Method for utilizing spartina alterniflora straw

Abstract

The invention discloses application of spartina alterniflora straw, and particularly relates to application of the spartina alterniflora straw as feed for tenebrio molitor larvae after the spartina alterniflora straw is crushed. Tenebrio molitor larvae fed with spartina alterniflora straw can be used as live initial feed for feeding carnivorous economic fish fries such as ricefield eels, perches, mandarin fishes and snakeheads. According to the application of the spartina alterniflora straw provided by the invention, compared with tenebrio molitor larvae obtained by traditional wheat bran culture, the nutrition ingredients are not lost, and meanwhile, the culture cost of the tenebrio molitor is greatly saved. After the bred tenebrio molitor larvae are used as live initial feed, the initial feeding desire of the monopterus albus fries is obviously improved, and then the growth performance of the monopterus albus fries is enhanced.

Description

Technical Field

[0001] The invention relates to the technical field of yellow mealworm breeding, and in particular to application of Spartina alterniflora straw. Technical Background

[0002] Spartina alterniflora is a perennial herbaceous plant of the genus Spartina in the Poaceae family, native to the Atlantic coast of the United States and other countries. Due to its strong adaptability and reproductive capacity, Spartina alterniflora is widely distributed in coastal areas of my country and has caused serious impacts on the ecological environment. Therefore, it is listed as one of the most serious invasive alien species in the world and one of the most prominent marine invasive species in my country. The harm of Spartina alterniflora is diverse, including destroying the habitat of marine organisms, destroying the coastal wetland ecosystem, polluting water quality and blocking rivers, threatening offshore aquaculture, etc.

[0003] In order to prevent the large-scale expansion of Spartina alterniflora, the main control method in China is physical mowing technology, which has the characteristics of wide application range, low control cost, good control effect, and less damage to the environment than chemical control methods. However, the utilization of the harvested Spartina alterniflora straw is still mainly focused on fertilizer and fuel, and the development of its feed is still relatively small.

[0004] Currently, feed is an important factor restricting the development of aquaculture. The price of major raw materials such as fish meal has increased year by year, bringing tremendous pressure to farmers of carnivorous economic fish.

[0005] Therefore, finding economical and effective feed is of great significance to the development of aquaculture industry. Summary of the invention

[0006] The present invention firstly provides an application of Spartina alterniflora straw, specifically, crushing the straw into feed for mealworm larvae;

[0007] The stalks of Spartina alterniflora are crushed, and the specific steps are as follows: the freshly harvested spartina alterniflora stalks are dried naturally, crushed into powder feed with a diameter of about 1 cm by a straw crusher, and collected and stored in a cool place;

[0008] The daily feeding amount of the crushed Spartina alterniflora straw to the mealworm larvae is: 40-50 grams of Spartina alterniflora straw powder per kilogram of mealworm larvae; preferably, fresh lettuce leaves are fed in the mealworm breeding box every three days to supplement water;

[0009] The mealworm larvae fed with the Spartina alterniflora straw can be used as live starter bait to feed the seedlings of carnivorous economic fish such as yellow eel, sea bass, mandarin fish and snakehead fish after being cultured to be fat;

[0010] The present invention also provides a method for feeding yellow eel seedlings, which comprises feeding yellow mealworm larvae fed with the Spartina alterniflora straw to the yellow eel seedlings;

[0011] The specific method is: the breeding water temperature is maintained at 26-30°C, the pH value is maintained at 7.0-7.5, the dissolved oxygen is 6.0-6.5 mg / L, the initial weight of the eel seedlings is 25.60±0.52g, and the ratio of the eel seedlings and the mealworm larvae in feeding is 1:3-1:5 (head to head ratio).

[0012] Compared with the prior art, the present invention has the following advantages and effects:

[0013] (1) The large amount of Spartina alterniflora straw accumulated by physical mowing to prevent the expansion of Spartina alterniflora can be effectively utilized as a resource;

[0014] (2) By crushing the Spartina alterniflora straw into powder and feeding it to the mealworm larvae, the cost of raising the mealworm larvae can be greatly reduced, and the nutritional components of the mealworm larvae will not be lost compared to the traditional wheat bran breeding;

[0015] (3) Mealworm larvae fed with Spartina alterniflora straw can be used as live bait for carnivorous economic fish such as yellow eel, which significantly improves the feeding appetite of yellow eel seedlings and enhances their growth performance. DETAILED DESCRIPTION

[0016] The following examples are only used to further illustrate the content of the present invention, but should not be construed as limiting the present invention. Without departing from the spirit and essence of the present invention, modifications or substitutions made to the method, steps or conditions of the present invention all belong to the scope of the present invention. The experimental methods and reagents without specifying the specific conditions in the examples are all in accordance with the conventional conditions in the art.

[0017] The Spartina alterniflora straw used below was harvested from the coastal beach of Chongming District, Shanghai, and the mealworm larvae and eel seedlings used were from the Zhuangxing Comprehensive Experimental Station of Shanghai Academy of Agricultural Sciences.

[0018] Example 1: Feeding Tenebrio molitor larvae with Spartina alterniflora straw

[0019] (1) Preparation of Spartina alterniflora straw powder

[0020] The freshly harvested Spartina alterniflora straw is naturally dried and then crushed into powdered feed with a diameter of about 1 cm by a straw crusher. The powdered feed is collected and stored in a cool place.

[0021] (2) Screening of mealworm larvae

[0022] The larvae of yellow mealworm (40-60 mg) of similar size were screened and collected using a 20-mesh sieve. Feeding was stopped for 24 hours before the experiment. A total of 12 jin of yellow mealworm larvae were collected and evenly distributed in 6 breeding boxes (0.8 m×0.4 m×0.1 m) with 2 jin per group.

[0023] (3) Experimental design

[0024] Six breeding boxes were randomly divided into a control group and an experimental group, with three replicates in each group. The control group was fed with wheat bran purchased from the market, and the control group was fed with Spartina alterniflora straw powder. Fresh lettuce leaves (commonly purchased) were fed every three days to supplement water. The experiment was carried out indoors, the temperature was maintained at 24-28°C, the humidity was maintained at 55-65%, and shading was adopted throughout the breeding process. The experimental time was 6 weeks. Feeding was scheduled at 15:00 every day, and each breeding box was fed with 80-100g of equal weight of feed at a time, and dead and pupated insect bodies were picked out in time. After the experiment, fasting for 24h, all mealworm larvae were evenly spread in the breeding box, and 25 mealworm larvae were randomly selected from each breeding box according to the principle of the five-point sampling method. 5 larvae at each point were regarded as 1 sample, and 15 groups of samples were respectively provided in the control group and the experimental group.

[0025] (4) Determination and comparison of nutritional components of mealworm larvae

[0026] All samples were freeze-dried in a freeze dryer until a stable weight was reached to determine the moisture content. The crude protein content was determined by the Kjeldahl method. The crude fat content was calculated by Soxhlet extraction using a low-boiling organic solvent (ether or petroleum ether; purchased from Sinopharm Chemical Reagent Co., Ltd.). Data were calculated using Microsoft Excel and analyzed using SPSS22.0 software. The independent sample t-test was used to evaluate the significant differences between the groups, and the data were expressed as mean ± standard deviation, and p < 0.05 was considered significant.

[0027] Table 1 Nutritional composition of mealworm larvae fed with different feeds for 6 weeks

[0028] Wheat bran Spartina alterniflora Moisture (g / 100g fresh larvae) 61.55±0.24 61.44±0.27 Crude protein (g / 100g larvae meal) 56.69±1.88 57.01±1.91 Crude fat (g / 100g larvae meal) 31.81±1.02 31.12±1.22

[0029] The test results are shown in Table 1. There was no significant difference in the above nutrients when feeding mealworm larvae with wheat bran powder and Spartina alterniflora straw powder (p>0.05).

[0030] Example 2: Feeding yellow eel seedlings with yellow mealworm larvae

[0031] (1) Screening of eel seedlings

[0032] A total of 60 rice field eel fry with the same body weight (25.60±0.52g) and good health were selected and randomly and evenly distributed into three breeding ponds (1.0m×1.0m×0.4m), with 20 rice field eel fry in each breeding pond.

[0033] (2) Experimental design

[0034] At 16:00 every day, about 80 yellow mealworm larvae (the yellow mealworm larvae fed with Spartina alterniflora straw in Example 1) of equal weight were fed to each breeding pond according to the ratio of 1:4 of yellow mealworm seedlings and yellow mealworm larvae. The experiment lasted for 8 weeks, during which the breeding water temperature was maintained at 26-30°C, the pH value was maintained at 7.0-7.5, and the dissolved oxygen was 6.0-6.5 mg / L. The uneaten residual bait was salvaged 30 minutes after the daily feeding. The water quality was checked every day during the experiment, and half of the water body was replaced if necessary, and the mortality was recorded. After fasting for 24 hours after the experiment, the weight of the yellow eel in each breeding pond was weighed.

[0035] (3) Data analysis

[0036] The data were calculated using Microsoft Excel and presented as mean ± standard deviation. The growth performance calculation formula was as follows:

[0037] Survival rate (%) = 100 × final number / initial number

[0038] Weight gain rate (%) = 100 × (final weight - initial weight) / initial weight

[0039] Specific growth rate (% / day) = 100 × [(ln final body weight - ln initial body weight) / number of days of feeding]

[0040] Table 2 Growth performance of mealworm larvae fed with yellow eel seedlings for 8 weeks

[0041] Breeding pond 1 Breeding pond 2 Breeding pond 3 Initial body weight (g) 25.60±0.52 25.60±0.52 25.60±0.52 Final body weight (g) 56.69±1.88 57.01±1.91 56.85±1.83 Survival rate (%) 90.00 90.00 95.00 Weight gain rate (%) 121.45±7.34 122.70±7.47 122.08±7.13 Specific growth rate (%) 1.42±0.06 1.43±0.06 1.42±0.06

[0042] The test results are shown in Table 2. It was observed that feeding yellow mealworm larvae to yellow eel seedlings can significantly improve their appetite and have a positive effect on their growth performance.

Claims

1. An application of Spartina alterniflora straw, characterized in that The Spartina alterniflora straw is crushed and used as feed for yellow mealworm larvae; the daily feeding amount is: 40-50 grams of Spartina alterniflora straw powder per kilogram of yellow mealworm larvae.

2. The use of Spartina alterniflora straw according to claim 1, wherein the Spartina alterniflora straw is crushed, specifically comprising the following steps: drying the freshly harvested Spartina alterniflora straw, crushing it into powdered feed with a diameter of 1 cm, collecting it and storing it in a cool place.

3. The use of Spartina alterniflora straw according to any one of claims 1 or 2, wherein when the crushed Spartina alterniflora straw is fed to Tenebrio molitor larvae, lettuce leaves are fed every three days to replenish water.

4. A method for feeding yellow eel seedlings, characterized in that The mealworm larvae fed with crushed Spartina alterniflora straw were used to feed the eel seedlings; Among them, the breeding water temperature was maintained at 26-30℃, the pH value was maintained at 7.0-7.5, the dissolved oxygen was 6.0-6.5mg / L, the initial weight of the eel seedlings was 25.60±0.52g, and the ratio of eel seedlings and mealworm larvae in feeding was 1:3-1:5.