A breeding method and a cultivation method for a relatively slender largemouth bass

Abstract

The present invention provides a selective breeding method and a cultivation method for largemouth bass with a slender body type, belonging to the technical field of aquaculture. In order to selectively breed and cultivate largemouth bass with a high proportion of slender body types, the present invention provides a selective breeding method and a cultivation method for largemouth bass with a slender body type. Through continuous selection with the slender body type standard and body weight as indicators, a largemouth bass population with a significantly increased proportion of largemouth bass with a slender body type is obtained after 4 years of screening. At the same time, by feeding a feed containing dandelion, purslane, and wild chrysanthemum in combination with water quality treatment, adult fish groups with uniform body types and a large proportion of slender body types are cultivated, greatly increasing the economic benefits of farmers and being suitable for large-scale popularization and application.

Description

Technical Field

[0001] The invention belongs to the technical field of aquaculture, and particularly relates to a breeding method and a breeding method for a slender largemouth black bass. Background Art

[0002] The output of largemouth bass reached 702,000 tons in 2021, an increase of 13.3% over 2020, accounting for 2.65% of the total output of freshwater aquaculture, an increase of 0.25%. As an important characteristic freshwater aquaculture fish in my country, it is suitable for survival in water temperatures of 1-36℃, so it is widely farmed in Guangdong, Sichuan, Jiangsu and Xinjiang, and the breeding areas are spread all over the country. In recent years, due to the influence of factors such as germplasm degradation, artificial selection, bait and environment, there is a large genetic variation in the cultured largemouth bass population, which can be divided into two types according to body shape: short round and slender. When collecting fish at the pond, fishmongers prefer largemouth bass with slender bodies. When purchasing in currency, if the proportion of short and round largemouth bass is higher than 30%, the pond price will be 2 to 3 yuan lower per catty; when the proportion of slender largemouth bass exceeds 90%, the market acceptance is higher, and it can often be sold at a price increase of 0.5 to 1 yuan per catty. It can be seen that the body shape of largemouth bass directly affects the sales profit of farmers. Therefore, it has become an urgent need for farmers to breed largemouth black bass that grow fast and have a slender body, and to increase the proportion of largemouth black bass of this size.

[0003] In addition, the feeding of bait and water quality during the breeding process may also affect the growth and body development of largemouth bass. Largemouth bass are originally carnivorous fish with short intestines and low digestion and absorption rates of high nutrients. However, many largemouth bass feeds are high in protein, sugar and fat. Too high protein content will not only waste feed protein resources, but also cause largemouth bass hepatobiliary disease, fish obesity, and increase the pressure on pond water quality management. If the protein content is too high, fish cannot metabolize it and will excrete more organic waste into the water, which not only increases costs, but also causes damage to the water environment and forms eutrophic fertilizer water. Summary of the invention

[0004] In view of this, the object of the present invention is to provide a method for selecting and breeding largemouth black bass with a slender body and a breeding method, which can significantly increase the proportion of largemouth black bass with a slender body in the breeding population through continuous breeding.

[0005] The present invention provides a method for breeding largemouth black bass with a slender body, comprising the following steps:

[0006] The P0 generation of largemouth bass were self-fertilized to breed the F1 generation. When the F1 generation grew to 100-600g in weight, the F1 generation broodstock were selected based on the slender body shape and weight.

[0007] Using the F1 generation of breeding fish as parents for paired breeding, and screening the obtained F2 to F5 generations respectively with the above-mentioned slender body type standard and body weight as indicators;

[0008] The above-mentioned slender body type standard is the ratio of body length to body height and the ratio of body length to caudal peduncle length;

[0009] The ratio of body length to body height is 2.50 - 3.00;

[0010] The ratio of body length to caudal peduncle length is 4.20 - 5.10.

[0011] Preferably, the number of screenings is 2 - 3 times.

[0012] Preferably, when screening twice, the first screening is carried out when the body weight of the F1 generation grows to 100 - 150 g, and the top 55% - 65% of the F1 generation ranked from high to low in body weight are selected to form a target population under the condition of meeting the slender body type standard. The second screening is carried out when the body weight of the F1 generation individuals in the target population grows to 450 - 600 g, and the top 8% - 12% of the F1 generation ranked from high to low in body weight are selected under the condition of meeting the slender body type standard.

[0013] Preferably, in the first screening, the top 60% of the F1 generation ranked by body weight are selected to form a target population;

[0014] In the second screening, the top 10% of the F1 generation ranked by body weight are selected.

[0015] Preferably, during the screening process of each generation from F1 to F5, the average increase in inbreeding coefficient is controlled below 1%.

[0016] Preferably, the method of controlling the inbreeding coefficient is to identify the parents based on PIT tags and calculate the inbreeding coefficient according to formula I

[0017]

[0018] In the formula, F x represents the inbreeding coefficient of individual x; 1 / 2 represents half of the genetic structure of each generation; n1 represents the number of generations from the father to the common ancestor; n2 represents the number of generations from the mother to the common ancestor; F A represents the inbreeding coefficient of the common ancestor itself; n1 + n2 + 1 = N is the number of individuals in the parental related path chain;

[0019] The PIT tags are injected when the body weight of the F1 generation grows to 10 - 20 g.

[0020] Preferably, the number of breeding fish screened in each generation from F1 to F5 is not less than 400 tails.

[0021] The present invention provides a breeding method for largemouth bass with a relatively slender body type selected for the said method, comprising the following steps:

[0022] Feed the largemouth bass with the modified feed, disinfect the breeding environment and purify the water quality;

[0023] The modified feed includes Chinese herbal medicines and basic feed; the mass of the Chinese herbal medicines accounts for 0.8 - 1.2% of the basic feed;

[0024] The Chinese herbal medicines include dandelion, purslane and wild chrysanthemum;

[0025] The mass ratio of the dandelion, purslane and wild chrysanthemum is (0.8 - 1.2):(1.6 - 2.4):(0.6 - 1.4).

[0026] Preferably, the method for disinfecting the breeding environment is to sprinkle EM bacterial liquid once every 1 week;

[0027] The final concentration of the EM bacterial liquid is 0.5 - 1 kg / mu.

[0028] Preferably, the method for purifying the water quality is to stock silver carp and bighead carp; the stocking density of the silver carp is 30 - 50 tails / mu; the stocking density of the bighead carp is 20 - 40 tails / mu.

[0029] The breeding method for largemouth bass with a relatively slender body type provided by the present invention defines the relatively slender body type with 3 indicators significantly related to body length, body height and caudal peduncle length significantly related to body type. At the same time, continuous breeding in combination with body weight advantage can significantly increase the proportion of relatively slender body types in the breeding population. After 5 generations of breeding, a new variety of largemouth bass with good body type and fast growth rate is cultivated. From the results of the examples, it can be seen that by using the breeding method provided by the present invention, the proportion of largemouth bass with a relatively slender body type can be greatly increased, and the proportion of the target body type reaches more than 85%, which is significantly better than the proportion of largemouth bass with a relatively slender body type obtained by the conventional method (65%). The proportion of the target body type in the breeding group is increased by more than 30.76% compared with the control group. It can be seen that the breeding method provided by the present invention is beneficial to breeding adult fish with uniform body type and a large proportion of relatively slender body types, greatly increasing the economic benefits of farmers and being suitable for wide popularization and application.

[0030] The present invention also provides a method for culturing largemouth bass with a relatively slender body type. By adding Chinese medicinal herbs such as dandelion, purslane, and wild chrysanthemum to the feed during the cultivation stage and combining water quality treatment, the present invention can effectively increase the weight of largemouth bass. The results of the examples show that after 150 days of cultivation, the weight of the selected largemouth bass group increased by more than 10.09% compared to the control group, promoting the growth of largemouth bass. At the same time, by adding Chinese medicinal herbs to the feed, the degree of abdominal fat enrichment in fish can be significantly reduced, and the fat accumulation in the liver and viscera of adult fish can be reduced, further improving the body type of largemouth bass. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a standard diagram for measuring the morphological indexes of largemouth bass;

[0032] Figure 2 It is a body type diagram of several common body types of largemouth bass. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] The present invention provides a method for selecting largemouth bass with a relatively slender body type, including the following steps:

[0034] Self-cross within the P0 generation population of largemouth bass to breed the F1 generation. When the weight of the F1 generation grows to 100 - 600 g, select the F1 generation broodstock with the relatively slender body type standard and weight as the indexes;

[0035] Use the F1 generation broodstock as parents for paired breeding, and respectively screen the obtained F2 generation to F5 generation with the relatively slender body type standard and weight as the indexes;

[0036] The relatively slender body type standard is the ratio of body length to body height and the ratio of body length to caudal peduncle length;

[0037] The ratio of body length to body height is 2.50 - 3.00;

[0038] The ratio of body length to caudal peduncle length is 4.20 - 5.10.

[0039] In the present invention, the body length, body height, and caudal peduncle length involved in the relatively slender body type standard are all significantly correlated with the body type result, while other morphological indexes (including total length, head length, caudal peduncle height, eye diameter, etc.) are not significantly correlated with the body type. The measurement standards for indexes such as body length, body height, caudal peduncle length, total length, head length, caudal peduncle height, and eye diameter in the morphological indexes can be seen in Figure 1, conventional measurement methods can be adopted. Based on the morphological data and body shape of each fish, it is determined that when 2.50 < body length / body height < 3.00 and 4.20 < body length / caudal peduncle length < 5.10, the largemouth bass shows a relatively slender body shape characteristic. When body length / body height < 2.50 and body length / caudal peduncle length > 5.10, the largemouth bass shows a relatively short and round body shape characteristic. When body length / body height > 3.00 and body length / caudal peduncle length < 4.20, the largemouth bass may be too thin or have growth deformities.

[0040] In the present invention, the number of screenings preferably includes 2 to 3 times, more preferably 2 times. The more the number of screenings, the more beneficial it is to increase the proportion of largemouth bass with the target body shape, but it will greatly increase the breeding workload. In the embodiments of the present invention, through 2 screenings, the proportion of largemouth bass with the target body shape can be effectively increased, and the workload is not large. When screening twice, the first screening is carried out when the weight of the F1 generation grows to 100 - 150 g (April), and the top 55% - 65% of the F1 generation ranked from high to low in weight are selected to form the target population under the condition of meeting the standard of relatively slender body shape. The second screening is carried out when the weight of the F1 generation individuals in the target population grows to 450 - 600 g (August of the same year), and the top 8% - 12% of the F1 generation ranked from high to low in weight are selected under the condition of meeting the standard of relatively slender body shape. In the first screening, preferably the top 60% of the F1 generation in weight are selected to form the target population. In the second screening, preferably the top 10% of the F1 generation in weight are selected. During the screening process of the F1 generation, the average increment of the inbreeding coefficient is controlled below 1%, which is beneficial to avoiding inbreeding and the number of deformed fish. The method of controlling the inbreeding coefficient is preferably to identify the parents according to the PIT tag and calculate the inbreeding coefficient according to formula I. The PIT tag is injected when the weight of the F1 generation grows to 10 - 20 g. The method of injecting the PIT tag to identify the parents has no special limitation, and the well-known injection method of the PIT tag in the art can be adopted. The number of broodstock for F1 generation screening is preferably not less than 400 tails.

[0041] The inbreeding coefficient is calculated according to formula I.

[0042]

[0043] In the formula, F x represents the inbreeding coefficient of individual x; 1 / 2 represents half of the genetic structure of each generation; n1 represents the number of generations from the father to the common ancestor; n2 represents the number of generations from the mother to the common ancestor; F A represents the inbreeding coefficient of the common ancestor itself; n1 + n2 + 1 = N is the number of individuals in the parental related path chain.

[0044] The F2 to F5 generations of the bred fish are screened using the same method as for screening the F1 generation broodstock, which will not be elaborated here. During the screening process of the F2 - F5 generations, the average increment of the inbreeding coefficient is controlled below 1%, which is beneficial to avoiding inbreeding and reducing the number of deformed fish. The number of broodstock screened in each generation of the F2 - F5 generations is preferably not less than 400 tails.

[0045] In the present invention, after 4 years of breeding, a new variety of largemouth bass with good body shape and fast growth rate is cultivated.

[0046] The present invention provides a cultivation method for the slender - shaped largemouth bass bred by the above - mentioned method, comprising the following steps:

[0047] Feeding the slender - shaped largemouth bass with modified feed, disinfecting the cultivation environment and purifying the water quality;

[0048] The modified feed comprises Chinese herbal medicines and basic feed; the mass of the Chinese herbal medicines accounts for 0.8% - 1.2% of the basic feed;

[0049] The Chinese herbal medicines include dandelion, purslane and wild chrysanthemum;

[0050] The mass ratio of the dandelion, purslane and wild chrysanthemum is (0.8 - 1.2):(1.6 - 2.4):(0.6 - 1.4).

[0051] In the present invention, the mass ratio of the dandelion, purslane and wild chrysanthemum is preferably 1:2:1. The synergistic effect of the dandelion, purslane and wild chrysanthemum can not only improve the growth rate of the new variety of largemouth bass, but also reduce the fat accumulation in the abdominal viscera and further improve the fish body shape. There is no special limitation on the type of the basic feed in the present invention, and the well - known fish feed in the art can be used. For example, in the embodiment of the present invention, the mass ratio of protein in the basic feed is 46% and the mass ratio of fat is 8%, and it is purchased from Wuxi Tongwei Biotechnology Co., Ltd. The feeding amount of the improved feed each time is 3% of the fish body weight. The improved feed is preferably fed 2 times a day, at 7:00 in the morning and 17:00 in the afternoon respectively.

[0052] In the present invention, the method for disinfecting the cultivation environment is preferably to sprinkle EM bacterial liquid once every 1 week. The final concentration of the EM bacterial liquid is preferably 0.5 kg / mu - 1 kg / mu, and more preferably 0.8 kg / mu. In the embodiment of the present invention, the EM bacterial liquid is purchased from Jiangsu Hengtai Environmental Protection Technology Development Co., Ltd.

[0053] In the present invention, the method for purifying water quality preferably involves stocking silver carp and bighead carp. The stocking density of silver carp is preferably 30 - 50 tails per mu; more preferably 40 tails per mu. The stocking density of bighead carp is preferably 20 - 40 tails per mu, more preferably 30 tails per mu. By feeding a feed containing specific Chinese medicinal materials and treating water quality during the adult fish farming stage, it is beneficial to cultivate adult fish with uniform body shapes and a higher proportion of slender body shapes, increasing the economic benefits of farmers.

[0054] The following is a detailed description of a method for selecting and breeding largemouth bass with a slender body shape and a farming method provided by the present invention in combination with examples, but they should not be construed as limiting the protection scope of the present invention.

[0055] Example 1

[0056] A method for selecting and breeding largemouth bass with a slender body shape

[0057] 1. Screening of indicators related to slender body shape

[0058] 1.1 Determination of the basic breeding population

[0059] 802 fish were randomly selected from 3000 fry of the northern subspecies of largemouth bass (P0 generation) that had been cultured for 7 months, ensuring that the caudal fins were intact and there were no obvious deformities. The largemouth bass to be tested was lightly anesthetized with 60 mg / L of fish anesthetic (MS-222);

[0060] 1.2 Measurement of morphological data.

[0061] The live weight of each test fish was weighed with an electronic balance (accurate to 0.01 g); indicators such as total length, body length, head length, body height, caudal peduncle length, caudal peduncle height, and eye diameter were measured with a ruler (accurate to 0.01 cm); the caudal peduncle height and body width were measured with a vernier caliper (accurate to 0.01 cm), as shown specifically in Figure 1 ;

[0062] 1.3 Correlation analysis of morphological indicators and body weight

[0063] Calculate the correlations between the full length, body length, body height, body thickness, caudal peduncle length, caudal peduncle height and other indicators and body weight through principal component analysis. The indicators such as full length, body length, body height, body thickness, caudal peduncle length show high correlations with body weight. Therefore, selecting based on indicators such as body length, body height, caudal peduncle length can improve weight gain. At the same time, the ratios of body length / caudal peduncle length and body length / body height also contribute greatly to body weight. Among them, the ratio of body length / body height is negatively correlated with body weight, indicating that the larger the body height and the shorter the body length, the greater the body weight; the ratio of body length / caudal peduncle length is positively correlated with body weight, indicating that the longer the body length and the shorter the caudal peduncle length, the greater the body weight. The largemouth bass selected according to these two indicators is the common short and round body type we see. Therefore, setting the ratios of body length / caudal peduncle length and body length / body height within a reasonable range can not only select a satisfactory body type but also improve the growth rate.

[0064] Table 1 Correlation analysis of morphological indicators and body weight of largemouth bass

[0065] Index Body mass Total length <![CDATA[0.952 ** > Body length <![CDATA[0.923 ** > Body height <![CDATA[0.932 ** > Body thickness <![CDATA[0.862 ** > Head length <![CDATA[0.808 ** > Caudal peduncle length <![CDATA[0.457 ** > Caudal peduncle height <![CDATA[0.751 ** > Body length / Body height <![CDATA[-0.418 ** > Body length / Caudal peduncle length <![CDATA[0.162 ** >

[0066] 1.4 Relationship between morphological indicators and body type

[0067] Based on the morphological data and body type of each fish, it is determined that when 2.50 < body length / body height < 3.00 and 4.20 < body length / caudal peduncle length < 5.10, the largemouth bass shows a slender body type characteristic. When body length / body height < 2.50 and body length / caudal peduncle length > 5.10, the largemouth bass shows a short and round body type characteristic. When body length / body height > 3.00 and body length / caudal peduncle length < 4.20, the largemouth bass may be too thin or have growth deformities.

[0068] 2. Breeding method

[0069] 2.1 Establishment of F1 generation population

[0070] Using the method of mass sub-line selection, when the F1 generation grew to about 15 g, 8,000 juvenile fish with neat tail patterns and no deformities were selected and injected with PIT tags. According to the breeding goal, body shapes with 2.50 < body length / body height < 3.00 and 4.20 < body length / caudal peduncle length < 5.10 were determined as the breeding goals. When the F1 generation reached a size of 100 - 150 g in April, the body weight, body length, body height, and caudal peduncle length of the selected breeding fish were measured respectively. First, breeding fish with a body length / body height ratio between 2.50 - 3.00 and a body length / caudal peduncle length ratio between 4.20 - 5.10 were selected. Among the selected largemouth bass breeding fish with the target body shape, the top 60% in terms of body weight were screened for further cultivation. In August 2022, when the F1 generation breeding fish grew to 450 - 600 g, a second selection was carried out. Similarly, breeding fish with a body length / body height ratio between 2.50 - 3.00 and a body length / caudal peduncle length ratio between 4.20 - 5.10 were selected, and then the top 10% were further screened for mating and breeding of the F2 generation parents. During the mating and breeding process, to avoid inbreeding, the parents were identified based on the PIT tags, and the inbreeding coefficient was calculated according to formula I;

[0071]

[0072] In the formula, Fx represents the inbreeding coefficient of individual x; 1 / 2 represents half of the genetic structure of each generation; n1 represents the number of generations from the father to the common ancestor; n2 represents the number of generations from the mother to the common ancestor; FA represents the inbreeding coefficient of the common ancestor itself; n1 + n2 + 1 = N is the number of individuals in the parental related path chain

[0073] The number of selected parents was more than 400 tails, and the average increment of the inbreeding coefficient of the population per generation was controlled below 1%.

[0074] 2.2 Multi-generation continuous selection

[0075] From the F2 generation to the F5 generation, continuous selection was carried out according to the selection method of the F1 generation. The number of selected parents in each generation was more than 400 tails, and the average increment of the inbreeding coefficient of the population per generation was controlled below 1%. After 4 years of continuous selection, a new variety of largemouth bass with a good body shape and fast growth rate was cultivated.

[0076] Example 2

[0077] In Wuxi, Jiangsu, six 2-acre aquaculture ponds were selected. Among them, three ponds were used as the experimental group, and 4,000 largemouth bass after four generations of breeding in Example 1 were stocked in each pond, with the fish body size being about 50 g. Another three ponds were stocked with largemouth bass purchased from the market as the control group, and 4,000 were stocked in each pond as well, with the size being about 50 g. The experimental group and the control group were both fed the same kind of feed (Wuxi Tongwei Biotechnology Co., Ltd. California bass expanded compound feed 8902, with 46% protein and 8% fat). They were fed once at 7:00 in the morning and once at 17:00 in the afternoon, and the feeding amount was 3% of the fish body weight. The breeding cycle was 150 days. The test results are shown in Table 2.

[0078] Table 2 Comparison of body weight and body shape of largemouth bass between the breeding group and the control group

[0079]

[0080]

[0081] Note: "*" indicates a significant difference between different treatment groups (P < 0.05), and the same applies hereinafter.

[0082] Proportion of target body shape: In the experimental group and the control group, 800 - 1,000 fish were randomly netted respectively, and the proportion of the number of largemouth bass with body shape ratios within 2.50 < body length / body height < 3.00 and 4.20 < body length / caudal peduncle length < 5.10 in the selected population was measured.

[0083] The results showed that: after 150 days of breeding, the body weight of the largemouth bass in the breeding group increased by 10.09% compared with the control group, and the proportion of the target body shape in the breeding group increased by 30.76% compared with the control group. Therefore, the largemouth bass bred by the technology of the present invention has the characteristics of fast growth rate and good body shape.

[0084] Example 3

[0085] In Suzhou, Jiangsu, six 0.5-acre aquaculture ponds were selected. Among them, 800 largemouth bass (experimental group) after 4 generations of breeding in Example 1 were stocked in 3 ponds respectively, and the fish body size was about 150 g. In the other 3 ponds, largemouth bass purchased from the market (control group) were put in, and 800 tails were stocked in each pond with a size of about 150 g. The experimental group was fed with conventional feed (protein 46%, fat 8%) + 1% of Chinese herbal medicine mixture (dandelion, purslane, wild chrysanthemum were added according to the mass ratio of 1:2:1); the control group was only fed with conventional feed (California bass extruded compound feed 8902 of Wuxi Tongwei Biotechnology Co., Ltd., protein 46%, fat 8%). Feed was given once at 7:00 in the morning and 17:00 in the afternoon respectively, and the feeding amount was 3% of the fish body weight. The breeding cycle was 120 days. The experimental group splashed EM bacteria solution once every week. After diluting 0.2 liters of EM bacteria 1000 times, it was splashed on the 0.5-acre water surface. In addition, 15 silver carp and 10 bighead carp were stocked in each pond. The results are shown in Table 3.

[0086] Table 3 Comparison of body shape and abdominal fat rate of largemouth bass between the experimental group and the control group

[0087] Index Experimental group Control group Average initial body weight (g) 153.55±8.92 151.28±9.33 Average final body weight (g) <![CDATA[541.78 * ±32.94]]> 492.54±28.17 Target body shape ratio (%) <![CDATA[92 * > 68 Abdominal fat rate (%) 2.16±0.47 <![CDATA[3.57 * ±0.53]]>

[0088] Note: "*" indicates significant differences between different treatment groups (P < 0.05), the same below.

[0089] Among them, abdominal fat rate (%) = 100 * abdominal fat weight / body weight

[0090] The largemouth bass bred and cultured according to the present invention not only has a faster growth rate than ordinary largemouth bass, but also has a significantly increased proportion of the target body shape and significantly reduced abdominal fat enrichment.

[0091] Example 4

[0092] In Wuxi, Jiangsu, 12 aquaculture ponds with an area of 0.5 mu each were selected. 800 largemouth bass purchased from the market were stocked in each pond, and the fish body size was about 100 g. Three aquaculture ponds were used as experimental group 1, and 1% of a Chinese herbal medicine mixture preparation (dandelion, purslane, and wild chrysanthemum were added in a ratio of 1:2:1) was added to the conventional feed (Wuxi Tongwei Biotechnology Co., Ltd. California bass expanded compound feed 8902, with 46% protein and 8% fat). Three aquaculture ponds were used as experimental group 2, and 1% of a Chinese herbal medicine mixture preparation (dandelion and purslane were added in a ratio of 1:1) was added to the conventional feed (46% protein and 8% fat). Three aquaculture ponds were used as experimental group 3, and 1% of a Chinese herbal medicine mixture preparation (dandelion, honeysuckle leaves, and wild chrysanthemum were added in a ratio of 1:2:1) was added to the conventional feed (46% protein and 8% fat). Three aquaculture ponds were used as the control group (experimental group 4), and the conventional feed without the addition of the Chinese herbal medicine mixture preparation (46% protein and 8% fat) was fed. Feeding was carried out once at 7:00 in the morning and once at 17:00 in the afternoon, and the feeding amount was 3% of the fish body weight. The aquaculture cycle was 120 days. The results are shown in Table 4.

[0093] Table 4 Effects of adding different Chinese herbal medicine mixture preparations to the feed on body shape and fat metabolism

[0094]

[0095]

[0096] Note: Different lowercase letters indicate significant differences among treatment groups.

[0097] Compared with experimental group 3 (control group), adding the Chinese herbal medicine mixture preparation provided by the present invention to the feed in experimental group 1 can significantly reduce the serum triglyceride level, reduce the hepatosomatic index, viscerosomatic index, and abdominal fat rate, and increase the proportion of adult fish with the target body shape. The results of experimental group 2 show that if only two Chinese herbal medicine mixture preparations are added, the effect of reducing serum triglyceride is relatively limited, and at the same time, the hepatosomatic index, viscerosomatic index, and abdominal fat rate are significantly higher than those in experimental group 1, and the proportion of adult fish with the target body shape decreases. If one of the three Chinese herbal medicines is replaced (experimental group 3), the proportion of the target body shape is lower than that in experimental group 1, while the abdominal fat rate and hepatosomatic index are significantly higher than those in experimental group 1. Purslane is rich in malic acid, vitamin E, calcium, and phosphorus nutrients, which helps to promote intestinal digestion and absorption and reduce digestive tract diseases. Therefore, the three Chinese herbal medicine mixture preparations provided by the present invention have a synergistic effect, and according to this mixture preparation, it helps to relieve visceral fat deposition and improve the body shape of largemouth bass.

[0098] The above is only the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can still be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A breeding method for largemouth bass with a slender body type, characterized in that, It includes the following steps: Inbreed within the Micropterus salmoides P0 generation to breed the F1 generation. When the weight of the F1 generation grows to 100 - 600 g, screen the F1 generation broodstock with the slender body shape standard and weight as indicators; Use the F1 generation broodstock as parents for paired breeding, and screen the obtained F2 to F5 generations with the slender body shape standard and weight as indicators; Under the condition of meeting the slender body shape standard, screen with the weight indicator; The slender body shape standard is the ratio of body length to body height and the ratio of body length to caudal peduncle length; The ratio of body length to body height is 2.50 - 3.00; The ratio of body length to caudal peduncle length is 4.20 - 5.

10.

2. The breeding method of the slender largemouth bass according to claim 1, characterized in that The number of screenings is 2 - 3 times.

3. The breeding method of the slender and large-mouthed largemouth bass according to claim 2, characterized in that, When screening twice, conduct the first screening when the weight of the F1 generation grows to 100 - 150 g. Under the condition of meeting the slender body shape standard, select the F1 generation with the top 55% - 65% in weight from high to low to form the target population. When the weight of the F1 generation individuals in the target population grows to 450 - 600 g, conduct the second screening. Under the condition of meeting the slender body shape standard, select the F1 generation with the top 8% - 12% in weight from high to low.

4. The breeding method of the slender largemouth bass according to claim 3, characterized in that, During the first screening, select the F1 generation with the top 60% in weight to form the target population; During the second screening, select the F1 generation with the top 10% in weight.

5. The breeding method of the slender largemouth bass according to claim 1, characterized in that, During the screening process of each generation from F1 to F5, the average increment of inbreeding coefficient is controlled below 1%.

6. The breeding method of the slender largemouth bass according to claim 5, characterized in that, The method of controlling the inbreeding coefficient is to identify the parents according to the PIT tag and calculate the inbreeding coefficient according to formula I Formula I In the formula, F x represents the inbreeding coefficient of individual x; 1 / 2 represents half of the genetic structure of each generation; n 1 represents the number of generations from the father to the common ancestor; n 2 represents the number of generations from the mother to the common ancestor; F A represents the inbreeding coefficient of the common ancestor itself; n 1 + n 2 + 1 = N is the number of individuals in the parental correlation path chain; The PIT tag is injected when the weight of the F1 generation grows to 10 - 20 g.

7. The breeding method of the slender largemouth bass according to any one of claims 1 to 6, characterized in that The number of broodstock screened in each generation from F1 to F5 is not less than 400 tails.

Images