White gourd and pig hybrid combination method

Abstract

The invention discloses a white gourd pig hybridization combination method, Yunba wild Duroc pigs obtained by hybridization through the method have higher growth speed, lower breeding cost, higher reproductive capacity and better slaughter performance, and the production efficiency of pig raising is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of winter melon-pig hybridization, and in particular to a winter melon-pig hybridization combination method. Background Art

[0002] The Donggua pig belongs to the southern Yunnan small-eared pig family, commonly known as the Banna small-eared pig, Hani pig, fine-bone pig, or small fragrant pig. It is primarily produced in Mengla County, Yunnan Province, with the core production area encompassing the ethnic villages within Mengla and Menghai counties and Jinghong City. This native breed, domesticated from native wild boars by local ethnic minorities (including the Dai, Hani, Jinuo, and Hani), boasts a history of over 2,000 years dating back to the Eastern Han Dynasty. It is primarily found in tropical and subtropical regions with high temperatures and humidity, and thrives at altitudes between 500 and 2,000 meters.

[0003] The slow growth, small adult size, and low lean meat percentage of the winter melon pig have long been major issues plaguing pig breeding and impacting economic profitability. Therefore, crossbreeding the winter melon pig with high-quality foreign breeders to produce hybrid winter melon pigs with superior meat quality, rapid growth, a high lean meat percentage, and larger size is a top priority for animal husbandry professionals and holds significant practical significance. This will improve pig production efficiency and meet production and market demands. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a winter melon pig hybrid combination method.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: The present invention provides a winter melon pig hybrid combination method, comprising the following steps: Step 1: Select and breed the fine traits of the Yunnan small-ear pigs, and select a basic population of Yunnan small-ear pigs with excellent reproductive performance and meat quality performance; Step 2: Select and breed Berkshire pigs for their excellent traits, and choose a base population of Berkshire pigs with excellent growth and slaughter performance; Step three: Select and breed purebred wild boars for their excellent traits, and choose a base population of purebred wild boars with excellent growth and slaughter performance; Step 4: Select and breed Duroc pigs for their excellent traits, and choose a base population of Duroc pigs with excellent growth and slaughter performance; Step 5: Using the Diannan Small-eared Pig and the Berkshire Pig as breeding materials, hybridizing and breeding a synthetic line, which is named the Dianba Pig Synthetic Line, and breeding the Dianba Pig Synthetic Line with excellent reproductive performance and meat quality as the supporting parent pigs; Step 6: Using purebred wild boars and Duroc pigs as breeding materials, hybridizing and breeding a synthetic line, which is named the Wild Duroc synthetic line, and breeding a Wild Duroc synthetic line with high growth performance and slaughter performance as the supporting parent pigs; Step seven, hybridizing the parent generation Dianba pig sows with the parent generation Yedu pig boars to obtain a matching line of high-quality commercial pigs, which are named Dianba Yedu pig matching line.

[0006] As a preferred technical solution of the present invention, the selection criteria for the Yunnan small-eared pigs in the step one are: the number of first-born piglets of the Yunnan small-eared sows used is greater than 6, the number of multiparous piglets is greater than 8, the daily weight gain of fattening pigs is greater than 250 grams, the feed-to-meat ratio is less than 3.0:1, the back fat thickness is less than 35 mm, the eye muscle area is greater than 20 cm², the ketone body lean meat rate is greater than 40%, the intramuscular fat content is greater than 5.5%, the weight of 21-day-old piglets is greater than 4.5 kg, the skin sweat gland density is greater than 30 / cm², and there are no recessive genetic diseases.

[0007] As a preferred technical solution of the present invention, the selection criteria for the Berkshire pigs in step 2 are: the Berkshire boars used have a daily weight gain of greater than 700 grams for finishing pigs, a feed-to-meat ratio of less than 2.9:1, a backfat thickness of less than 16 mm, an eye muscle area of greater than 36 cm², a carcass length greater than 90 cm, a ketone body lean meat rate greater than 58%, an intramuscular fat content greater than 2.7%, a skin sweat gland density greater than 25 / cm², a weight at 160 days of age greater than 90 kg, a sperm motility greater than 0.7, a semen deformity rate less than 15%, and no recessive genetic diseases.

[0008] As a preferred technical solution of the present invention, the selection criteria for purebred wild boars in the step three are: the number of first-born piglets of the purebred wild sows used is greater than 4, the number of multiparous piglets is greater than 6, the daily weight gain of fattening pigs is greater than 500 grams, the feed-to-meat ratio is less than 3.5:1, the back fat thickness is less than 14 mm, the eye muscle area is greater than 32 cm², the ketone body lean meat rate is greater than 68%, the intramuscular fat content is greater than 2.3%, the weight of 21-day-old piglets is greater than 4.9 kg, the skin sweat gland density is greater than 27 / cm², and there are no recessive genetic diseases.

[0009] As a preferred technical solution of the present invention, the selection criteria for the Duroc pigs in the step 4 are: the Duroc boars used have a daily weight gain of more than 800 grams for fattening pigs, a feed-to-meat ratio of less than 2.8:1, a backfat thickness of less than 18 mm, an eye muscle area of more than 45 cm², a carcass length greater than 95 cm, a ketone body lean meat rate greater than 50%, an intramuscular fat content greater than 3.2%, a skin sweat gland density greater than 25 / cm², a weight at 160 days of age greater than 100 kg, a sperm motility greater than 0.8, a semen deformity rate less than 10%, and no recessive genetic diseases.

[0010] As a preferred technical solution of the present invention, the step five includes the following sub-steps: The F1A generation was obtained by hybridizing high-quality Diannan small-eared sows with high-quality Berkshire boars; The F2A generation is obtained by mating the male and female pigs of the F1A generation, and high-quality sows are selected from the F2A generation as a backup for the Dianba pig synthetic line.

[0011] As a preferred technical solution of the present invention, the criteria for selecting high-quality sow individuals in the F2A generation are: The number of first-born piglets is greater than 8, the number of multiparous piglets is greater than 11, the daily weight gain of fattening pigs is greater than 450 grams, the feed-to-meat ratio is less than 3.0:1, the backfat thickness is less than 30mm, the eye muscle area is greater than 27cm², the ketone body lean meat rate is greater than 48%, the intramuscular fat content is greater than 4.9%, the weight of piglets at 21 days old is greater than 4.8kg, the skin sweat gland density is greater than 28 / cm², and there are no recessive genetic diseases.

[0012] As a preferred technical solution of the present invention, step six includes the following sub-steps: Crossbreeding high-quality purebred wild sows with high-quality Duroc boars to obtain the F1B generation; The F2B generation is obtained by mating the male and female pigs in the F1B generation, and the high-quality male pigs in the F2B generation are selected as the backup for the Yedu pig synthetic line.

[0013] As a preferred technical solution of the present invention, the criteria for selecting high-quality boar individuals in the F2B generation are: The daily weight gain of fattening pigs is greater than 710 grams, the feed-to-meat ratio is less than 3.1:1, the backfat thickness is less than 18 mm, the eye muscle area is greater than 37 cm², the carcass length is greater than 91 cm, the ketone body lean meat rate is greater than 58%, the intramuscular fat content is greater than 2.7%, the skin sweat gland density is greater than 25 / cm², the body weight at 160 days of age is greater than 100 kg, the sperm motility is greater than 0.8, the semen deformity rate is less than 10%, and there are no recessive genetic diseases.

[0014] As a preferred technical solution of the present invention, the Dianbaye pig obtained by hybridization in step seven has the following slaughter performance: Slaughter age less than 265 days, live weight before slaughter greater than 87.67 kg, carcass weight greater than 63.83 kg, dressing percentage greater than 72.8%, carcass vertical length greater than 91.87 cm, carcass oblique length greater than 80 cm, backfat thickness less than 23.11 mm, number of ribs greater than 14.83 pairs, loin eye area 43.25 cm², skin rate 10.17-0.26%, bone rate 12.34-0.3%, fat rate 29.96-0.38%, lean meat rate 47.53-0.49%, drip loss less than 1.54%, water holding capacity less than 77.53%, pH1 6.3-0.17, pH24 5.97-0.08, marbling score greater than 3.2, shear strength 66.0-1.43 N; The number of first-born piglets of sows in the Dianbayedu pig strain is greater than 9, and the number of multiparous piglets is greater than 12.

[0015] Compared with the prior art, the Dianbaye pigs obtained by hybridization using the method of the present invention have faster growth rate, lower breeding cost, stronger reproductive capacity, better slaughter performance, and improved pig production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 is a flow chart of the steps of the present invention; Figure 2 It is a hybridization flow chart of the present invention. DETAILED DESCRIPTION

[0017] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0018] The genetic resources of the breeding material pigs used in the following examples for cultivating the Sumei pig complementary lines are as follows: Diannan Small-eared Pig (D), a local Yunnan quality, provided by the Mengla County Animal Husbandry Technology Extension Station; Berkshire pigs (B) are imported American breeds, introduced and produced by Anhui Haoxiang Agriculture and Animal Husbandry Company; Native purebred wild boar (Y); Duroc pigs (L) are an imported American breed of pigs provided by Beijing Shunxin Agriculture Co., Ltd.

[0019] like Figure 1-2 As shown, the present invention provides a winter melon pig hybrid combination method, comprising the following steps: Step 1: Select and breed the fine traits of the Diannan Small-ear Pig (D) to select a base population of Diannan Small-ear Pig (D) with excellent reproductive performance and meat quality; Step 2: Select and breed the excellent traits of Berkshire pigs (B) to select a basic population of Berkshire pigs (B) with excellent growth performance and slaughter performance; Step 3: Select and breed the excellent traits of purebred wild boars (Y) to select a basic population of purebred wild boars (Y) with excellent growth performance and slaughter performance; Step 4: Select and breed the excellent traits of Duroc pigs (L) to select a basic population of Duroc pigs (L) with excellent growth performance and slaughter performance; Step 5: Using the Diannan Small-eared Pig (D) and the Berkshire Pig (B) as breeding materials, a hybrid strain is bred, which is named the Dianba Pig Synthetic Strain. The Dianba Pig Synthetic Strain with excellent reproductive performance and meat quality is selected and used as the parent stock of the complementary strain. Step 6: Using purebred wild boars (Y) and Duroc pigs (L) as breeding materials, hybridizing and breeding a synthetic line, which is named the Wild Duroc synthetic line. The Wild Duroc synthetic line with high growth performance and slaughter performance is selected and bred as the parent stock pig of the matching line; Step seven, hybridizing the parent generation Dianba pig sows with the parent generation Yedu pig boars to obtain a matching line of high-quality commercial pigs, which are named Dianba Yedu pig matching line.

[0020] Furthermore, the selection criteria for the Yunnan small-eared pigs (D) in the step 1 are: the number of first-time piglets of the Yunnan small-eared sows used is greater than 6, the number of multiparous piglets is greater than 8, the daily weight gain of fattening pigs is greater than 250 grams, the feed-to-meat ratio is less than 3.0:1, the backfat thickness is less than 35 mm, the eye muscle area is greater than 20 cm², the ketone lean meat rate is greater than 40%, the intramuscular fat content is greater than 5.5%, the weight of 21-day-old piglets is greater than 4.5 kg, the skin sweat gland density is greater than 30 / cm², and there are no recessive genetic diseases.

[0021] Furthermore, the selection criteria for the Berkshire pigs (B) in step 2 are: the Berkshire boars used have a daily fattening weight gain greater than 700 grams, a feed-to-meat ratio less than 2.9:1, a backfat thickness less than 16 mm, an eye muscle area greater than 36 cm², a carcass length greater than 90 cm, a ketone lean meat rate greater than 58%, an intramuscular fat content greater than 2.7%, a skin sweat gland density greater than 25 cells / cm², a weight greater than 90 kg at 160 days of age, a sperm motility greater than 0.7, a semen deformity rate less than 15%, and no recessive genetic diseases.

[0022] Furthermore, the selection criteria for the purebred wild boar (Y) in the step three are: the number of first-born piglets of the purebred wild sows used is greater than 4, the number of multiparous piglets is greater than 6, the daily weight gain of fattening pigs is greater than 500 grams, the feed-to-meat ratio is less than 3.5:1, the back fat thickness is less than 14 mm, the eye muscle area is greater than 32 cm², the ketone lean meat rate is greater than 68%, the intramuscular fat content is greater than 2.3%, the weight of 21-day-old piglets is greater than 4.9 kg, the skin sweat gland density is greater than 27 / cm², and there are no recessive genetic diseases.

[0023] Furthermore, the selection criteria for the Duroc pigs (L) in the step 4 are: the daily weight gain of the fattening pigs of the Duroc boars used is greater than 800 grams, the feed-to-meat ratio is less than 2.8:1, the backfat thickness is less than 18 mm, the eye muscle area is greater than 45 cm², the carcass length is greater than 95 cm, the ketone body lean meat rate is greater than 50%, the intramuscular fat content is greater than 3.2%, the skin sweat gland density is greater than 25 / cm², the weight at 160 days of age is greater than 100 kg, the sperm motility is greater than 0.8, the semen deformity rate is less than 10%, and there are no recessive genetic diseases.

[0024] Furthermore, the step 5 includes the following sub-steps: The F1A generation was obtained by hybridizing high-quality Diannan small-eared sows with high-quality Berkshire boars; The F2A generation is obtained by mating the male and female pigs of the F1A generation, and high-quality sows are selected from the F2A generation as a backup for the Dianba pig synthetic line.

[0025] Furthermore, the criteria for selecting high-quality sows in the F2A generation are: The number of first-born piglets is greater than 8, the number of multiparous piglets is greater than 11, the daily weight gain of fattening pigs is greater than 450 grams, the feed-to-meat ratio is less than 3.0:1, the backfat thickness is less than 30mm, the eye muscle area is greater than 27cm², the ketone body lean meat rate is greater than 48%, the intramuscular fat content is greater than 4.9%, the weight of piglets at 21 days old is greater than 4.8kg, the skin sweat gland density is greater than 28 / cm², and there are no recessive genetic diseases.

[0026] Furthermore, the step six includes the following sub-steps: Crossbreeding high-quality purebred wild sows with high-quality Duroc boars to obtain the F1B generation; The F2B generation is obtained by mating the male and female pigs in the F1B generation, and the high-quality male pigs in the F2B generation are selected as the backup for the Yedu pig synthetic line.

[0027] Furthermore, the criteria for selecting high-quality boar individuals in the F2B generation are: The daily weight gain of fattening pigs is greater than 710 grams, the feed-to-meat ratio is less than 3.1:1, the backfat thickness is less than 18 mm, the eye muscle area is greater than 37 cm², the carcass length is greater than 91 cm, the ketone body lean meat rate is greater than 58%, the intramuscular fat content is greater than 2.7%, the skin sweat gland density is greater than 25 / cm², the body weight at 160 days of age is greater than 100 kg, the sperm motility is greater than 0.8, the semen deformity rate is less than 10%, and there are no recessive genetic diseases.

[0028] Furthermore, the Dianbaye pig obtained by hybridization in step seven has the following slaughter performance: Slaughter age less than 265 days, live weight before slaughter greater than 87.67 kg, carcass weight greater than 63.83 kg, dressing percentage greater than 72.8%, carcass vertical length greater than 91.87 cm, carcass oblique length greater than 80 cm, backfat thickness less than 23.11 mm, number of ribs greater than 14.83 pairs, loin eye area 43.25 cm², skin rate 10.17-0.26%, bone rate 12.34-0.3%, fat rate 29.96-0.38%, lean meat rate 47.53-0.49%, drip loss less than 1.54%, water holding capacity less than 77.53%, pH1 6.3-0.17, pH24 5.97-0.08, marbling score greater than 3.2, shear strength 66.0-1.43 N; The number of first-born piglets of sows in the Dianbayedu pig strain is greater than 9, and the number of multiparous piglets is greater than 12.

[0029] In a specific embodiment, the hybridization test is set up with 2 hybridization combinations: The Dianba pig hybrid line (D × B) and the Dianba Yedu pig hybrid line (DB × YL) were randomly prepared from 10 litters of each crossbreeding combination, with one piglet selected from each litter, for a total of 50 test pigs for compatibility testing.

[0030] Table 1 Effects of different hybrid combinations on pig reproductive performance

[0031] As shown in Table 1, the number of primiparous piglets, the number of multiparous piglets and the weight of piglets at 21 days of age in the D × B group were significantly higher than those in the Yunnan small-eared pig (D); the number of primiparous piglets, the number of multiparous piglets and the weight of piglets at 21 days of age in the DB × YL group were significantly higher than those in the Yunnan small-eared pig (D) and D × B groups.

[0032] Table 2 Effects of different hybrid combinations on pig growth performance

[0033] As shown in Table 2, the daily weight gain, backfat thickness and feed-to-meat ratio of the fattening pigs in the D × B group were significantly better than those in the Yunnan small-ear pigs (D), and the daily weight gain, backfat thickness and feed-to-meat ratio of the fattening pigs in the DB × YL group were significantly better than those in the Yunnan small-ear pigs (D) and D × B group.

[0034] Table 3 Effects of different hybrid combinations on pig slaughter performance

[0035] As shown in Table 3, the slaughter performance of the D × B group was significantly better than that of the Diannan small-ear pig (D), and the slaughter performance of the DB × YL group was significantly better than that of the Diannan small-ear pig (D) and the D × B group.

[0036] Table 4 Effects of different hybrid combinations on pork quality

[0037] As shown in Table 4, the meat quality performance of the D × B group was significantly better than that of the Yunnan small-ear pig (D), and the meat quality performance of the DB × YL group was significantly better than that of the Yunnan small-ear pig (D) and the D × B group.

[0038] The total amino acid content (16 types) in muscle of the DB × YL group was 21.13%, the total content of the three major umami amino acids (glutamic acid, alanine, and aspartic acid) was 6.83%, and the total content of the seven essential amino acids (methionine, valine, isoleucine, leucine, phenylalanine, threonine, and lysine) was 8.60%. The total content of saturated fatty acids was 41.22%, the total content of monounsaturated fatty acids was 40.25%, the total content of polyunsaturated fatty acids (linoleic acid, arachidonic acid, etc.) was 18.48%, and the content of omega-3 fatty acids (α-linolenic acid, EPA, and DHA) was 0.56%. Protein content was 21.78g / 100g, and cholesterol content was 49.58mg / 100g.

[0039] Based on the above conclusions, it can be concluded that the various indicators of the DB × YL group are better than those of other control groups, which improves the comprehensive performance indicators of pigs and thus improves the efficiency of pig production.

[0040] 1. The standards for the determination of ketone body traits in the above groups of pigs: The day before the end of the experiment, the experimental pigs were fasted for 24 h, with free access to water, and then slaughtered.

[0041] (1) Carcass straight length (cm) = length from the midpoint of the anterior edge of the pubic symphysis to the midpoint of the anterior edge of the first cervical vertebra.

[0042] (2) Carcass oblique length (cm) = the straight line from the center point of the junction of the first rib and sternum to the center point of the anterior edge of the pubic symphysis.

[0043] (3) Back fat thickness (cm) = Use a vernier caliper to measure the thickness of the subcutaneous fat layer at the 6th to 7th ribs, the last rib, the lumbar sacral junction, and the midline of the back, and take the average value of the three points.

[0044] 2. Growth performance: The pen was weighed before feeding in the morning at the beginning and end of the experiment, and the average daily weight gain was calculated. The feed intake was recorded every day during the experiment, and the average daily feed intake was calculated.

[0045] 3. Carcass traits: Feed was stopped the day before the end of the experiment. On the day of the experiment, six pigs (three males and three females) were selected from each replicate group, weighed before slaughter, and then slaughtered. The slaughter process strictly followed the national standard "Slaughtering Operation Procedures for Pigs" (GB / T17236-2008).

[0046] Carcass weight: The weight of the carcass without the viscera, head, hooves and tail.

[0047] Dressing rate: the ratio of carcass weight to live weight before slaughter.

[0048] Back fat thickness: The fat thickness at three points of the carcass is measured: the thickest part of the shoulder, the junction of the thoracic and lumbar vertebrae, and the junction of the lumbar and sacral vertebrae. The average of the three points is taken as the average back fat thickness.

[0049] Carcass straight length: the distance from the front edge of the bottom of the occipito-atlantal joint (the depression of the first cervical vertebra) to the midline of the front edge of the pubic symphysis.

[0050] Carcass oblique length: the distance from the junction of the first rib and sternum to the midline of the pubic symphysis.

[0051] 4. Meat quality: pH value: Take meat samples with a width and thickness greater than 3.0 cm directly from the longissimus dorsi muscle at the first and second thoracic vertebrae from the carcass, and measure the pH value within 1 hour and 24 hours after slaughter.

[0052] Water-binding strength: Take the longissimus dorsi muscle at the 1st-2nd lumbar vertebrae and cut a 1cm thick slice. Weigh the meat sample (W1) and place it on a compression instrument with 18 layers of filter paper on top and bottom. Apply pressure uniformly to 35kg and maintain for 5 minutes. Immediately after removing the pressure, weigh the meat sample (W2). Calculate the water loss rate (%) according to the following formula: Water loss rate = [(W1-W2) / W1]×100%.

[0053] Shear force: The longissimus dorsi and leg muscles were measured in sections parallel to the muscle fibers, measuring 3 cm in length × 1.5 cm in width × 1.5 cm in height. The tendons, skeletal muscles, membranes, and fat on the surface of the meat were removed. The shear force was measured using a C-LM3B digital muscle tenderizer (Beijing Dingheli Technology Co., Ltd.). Each sample was measured three times, and the average value was taken.

[0054] Meat color: The L* (lightness), a* (redness), and b* (yellowness) values of the longissimus dorsi muscle were measured using a TCP2 fully automatic colorimeter (Beijing Aoike Optoelectronic Instrument Co., Ltd.). Each sample was measured three times in parallel and the average value was calculated.

[0055] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A winter melon pig hybrid combination method, characterized in that: The following steps are involved: Step 1: Select and breed the fine traits of the Yunnan small-ear pigs, and select a basic population of Yunnan small-ear pigs with excellent reproductive performance and meat quality performance; Step 2: Select and breed Berkshire pigs for their excellent traits, and choose a base population of Berkshire pigs with excellent growth and slaughter performance; Step three: Select and breed purebred wild boars for their excellent traits, and choose a base population of purebred wild boars with excellent growth and slaughter performance; Step 4: Select and breed Duroc pigs for their excellent traits, and choose a base population of Duroc pigs with excellent growth and slaughter performance; Step 5: Using the Diannan Small-eared Pig and the Berkshire Pig as breeding materials, hybridizing and breeding a synthetic line, which is named the Dianba Pig Synthetic Line, and breeding the Dianba Pig Synthetic Line with excellent reproductive performance and meat quality as the supporting parent pigs; Step 6: Using purebred wild boars and Duroc pigs as breeding materials, hybridizing and breeding a synthetic line, which is named the Wild Duroc synthetic line, and breeding the Wild Duroc synthetic line with high growth performance and slaughter performance as the supporting parent pigs; Step seven, hybridizing the parent generation Dianba pig sows with the parent generation Yedu pig boars to obtain a matching line of high-quality commercial pigs, which are named Dianba Yedu pig matching line.

2. A winter melon pig hybrid combination method according to claim 1, characterized in that, The selection criteria for the Yunnan small-eared pigs in the step 1 are: the number of first-time piglets of the Yunnan small-eared sows used is greater than 6, the number of multiparous piglets is greater than 8, the daily weight gain of fattening pigs is greater than 250 grams, the feed-to-meat ratio is less than 3.0:1, the backfat thickness is less than 35 mm, the eye muscle area is greater than 20 cm², the ketone lean meat rate is greater than 40%, the intramuscular fat content is greater than 5.5%, the weight of 21-day-old piglets is greater than 4.5 kg, the skin sweat gland density is greater than 30 / cm², and there are no recessive genetic diseases.

3. A winter melon pig hybrid combination method according to claim 1, characterized in that, The selection criteria for the Berkshire pigs in step 2 are: the Berkshire boars used have a daily weight gain of greater than 700 grams for finishing pigs, a feed-to-meat ratio of less than 2.9:1, a backfat thickness of less than 16 mm, an eye muscle area greater than 36 cm², a carcass length greater than 90 cm, a ketone lean meat rate greater than 58%, an intramuscular fat content greater than 2.7%, a skin sweat gland density greater than 25 cells / cm², a weight greater than 90 kg at 160 days of age, a sperm motility greater than 0.7, a semen deformity rate less than 15%, and no recessive genetic diseases.

4. A winter melon pig hybrid combination method according to claim 1, characterized in that, The selection criteria for the purebred wild boars in the step three are as follows: the number of first-born piglets of the purebred wild sows used is greater than 4, the number of multiparous piglets is greater than 6, the daily weight gain of fattening pigs is greater than 500 grams, the feed-to-meat ratio is less than 3.5:1, the backfat thickness is less than 14 mm, the eye muscle area is greater than 32 cm², the ketone lean meat rate is greater than 68%, the intramuscular fat content is greater than 2.3%, the weight of 21-day-old piglets is greater than 4.9 kg, the skin sweat gland density is greater than 27 / cm², and there are no recessive genetic diseases.

5. The winter melon-pig hybrid combination method according to claim 1, characterized in that: The selection criteria for the Duroc pigs in the step 4 are: the Duroc boars used have a daily weight gain of more than 800 grams for fattening pigs, a feed-to-meat ratio of less than 2.8:1, a backfat thickness of less than 18 mm, an eye muscle area of more than 45 cm², a carcass length greater than 95 cm, a ketone body lean meat rate greater than 50%, an intramuscular fat content greater than 3.2%, a skin sweat gland density greater than 25 / cm², a weight at 160 days of age greater than 100 kg, a sperm motility greater than 0.8, a semen deformity rate less than 10%, and no recessive genetic diseases.

6. A winter melon pig hybrid combination method according to claim 1, characterized in that: The step five includes the following sub-steps: The F1A generation was obtained by hybridizing high-quality Diannan small-eared sows with high-quality Berkshire boars; The F2A generation is obtained by mating the male and female pigs of the F1A generation, and high-quality sows are selected from the F2A generation as a backup for the Dianba pig synthetic line.

7. A winter melon pig hybrid combination method according to claim 6, characterized in that: The criteria for selecting high-quality sows in the F2A generation are: The number of first-born piglets is greater than 8, the number of multiparous piglets is greater than 11, the daily weight gain of fattening pigs is greater than 450 grams, the feed-to-meat ratio is less than 3.0:1, the backfat thickness is less than 30mm, the eye muscle area is greater than 27cm², the ketone body lean meat rate is greater than 48%, the intramuscular fat content is greater than 4.9%, the weight of piglets at 21 days old is greater than 4.8kg, the skin sweat gland density is greater than 28 / cm², and there are no recessive genetic diseases.

8. The winter melon-pig hybrid combination method according to claim 1, characterized in that: The step six includes the following sub-steps: Crossbreeding high-quality purebred wild sows with high-quality Duroc boars to obtain the F1B generation; The F2B generation is obtained by mating the male and female pigs in the F1B generation, and the high-quality male pigs in the F2B generation are selected as the backup for the Yedu pig synthetic line.

9. A winter melon pig hybrid combination method according to claim 8, characterized in that: The criteria for selecting high-quality boar individuals in the F2B generation are: The daily weight gain of fattening pigs is greater than 710 grams, the feed-to-meat ratio is less than 3.1:1, the backfat thickness is less than 18 mm, the eye muscle area is greater than 37 cm², the carcass length is greater than 91 cm, the ketone body lean meat rate is greater than 58%, the intramuscular fat content is greater than 2.7%, the skin sweat gland density is greater than 25 / cm², the body weight at 160 days of age is greater than 100 kg, the sperm motility is greater than 0.8, the semen deformity rate is less than 10%, and there are no recessive genetic diseases.

10. The winter melon-pig hybrid combination method according to claim 1, characterized in that: The Dianbaye pig obtained by hybridization in step 7 has the following slaughter performance: Slaughter age less than 265 days, live weight before slaughter greater than 87.67 kg, carcass weight greater than 63.83 kg, dressing percentage greater than 72.8%, carcass vertical length greater than 91.87 cm, carcass oblique length greater than 80 cm, backfat thickness less than 23.11 mm, number of ribs greater than 14.83 pairs, loin eye area 43.25 cm², skin rate 10.17-0.26%, bone rate 12.34-0.3%, fat rate 29.96-0.38%, lean meat rate 47.53-0.49%, drip loss less than 1.54%, water holding capacity less than 77.53%, pH1 6.3-0.17, pH24 5.97-0.08, marbling score greater than 3.2, shear strength 66.0-1.43 N; The number of first-born piglets of sows in the Dianbayedu pig strain is greater than 9, and the number of multiparous piglets is greater than 12.

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