Cultivation and breeding of grass carp in industrial and domestic conditions has become possible thanks to the research of Russian and Japanese scientists. Indeed, in captivity they do not breed! Following the rules and breeding technologies, you can successfully start a new business!
Breeding Features
Grass carp or grass carp is a large herbivorous species of freshwater fish of the Cyprinidae family, and the only species of the genus Ctenopharyngodon Idella. In the natural environment, it prefers slow-flowing or standing water bodies.
Grass carp are bred for two reasons:
- Thick white meat of high quality.
- As a way to control algae growth in water bodies.
Advantages of breeding grass carp:
- They have increased industrial potential due to rapid growth. Subject to the rules of cultivation, grass carp gain 800 g in two years, 1.5 kg in three years, and four-year-old individuals reach 3-3.2 kg. Adult fish are able to grow up to 1.2-2 m long and weigh up to 35 kg.
- Weakly susceptible to infectious diseases.
- The meat has good taste.
- Unpretentious to the level of oxygen in the water.
- Cope well with water treatment preventing flowering.
The most common cultivation methods are:
- Growing experience in China. In China, grass carp are grown in intensive and semi-intensive ponds, stocking them as the main or secondary species along with other carps. The density is 750-3000 fish per hectare. Weed algae and near-pond terrestrial herbs are the main food source for grass carp. Special feeds are also used in the form of granulate and by-products of the processing of grain and vegetable oil. Feed is used to save labor costs for the care of pond algae.
The second most popular method of growing is an intensive monoculture system in cells, where grass carp will be the main species. For this, cells of 60 square meters are used. m and a depth of 2-2.5 m. The fish feeds on weed algae, terrestrial vegetation and feed. The harvesting period is 8-10 months with a yield of 30-50 kg of fish per cubic meter. m - The experience of breeding Vietnam. Grass carp is grown in clay ponds using cells. A multicultural system is used with other species, for example, with silver and common carp, roha and others. Amur makes up 60% of the total density of the pond. Grass carp is fed with green food from terrestrial herbs, cassava leaves and corn, banana stems.
- Breeding Experience of India. In India, grass carp is grown together with Indian and Chinese large carps. The stocking density of 5–20% of grass carp from the total number of fish, depending on the volume of algae (Hydrilla, Vallisneria, Wolffia) and amphibian grass.
Herbal carps reach 0.5-1.5 kg of weight in 8-10 months. Normal catch in such systems can reach 8-10 t / ha per year.
Conditions of detention
When breeding grass carp in Russia, it should be borne in mind that when the temperature drops to below 12 ° C, the fish stop eating completely. At optimal temperatures of 25-30 ° C, the lack of food is easily compensated by mowed grass, while carp develops very quickly.
In the southern part of the country, carp is gaining mass faster and growing larger than in the northern regions.
Herb carps are currently bred using a variety of production systems:
- semi-intensive - the natural feeding of grass carp with algae with a minimal addition of feed is used;
- intensive ponds - keeping in closed ponds using artificial feeding methods.
- cells in open reservoirs (reservoirs, lakes, ponds) - grow only one species of fish.
For growing in semi-intensive and intense ponds, the polyculture method is used - the maintenance of different types of fish in one territory.
Stocking
When breeding grass carp in a natural reservoir produce its stocking. For this, you must adhere to the rules:
- to get high-quality material for breeding (fry or adults);
- transport it according to the rules of transportation;
- during transportation, the temperature of the water should be approximately equal to that in the body of water;
- for transportation, do not draw water from the water supply system, wells, springs, only from a river, pond, lake;
- carry out transportation in a cool time, in the morning or in the evening;
- if transportation occurs during the day, the water should be cooled with ice wrapped in burlap or gauze;
- gradually mix the water from the reservoir with the water used for transportation, allowing the fish to get used to new conditions.
You can not immediately release fish into a reservoir, especially with a large temperature difference, it can die from temperature shock.
The video clip shows how to stock up a reservoir in order to further breed grass carp to prevent overgrowing of the reservoir with vegetation.
Caviar Growing
The main problem with the cultivation is that the fish does not reproduce naturally, although it reaches puberty at home cultivation.
Hormone injections and environmental stimulants such as running water are used for spawning under such conditions.
Gender difference
The body of the grass carp is elongated, cylindrical, torpedo-shaped, compressed in the back. To establish a female or male is practically impossible, but there are some signs that determine the sex of grass carp in the spawning period.
Features of the female:
- reaching puberty, females begin to overtake males in growth, acquiring a rounded abdomen, in which up to 500,000 eggs ripen;
- during the spawning period, female amur females have a larger sexual opening, become slightly swollen and acquire a reddish tint;
- pectoral fins are rounded;
- gill covers are covered with mucus and smooth to the touch;
- when the female is pressed on the abdomen, the eggs do not stand out until it ripens;
- anal oval elongated.
Features of the male:
- the body of males is thin and long;
- during the spawning period on the gill wings, cheeks and on the back of the head, you can notice something like the whitish warts;
- pectoral fins are acute;
- gill covers are rough to the touch;
- when the male is pressed on the abdomen, a little milk or whitish liquid will stand out;
- the anus extends from the head towards the tail, resembles a triangular fold.
In flocks, the number of males doubles the number of females.
Preparatory stage
Females who are ready to throw eggs create optimal temperature conditions with the achievement of spring-summer temperatures of 25-30 degrees. At the stage of fertilization, two-stage pituitary injections are used.
Material for pituitary injection is an extract from the pituitary of crucian carp or carp.
At this stage, the following manipulations are carried out:
- males are separated from females;
- carry out preliminary injections;
- immediately after the first injection, the cupids go to the reservoir with running water;
- after 1 day, final injections are administered;
- fish are placed in calm, slightly running water (pond).
After these procedures, caviar is collected by draining.
Fertilization and incubation
For fertilization, eggs of 4-5 year old females are collected. 5 ml of the seminal fluid of males (using the seeds of two males of cupid due to the low level of productivity) is mixed with the eggs of one female.
From time to time, the use of seed collected in the wild helps maintain the quality of the population’s genetics.
Then you need to carefully mix the contents, since the caviar is easily damaged, often a feather is used for mixing. After that, water is added to the mixture in a ratio of 1: 2 and washed 9-11 times. After this procedure, the caviar noticeably increases in size and is placed for incubation in the Weiss apparatus.
During the incubation process, a high level of waste is observed. The average survival rate is 1 out of 5, which is 100,000 yearlings out of 500,000 eggs.
Hatching
After hatching, the larvae are placed in special nylon networks, installed in an artificial pool or in a reservoir with a low current.
The specific mode is set:
- within 6 days, a temperature of 21 ° C is established;
- the next 4 days the temperature rises to 23 ° C;
- the next 2-3 days, a maximum temperature of 30 ° C is maintained.
Subject to the temperature regime, the larvae occupy the desired position in the pond and begin to feed.
Larval content
Before placing nets with larvae in a pond, it is necessary to clean it from pests, since insects can eat cupid larvae. This is done after complete drying with quicklime to eliminate all pests. The usual dose is 900-1125 kg / ha.
In addition to the zooplankton, which the larvae feed on, in the conditions of home cultivation, a mixture of cottage cheese and egg yolk is used to feed.
Organic feed, compound feed or green feed is added to increase the natural biomass of algae and zooplankton 5-10 days before the installation of nets. The amount of feed used is 3,000 kg / ha for feed or 4,500 kg / ha for green feed. Green and organic feed can be used at the same time, but the amount of each should be reduced accordingly.
Soy milk can also be used both as a main feed and for feeding. The norm is 3-5 kg (dry soy) per 100,000 fish daily. Pasty soybean meal or other by-products of grain processing are used from the 5th day after the installation of nets, usually in the amount of 1.5-2.5 kg per 100,000 fish daily.
Normal survival in nurseries is 70-80%, although it can reach more than 90%. Typically, the larvae reach a length of about 30 mm after 2-3 weeks of cultivation.
Maintenance of yearlings
To maintain yearlings, fry ponds with a volume of up to 200 square meters are used. m. When the fry grow to 2-3 cm, they are transferred to a pond up to 500 square meters. Young growth is grown at the rate of 250 larvae or 45 fry per 1 sq. Based on the density of the pond stocking - 120,000-150,000 year-olds per 1 ha, if this is the main species in the pond, or 30,000 fish per 1 ha, if grass carp is a minor species.
Grass carp can be grown together with other species of carps except black (Mylopharyngodon piceus).
Grass carp up to 70 mm in size mainly feeds on wolfia. Initially, feeding is 10-15 kg per 10,000 fish per day and gradually increases in accordance with the growing needs of fish. The food is replaced by duckweed (Lemna minor) when the fish grows to 70-100 mm in length. After that, the fish can be fed with delicate weed algae and land grasses. In addition, feed (soybean and rapeseed meal, wheat or rice bran, and others) are added in the daily norm of 1.5-2.5 kg per 10,000 fish.
Young fingerlings are fed, even if zooplankton is enough, 1 time per day. To do this, you need to install and fix the feeder with food mixtures on the surface of the water against drift by the current.
Normal survival over the entire period of growing fry should be above 95%.
The maintenance of young individuals
The diet is similar, but increases with the growing body of fish that eat food 1.2-2 times their own weight. By the end of this period, the fish usually reaches about 250 g. The weight gain is directly dependent on nutrition and on ambient temperature.
Adult fish maintenance
Adult white cupids feed themselves exclusively on plant-based foods. With a large stocking of the pond, special compound feeds are used. For additional nutrition, ground vegetation is also used in the form of mowed grass, corn leaves and more. Adult grass carp need four meals a day.
In order for the amur to fully develop and grow, it is necessary to calculate the population size at the rate of 1-2 individuals per square meter of vegetation.
One way to feed grass carp in household fisheries is shown in the video clip. The idea is shared by Igor Kramarchuk.
Profitability
The basis for the successful cultivation of grass carp is the calculation of profitability, minimizing the cost of animal feed and other plant diets. The right approach to growing increases the fishing effect - your income.
An approximate calculation of the main costs
Profitability is designed for an area of 2000 m2. The calculations use averaged data:
- Estimated productivity - 1000 kg / ha;
- the average weight of the annual grass carp is 50 g;
- indicative price - 235 rub / kg;
- average survival - 75%;
- marketable weight - 1000 g;
- Wholesale price - 125 rubles / kg;
- the cost of feed - 7 rubles / kg;
- the coefficient of grain in the feed - 5 kg;
- the cost of lime (counting 1500 kg per ha) - 7 rubles / kg;
- the total weight of the fish is - 1500 kg;
- a landing density of 2000 m2 will be 2666 pcs.;
- the price of planting materials - 30590 rubles;
- the total cost of offspring - 239,400 rubles;
- feed: 69825 rub;
- lime: 20950 rub;
Total expenses: 121360 RUB
Net income: 118 000 rub.
In this example, it can be seen that at a cost of 121,360 rubles for the maintenance of a pond, breeding and cultivation of grass carp at home, the profit will be 239,400 rubles, which indicates a profitability of 197%.
Net profit from the supply of adults to store shelves and catering places will appear after the implementation of the first conclusion. This indicates a good profitability of growing and breeding grass carp.
Only those who follow all stages can start breeding and breeding grass carp in ponds and other bodies of water: starting from preparing a pond, incubating, setting proper nutrition, according to age groups, to catching fish. Only then will breeding be cost-effective.