris, magnolia bark and tuckahoe.

[0009] Preferably, the weight proportions of the raw materials in the Chinese herbal medicine complex are 20-40 parts of patchouli, 20-30 parts of turmeric, 15-30 parts of capillaris, 10-20 parts of magnolia bark, and 5-15 parts of poria.

[0010] The present invention also provides a preparation method of the above-mentioned feed, comprising the following steps: mixing fish meal, chicken meal, soybean meal, rapeseed meal, flour, rice bran, rice bran meal, calcium dihydrogen phosphate, lysine, methionine, VC phosphate, choline chloride and trace mineral element premix feed to obtain a mixture, and crushing the mixture to obtain a mixture powder; ultrafinely crushing the Chinese herbal medicine complex to obtain Chinese herbal medicine complex powder; mixing the mixture powder, the Chinese herbal medicine complex powder and the vitamin premix feed, extruding and puffing at a low temperature below 70°C to obtain puffed slow-sinking particles, and spraying soybean oil on them after drying to obtain feed.

[0011] Preferably, the mixture is crushed and passed through an 80-mesh sieve.

[0012] Preferably, the ultrafine powder is sieved through a 200-mesh sieve.

[0013] Preferably, the spraying is performed by a vacuum sprayer, the vacuum value is 5 mbar, and the spraying time is 5 minutes.

[0014] The present invention also provides a fermented feed for improving the heat stress resistance of channel catfish, the fermented feed comprising the following raw materials in parts by weight: 100 parts of the above feed and 15 parts of fermented bacterial liquid; the fermented bacterial liquid consists of fermented bacteria and water, and the fermented bacteria include plant lactobacillus, bacillus and yeast.

[0015] Preferably, the weight-to-volume ratio of the fermentation bacteria to water is 1 g:10 mL.

[0016] Preferably, the fermentation bacteria contains >1×10 Lactobacillus plantarum 8 CFU / g, Bacillus>1×10 7 CFU / g, yeast>1×10 7 CFU / g.

[0017] The present invention also provides a method for preparing the fermented feed, comprising the following steps: after preparing the feed according to the preparation method, spraying the fermentation liquid, and performing anaerobically fermentation for 3-5 days to obtain the fermented feed.

[0018] Beneficial effects of the present invention:

[0019] The feed and fermented feed provided by the present invention have the advantages of heat stress resistance, high digestibility, and liver and intestine protection. When used at a water temperature exceeding 32° C., they can effectively reduce the incidence of channel catfish during high temperature periods, improve survival rates, and improve breeding benefits. In addition, the feed and fermented feed provided by the present invention have strong operability, a controllable cost, and high economic efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The survival rate results of Example 8 are shown below;

[0021] Figure 2 The weight gain results of Example 8;

[0022] Figure 3 The bait coefficient results of Example 8;

[0023] Figure 4 The serum T-AOC results of Example 8;

[0024] Figure 5 The serum MDA results of Example 8;

[0025] Figure 6 is the survival rate result of Example 12;

[0026] Figure 7 is the food intake rate result of Example 12;

[0027] Figure 8 The weight gain result of Example 12;

[0028] Fig. 9 The bait coefficient result of Example 12;

[0029] Fig.10 is the serum T-AOC result of Example 12;

[0030] Fig.11 is the serum MDA result of Example 12;

[0031] Fig.12 is the serum AST result;

[0032] Fig.13 is the serum ALT result;

[0033] Fig.14 It is the result of serum endotoxin content;

[0034] Fig.15 It is the result of serum diamine oxidase activity;

[0035] Fig.16 The relative expression results of liver HSP70 gene;

[0036] Fig.17 The relative expression results of intestinal HSP70 gene;

[0037] Fig.18 The results of liver sections, the left picture is the result of treatment 1 group, and the right picture is the result of treatment 4 group. DETAILED DESCRIPTION

[0038] The invention provides a feed for improving the heat stress resistance of channel catfish. The feed comprises the following raw materials in parts by weight: 5-15 parts of fish meal, 3-8 parts of chicken meal, 20-35 parts of soybean meal, 5-15 parts of rapeseed meal, 20-30 parts of flour, 3-8 parts of rice bran, 3-8 parts of rice bran meal, 1.5-2.5 parts of calcium dihydrogen phosphate, 3.0-5.0 parts of soybean oil, 0.1 part of lysine, 0.1 part of methionine, 0.02-0.15 parts of VC phosphate, 0.1-0.3 parts of choline chloride, 0.2-0.3 parts of vitamin premix feed, 2-3 parts of trace mineral element premix feed and 1-5 parts of Chinese herbal medicine compound; the Chinese herbal medicine compound consists of patchouli, turmeric, wormwood, magnolia bark and tuckahoe.

[0039] In the present invention, the VC phosphate is preferably 35% VC phosphate, the vitamin premix feed is preferably an omnivorous fish vitamin premix feed, and the trace mineral element premix feed is preferably an omnivorous fish trace mineral element premix feed. The present invention does not specifically limit the specific sources of the raw materials in the feed, and conventional commercial products in the field can be used. In the present invention, the weight proportions of the raw materials in the Chinese herbal medicine complex are preferably 20-40 parts of patchouli, 20-30 parts of turmeric, 15-30 parts of scutellaria baicalensis, 10-20 parts of magnolia bark, and 5-15 parts of poria, more preferably 25-35 parts of patchouli, 23-26 parts of turmeric, 18-25 parts of scutellaria baicalensis, 13-18 parts of magnolia bark, and 8-12 parts of poria. The feed of the present invention preferably includes the following raw materials in parts by weight: 8-12 parts of fish meal, 4-6 parts of chicken meal, 25-32 parts of soybean meal, 8-12 parts of rapeseed meal, 22-26 parts of flour, 4-6 parts of rice bran, 3.5-5 parts of rice bran meal, 1.6-2.2 parts of monocalcium phosphate, 3.5-4.5 parts of soybean oil, 0.1 parts of lysine, 0.1 parts of methionine, 0.08-0.12 parts of VC phosphate, 0.15-0.25 parts of choline chloride, 0.22-0.28 parts of vitamin premix feed, 2-3 parts of trace mineral element premix feed, and 2-4 parts of Chinese herbal medicine complex.

[0040] The present invention also provides a preparation method of the above-mentioned feed, comprising the following steps: mixing fish meal, chicken meal, soybean meal, rapeseed meal, flour, rice bran, rice bran meal, calcium dihydrogen phosphate, lysine, methionine, VC phosphate, choline chloride and trace mineral element premix feed to obtain a mixture, and crushing the mixture to obtain a mixture powder; ultrafinely crushing the Chinese herbal medicine complex to obtain Chinese herbal medicine complex powder; mixing the mixture powder, the Chinese herbal medicine complex powder and the vitamin premix feed, extruding and puffing at a low temperature below 70°C to obtain puffed slow-sinking particles, and spraying soybean oil on them after drying to obtain feed.

[0041] In the preparation method of the present invention, the mixture is preferably pulverized by an ultrafine pulverizer, and the mixture is preferably sieved through an 80-mesh sieve after pulverization. When the Chinese herbal medicine complex is ultrafinely pulverized, it is preferably carried out by an ultrafine pulverizer, and the mixture is preferably sieved through a 200-mesh sieve after ultrafine pulverization. In the present invention, low-temperature extrusion puffing is preferably carried out by a twin-screw puffer, and the die density is preferably 500-520g / L. The drying temperature of the present invention is preferably 60°C, and when spraying soybean oil, it is preferably sprayed by a vacuum sprayer, the vacuum value is preferably 5mbar, and the spraying time is preferably 5min.

[0042] The invention adds five Chinese medicinal herbs, namely patchouli, turmeric, wormwood, magnolia bark and tuckahoe, to the feed, increases the amount of VC added, and prepares the expanded sinking feed at low temperature, which can effectively alleviate the loss of channel catfish caused by high temperature stress.

[0043] The present invention also provides a fermented feed for improving the heat stress resistance of channel catfish, the fermented feed comprising the following raw materials in parts by weight: 100 parts of the above feed and 15 parts of fermented bacterial liquid; the fermented bacterial liquid consists of fermented bacteria and water, and the fermented bacteria include plant lactobacillus, bacillus and yeast.

[0044] In the present invention, the weight volume ratio of the fermentation bacteria to water is preferably 1 g:10 mL; the Lactobacillus plantarum in the fermentation bacteria is preferably >1×10 8 CFU / g, preferably >1×10 7 CFU / g, preferably >1×10 7 CFU / g. The present invention does not specifically limit the specific sources of the above three bacteria. In the present invention, the water is preferably sterilized water, and the sterilization method is preferably steam sterilization at 120°C for 30 minutes. When the water temperature is higher than 32°C, the fermented feed of the present invention and the existing channel catfish feed in the art are used in combination, and the weight ratio of the fermented feed of the present invention to the existing channel catfish feed in the art is preferably (2-4): (8-6), and more preferably 3:7.

[0045] The present invention also provides a method for preparing the fermented feed, comprising the following steps: after preparing the feed according to the preparation method, spraying the fermentation liquid, and performing anaerobically fermentation for 3-5 days to obtain the fermented feed.

[0046] In the present invention, after the feed is prepared according to the above preparation method, it is preferably left to stand for 60 minutes before spraying the fermentation liquid. After spraying, anaerobic fermentation is performed, and the anaerobic fermentation is preferably performed using a breathing membrane one-way exhaust valve plastic bag, the fermentation temperature is preferably room temperature above 25°C, and the fermentation time is preferably 3.5-4.5 days.

[0047] The present invention ferments the puffed slow-settling feed by adding fermentation bacteria, and a large amount of live bacteria and their metabolites can optimize the intestinal flora, repair damage, and improve the digestibility and utilization rate of feed. It can be seen from experiments that when the feed and fermented feed provided by the present invention are fed, the feeding amount, survival rate, weight gain rate and feed efficiency of channel catfish in the high temperature period can be significantly improved.

[0048] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0049] In the following embodiments, unless otherwise specified, all of them are conventional methods.

[0050] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0051] Example 1

[0052] A feed for improving the heat stress resistance of channel catfish, comprising the following raw materials in parts by weight:

[0053] 5 parts of fish meal, 8 parts of chicken meal, 35 parts of soybean meal, 5 parts of rapeseed meal, 30 parts of flour, 3 parts of rice bran, 8 parts of rice bran meal, 1.5 parts of calcium dihydrogen phosphate, 3 parts of soybean oil, 0.1 parts of lysine, 0.1 parts of methionine, 0.02 parts of VC phosphate (35%), 0.1 parts of choline chloride, 0.2 parts of vitamin premix feed F22V for omnivorous fish (purchased from Sichuan Tongwei Feed Co., Ltd.), 3 parts of trace mineral element premix feed F29M for omnivorous fish (purchased from Sichuan Tongwei Feed Co., Ltd.), and 5 parts of Chinese herbal medicine complex; the Chinese herbal medicine complex consists of 20 parts of patchouli, 20 parts of turmeric, 15 parts of capillaris, 20 parts of magnolia bark and 15 parts of tuckahoe.

[0054] The preparation method is:

[0055] (1) putting fish meal, chicken meal, soybean meal, rapeseed meal, flour, rice bran, rice bran meal, calcium dihydrogen phosphate, lysine, methionine, VC phosphate, choline chloride and omnivorous fish trace mineral element premix feed F29M into a mixer for mixing for 30 seconds to obtain a mixture; the mixture is ultrafinely pulverized by an ultrafine pulverizer, and 95% of the pulverized materials pass through an 80-mesh grading sieve to obtain a mixture powder;

[0056] (2) ultrafinely grinding the Chinese herbal compound to achieve 100% passing through a 200-mesh sieve to obtain Chinese herbal compound powder;

[0057] (3) The mixture powder, the Chinese herbal compound powder and the vitamin premix feed F22V for omnivorous fish are put into a mixer for secondary mixing, and the mixing time is 30 seconds; the mixed materials are extruded and puffed at low temperature through a twin-screw extruder (the low temperature is to add cooling water to the jacket of the extruder to reduce the temperature of the extrusion chamber to below 70° C.) to prepare puffed slow-sinking particles with a die density of 500 g / L;

[0058] (4) drying the expanded slow-sinking granules at 60° C.; the dried granules enter a vacuum sprayer and are sprayed with soybean oil at a vacuum degree of 5 mbar for 5 minutes to obtain feed.

[0059] Example 2

[0060] A feed for improving the heat stress resistance of channel catfish, comprising the following raw materials in parts by weight:

[0061] 15 parts of fish meal, 3 parts of chicken meal, 20 parts of soybean meal, 15 parts of rapeseed meal, 20 parts of flour, 8 parts of rice bran, 3 parts of rice bran meal, 2.5 parts of calcium dihydrogen phosphate, 5 parts of soybean oil, 0.1 parts of lysine, 0.1 parts of methionine, 0.15 parts of VC phosphate (35%), 0.3 parts of choline chloride, 0.3 parts of vitamin premix feed F22V for omnivorous fish, 2 parts of mineral element premix feed F29M for omnivorous fish, and 3 parts of Chinese herbal medicine complex; the Chinese herbal medicine complex consists of 40 parts of patchouli, 30 parts of turmeric, 30 parts of capillaris, 10 parts of magnolia bark and 5 parts of tuckahoe.

[0062] The preparation method is:

[0063] (1) putting fish meal, chicken meal, soybean meal, rapeseed meal, flour, rice bran, rice bran meal, calcium dihydrogen phosphate, lysine, methionine, VC phosphate, choline chloride and omnivorous fish trace mineral element premix feed F29M into a mixer for mixing once, the mixing time is 60 seconds, and a mixture is obtained; the mixture is ultrafinely pulverized by an ultrafine pulverizer, and 95% of the pulverized materials pass through an 80-mesh grading sieve, and a mixture powder is obtained;

[0064] (2) ultrafinely grinding the Chinese herbal compound to achieve 100% passing through a 200-mesh sieve to obtain Chinese herbal compound powder;

[0065] (3) The mixture powder, the Chinese herbal compound powder and the vitamin premix feed F22V for omnivorous fish are put into a mixer for secondary mixing, and the mixing time is 60 seconds; the mixed materials are extruded and puffed at low temperature through a twin-screw extruder (the low temperature is to add cooling water to the jacket of the extruder to reduce the temperature of the extrusion chamber to below 70° C.) to prepare puffed slow-sinking particles with a die density of 520 g / L;

[0066] (4) drying the expanded slow-sinking granules at 60° C.; the dried granules enter a vacuum sprayer and are sprayed with soybean oil at a vacuum degree of 5 mbar for 5 minutes to obtain feed.

[0067] Example 3

[0068] A feed for improving the heat stress resistance of channel catfish, comprising the following raw materials in parts by weight:

[0069] 10 parts of fish meal, 5 parts of chicken meal, 30 parts of soybean meal, 10 parts of rapeseed meal, 25 parts of flour, 5 parts of rice bran, 5.51 parts of rice bran meal, 1.8 parts of calcium dihydrogen phosphate, 4 parts of soybean oil, 0.1 parts of lysine, 0.1 parts of methionine, 0.04 parts of VC phosphate (35%), 0.2 parts of choline chloride, 0.25 parts of vitamin premix feed F22V for omnivorous fish, 2 parts of mineral element premix feed F29M for omnivorous fish, and 1 part of Chinese herbal medicine complex; the Chinese herbal medicine complex consists of 30 parts of patchouli, 25 parts of turmeric, 20 parts of wormwood, 15 parts of magnolia bark and 10 parts of tuckahoe. The preparation method is the same as that of Example 1.

[0070] Example 4

[0071] The difference from Example 3 is that the rice bran meal is 4.99 parts, the Chinese herbal medicine compound is 1.5 parts, and VC phosphate (35%) is 0.06 parts. The rest is the same as Example 3.

[0072] Example 5

[0073] The difference from Example 3 is that the rice bran meal is 4.47 parts, the Chinese herbal medicine compound is 2.0 parts, and VC phosphate (35%) is 0.08 parts. The rest is the same as Example 3.

[0074] Example 6

[0075] The difference from Example 3 is that the rice bran meal is 3.95 parts, the Chinese herbal medicine compound is 2.5 parts, and VC phosphate (35%) is 0.10 parts. The rest is the same as Example 3.

[0076] Example 7

[0077] The difference from Example 3 is that the rice bran meal is 3.43 parts, the Chinese herbal medicine compound is 3.0 parts, and VC phosphate (35%) is 0.12 parts. The rest is the same as Example 3.

[0078] Comparative Example 1

[0079] The difference from Example 3 is that the rice bran meal is 6.53 parts, the Chinese herbal medicine compound is 0 parts, and VC phosphate (35%) is 0.02 parts. The rest is the same as Example 3 (the preparation method does not contain step (2)).

[0080] Example 8

[0081] Adopt channel catfish fingerlings of the year, channel catfish fingerlings with an average body weight of 25.23g, divided into 30 boxes (2m×2m×2.0m) by 80 tails per box, each box of initial weight is basically the same, 30 boxes of fish are randomly divided into 6 treatments, corresponding to embodiments 3 to 7 and comparative example 1, respectively, wherein comparative example 1 group is recorded as treatment 1, embodiment 3 group is recorded as treatment 2, embodiment 4 group is recorded as treatment 3, embodiment 5 group is recorded as treatment 4, embodiment 6 group is recorded as treatment 5, embodiment 7 group is recorded as treatment 6, each treatment 5 repetitions, and initial body weight difference between each treatment is not significant (P>0.05). Formal test feed of corresponding group is fed 2 times every day, and feeding time is respectively 07:00 and 19:00, and feeding rate is 2% (i.e. 100kg fish, 2kg feed is fed every day). During the experiment, the water temperature was 31.7-35.1℃, with an average of 33.4℃; the dissolved oxygen in the water was ≥5mg / L, ammonia nitrogen was ≤0.2mg / L, nitrite was ≤0.1mg / L, and the breeding period was 35 days.

[0082] After the 35-day culture period, the experimental fish were fasted for 24 h, and the experimental fish were weighed and counted for the calculation of survival rate, weight gain rate and feed conversion rate. Serum of 10 fish was collected from each treatment for the determination of serum total antioxidant capacity (T-AOC) and malondialdehyde content (MDA).

[0083] Survival rate (%) = 100 × (number of fish at the end of the experiment - number of fish at the beginning of the experiment) / number of fish at the beginning of the experiment;

[0084] Weight gain rate (%) = 100 × (weight of fish at the end of the test - weight of fish at the beginning of the test) / weight of fish at the beginning of the test;

[0085] Feed coefficient = weight of ingested feed / (weight of fish at the end of the experiment - weight of fish at the beginning of the experiment);

[0086] Serum T-AOC and MDA were measured using kits manufactured by Nanjing Jiancheng.

[0087] The survival results are shown in Figure 1 ,from Figure 1It can be seen that the survival rates of treatment groups 2-6 are all higher than those of treatment group 1, among which treatment group 5 has the highest survival rate.

[0088] The results of weight gain rate are shown in Figure 2 ,from Figure 2 It can be seen that the weight gain rates of treatment groups 2-6 are all higher than those of treatment group 1, among which treatment group 5 has the highest weight gain rate.

[0089] The bait coefficient results are shown in Figure 3 ,from Figure 3 It can be seen that the feed coefficients of treatment groups 2-6 are all lower than those of treatment group 1, among which the feed coefficient of treatment group 5 is the lowest.

[0090] Serum T-AOC results are shown in Figure 4 .from Figure 4 It can be seen that the serum total antioxidant capacity content of treatment groups 2-6 was higher than that of treatment group 1, among which the serum T-AOC content of treatment group 5 was the highest.

[0091] Serum MDA results are shown in Figure 5 ,Depend on Figure 5 It can be seen that the serum MDA content in treatment groups 2-6 was lower than that in treatment group 1, and the serum MDA content in treatment group 5 was the lowest.

[0092] Example 9

[0093] A fermented feed for improving the heat stress resistance of channel catfish, the fermented feed is composed of the following raw materials in parts by weight: 100 parts of the feed obtained in Example 1 and 15 parts of fermented bacterial liquid; the fermented bacterial liquid is composed of fermented bacteria and water, the weight volume ratio of the fermented bacteria to water is 1g:10mL, the fermented bacteria include plant lactobacillus, bacillus and yeast, the plant lactobacillus in the fermented bacteria is greater than 1×10 8 CFU / g, Bacillus>1×10 7 CFU / g, yeast>1×10 7 CFU / g.

[0094] The preparation method is:

[0095] (1) Preparation of fermentation liquid: steam sterilize water at 120° C. for 30 min, cool to room temperature to obtain sterilized water; stir and mix evenly at a ratio of fermentation bacteria: sterilized water = 1 g: 10 mL to obtain fermentation liquid.

[0096] (2) The feed obtained in Example 1 was sprayed with fermentation liquid by a vacuum sprayer at a vacuum value of 10 mbar for 10 min, and then packed into a plastic packaging bag with a breathing membrane and a one-way exhaust valve for fermentation at room temperature above 25° C. for 5 days to obtain a fermented feed.

[0097] Example 10

[0098] A fermented feed for improving the heat stress resistance of channel catfish, the fermented feed is composed of the following raw materials in parts by weight: 100 parts of the feed obtained in Example 2 and 15 parts of fermented bacterial liquid; the fermented bacterial liquid is composed of fermented bacteria and water, the weight volume ratio of the fermented bacteria to water is 1g:10mL, the fermented bacteria include plant lactobacillus, bacillus and yeast, the plant lactobacillus in the fermented bacteria is greater than 1×10 8 CFU / g, Bacillus>1×10 7 CFU / g, yeast>1×10 7 CFU / g.

[0099] The preparation method is:

[0100] (1) Preparation of fermentation liquid: steam sterilize water at 120° C. for 30 min, cool to room temperature to obtain sterilized water; stir and mix evenly at a ratio of fermentation bacteria: sterilized water = 1 g: 10 mL to obtain fermentation liquid.

[0101] (2) The feed obtained in Example 2 was sprayed with fermentation liquid by a vacuum sprayer at a vacuum value of 10 mbar for 10 min. The feed was then packed into a plastic packaging bag with a breathing membrane and a one-way exhaust valve for fermentation at room temperature above 25° C. The fermentation lasted for 3 days to obtain a fermented feed.

[0102] Embodiment 11

[0103] A fermented feed for improving the heat stress resistance of channel catfish, the fermented feed is composed of the following raw materials in parts by weight: 100 parts of the feed obtained in Example 6, 15 parts of fermented bacterial liquid; the fermented bacterial liquid is composed of fermented bacteria and water, the weight volume ratio of the fermented bacteria to water is 1g:10mL, the fermented bacteria include plant lactobacillus, bacillus and yeast, the plant lactobacillus in the fermented bacteria>1×10 8 CFU / g, Bacillus>1×10 7 CFU / g, yeast>1×10 7 CFU / g. The preparation method is the same as Example 9.

[0104] Example 12

[0105] The fermented feed obtained in Example 11 was combined with the feed in Comparative Example 1 for use. The combined ratio is shown in Table 1.

[0106] Table 1 Fermented feed combination ratio

[0107] Group Comparative Example 1 Feed (%) Example 11 Fermented feed obtained (%) Process 1 100 0 Process 2 90 10 Process 3 80 20 Process 4 70 30 Process 5 60 40 Process 6 50 50

[0108] The channel catfish fingerlings of the year were used, and the average weight of the channel catfish fingerlings was 43.89g. They were divided into 30 boxes (2m×2m×2.0m) with 60 fish in each box. The initial weight of each box was basically the same. The 30 boxes of fish were randomly divided into 6 treatments, corresponding to treatments 1 to 6 in Table 1, 5 replicates for each treatment, and the initial weight difference between each treatment was not significant (P>0.05). In the formal experiment, the corresponding group of feed was fed twice a day, the feeding time was 07:00 and 19:00, and the feeding rate was 2% (i.e., 100kg of fish was fed 2kg of feed every day). During the experiment, the water temperature was 31.3-34.9℃, with an average of 33.1℃; the dissolved oxygen in the water was ≥5mg / L, the ammonia nitrogen was ≤0.2mg / L, and the nitrite was ≤0.1mg / L. The breeding period was 28 days.

[0109] After the 28-day culture cycle, the test fish were fasted for 24 h, and the test fish were weighed and counted for the calculation of food intake, survival rate, weight gain rate and feed coefficient (the calculation of survival rate, weight gain rate and feed coefficient was the same as in Example 8). Serum of 10 fish was collected from each treatment for the determination of serum total antioxidant capacity (T-AOC), malondialdehyde content (MDA), aspartate aminotransferase activity (AST), alanine aminotransferase activity (ALT), endotoxin content and diamine oxidase activity (DAO), intestinal tract and liver samples of treatment group 1 and treatment group 4 were taken for the determination of heat shock protein (HSP70) gene expression, and liver slice samples of treatment group 1 and treatment group 4 were taken for liver tissue morphology observation.

[0110] Feeding rate (%) = 100 × feeding amount during the experiment / {[(fish weight at the end of the experiment + fish weight at the beginning of the experiment) / 2] / number of breeding days}; serum T-AOC, MDA, AST, ALT, endotoxin and DAO were determined using kits from Nanjing Jiancheng; HSP70 gene and liver tissue sections were sent to Sevier Biotechnology Co., Ltd. for determination.

[0111] The survival results are shown in Figure 6 , the survival rates of treatment 2-6 groups were higher than those of treatment 1 group, among which treatment 4 group had the highest survival rate;

[0112] The results of feeding rate are shown in Figure 7 The feeding rates of treatment 2-6 groups were all higher than that of treatment 1 group.

[0113] The results of weight gain rate are shown in Figure 8 The weight gain rates of treatment 2-6 groups were all higher than those of treatment 1 group, among which treatment 4 group had the highest weight gain rate.

[0114] The bait coefficient results are shown in Fig. 9 The feed coefficients of treatment 2-6 groups were all lower than those of treatment 1 group, among which treatment 4 group had the lowest feed coefficient.

[0115] Serum T-AOC results are shown in Fig.10 The serum T-AOC levels in treatment 3-6 groups were all higher than those in treatment 1 group, and those in treatment 4 group were the highest.

[0116] Serum MDA results are shown in Fig.11 The serum MDA of treatment 2-6 was lower than that of treatment 1, and the serum MDA of channel catfish in treatment 4 and treatment 5 was lower than that in other groups.

[0117] Liver function results are shown in Fig.12 and Fig.13 , of which Fig.12 It can be seen that the serum aspartate aminotransferase (AST) activity in treatment 2-6 groups was lower than that in treatment 1 group, and treatment 4 group had the lowest level. Fig.13 It can be seen that the serum alanine aminotransferase (ALT) activities of treatments 2 to 6 were all lower than those of treatment 1, and the serum ALT activities of channel catfish in treatments 4 and 5 were lower than those in the other groups.

[0118] Intestinal function Fig.14 and Fig.15 The serum endotoxin content and diamine oxidase activity of treatment 2-6 groups were lower than those of treatment 1 group, and treatment 4 group had the lowest level.

[0119] The relative expression of heat shock protein (HSP70) gene in intestine and liver is shown in Fig.16 and Fig.17 Compared with treatment group 1, the relative expression levels of HSP70 in the liver and intestine of treatment group 4 were higher than those of treatment group 1.

[0120] Liver slices Fig.18 In treatment group 1, the hepatocytes were arranged radially in all directions, and the arrangement of the hepatocytes was not tight, with gaps and dispersion. In treatment group 4, the liver structure was complete, the lobule structure was obvious, and the hepatocytes were centered on the central vein.

[0121] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A feed for improving the heat stress resistance of channel catfish, characterized in that: The invention comprises the following raw materials in parts by weight: 5-15 parts of fish meal, 3-8 parts of chicken meal, 20-35 parts of soybean meal, 5-15 parts of rapeseed meal, 20-30 parts of flour, 3-8 parts of rice bran, 3-8 parts of rice bran meal, 1.5-2.5 parts of calcium dihydrogen phosphate, 3.0-5.0 parts of soybean oil, 0.1 parts of lysine, 0.1 parts of methionine, 0.02-0.15 parts of VC phosphate, 0.1-0.3 parts of choline chloride, 0.2-0.3 parts of vitamin premix feed, 2-3 parts of trace mineral element premix feed, 1-5 parts of Chinese herbal medicine compound; The Chinese herbal medicine compound consists of patchouli, turmeric, capillaris, magnolia bark and tuckahoe.

2. The feed according to claim 1, characterized in that The weight proportions of the raw materials in the Chinese herbal medicine compound are 20-40 parts of patchouli, 20-30 parts of turmeric, 15-30 parts of capillaris, 10-20 parts of magnolia bark, and 5-15 parts of poria.

3. The method for preparing the feed according to claim 1 or 2, characterized in that: The method comprises the following steps: mixing fish meal, chicken meal, soybean meal, rapeseed meal, flour, rice bran, rice bran meal, calcium dihydrogen phosphate, lysine, methionine, VC phosphate, choline chloride and trace mineral element premix feed to obtain a mixture, and crushing the mixture to obtain mixture powder; ultrafinely crushing the Chinese herbal medicine compound to obtain Chinese herbal medicine compound powder; mixing the mixture powder, the Chinese herbal medicine compound powder and the vitamin premix feed, extruding and puffing at a low temperature below 70 DEG C to obtain puffed slow-sinking particles, and spraying soybean oil on the particles after drying to obtain feed.

4. The preparation method according to claim 3, characterized in that: The mixture was crushed and passed through an 80-mesh sieve.

5. The preparation method according to claim 3, characterized in that: After ultrafine grinding, pass through a 200-mesh sieve.

6. The preparation method according to claim 3, characterized in that: The spraying is performed by a vacuum sprayer, the vacuum value is 5 mbar, and the spraying time is 5 minutes.

7. A fermented feed for improving the heat stress resistance of channel catfish, characterized in that: The fermented feed comprises the following raw materials in parts by weight: 100 parts of the feed according to any one of claims 1 to 2, and 15 parts of fermentation liquid; the fermentation liquid consists of fermentation bacteria and water, and the fermentation bacteria include plant lactobacillus, bacillus and yeast.

8. The fermented feed according to claim 7, characterized in that: The weight-to-volume ratio of the fermentation bacteria to water is 1 g:10 mL.

9. The fermented feed according to claim 7, characterized in that: The fermentation bacteria contains plant lactobacillus>1×10 8 CFU / g, Bacillus>1×10 7 CFU / g, yeast>1×10 7 CFU / g.

10. The method for preparing a fermented feed according to any one of claims 7 to 9, characterized in that: The method comprises the following steps: after preparing the feed according to the preparation method described in any one of claims 3 to 6, spraying the fermentation bacterial liquid, and performing anaerobic fermentation for 3 to 5 days to obtain the fermented feed.

Images