Ecological breeding method of hybrid black Berkshire pig

Abstract

The application discloses a hybrid black meat pig ecological breeding method and belongs to the technical field of livestock genetics and breeding. The method uses Chenghua pig sows as the female parent, sequentially carries out three-generation step-by-step hybridization with Neijiang pig boars, Duroc boars, Yannan pig boars or Meishan pig boars, carries out inter-family cross fixation after phenotype screening, and obtains a genetically stable black meat hybrid pig population through continuous generation population phenotype breeding. The application does not need molecular markers or gene sequencing, can be implemented only by means of conventional phenotype determination, is suitable for ecological feeding management, and does not add chemical growth promoters in the whole process. The obtained hybrid pig population has a black hair rate of 95% or above, significantly improves growth performance while keeping excellent meat quality and flavor, and is suitable for large-scale ecological breeding.

Description

Technical Field

[0001] This invention belongs to the field of livestock genetics and breeding and ecological farming technology, specifically relating to an ecological breeding method for hybrid black-haired meat pigs. Background Technology

[0002] Currently, commercial pig production mainly relies on imported three-way crossbreeding systems, which have advantages such as fast growth rate, high lean meat percentage, and good feed conversion ratio. However, their intramuscular fat content is generally below 1.5%, the meat is pale, lacks marbling, has insufficient flavor compound deposition, and has a dry texture, making it difficult to meet the needs of the high-end fresh market and traditional cured meat processing.

[0003] Local black pig breeds in my country, such as Chenghua pig, Neijiang pig, Yanan pig, and Meishan pig, have significant advantages such as tender meat, rich intramuscular fat, bright red meat color, and rich flavor. However, they also have drawbacks such as long growth cycle, low daily weight gain, low lean meat percentage, excessive back fat, and poor feed conversion ratio. Purebred breeding is not economically viable and is difficult to promote on a large scale.

[0004] While existing technologies involving simple crossbreeding of local black pigs with imported lean-type pigs can improve growth performance to some extent, they generally suffer from the following technical drawbacks: Firstly, severe coat color segregation occurs. The reddish-brown coat of Duroc pigs is a recessive gene; after crossbreeding with local black pigs, the F2 generation and backcrosses produce individuals with mixed colors such as brown, spotted, and white coats, resulting in poor uniformity in the appearance of the commercial pig population and failing to meet consumer perception of the black pig brand. Secondly, meat quality deteriorates too rapidly. When the proportion of imported lean-type pig bloodlines exceeds 25%, the intramuscular fat content of the offspring drops sharply, typically below 2.0%, losing the core meat quality advantage of local black pigs. Thirdly, existing crossbreeding methods rely heavily on advanced techniques such as marker-assisted selection, genomic selection, and BLUP breeding value estimation, requiring specialized laboratories and extensive data accumulation, which are beyond the capabilities of ordinary large-scale farming enterprises. Fourthly, existing technologies disconnect crossbreeding from ecological feeding management, lacking technical solutions that integrate crossbreeding with ecological farming systems, leading to further decline in the growth performance of ecological pigs and excessively long breeding cycles. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides an ecological breeding method for four-way stepwise hybrid black-haired meat pigs. By controlling the specific hybridization sequence, bloodline ratio, and generational representative breeding standards, growth performance is improved while maintaining intramuscular fat content.

[0006] The technical solution adopted in this invention is as follows:

[0007] An ecological breeding method for hybrid black-haired meat pigs includes the following steps:

[0008] Step 100: Select Chenghua sows as the maternal line and Neijiang boars as the paternal line, and perform artificial insemination to obtain the F1 generation.

[0009] Step 200: Select F1 generation sows as the maternal line and Duroc boars as the paternal line, and perform artificial insemination to obtain F2 generation.

[0010] Step 300: Select F2 generation sows as the maternal line and select Yanan pig boars as the paternal line to perform artificial insemination to obtain F3 generation.

[0011] Step 400: Select the F3 generation for interfamilial cross-fixation to obtain the F4 generation base group.

[0012] Step 500: Conduct phenotypic selection on the F4 generation base population for 2-3 consecutive generations to obtain a genetically stable black-haired meat hybrid pig population.

[0013] In conjunction with the above technical solutions, the present invention provides a first embodiment. In step 100, the Chenghua sows are multiparous with 2-4 litters, weigh ≥100kg, have a body length ≥110cm, have all-black hair, large drooping ears, and more than 6 pairs of effective teats; the Neijiang boars are 12-14 months old, weigh ≥130kg, have a body length ≥135cm, have all-black hair, have whorls of hair on their foreheads, and have a backfat thickness of 30-40mm.

[0014] In conjunction with the above technical solutions or the first implementation method, the present invention provides a second implementation method. In step 100, phenotypic screening is performed on the F1 generation to select individuals with completely black fur, a weaning weight ≥ 6.5 kg, a body length ≥ 95 cm at 6 months of age, and a weight ≥ 75 kg at 6 months of age.

[0015] In conjunction with the above technical solutions, the present invention provides a third implementation method. In step 200, the Duroc boars are 12-14 months old, weigh ≥150kg, have a body length ≥145cm, and have brownish-red coats. Phenotypic screening is performed on the F2 generation, and individuals with all-black coats, weaning weight ≥7.0kg, body length ≥100cm at 6 months of age, and weight ≥85kg at 6 months of age are selected. Individuals with non-all-black coats are all culled at weaning.

[0016] In conjunction with the above technical solutions or the third implementation method, the present invention provides a fourth implementation method. In step 300, the Yanan pig boars are 12-14 months old, weigh ≥120kg, have a body length ≥125cm, have all-black hair, a relatively long body, a straight back, and are isolated and observed for 30 days after introduction without any stress response.

[0017] In conjunction with the above technical solutions or the fourth implementation method, the present invention provides a fifth implementation method. In step 300, phenotypic screening is performed on the F3 generation to select individuals with completely black fur, a weaning weight ≥7.5kg, a body length ≥105cm at 8 months of age, and a weight ≥95kg at 8 months of age. Meat quality sampling and testing are performed on the F3 generation to select family individuals with intramuscular fat content ≥3.0% and lean meat percentage ≥45%.

[0018] In conjunction with the above technical solutions, or the fourth or fifth implementation method, the present invention provides a sixth implementation method. In step 300, the Yanan pig boar is replaced with a Meishan pig boar. The Meishan pig boar is 12-14 months old, weighs ≥110kg, has a body length ≥120cm, has black or bluish-gray coat, and white lower limbs. The 8-month-old weight selection standard for F3 generation is adjusted to sows ≥90kg and boars ≥95kg.

[0019] In conjunction with the above technical solutions, the present invention provides a seventh implementation method. In step 400, the male-to-female ratio of the interlineage is fixed at 1:10-1:15, the kinship coefficient between the paired parties is <0.125, and the offspring of the same grandfather are not paired, full siblings are not paired, and half siblings are not paired.

[0020] In conjunction with the above technical solutions or the seventh implementation method, the present invention provides an eighth implementation method. In step 500, the population phenotypic selection includes growth performance selection, reproductive performance selection, coat color fixation selection and meat quality performance selection; the retention rate of each generation is 15%-25%, and after 2-3 consecutive generations of selection, the population has a full black coat rate of ≥95% and reaches this standard for two consecutive generations.

[0021] In conjunction with the above technical solutions, the present invention provides a ninth embodiment, which further includes step 600 ecological feeding management, wherein the breeding environment is hilly or semi-mountainous, and each fattening pig is provided with an outdoor exercise area of ​​≥3m². 2 The semi-grazing model is implemented, with free-range grazing during the day and returning animals to their enclosures at night; the slaughter weight is 100-110kg, and the feeding cycle is 10-12 months; among them, chemical growth promoters refer to antibiotic growth promoters, β-receptor agonists, and hormone growth promoters.

[0022] The technical effects of the aforementioned specific four-breed stepwise hybridization sequence are as follows: with Duroc bloodline accounting for about 25%, through backcrossing of Yanan pigs or Meishan pigs and strict phenotypic selection generation by generation, not only can the percentage of all-black hair in the population reach more than 95%, but also the daily weight gain can be increased to more than 500g while maintaining intramuscular fat content of not less than 2.5%. This achieves a synergistic improvement of the local black pork flavor and the growth performance of imported lean-type pigs. This effect cannot be expected by those skilled in the art through simple breed combinations.

[0023] It is worth noting that Chenghua pigs and Neijiang pigs are both local breeds of the Sichuan Basin and are genetically close. After hybridization, they do not produce severe phenotypic segregation, and the additive effect of their excellent meat quality genes is preserved. Duroc pigs, as terminal sires with high lean meat percentage, improve the growth rate of offspring through a single introduction of their growth rate gene without excessively diluting the intramuscular fat deposition gene of local pigs. Yanan pigs or Meishan pigs, as terminal backcross sires, can effectively cover the brown hair recessive trait that may appear after the introduction of Duroc pigs with their homozygous black hair dominant gene. At the same time, their stress resistance and meat quality genes complement those of the previous hybrid maternal line.

[0024] The beneficial effects of this invention are as follows:

[0025] This invention achieves a balance between growth performance and meat flavor by using a specific stepwise hybridization sequence of four breeds: Chenghua pig, Neijiang pig, Duroc pig, Yanan pig, or Meishan pig, combined with generation-by-generation phenotypic screening standards. While maintaining intramuscular fat ≥2.5%, it increases daily weight gain to 500-600g and shortens the slaughter period to 10-12 months.

[0026] This invention improves growth rate and lean meat percentage by introducing a foreign lean meat type into Duroc pigs, and then restores and fixes the black coat color through backcrossing with Yanan or Meishan pigs and strict phenotypic selection for consecutive generations, so that the percentage of all-black coat color in the final commercial pig population reaches more than 95%, thus solving the problem of coat color separation after the introduction of Duroc bloodline.

[0027] This invention, through targeted breeding of maternal reproductive performance, ensures a stable average number of live piglets per sow and a weaning survival rate of ≥85%, thus guaranteeing the supply of breeding stock for large-scale production.

[0028] The entire breeding process of this invention only requires conventional tools such as weight scales, vernier calipers, and color charts, without the need for high-tech methods such as molecular markers, gene sequencing, and BLUP breeding value estimation, making it suitable for large-scale breeding enterprises. Attached Figure Description

[0029] Figure 1 The above are photographs of the original Chenghua pig generation 0 maternal line selected in this embodiment of the invention.

[0030] Figure 2 The above is a photograph of the body shape and appearance of the first sire of the Neijiang Black Boar used in this embodiment of the invention.

[0031] Figure 3 The image shows the body shape and appearance of F1 generation hybrid sows obtained in step 100 in this embodiment of the invention.

[0032] Figure 4 The photograph shows the body shape and appearance of the second sire of the Duroc boar used in this embodiment of the invention.

[0033] Figure 5 The image shows the body shape and appearance of the F2 generation three-hybrid black sows obtained in step 200 in this embodiment of the invention.

[0034] Figure 6 The photograph shows the physical appearance of the third sire of the Yanan boar used in this embodiment of the invention.

[0035] Figure 7 This is a group photo of F3 generation four-hybrid black piglets obtained in step 300 in this embodiment of the invention;

[0036] Figure 8 These are group photos of F4 generation and subsequent generations of hybrid black commercial pigs obtained through steps 400 and 500 in this embodiment of the invention.

[0037] Figure 9 This is a schematic diagram of a pregnant sow pen in an embodiment of the present invention;

[0038] Figure 10 This is a schematic diagram of a birthing and nursing shed in an embodiment of the present invention;

[0039] Figure 11 This is a schematic diagram of a weaned piglet nursery in an embodiment of the present invention;

[0040] Figure 12 This is a schematic diagram of a fattening pig house in an embodiment of the present invention. Detailed Implementation

[0041] The present invention will be further explained below with reference to the accompanying drawings and specific embodiments.

[0042] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this application, but not all embodiments.

[0043] In this invention, the term "artificially assisted natural mating" refers to a natural mating method in which a boar is assisted by a technician to complete the mounting mating, which is different from artificial insemination; the term "family" refers to a group of pigs that share a common ancestor and are classified according to paternal or maternal pedigrees; the term "kinship coefficient" refers to the kinship coefficient between individuals calculated based on pedigree records, and the calculation method is the pedigree path method, that is, by tracing back to the common ancestor of both parties to calculate the inbreeding coefficient and kinship coefficient; the term "chemical growth promoter" refers to chemically synthesized substances used to promote animal growth, including antibiotic growth promoters, β-receptor agonists, and hormone growth promoters, but excluding probiotics, traditional Chinese medicine, and conventional feed additives.

[0044] Example 1:

[0045] This embodiment discloses an ecological breeding method for hybrid black-haired meat pigs, which is used to solve the problems of slow growth of local black pigs, poor quality of pork from foreign breeds, severe hair color separation in hybrid offspring, and the difficulty in popularizing high-tech breeding methods in large-scale breeding enterprises in the existing technology.

[0046] The method includes the following steps:

[0047] Step 100: Parental preparation and first round of hybridization

[0048] Chenghua sows were selected as the maternal line for Generation 0, referring to... Figure 1 Chenghua pigs are characterized by their all-black, dense, and glossy coats, large, drooping ears, slightly concave forehead, relatively long snout, sturdy limbs, medium body size, and pronounced maternal characteristics. In this example, 50 breeding Chenghua sows were introduced from the Chengdu Chenghua Pig Breeding Farm. The selection criteria were: 2-4 litters, weight 100-130 kg, body length 110-120 cm, all-black coats, large, drooping ears, at least 6 pairs of effective teats, and an average of 9-11 live piglets produced in the past six months.

[0049] Neijiang boars were selected as the primary sire, referring to... Figure 2 Neijiang boars are entirely black with a prominent whorl of hair on their forehead, large, drooping ears, a broad and deep body, well-developed forequarters, strong limbs, and symmetrically developed testes. In this example, three Neijiang boars were imported from the National Neijiang Pig Breeding Farm in Neijiang City. The selection criteria were: 12-14 months of age, weight 135-150 kg, body length 135-145 cm, backfat thickness 30-40 mm, semen volume ≥150 mL / semen, and sperm motility ≥0.75.

[0050] Chenghua sows and Neijiang boars were artificially mated at a ratio of 1:20. Estrus was detected using the back-pressing standing reflex observation method. The first mating was performed 24-36 hours after estrus, followed by a second mating 12 hours later. F1 generation hybrid sows were obtained.

[0051] First-generation crossbred sows were screened for their phenotypic characteristics, referring to... Figure 3 The F1 generation individuals have completely black fur, drooping ears, and a body size between Chenghua pigs and Neijiang pigs. Their bodies are longer than those of Chenghua pigs, and their limbs are thicker than those of Chenghua pigs, retaining the typical appearance characteristics of local black pigs.

[0052] The selection criteria were as follows: deformed and poorly active individuals were culled at birth; at 28 days of age, each piglet was weighed individually, and those with a weaning weight of 6.5-8.0 kg, completely black coat without spots, and strong limbs without lameness were selected; at 6 months of age, body length, weight, and backfat thickness were measured, and those with a body length ≥95 cm, weight ≥75 kg, and backfat thickness 25-35 mm were selected; three technicians scored the piglets' appearance on a 10-point scale, with a total score ≥26 points; the breeding rate was 35%. In this example, 486 F1 generation piglets were obtained in 2010, and after selection, 62 were selected for breeding and entered the core group.

[0053] Step 200: Second round of hybridization

[0054] Sixty-two F1 generation crossbred sows selected in step 100 were chosen as the maternal line, and Duroc boars were chosen as the paternal line.

[0055] Reference Figure 4 Duroc boars have reddish-brown coats, medium-sized ears that tilt slightly forward, a broad and deep body, full hindquarters, well-defined muscles, and sturdy limbs. In this example, three Duroc boars were imported from the Duroc Core Breeding Farm. The selection criteria were: 12-14 months of age, weight 150-165 kg, body length 145-155 cm, eye muscle area ≥35 cm², and age ≤165 days at 100 kg weight.

[0056] F1 generation two-crossbred sows were artificially assisted with natural mating with Duroc boars at a ratio of 1:15. Due to the larger size of Duroc boars, close monitoring was conducted during mating to prevent excessive mounting that could injure the sows. This resulted in F2 generation three-crossbred black sows.

[0057] The second phenotypic screening was conducted on F2 generation three-crossbred black sows, referring to... Figure 5 The F2 generation individuals have completely black fur, slightly smaller ears than the F1 generation, significantly increased body length, fuller hindquarters, and a leaner body type, but still retain the characteristic of black fur.

[0058] The selection criteria were as follows: at 28 days of age, the coat color of each piglet was checked, and individuals with brown, spotted, or white coats were strictly culled, retaining only those with completely black coats and a weaning weight ≥7.0kg; at 6 months of age, individuals with a body length ≥100cm, weight ≥85kg, backfat thickness 20-32mm, and an average daily weight gain ≥550g from weaning to 6 months of age were selected; the total appearance score was ≥26 points with a perfect score in the coat color category; the breeding rate was 25%. In this example, 512 F2 generation piglets were obtained in 2011-2012, 23 non-completely black individuals were culled at weaning, and 58 were retained for breeding after selection at 6 months of age.

[0059] Step 300: Third round of hybridization

[0060] Fifty-eight F2 generation hybrid black sows selected through step 200 were chosen as the maternal line, and Ya'nan boars were chosen as the paternal line.

[0061] Reference Figure 6 The Yanan boar has entirely black hair, a relatively long body, a straight back, and strong, sturdy limbs, exhibiting significant resistance to disease. In this example, two Yanan boars were imported from the Yanan Pig Breeding Farm in Qionglai City. The selection criteria were: 12-14 months of age, weight 125-140 kg, body length 125-135 cm, and after importation, they were quarantined and observed for 30 days with normal feed intake and no respiratory symptoms.

[0062] F2 generation three-crossbred black sows were artificially assisted to mate with Yanan boars at a ratio of 1:15. F3 generation four-crossbred black pigs were obtained.

[0063] The third phenotypic screening of F3 generation four-hybrid black pigs was carried out, referring to... Figure 7 The F3 generation crossbred black piglets have completely black hair, large drooping ears, short and thick limbs, and a compact body. After weaning, their hair becomes thick and glossy, their body shape is relatively long, and their hindquarters are full.

[0064] The selection criteria are as follows: at 28 days of age, individuals with completely black fur, a weaning weight of ≥7.5kg, a relatively long body, a full hindquarters, and sturdy limbs are selected; at 8 months of age, individuals with a body length of ≥105cm, a weight of ≥95kg, and a backfat thickness of 18-30mm are selected; the breeding rate is 28%.

[0065] Meat quality was sampled and tested from the F3 generation: 8 piglets were randomly selected from the replacement gilts and sent to a designated slaughterhouse. The results showed an average dressing percentage of 73.8%, a lean meat percentage of 48.6%, a backfat thickness of 24.5 mm, an eye muscle area of ​​32.5 cm², a meat color score of 4.1, a marbling score of 3.5, an intramuscular fat content of 3.2%, and a pH of 16.25. Individuals from families with an intramuscular fat content ≥3.0% and a lean meat percentage ≥45% were selected. In this example, 623 F3 generation piglets were obtained from 2013 to 2014, 245 were weaned, and 72 were selected for breeding at 8 months of age.

[0066] Step 400: Horizontal Fixation

[0067] Seventy-two F3 generation mixed-breed black pigs selected in step 300 were subjected to interfamilial crossbreeding fixation. Before pairing, pedigree records were consulted, and the kinship coefficient between the paired pigs was calculated using the pedigree path method to ensure that the kinship coefficient was <0.125, meaning that the pedigrees of both pigs had no common ancestor tracing back to their grandparents, descendants of the same grandfather were not paired, full siblings were not paired, and half siblings were not paired. The male-to-female ratio was 1:12, resulting in the F4 generation base population. In this embodiment, crossbreeding fixation was completed in 2014-2015, establishing the F4 generation base population.

[0068] Step 500: Population Selection and Breeding

[0069] The F4 generation base population was subjected to three consecutive generations of population phenotypic selection, with the following procedure performed in each generation:

[0070] Growth performance selection: Measure the body weight at 6 months of age and the daily weight gain from weaning to 6 months of age, and select individuals with a daily weight gain ≥480g.

[0071] Reproductive performance selection: Record the number of live offspring in primiparous and multiparous litters, and select individuals with ≥11 live offspring in multiparous litters and a weaning survival rate ≥85%.

[0072] Color-fixed selection: From weaning to 6 months of age, the coat color of each animal is checked, and individuals that are not completely black are eliminated.

[0073] Meat quality selection: Six 6-month-old individuals were randomly selected from each generation and sent to a designated slaughterhouse for testing of intramuscular fat content, lean meat percentage, meat color score, and marbling score. Individuals from families with an intramuscular fat content ≥2.5% and a lean meat percentage of 45%-52% were selected. Specifically, the selection standard for intramuscular fat content in the F3 generation was ≥3.0%, while the selection standard for intramuscular fat content in the F4 and subsequent generations was ≥2.5%. The latter standard was slightly lower because the population traits tend to be stable after cross-pollination fixation, allowing for a slight relaxation of the selection threshold to increase the retention rate while maintaining excellent meat quality.

[0074] The breeding rate was 20% per generation. After three generations of selective breeding, a genetically stable black-haired meat hybrid pig population was obtained. (Refer to...) Figure 8 The group has a coat black rate of over 97%, with consistent coat color among individuals, a symmetrical body shape, a straight back and loin, a full hindquarters, strong limbs, and large, drooping ears, exhibiting stable typical physical characteristics of black-haired meat hybrid pigs.

[0075] Example 2:

[0076] Based on Example 1, this embodiment further optimizes and refines the parameters of each step, and details the configuration of breeding facilities in conjunction with photos of pig houses at each stage.

[0077] In step 100, the number of Chenghua sows introduced was increased to 80, and the number of Neijiang boars introduced was increased to 5, to ensure that the zero-generation maternal population has sufficient genetic diversity.

[0078] The preferred criteria for Chenghua sows are: three litters, weight 110-125kg, body length 115-125cm, and an average litter size of 10-11 live piglets per litter in the past year. The preferred criteria for Neijiang boars are: 13 months old, weight 140-150kg, semen volume ≥180mL / session, and sperm motility ≥0.80. The preferred criteria for the first generation F1 genotype screening are: weaning weight ≥7.0kg, body length ≥100cm at 6 months, weight ≥80kg for sows and ≥85kg for boars at 6 months, backfat thickness 28-32mm at 6 months, total appearance score ≥27 points, and a breeding rate of 30%.

[0079] In step 200, the number of Duroc boars introduced increased to four, from two different breeds: two American and two Taiwanese. Estrogenic cycles of F1 generation sows were recorded before mating, and only individuals with regular estrous cycles of 18-24 days and obvious estrus were selected for mating. The selection criteria for the second-generation F2 generation were: weaning weight ≥ 7.5 kg, body length ≥ 105 cm at 6 months of age, weight ≥ 90 kg for sows and ≥ 95 kg for boars at 6 months of age, backfat thickness 22-28 mm at 6 months of age, average daily weight gain ≥ 580 g from weaning to 6 months of age, and a breeding rate of 22%.

[0080] In step 300, the number of Ya'nan boars introduced increased to 3, from different families. F2 generation sows underwent health screening before mating, with only individuals without a history of respiratory disease or reproductive disorders selected for breeding. The preferred selection criteria for the third-generation F3 phenotypic screening were: weaning weight ≥ 8.0 kg, body length ≥ 110 cm at 8 months of age, weight ≥ 100 kg for sows and ≥ 105 kg for boars at 8 months of age, and backfat thickness 20-25 mm at 8 months of age. Meat quality sampling was increased to 10 heads per batch, with pH and eye muscle area added to the testing indicators. Individuals from families with intramuscular fat content of 3.2%-4.0%, lean meat percentage of 48%-52%, meat color score ≥ 4.0, and pH 16.0-6.5 were selected, with a breeding rate of 25%.

[0081] In step 400, the family-based recurrent pairing method is used during crossbreeding fixation: F3 generation boars are paired with sows from the 1st family line, sows from the 2nd family line, and so on, to ensure sufficient gene exchange between families and to keep the inbreeding coefficient at the lowest level.

[0082] In step 500, the selection of the population includes health and stress resistance as selection indicators: the disease incidence of individuals is recorded in each generation, and individuals with strong disease resistance and adaptability to extensive farming are selected under ecological free-range conditions, while individuals with repeated disease are culled. Selection is carried out continuously for four generations, with a seed retention rate of 18% per generation.

[0083] Regarding the configuration of aquaculture facilities:

[0084] Reference Figure 9The gestation sow pens adopt a semi-open structure, with 4-6 gestation sows housed in each pen, and each sow occupying an area of ​​1.5-2.0 square meters. 2 The building is equipped with automatic water dispensers and feeding troughs. The floor is made of cement and covered with straw bedding. The north-facing ventilation window is closed for insulation in winter and the side ventilation windows are opened for ventilation and cooling in summer.

[0085] Reference Figure 10 The farrowing and lactation pens are fully enclosed, with each pen equipped with one farrowing crate measuring 2.0m x 1.8m. The sow gestation crates are 60-65cm wide. The piglet activity area is equipped with an insulated box with an electric heating pad at the bottom, maintaining a temperature of 28-32℃. The farrowing pen floor uses a combination of slatted and solid flooring, with slat gaps 1.0-1.2cm wide, ensuring sow feces drain properly while preventing piglets' hooves from getting stuck. Each farrowing pen has an independent ventilation system, providing 8-10 air changes per hour.

[0086] Reference Figure 11 The weaned piglet nursery uses a raised, fully slatted design, with the bed surface 40-50cm above the ground. Each pen houses 15-20 weaned piglets, with each piglet occupying 0.3-0.5m² of space. 2 The pens are equipped with automatic drinking nipples and feed troughs, and rubber mats are laid on the floor to prevent piglets from slipping. The temperature is controlled at 22-26℃, and the humidity is controlled at 60%-70%.

[0087] Reference Figure 12 The fattening pig pens are semi-open and connected to the exercise area. Each pen houses 8-12 fattening pigs, with each pig occupying 0.8-1.2 square meters of space. 2 The sheds are equipped with long, narrow feeding troughs and automatic waterers. Each fattening shed is connected to an outdoor exercise area on the south side, with an area of ​​≥3m² per pig. The ground is soil planted with ryegrass and alfalfa, and the exercise area is surrounded by a fence with a height of 1.0-1.2m.

[0088] The preferred ecological feeding management solution is to increase fermented soybean meal by 5% by weight in the feed formula, replacing part of the ordinary soybean meal; and to add 100g of probiotic preparation per 100kg of feed, with a live bacteria count ≥1×10⁻⁶. 9 CFU / g, feed for 10 days per month; add Chinese herbal decoction to drinking water for 7 days per month, honeysuckle, isatis root, houttuynia cordata and licorice in a mass ratio of 1:1:1:0.5.

[0089] Example 3:

[0090] This embodiment provides an extended solution under different geographical and climatic conditions, mainly targeting the adjustment of feeding management due to seasonal changes.

[0091] The breeding base is located in the semi-mountainous area of ​​Duoyue Town, Dongpo District, Meishan City, at an altitude of 350-600m, with an average annual temperature of 16-18℃ and humidity of 75%-85%.

[0092] Summer management (June-September): Shade nets should be used to cover the fattening sheds and exercise areas. Morning grazing should begin at 7:00 AM, and afternoon grazing at 6:30 PM. During the midday heat (11:00-4:00 PM), grazing animals should be brought back indoors to avoid the heat. The feed formula should increase the proportion of wheat bran to 15%, reduce the proportion of corn to 48%, and increase the use of heat-clearing Chinese herbal fodder such as bitter melon vines and dandelion.

[0093] Winter management (December-February): Close the north-side ventilation windows of the fattening shed, add windproof barriers to the exercise area, delay the morning grazing time to 9:00 AM, and bring the animals back to the shed at 4:00 PM. Increase the proportion of corn in the feed formula to 55%, increase the amount of sweet potato root energy feed, and increase the amount of Artemisia argyi powder in the feed to 1.5 kg / 100 kg.

[0094] Rainy season management: Dig drainage ditches in low-lying areas of the exercise area to prevent water accumulation; keep the pigsty floor dry and replace the straw bedding regularly; add Chinese herbal medicines such as purslane and Pulsatilla chinensis to the feed to prevent diarrhea.

[0095] Example 4:

[0096] This embodiment provides an exemplary implementation plan combining a specific breeding base and accompanying photographs. Taking the first breeding base as an example, it combines... Figures 1 to 12 Please provide a detailed explanation.

[0097] The complete breeding process in this embodiment is as follows:

[0098] In March 2009, 50 breeding Chenghua sows were imported from the Chengdu Chenghua Pig Breeding Farm. (Reference) Figure 1 The sows in this batch of Chenghua pigs have all-black hair, large drooping ears, strong limbs, and a docile maternal nature. They weigh 100-130kg and are 110-125cm long.

[0099] In May 2009, three Neijiang boars were imported from the Neijiang City Breeding Pig Farm. (Refer to...) Figure 2 The Neijiang boars in this batch have completely black hair, prominent whorls of hair on their foreheads, broad and deep bodies, well-developed forequarters, and weigh 135-150 kg.

[0100] In 2010, Chenghua sows were bred with Neijiang boars, resulting in 486 F1 generation piglets. (Reference) Figure 3 The F1 generation of crossbred sows had completely black hair, drooping ears, and a longer body than adult Chinese pigs, with strong limbs, combining the maternal characteristics of adult Chinese pigs and the growth performance of Neijiang pigs. After first-generation phenotypic selection, 62 sows were retained for breeding.

[0101] In January 2010, three Duroc boars were imported from the Duroc Core Breeding Farm. (Refer to...) Figure 4 The Duroc boars in this batch have reddish-brown coats, full hindquarters, well-developed muscles, and weigh 150-165 kg.

[0102] In 2011-2012, F1 generation crossbred sows were bred with Duroc boars, resulting in 512 F2 generation piglets. (Refer to...) Figure 5 After strict culling, the F2 generation of crossbred black sows retained all-black individuals. Their ears were slightly smaller than those of the F1 generation, their body length increased significantly, their hindquarters were fuller, and their body type developed towards a lean-meat type. At weaning, 23 non-all-black individuals were culled, and after second-generation phenotypic selection, 58 were retained for breeding.

[0103] In March 2012, two Yanan boars were imported from the Yanan Pig Breeding Farm in Qionglai City. (Refer to...) Figure 6 The Ya'nan boars have all-black hair, long bodies, straight backs, and strong limbs, and weigh 125-140 kg.

[0104] In 2013-2014, F2 generation all-black sows were bred with Yalnam boars, resulting in 623 F3 generation piglets. (Reference) Figure 7 The F3 generation of crossbred black piglets has completely black hair, large drooping ears, short and thick limbs, and a compact body shape. After third-generation phenotypic selection, 72 piglets were retained for breeding. Eight piglets were randomly selected for slaughter testing. The results showed an average dressing percentage of 73.8%, a lean meat percentage of 48.6%, a backfat thickness of 24.5 mm, an eye muscle area of ​​32.5 cm², a meat color score of 4.1, a marbling score of 3.5, an intramuscular fat content of 3.2%, and a pH of 16.25.

[0105] In 2014-2015, 72 outstanding individuals from the F3 generation were crossbred between families to fix their lineages. The kinship coefficients of both pairs were <0.125, thus obtaining the base population of the F4 generation.

[0106] From 2015 to 2023, four generations of population phenotypic selection were carried out. Each generation strictly adhered to six selection standards: growth, reproduction, coat color, meat quality, body shape, and health. The retention rate for each generation was 18%.

[0107] By 2023, the main performance indicators of the herd remained stable as follows: all-black coat rate 97.3%, average number of live piglets per sow 11.2, average weight at 6 months of age 92.5 kg, average daily weight gain from weaning to 6 months of age 528 g, slaughter weight at 10 months of age 105-110 kg, and slaughter survival rate 94.2%. (Reference) Figure 8 The finished commercial pigs have all-black hair, a symmetrical body shape, a straight back and loin, a full hindquarters, and large, drooping ears, exhibiting a high degree of uniformity in appearance.

[0108] Regarding the actual configuration of aquaculture facilities:

[0109] Reference Figure 9The gestation sow pens were built in 2009, with a building area of ​​800 square meters. 2 It can accommodate 120 pregnant sows and is equipped with both individual stalls and group stalls. Each group stall has 4-6 sows and is equipped with an electronic feeding station.

[0110] Reference Figure 10 The maternity and nursing shed was built in 2010, with a building area of ​​600 square meters. 2 The facility is equipped with 30 farrowing crates, each containing a sow restraint crate, a piglet heat lamp, and an electric heating plate. The temperature inside the shed is controlled at 18-26℃ via a water curtain fan system.

[0111] Reference Figure 11 The weaned piglet nursery was built in 2010, with a building area of ​​500 square meters. 2 It adopts a raised, fully slatted design and is equipped with 20 nursery pens, each holding 15-20 weaned piglets. The pens are also equipped with automatic heat lamps and ventilation fans.

[0112] Reference Figure 12 The fattening pig pens were built in 2012 and 2014 respectively, each with a building area of ​​1000m². 2 Each building is equipped with 30 fattening pens, each housing 10-12 fattening pigs. The south side connects to an outdoor exercise area with a total area of ​​6000 square meters. 2 They planted ryegrass and alfalfa.

[0113] Supplemental feeding with self-prepared concentrate twice daily, from 8:00-10:00 AM and 5:00-6:00 PM. From 10:00 AM to 5:00 PM, the pigs roam freely in the exercise area, grazing on pasture and rooting in the soil. They return to their pens in the evening. The feed formula is: 52% corn, 16% soybean meal, 11% wheat bran, 9% rice bran, 4% rapeseed meal, and 3% premix. 2 kg of pine needle powder and 1 kg of mugwort powder are added per 100 kg of feed.

[0114] Ten 6-month-old replacement gilts were randomly selected from the herd and compared with ten Duroc-Landrace-Large White crossbred pigs and ten purebred Chenghua pigs raised at the same time. The testing method was performed according to NY / T825-2004, and the results are shown in the table below:

[0115] Pre-slaughter live weight / kg 95.2±4.5 105.3±3.8 88.6±5.2 Slaughter rate / % 73.8±1.2 75.2±0.8 71.5±1.5 Lean meat percentage 48.6±2.1 63.5±1.5 43.2±2.8 Back fat thickness / mm 24.5±2.3 15.2±1.5 42.3±3.5 Eye muscle area / cm² 32.5±2.1 38.6±1.8 26.8±2.5 flesh color rating 4.1±0.3 2.8±0.4 4.5±0.2 Marble pattern rating 3.5±0.4 1.8±0.3 4.2±0.3 Intramuscular fat / % 3.2±0.4 1.2±0.2 4.8±0.5 <![CDATA[pH1]]> 6.25±0.15 5.85±0.12 6.35±0.18

[0116] The above measurement data shows that the intramuscular fat content of the four-hybrid black pig bred in this embodiment is 2.7 times that of Duroc, Landrace, and Large White crossbred pigs. The meat color score and marbling score are significantly better than Duroc, Landrace, and Large White crossbred pigs. At the same time, the lean meat percentage and daily weight gain are significantly higher than those of purebred Chenghua pigs, achieving a balance between growth performance and meat flavor.

[0117] The pork samples from this embodiment were sent to the Agricultural Product Quality and Safety Supervision and Testing Center of the Ministry of Agriculture and Rural Affairs for testing. The tests included heavy metals such as lead, cadmium, mercury, arsenic, and chromium; β-receptor agonists such as clenbuterol, ractopamine, and salbutamol; and antibiotic residues such as tetracyclines, sulfonamides, and fluoroquinolones. The test results all met the green food standards.

[0118] Example 5:

[0119] This embodiment provides an alternative implementation scheme in which Meishan pigs are used to replace Yanan pigs as the third paternal line, which is mainly applicable to breeding scenarios with higher requirements for reproductive performance.

[0120] The difference between this embodiment and Embodiment 1 is that in step 300, the third sire is replaced with a Meishan boar. Meishan boars are introduced from Meishan breed conservation farms in Jiangsu or Anhui. The selection criteria are: 12-14 months old, weight 110-125kg, body length 120-130cm, black or bluish-gray coat, white lower limbs, large drooping ears, many and deep wrinkles on the forehead, thin skin and fine bones, clear breeding pedigree, and an average litter size of ≥14 piglets for their paternal relatives.

[0121] The F2 generation three-crossbred black sows selected in step 200 were artificially assisted to mate with Meishan boars to obtain the F3 generation four-crossbred black pigs. Because Meishan pigs grow slower than Yanan pigs, the 8-month-old weight selection criteria for the third generation phenotypic screening were adjusted accordingly: sows ≥90kg, boars ≥95kg, backfat thickness 18-32mm at 8 months of age, and average daily weight gain ≥450g from weaning to 8 months of age. Meat quality sampling and testing standards were the same as in Example 1.

[0122] The hybrid pig herd bred in this embodiment shows that the average number of live piglets produced by sows is 2-3 more than that of the Yanan pig program, reaching 13-14 piglets. Intramuscular fat content remains within the high-quality range of 2.8%-3.5%, and the percentage of all-black coats reaches over 95%. This embodiment is suitable for the expansion stage of breeding farms and can significantly improve the efficiency of breeding pig supply.

[0123] This invention is not limited to the optional embodiments described above, and anyone can derive other various forms of products based on the inspiration of this invention. The specific embodiments described above should not be construed as limiting the scope of protection of this invention; the scope of protection of this invention should be determined by the claims, and the specification can be used to interpret the claims.

Claims

1. An ecological breeding method for hybrid black-haired meat pigs, characterized in that, Includes the following steps: Step 100: Select Chenghua sows as the maternal line and Neijiang boars as the paternal line, and perform artificial insemination to obtain the F1 generation; Step 200: Select F1 generation sows as the maternal line and Duroc boars as the paternal line, and perform artificial insemination to obtain F2 generation; Step 300: Select F2 generation sows as maternal lines and select Yanan pig boars as paternal lines, and perform artificial insemination to obtain F3 generation; Step 400: Select the F3 generation for interfamilial cross-fixation to obtain the F4 generation base group; Step 500: Conduct phenotypic selection on the F4 generation base population for 2-3 consecutive generations to obtain a genetically stable black-haired meat hybrid pig population.

2. The ecological breeding method for hybrid black-haired meat pigs according to claim 1, characterized in that, In step 100, the Chenghua sows are multiparous with 2-4 litters, weigh ≥100kg, have a body length ≥110cm, have all-black hair, large drooping ears, and at least 6 pairs of effective teats; the Neijiang boars are 12-14 months old, weigh ≥130kg, have a body length ≥135cm, have all-black hair, have whorls of hair on their foreheads, and have a backfat thickness of 30-40mm.

3. The ecological breeding method for hybrid black-haired meat pigs according to claim 1, characterized in that, In step 100, phenotypic screening is performed on the F1 generation, and individuals with completely black fur, a weaning weight ≥ 6.5 kg, a body length ≥ 95 cm at 6 months of age, and a weight ≥ 75 kg at 6 months of age are selected.

4. The ecological breeding method for hybrid black-haired meat pigs according to claim 1, characterized in that, In step 200, the Duroc boars are 12-14 months old, weigh ≥150kg, have a body length ≥145cm, and have brownish-red coats. Phenotypic screening is performed on the F2 generation, and individuals with all-black coats, weaning weight ≥7.0kg, body length ≥100cm at 6 months of age, and weight ≥85kg at 6 months of age are selected. Individuals with non-all-black coats are all culled at weaning.

5. The ecological breeding method for hybrid black-haired meat pigs according to claim 1, characterized in that, In step 300, the Ya'nan boars are 12-14 months old, weigh ≥120kg, have a body length ≥125cm, have all-black hair, a relatively long body, a straight back, and are isolated and observed for 30 days after introduction without any stress response.

6. The ecological breeding method for hybrid black-haired meat pigs according to claim 1, characterized in that, In step 300, phenotypic screening is performed on the F3 generation, and individuals with completely black fur, weaning weight ≥7.5kg, body length ≥105cm at 8 months of age, and weight ≥95kg at 8 months of age are selected; meat quality sampling is performed on the F3 generation, and family individuals with intramuscular fat content ≥3.0% and lean meat percentage ≥45% are selected.

7. The ecological breeding method for hybrid black-haired meat pigs according to claim 1, characterized in that, In step 300, the Yanan pig boars are replaced with Meishan pig boars. The Meishan pig boars are 12-14 months old, weigh ≥110kg, have a body length ≥120cm, have black or bluish-gray coats, and white lower limbs. The 8-month-old weight selection standard for F3 generation is adjusted to sows ≥90kg and boars ≥95kg.

8. The ecological breeding method for hybrid black-haired meat pigs according to claim 1, characterized in that, In step 400, the male-to-female ratio of the interfamilial lineage is fixed at 1:10-1:15, the kinship coefficient between the paired individuals is <0.125, and offspring of the same grandfather do not pair up, full siblings do not pair up, and half siblings do not pair up.

9. The ecological breeding method for hybrid black-haired meat pigs according to claim 1, characterized in that, In step 500, the phenotypic selection of the population includes selection of growth performance, selection of reproductive performance, selection of coat color fixation and selection of meat quality performance; the retention rate of each generation is 15%-25%, and after 2-3 consecutive generations of selection, the population has a full black coat rate of ≥95% and the standard is met for two consecutive generations.

10. The ecological breeding method for hybrid black-haired meat pigs according to claim 1, characterized in that, It also includes step 600, ecological feeding management, with the breeding environment being hilly or semi-mountainous, and each fattening pig being provided with an outdoor exercise area of ​​≥3m². 2 They are raised in a semi-grazing mode, free-range during the day and returned to their enclosures at night. The slaughter weight is 100-110kg, and the breeding cycle is 10-12 months.

Images