CN111938044A

CN111938044A - Nano-selenium feed for reducing excessive fat accumulation in abdominal cavity of grass carp

Info

Publication number: CN111938044A
Application number: CN202010890341.6A
Authority: CN
Inventors: 于海波; 吉红; 王驰; 李鹏举; 刘国豪; 张啸天; 刘莎
Original assignee: Northwest A&F University
Current assignee: Northwest A&F University
Priority date: 2020-08-29
Filing date: 2020-08-29
Publication date: 2020-11-17

Abstract

A nano selenium feed for reducing fat excess accumulation in abdominal cavity of grass carp comprises the following components in percentage by mass: 12% of fish meal, 24% of soybean meal, 10% of vegetable cake, 10% of cottonseed meal, 22.2% of wheat flour, 5% of DDGS, 7% of rice bran, 4.8% of soybean oil, 1% of vitamin premix, 1% of selenium-free mineral element premix, 1% of bentonite, 2% of monocalcium phosphate and 0.00003-0.00012% of nano selenium. The nano selenium feed disclosed by the invention can reduce excessive fat accumulation in abdominal cavities of the grass carps, reduce the blood fat content of the grass carps, relieve metabolic damage of the grass carps, improve the stress resistance and the survival rate of the grass carps and improve the muscle protein content of the grass carps, so that the yield and the quality of the grass carps are improved, and the culture economic benefit is improved.

Description

Nano-selenium feed for reducing excessive fat accumulation in abdominal cavity of grass carp

Technical Field

The invention belongs to the field of aquatic feeds, and particularly relates to a nano selenium feed for reducing excessive fat accumulation in abdominal cavities of grass carps.

Background

The grass carp is the first fresh water economic fish in the output of China. Excessive accumulation of lipids is a bottleneck problem in grass carp breeding, and the health and quality of grass carps are seriously affected. The method of feeding excessive energy feed in a short period is often adopted in the breeding process to improve the production performance of the grass carps. However, long-term feeding of high-fat feed has been found to result in fat accumulation in fish, especially in the abdominal cavity and liver. And excessive accumulation of lipids can cause increase of free fatty acids, cause oxidative stress of organisms, cause metabolic damage of the organisms, cause reduction of stress resistance of fishes, and even cause death of the fishes. The scientific solution of the problem of excessive accumulation of fat in grass carp is the key research point in the aquatic product industry.

In recent years, it has proven feasible to reduce excessive accumulation of fish lipids by regulating the metabolic processes of fish lipids through nutritional pathways. Selenium is a trace element essential for human and animal life activities, and has effects in regulating nucleic acid and protein metabolism, promoting DNA and RNA production, regulating vitamin A, C, E, K absorption and consumption, and increasing immunoglobulin content in body. Selenium is a good antioxidant, is an important component of glutathione peroxidase (GSH-Px), can effectively remove oxygen free Radicals (ROS) of organisms, maintain the balance of the ROS of the organisms and prevent the organisms from being damaged by oxidation. Therefore, selenium has various effects of improving the immune function of the organism, protecting the liver, delaying senility, regulating metabolism and the like. The nano selenium is red elemental selenium, and has the characteristics of easy absorption and low toxicity compared with inorganic selenium and organic selenium. At present, substances with the function of reducing fish lipid accumulation used in aquaculture are mainly choline, carnitine, betaine and the like, and the application of nano selenium in aquaculture is mainly to improve the antioxidant capacity of cultured fish by utilizing the antioxidant effect of nano selenium, but reports that the lipid accumulation in abdominal cavities of grass carps is reduced by adding nano selenium in feeds are not found.

Disclosure of Invention

Aiming at the problem of health and quality reduction of the grass carps caused by excessive fat accumulation in abdominal cavities of the cultured grass carps in the technical background, the invention aims to provide the grass carp feed containing nano selenium, which has the function of reducing the excessive fat accumulation in the abdominal cavities, can improve the lipid metabolism process of the grass carps, reduce the fat content in the abdominal cavities of the grass carps, reduce the blood fat content of the grass carps, relieve metabolic injury of the grass carps, improve the stress resistance and the survival rate of the grass carps and improve the muscle protein content of the grass carps. Has the advantages of high safety, obvious effect, simple and convenient method, suitability for large-scale production and the like.

In order to achieve the above purpose, the technical scheme of the invention is as follows:

the nano selenium feed for reducing excessive fat accumulation in abdominal cavity of grass carp is characterized by comprising the following components in percentage by mass: 12% of fish meal, 24% of soybean meal, 10% of rapeseed powder, 10% of cottonseed powder, 22.2% of wheat flour, 5% of DDGS, 7% of rice bran, 4.8% of soybean oil, 1% of vitamin premix, 1% of mineral element premix, 1% of bentonite, 2% of monocalcium phosphate and 0.00003-0.00012% of nano selenium.

Compared with the prior art, the invention has the following advantages:

(1) the feed with reasonable nutrient element proportion and positive regulation effect on fat metabolism of the grass carps is obtained by optimizing the feed formula based on the nutritional requirement characteristics of the grass carps, and the nano selenium is added on the basis of ensuring the nutritional requirement of the normal growth of the grass carps, so that the feed has the effect of reducing fat accumulation in abdominal cavities of the grass carps.

(2) The invention not only has the function of reducing the lipopexia of the abdominal cavity, but also can relieve the metabolic injury of the grass carp, improve the stress resistance and the survival rate of the grass carp and improve the muscle protein content of the grass carp.

(3) The addition process is simple, the production cost is low, and the method is suitable for mass development and production.

(4) Compared with other selenium dosage forms, the selenium-enriched preparation has the characteristics of easy absorption, low toxicity and the like.

Drawings

FIG. 1 shows the weight gain of grass carp in different test groups in the breeding test of the present invention.

FIG. 2 shows the survival rate of grass carp in different test groups in the cultivation experiment of the present invention.

FIG. 3 shows the serum triglyceride content of grass carp of different test groups in the cultivation experiment of the present invention.

FIG. 4 shows serum cholesterol levels of grass carp from different experimental groups in the cultivation experiment of the present invention.

FIG. 5 shows the serum glutamic pyruvic transaminase content of grass carp in different test groups in the culture experiment of the present invention.

FIG. 6 shows the serum glutamic-oxaloacetic transaminase contents of grass carp in different test groups in the culture experiment of the present invention.

FIG. 7 shows abdominal fat index of grass carp in different experimental groups in the breeding experiment of the present invention.

FIG. 8 shows liver pancreas index of grass carp in different experimental groups in the cultivation experiment of the present invention.

FIG. 9 shows fat tissue slices of grass carp from different experimental groups in the cultivation experiment of the present invention.

FIG. 10 shows liver slices of grass carp from different experimental groups in the cultivation experiment of the present invention.

FIG. 11 shows the protein content of grass carp in different groups of the present invention.

The present invention is further described in detail below with reference to specific embodiments, which are given for the purpose of illustration only and are not intended to limit the scope of the invention.

Detailed Description

Example 1

Respectively weighing 12% of fish meal, 24% of soybean meal, 10% of rapeseed powder, 10% of cottonseed powder, 22.2% of wheat flour, 5% of DDGS, 7% of rice bran, 4.8% of soybean oil, 1% of vitamin premix, 1% of mineral element premix (free of selenium), 1% of bentonite, 2% of monocalcium phosphate and 0.00003% of nano selenium according to the proportion. All feed raw materials are crushed and sieved by a 70-mesh sieve, and are uniformly mixed by adopting a step-by-step amplification method according to the formula proportion, so that the variation coefficient of the mixture is less than or equal to 5 percent, and the mixture is granulated by using a common feed granulator.

Example 2

Respectively weighing 12% of fish meal, 24% of soybean meal, 10% of rapeseed powder, 10% of cottonseed powder, 22.2% of wheat flour, 5% of DDGS, 7% of rice bran, 4.8% of soybean oil, 1% of vitamin premix, 1% of mineral element premix (free of selenium), 1% of bentonite, 2% of monocalcium phosphate and 0.00006% of nano selenium according to the proportion. All feed raw materials are crushed and sieved by a 70-mesh sieve, and are uniformly mixed by adopting a step-by-step amplification method according to the formula proportion, so that the variation coefficient of the mixture is less than or equal to 5 percent, and the mixture is granulated by using a common feed granulator.

Example 3

Respectively weighing 12% of fish meal, 24% of soybean meal, 10% of rapeseed powder, 10% of cottonseed powder, 22.2% of wheat flour, 5% of DDGS, 7% of rice bran, 4.8% of soybean oil, 1% of vitamin premix, 1% of mineral element premix (free of selenium), 1% of bentonite, 2% of monocalcium phosphate and 0.00009% of nano selenium according to the proportion. All feed raw materials are crushed and sieved by a 70-mesh sieve, and are uniformly mixed by adopting a step-by-step amplification method according to the formula proportion, so that the variation coefficient of the mixture is less than or equal to 5 percent, and the mixture is granulated by using a common feed granulator.

Example 4

Respectively weighing 12% of fish meal, 24% of soybean meal, 10% of rapeseed powder, 10% of cottonseed powder, 22.2% of wheat flour, 5% of DDGS, 7% of rice bran, 4.8% of soybean oil, 1% of vitamin premix, 1% of mineral element premix (free of selenium), 1% of bentonite, 2% of monocalcium phosphate and 0.00012% of nano selenium according to the proportion. All feed raw materials are crushed and sieved by a 70-mesh sieve, and are uniformly mixed by adopting a step-by-step amplification method according to the formula proportion, so that the variation coefficient of the mixture is less than or equal to 5 percent, and the mixture is granulated by using a common feed granulator.

Comparative example 1

Respectively weighing 12% of fish meal, 24% of soybean meal, 10% of rapeseed powder, 10% of cottonseed powder, 22.2% of wheat flour, 5% of DDGS, 7% of rice bran, 4.8% of soybean oil, 1% of vitamin premix, 1% of mineral element premix (free of selenium), 1% of bentonite and 2% of monocalcium phosphate according to the proportion. All feed raw materials are crushed and sieved by a 70-mesh sieve, and are uniformly mixed by adopting a step-by-step amplification method according to the formula proportion, so that the variation coefficient of the mixture is less than or equal to 5 percent, and the mixture is granulated by using a common feed granulator.

Comparative example 2

Respectively weighing 12% of fish meal, 24% of soybean meal, 10% of rapeseed meal, 10% of cottonseed meal, 22.2% of wheat meal, 5% of DDGS, 7% of rice bran, 4.8% of soybean oil, 1% of vitamin premix, 1% of mineral element premix (free of selenium), 1% of bentonite, 2% of monocalcium phosphate and 0.00006% of organic selenium (selenomethionine) according to the proportion. All feed raw materials are crushed and sieved by a 70-mesh sieve, and are uniformly mixed by adopting a step-by-step amplification method according to the formula proportion, so that the variation coefficient of the mixture is less than or equal to 5 percent, and the mixture is granulated by using a common feed granulator.

Comparative example 3

Respectively weighing 12% of fish meal, 24% of soybean meal, 10% of rapeseed powder, 10% of cottonseed powder, 22.2% of wheat flour, 5% of DDGS, 7% of rice bran, 4.8% of soybean oil, 1% of vitamin premix, 1% of mineral element premix (without selenium), 1% of bentonite, 2% of monocalcium phosphate and 0.00006% of inorganic selenium (sodium selenite) according to the proportion. All feed raw materials are crushed and sieved by a 70-mesh sieve, and are uniformly mixed by adopting a step-by-step amplification method according to the formula proportion, so that the variation coefficient of the mixture is less than or equal to 5 percent, and the mixture is granulated by using a common feed granulator.

Experimental example 1

The test grass carp is domesticated 2 weeks before the feeding test, and is fed with commercial feed. After domestication is finished, starving test fishes for 24 hours, selecting 315 grass carps with regular specifications and strong physique, randomly dividing the 315 grass carps into 21 net cages, randomly dividing the 21 net cages into 7 groups, and feeding 1 test feed in each group. The test period was 10 weeks, and the test diets were fed at 8:30, 12:30 and 16:30 portions during the test period. The water temperature is kept at about 28 ℃, the dissolved oxygen is 7.4 to 8.6 mg/L, the pH value is 6.96 to 7.36, and the ammonia content is 0.03 to 0.07 mg/L. And timely fishing out dead fish, weighing and calculating the survival rate. And after the test is finished, collecting a test fish sample, and determining indexes such as the weight gain rate, the survival rate and the like of the grass carp. The specific index calculation method comprises the following steps: weight gain (%) =100 × (final weight-initial weight)/initial weight; survival (%) = final number of fish × 100/initial number of fish; intraperitoneal fat index (%) = intraperitoneal fat weight (g) × 100/body weight (g); hepatopancreatic index (%) = hepatopancreatic weight (g) × 100/total body weight (g).

Test results show that the feed added with 0.00003-0.00012% of nano selenium does not remarkably increase the growth speed of the grass carp, but remarkably improves the survival rate of the grass carp (shown in figures 1 and 2), thereby improving the yield of the grass carp. The survival rate of grass carp fed with nano selenium feed is higher than that of the group without addition, inorganic selenium group and organic selenium group. The effect of the feed added with 0.00006 percent of nano selenium is optimal.

Experimental example 2

Grass carp samples of different test groups in the experimental example 1 are collected, and indexes such as abdominal fat index, liver pancreas index and the like of the grass carp are measured. The specific index calculation method comprises the following steps: intraperitoneal fat index (%) = intraperitoneal fat weight (g) × 100/body weight (g); hepatopancreatic index (%) = hepatopancreatic weight (g) × 100/total body weight (g).

Test results show that the feed added with 0.00003-0.00012% of nano selenium can obviously reduce the abdominal fat content of grass carp, and the abdominal fat index of the grass carp in a feed group added with 0.00003-0.00009% of nano selenium is obviously lower than that of a non-added group, an inorganic selenium group and an organic selenium group (shown in figure 3). The feed added with 0.00003-0.00012% of nano selenium can obviously reduce the liver and pancreas index of the grass carp (figure 4), and the nano selenium feed can also reduce the liver fat content of the grass carp.

Experimental example 3

Grass carp blood samples of different test groups in experimental example 1 were collected by tail vein blood sampling method, and after standing at 4 ℃ for 6h, the supernatant was obtained by centrifugation (3000 Xg, 4 ℃, 10 min) to obtain serum samples for analysis of serum biochemical indexes. Serum biochemical indicators were determined using a kit purchased from Nanjing Jiancheng Bioreagent company (Nanjing). The detection indexes include triglyceride (TG, mmol/L), total cholesterol (T-CHOL, mmol/L), alanine aminotransferase (ALT, U/ml) and aspartate aminotransferase (AST, U/ml).

The result shows that the feed added with 0.00003-0.00012% of nano selenium remarkably reduces the serum triglyceride and cholesterol content of the grass carp (figures 5 and 6), which shows that the nano selenium feed can remarkably reduce the blood fat content of the grass carp, and the effect of adding 0.00003-0.00006% of nano selenium is optimal. The feed added with 0.00006-0.00012% of nano selenium remarkably reduces the glutamic-pyruvic transaminase content in serum of the grass carp, and the feed added with 0.00003-0.00012% of nano selenium remarkably reduces the glutamic-oxalacetic transaminase content in serum of the grass carp, which shows that the nano selenium feed can remarkably reduce metabolic injury of the grass carp (shown in attached figures 7 and 8).

Experimental example 4

Samples of fat tissue and liver pancreas of grass carp of different test groups in experimental example 1 were collected and fixed with paraformaldehyde solution for 24 hours. Dehydration in ethanol increased the concentration from 75% to 100%. Then embedded in paraffin and sectioned at 5 μm with a microtome. It was stained with hematoxylin and eosin (H & E), and the tissue morphology was observed under a microscope and photographed.

The result shows that the diameter of the fat cells of the grass carp in the feed group added with 0.00003-0.00012% of nano selenium is obviously smaller than that of the feed group not added with the nano selenium, which indicates that the feed can reduce the fat content in the fat tissues of the grass carp and reduce the volume of the fat cells of the grass carp (figure 9). The amount and the size of fat drops in the liver of the grass carp in the feed group added with 0.00003-0.00012% of nano selenium are obviously lower than those in the group without the nano selenium (shown in figure 10), which shows that the feed disclosed by the invention can also reduce the fat content in the liver of the grass carp, relieve the fatty liver of the liver and reduce the liver injury. The effect of the group added with the nano-selenium feed of 0.00006 percent is optimal.

Experimental example 5

Grass carp samples of different test groups in experimental example 1 were collected, and the muscle protein content of grass carp was determined. The content of muscle protein is measured by adopting a Kjeldahl method, and the content of protein is calculated according to N x 6.25. Test results show that the feed added with 0.00003-0.00012% of nano selenium can obviously improve the muscle protein content of grass carp, and the feed added with 0.00006-0.00012% of nano selenium has the best effect (figure 11).

Claims

1. The nano selenium feed for reducing excessive fat accumulation in abdominal cavity of grass carp is characterized by comprising the following components in percentage by mass: 12% of fish meal, 24% of soybean meal, 10% of vegetable cake, 10% of cottonseed meal, 22.2% of wheat flour, 5% of DDGS, 7% of rice bran, 4.8% of soybean oil, 1% of vitamin premix, 1% of selenium-free mineral element premix, 1% of bentonite, 2% of monocalcium phosphate and 0.00003-0.00012% of nano selenium.

2. The nano-selenium feed for reducing excessive fat accumulation in abdominal cavities of grass carps as claimed in claim 1, wherein the mass percentage of nano-selenium in the feed is 0.00003-0.00009%.

3. The nano-selenium feed for reducing excessive fat accumulation in abdominal cavity of grass carp as claimed in claim 1, wherein the nano-selenium in the feed is 0.00006% by mass.

4. The nano-selenium feed as claimed in any one of claims 1 to 3, which has the function of reducing the fat excess accumulation in abdominal cavity of grass carp.