CN113016669B

CN113016669B - Domestication method for pomfret completely ingesting pellet feed

Info

Publication number: CN113016669B
Application number: CN202110303449.5A
Authority: CN
Inventors: 张鼎元; 柴学军; 王跃斌; 阮泽超; 张燕; 徐善良; 王亚军; 王丹丽
Original assignee: Ningbo University; Zhejiang Marine Fisheries Research Institute
Current assignee: Ningbo University; Zhejiang Marine Fisheries Research Institute
Priority date: 2021-03-22
Filing date: 2021-03-22
Publication date: 2022-12-23
Anticipated expiration: 2041-03-22
Also published as: CN113016669A

Abstract

The invention provides a domestication method for pomfret to eat pellet feed completely, which comprises the steps of feeding biological baits, namely rotifers and fairy shrimp nauplii during the period from initial feeding of pomfret fry to complete feeding of pellet feed; and feeding floating type pellet feed with the grain diameter of 0.20-0.30 at the age of 21-25 days after hatching, feeding floating type pellet feed with the grain diameter of 0.35-0.40mm at the age of 26-35 days after hatching, adding slow-sinking type feed with the grain diameter of 0.45-0.50mm at the age of 36-42 days after hatching, stopping feeding fairy shrimp nauplii after 43 days, and only feeding pellet feed. The method is to add antibacterial peptide screened from pomfret into bait. The method effectively solves the defects of the existing artificial breeding of the pomfret by adjusting the feeding type and the feeding time of the biological bait and the artificial compound feed during the artificial breeding and the breeding period of the pomfret, and effectively reduces the problem of flatulence of the digestive tract of the pomfret larvae by adjusting the feeding time and the feeding proportion of the biological bait and the pellet feed.

Description

Domestication method for pomfret completely ingesting pellet feed

Technical Field

The invention belongs to the technical field of fish domestication, and particularly relates to a domestication method for pomfret by completely feeding pellet feed.

Background

Silvery pomfret (Pampus argenteus) has thick flesh, less thorn, good taste and rich nutrition, and is a rare marine product in China due to high economic value and strong market demand. However, after the 90 s of the last century, the resource amount of over-fishing is obviously reduced, the marine fishing yield is maintained to be zero for a long time, and in addition, the marine environment is gradually deteriorated, and the resource of silvery pomfret is more rapidly declined.

At present, the artificial breeding of pomfret has achieved certain effect, but problems that the pomfret has low utilization of pellet feed, flatulence of the digestive tract of young pomfret is caused by splashing of artificial feed in a whole pool, influence of feeding of a ball-shaped material on water quality is large, labor cost is high and the like still exist.

Disclosure of Invention

The invention aims to provide a domestication method for pomfret to completely eat pellet feed, so that the problem of low utilization rate of artificial pellet feed for pomfret larvae is solved, the breeding cost of pomfret is reduced, the environment of a breeding water body is improved, and the problem of flatulence of the digestive tract of pomfret larvae is solved.

The domestication method of the pomfret completely ingesting the pellet feed, provided by the invention, is characterized in that biological baits, namely the rotifer and the fairy shrimp nauplius are fed during the period from the initial ingestion of the pomfret fry to the complete ingestion of the pellet feed;

more specifically, feeding rotifers at 5-26 days after hatching, and feeding fairy shrimp nauplii at 15-42 days after hatching;

and the floating type pellet feed with the grain diameter of 0.20-0.30 is fed when the fish is 21-25 days old after hatching,

feeding floating type pellet feed with the grain diameter of 0.35-0.40mm at the age of 26-35 days after hatching,

when feeding, stirring and mixing the floating feed with the grain diameter of 0.35-0.40mm and the fairy shrimp nauplii, uniformly sprinkling in a whole pool, and keeping the density of the fairy shrimp nauplii in the water body to be 0.5-1/ml;

after incubation for 36-42 days, adding slow-sinking type feed with the grain diameter of 0.45-0.50mm until acclimatization is completed;

in addition, the fairy shrimp nauplii are supplemented in the water body after the feed is fed in the noon and the evening every day; the density of the fairy shrimp in the water body is 0.5 per ml;

after the age of 43 days, the fairy shrimp nauplii are stopped to feed, and only the pellet feed is fed.

In order to reduce the infection of pathogenic bacteria on the young pomfret, antibacterial peptide screened from the pomfret is added into the bait;

one specific sequence of the antibacterial peptide is as follows (SEQ ID NO: 1): RRKRLNRGLRLLQRKQSLKRAKK.

The method effectively solves the defects of the existing artificial breeding of the pomfret by adjusting the feeding type and the feeding time of the biological bait and the artificial compound feed during the artificial breeding and the breeding period of the pomfret, and effectively reduces the problem of flatulence of the digestive tract of the pomfret larvae by adjusting the feeding time and the feeding proportion of the biological bait and the pellet feed.

Drawings

FIG. 1: bait sequence chart for cultivating pomfret.

Detailed Description

The present invention will be described in detail with reference to examples.

Example 1

In 2020, 4-7 months, experiments for domesticating granular feed for breeding pomfret were carried out in Xixuan fishery science and technology island base of research institute for marine aquaculture in Zhejiang.

1. Pomfret offspring seed source and breeding environment

The pomfret offspring seeds are bred from bred parent pomfret, collected fertilized eggs are placed in a 20-ton indoor cement pond for hatching after the parent pomfret spawns in the early 5 months, and hatching membranes after about 36-40 hours at the water temperature of 20-22 ℃. The water temperature is controlled at 20-26 deg.C during seedling raising, the illumination intensity is 200-500lx, the salinity is 22-26, the pH value is 8-8.6, and the dissolved oxygen is more than 6mg/L.

2. Cultivation of biological bait

The rotifer living body is purchased from a culturing farm in the Gangxi region of Jiangsu Lihongkong and is transported back to a test farm to be cultured in a cement pond with the specification of 15x5x1.5m, and the rotifer inoculation density is controlled to be 20-40 water bodies per liter. The water temperature is 20-26 ℃ and the salinity is 18-26 during the culture period of the rotifer. Observing the color of the water body and the quantity of the rotifers at regular time every day, supplementing the concentrated algae solution in time, and filtering out the rotifers to supply to the pomfret fries when the density of the rotifers reaches about 40/ml.

The fairy shrimp nauplii are formed by hatching fairy shrimp eggs which are market commodities, generally the fairy shrimp eggs are hatched in a 1 ton bucket with the water temperature of 26-30 ℃ and the salinity of 20-26, the air charging quantity is increased during the hatching period, the water surface is kept rolling, a plastic film is covered on the bucket, and an incandescent lamp is hung on the bucket.

3. Feeding mode of biological bait

Feeding biological baits including rotifers and fairy shrimp nauplii after fries of silvery pomfret are opened in a conventional mode, feeding rotifers at 5-26 days after hatching, adjusting feeding amount of the rotifers according to actual food intake of the silvery pomfret, checking rotifers density once in the morning and afternoon every day, keeping the number of the rotifers in water to be 3-5/ml, and reinforcing by concentrated algae before feeding the rotifers to supplement EPA and DHA.

Feeding fairy shrimp nauplii at 15-42 days after hatching, separating egg shells before feeding the fairy shrimp nauplii, adding the fairy shrimp nauplii into a water body for three times every day at 15-20 days after hatching, keeping the density in the water body at 1/ml, changing water for 2 times every day, and changing water amount for 30% every time;

feeding fairy shrimp nauplii 21-25 days after hatching in the manner, and sprinkling floating type particles with the particle size of 0.20-0.30mm, wherein the weight of the floating type particles is 10% of the fresh weight of biological bait during each feeding; the floating feed is a pellet feed capable of floating on the surface of seawater for a long time, and in this embodiment, pellet feeds with particle diameters of 0.20-0.30mm and 0.30-0.40mm are all floating.

Feeding the fairy shrimp nauplii for 6 times every day when the fairy shrimp nauplii are 26-35 days old after incubation, stirring and mixing floating type particles with the particle size of 0.35-0.40mm and the fairy shrimp nauplii according to 25-30% of wet weight of biological bait during feeding, uniformly sprinkling in a whole pool, and keeping the density of the fairy shrimp nauplii in water body to be 0.5-1/ml;

feeding slowly sinking type pellet feed with particle size of 0.45-0.50mm at fixed time and fixed point for 35-42 days after hatching, and supplementing a certain amount of fairy shrimp nauplii in water after the feed feeding is finished at noon and evening every day, and controlling the density at 0.5/ml. The slow-settling type feed is granular feed which is slowly settled and does not float, and sinks into the bottom of the cement pond with the depth of 1.2m for about 10-15 minutes.

The granulated feed fed during domestication is fish feed produced by Nippon forest company, and has a crude protein content of 52% or more, a crude fat content of 8% or more, a crude fiber content of 5% or less, and a crude ash content of 17% or less.

4. Feeding sequence of domesticated pellet feed

After 43 days of incubation, the juvenile pomfret can completely eat pellet feed, and the pellet feed is divided into yubao feed produced by Nippon forest and company and sea child feed produced by Weifang limited company. The crude protein content of the Yubao feed is more than 52 percent, the crude fat content is more than 8 percent, the crude fiber content is less than 5 percent, and the crude ash content is less than 17 percent; the sea child feed has the crude protein content of more than 55%, the crude fat content of more than 8%, the crude fiber content of less than 5%, the crude ash content of less than 16%, and the proportion of fish and shrimp raw materials is 85%.

The domestication of the pomfret fry according to the method can effectively improve the success rate of the pomfret fry which is excessively fed with biological bait into artificial pellet feed, and the seawater environment pollution can be effectively reduced only by finally converting the seawater fish culture into full artificial feed for feeding, and the use of the iced fresh fishes and shrimps is reduced, thereby achieving the purpose of protecting the marine ecological environment. The method is different from the traditional seedling raising process in that the artificial granulated feed is fed directly after the biological bait is fed, flatulence disease generated by the pomfret under the condition of feeding the granulated feed is reduced by continuously adjusting the feeding method of the fairy shrimp and the compound feed, and the breeding rate of the seedlings is improved.

In order to reduce the disease incidence of young pomfret during domestication, the used pellet feed is soaked by using an antibacterial peptide solution in the bait domestication process, and the soaked feed is dried and then fed.

The amino acid sequence of the antibacterial peptide is RRKRLNRGLRLLQRKQSLKRAKK (SEQ ID NO: 1), the antibacterial peptide is obtained by screening a cDNA reduction library, and the antibacterial peptide has obvious bacteriostatic ability on common microbial pathogenic bacteria in pomfret culture such as Nocardia, aeromonas hydrophila, vibrio parahaemolyticus and Vibrio parahaemolyticus (Table 1).

Table 1: minimum inhibitory concentration MIC (mug/mL) of antibacterial peptide on various aquatic pathogenic bacteria

Moreover, the antibacterial peptide used in the invention is separated from pomfret, so that the pomfret juvenile fish cannot generate obvious stress reaction, thereby influencing the feed utilization rate and the growth rate.

The granulated feed soaked by the antibacterial peptide with the amino acid sequence of SEQ ID NO. 1 is fed, and the stress effect of the polypeptide on the pomfret is detected through the content of cortisol in serum.

The determination of the Cortisol content in serum was carried out using an enzyme-linked immunoassay kit for Cortisol (Cortisol) from Hippocampus Biotech Ltd.

The result shows that compared with the antibacterial peptide Pt5e, the antibacterial peptide with the sequence of SEQ ID NO. 1 used in the invention can effectively reduce the stress reaction of fish bodies, and can be used for preparing a feed additive for pomfret.

Claims

1. A domestication method for pomfret completely ingests pellet feed is characterized in that the method comprises the steps of feeding biological baits of rotifers and fairy shrimp nauplii during the period from initial ingestion of pomfret fry to complete ingestion of pellet feed; feeding floating type granulated feeds with the grain diameter of 0.20-0.30 at the age of 21-25 days after incubation, feeding floating type granulated feeds with the grain diameter of 0.35-0.40mm at the age of 26-35 days after incubation, adding slow-sinking type feeds with the grain diameter of 0.45-0.50mm at the age of 36-42 days after incubation, stopping feeding fairy shrimp nauplii after the age of 43 days, and only feeding the granulated feeds;

the bait is added with antibacterial peptide with an amino acid sequence of SEQ ID NO. 1 screened from pomfret.

2. The method according to claim 1, wherein the rotifer is fed 5-26 days after hatching and the fairy shrimp nauplii are fed 15-42 days after hatching.

3. The method as claimed in claim 1, wherein the floating pellet feed with the particle size of 0.35-0.40mm is fed by uniformly sprinkling the floating pellet feed with the particle size of 0.35-0.40mm and the fairy shrimp nauplii in the whole pool after stirring and mixing, and the density of the fairy shrimp nauplii in the water body is kept to be 0.5-1/ml.

4. The method of claim 1, wherein the method comprises supplementing the water with fairy shrimp nauplii after the feed has been fed at noon and evening on a daily basis; the density of the fairy shrimp in the water body is 0.5 per ml.