A Detailed Guide to the Large-Scale Farming Methods and Precautions for Yuxi Black Pigs

The Yuxi black pig is a very popular pig breed, with good meat quality and flavor and high nutritional value. It has excellent economic benefits. Below is information on the large-scale farming methods and precautions for Yuxi black pigs; interested readers can refer to it.

I. Current Status of Yuxi Black Pig Farming

1. Origin and Current Status of Large-Scale Production

Traditional Yuxi black pig farming consisted of free-range raising by farming households, mainly through grazing. However, with the rapid development of society, the economic benefits of free-range Yuxi black pig raising became low, and combined with the impact of introduced pig breeds, the production number of Yuxi black pigs dropped sharply and faced the predicament of extinction. In order to preserve and continue this unique pig breed resource and to achieve its development and utilization, Sanmenxia Chuying Agriculture and Animal Husbandry Co., Ltd. has actively carried out conservation work for Yuxi black pigs since 2016, exploratorily conducting large-scale Yuxi black pig farming. The farming model adopted is: sows and nursery piglets (from weaning to 90 days of age) are raised entirely indoors; fattening and growing pigs adopt a "shed feeding + grazing" model, that is, at this stage the pigs move indoors at night and in cold seasons, and at other times move within a certain range outside the shed (10-20 mu). Up to now, the company has 205 sows on hand, with a cumulative 214 litters farrowed and 1,747 healthy piglets bred.

II. Performance of Related Traits in Large-Scale Farming of Yuxi Black Pigs

1. Living Habits and Disease Resistance

Traditional farming.

Yuxi black pigs are tolerant of coarse feed. The concave-faced short-snout black pig can consume 30% coarse feed such as rice bran, with relatively good feed intake performance; the straight-faced long-snout black pig is slightly less tolerant of coarse feed and also has poorer feed intake performance. Yuxi black pigs are lively and active, with strong climbing ability, and their range of activity reaches about 2 km, and they can return to the pig shed on time, so complete grazing can be implemented. Straight-faced long-snout black pigs are relatively docile in temperament, with disease resistance relatively poorer than short-snout black pigs, and occasionally become ill; concave-faced short-snout black pigs are fierce and combative, with strong disease resistance, and are basically disease-free year-round.

Large-scale farming.

Under conditions of complete indoor farming, the disease incidence of Yuxi black pigs is as follows: straight-faced long-snout black pigs become ill more often, generally showing consumptive diseases such as endometritis, infertility and emaciation. Concave-faced short-snout black pigs have relatively strong disease resistance and occasionally become ill. Under the "shed feeding + grazing" farming model, the constitution and disease resistance of straight-faced long-snout black pigs are greatly improved. Yuxi black pigs have relatively poor feed intake ability; if raised mixed with other pig breeds, their competitive feeding ability is relatively low, which easily causes large numbers of Yuxi black pigs to fall behind in growth.

2. Body Measurements, Body Weight, etc.

The body length, body height, chest circumference and body weight of 5 adult boars were measured, with averages of 149 cm, 83.8 cm, 148.6 cm and 221.6 kg respectively. The body length, body height and chest circumference of 161 adult sows were measured, with averages of 146.24 cm, 77.7 cm and 145.6 cm respectively, and standard deviations of 10.84 cm, 4.02 cm and 7.38 cm, showing that the body measurement indicators of Yuxi black pig sows are relatively consistent; their average body weight is 131.57 kg.

3. Reproductive Performance

Traditional farming.

Yuxi black pigs reach sexual maturity relatively early, generally reaching sexual maturity at 4-5 months of age; straight-faced long-snout sows come into estrus relatively earlier, while concave-faced short-snout sows are somewhat delayed. The gestation period of sows is 112-114 days, the estrous cycle is 18-21 days, the number of piglets born in the first litter is 8-11, and the number born in subsequent litters is 12-14, with a maximum of 16-18. Straight-faced long-snout sows give birth to fewer piglets, are lazy in temperament, and have average mothering behavior; concave-faced short-snout sows give birth to more piglets, have obvious piglet-protecting behavior, and have better milk. The average birth weight of piglets is 0.71 kg, and the survival rate is relatively high, reaching more than 85%.

Large-scale farming.

Under conditions of complete indoor farming, based on statistical analysis of 212 litters of farrowing data, the first estrus, estrous cycle and gestation period of replacement sows showed little difference from traditional farming: the gestation period was 111-117 days, with an average of 114.27 days, a standard deviation of 1.22 days and a coefficient of variation of 1.07%; the estrous cycle was 18-22 days, with an average of 20.19 days, a standard deviation of 1.13 days and a coefficient of variation of 5.60%. However, the farrowing rate of sows declined somewhat, with an average of 9.47 piglets total born per litter, 9.34 live piglets born per litter and 8.24 healthy piglets born per litter; the average total born in the first litter was 9.0 piglets, and the average total born in the second litter was 10.4 piglets; the average birth litter weight was 9.995 kg, and the average birth weight was 1.19 kg; the 21-day litter weight was 24.12 kg, with an average individual weight of 2.97 kg; the average 30-day weaning weight was 4.87 kg (white pigs are above 7.5 kg). The survival rate in the farrowing house was 90.26%.

Analysis of Results.

The first estrus, estrous cycle and gestation cycle of sows are greatly influenced by genetic factors, so they do not change much. The decline in farrowing rate and the increase in birth weight are related to changes in the farming model: under complete indoor farming conditions, sows have no exercise yard, their amount of exercise decreases, and their living habits change, leading to a decline in sow reproductive performance; the main reason for the increase in piglet birth weight is that sows obtain improved nutrition during gestation, but their amount of exercise decreases and consumption decreases, so that the fetus is fully supplied with nutrition and grows well, promoting an increase in piglet birth weight.

4. Growth Performance

According to observation, under the "shed feeding + grazing" model, the average body weight of boars at 45 days of age reached 8.125 kg (Duroc x Landrace x Yorkshire white pigs can reach this at 30 days of age), the average body weight of boars at 97 days of age reached 17.33 kg (Duroc x Landrace x Yorkshire white pigs can reach this at 50 days of age), and the average body weight of boars at about 215 days of age reached 130 kg (Duroc x Landrace x Yorkshire white pigs can reach this at 190 days of age). It can thus be seen that, compared with Duroc x Landrace x Yorkshire white pigs, Yuxi black pigs grow more slowly in the early stage and more rapidly in the later stage.

5. Slaughter Measurement and Meat Quality

According to records from Henan Agricultural University, 15 Yuxi black pigs were subjected to slaughter measurement, and their dressing percentage, backfat thickness, loin eye area and lean meat percentage were 75.7%, 31.9 mm, 31.86 cm 2 and 54.4% respectively, with standard deviations of 1.97%, 8.41 mm, 9.29 cm 2 and 4.78%. According to meat quality inspection and analysis conducted by the Ministry of Agriculture in June 2016 on 2 Yuxi black pigs of two types raised on a small scale: the dressing percentages of straight-faced long-snout and concave-faced short-snout Yuxi black pigs were 74.6% and 76.5% respectively, backfat thickness was 32.6 mm and 46.2 mm respectively, loin eye area was 32.84 cm 2 and 36.62 cm 2 respectively, lean meat percentage was 49.3% and 49.6% respectively, and intramuscular fat content was 6.03% and 4.16% respectively.

Overall, the dressing percentage of Yuxi black pigs is close to that of Duroc x Landrace x Yorkshire three-way cross white pigs, but their backfat thickness and loin eye area are greater than those of the latter, while their lean meat percentage is far lower than that of the latter. Most indicators of the two different types of black pigs within the breed are relatively close, but there are also certain differences in average backfat thickness and intramuscular fat content. The backfat thickness of concave-faced short-snout black pigs is greater than that of straight-faced long-snout black pigs, while the intramuscular fat content of straight-faced long-snout pigs is higher than that of concave-faced short-snout black pigs, indicating that the meat quality of the straight-faced long-snout type better meets people's consumption requirements. Surveys found that the fat meat of straight-faced long-snout black pigs often appears as multi-layered pork belly, with a rich meat aroma, and is highly favored by local people; while concave-faced short-snout black pigs are difficult to dehair, and after dehairing the skin shows obvious dark residue, and after being left overnight the skin turns bluish, giving a poor appearance and affecting market sales, which further confirms the advantages of straight-faced long-snout black pig meat.

III. Farming Recommendations

1. Persist in Large-Scale Farming

Conducting large-scale farming of Yuxi black pigs is the only way forward for conservation work on Yuxi black pigs under the new situation, and is also an effective way to develop and utilize Yuxi black pigs; at the same time, after implementing large-scale farming, the birth weight, growth speed and survival rate of black pigs are all greatly improved, and this can also be brought into play and utilized.

2. Focus on Solving Problems

Countermeasures for solving problems such as low farrowing rate and poor disease resistance in large-scale farming of Yuxi black pigs: first, an environment suitable for the living habits of Yuxi black pigs should be created as much as possible, especially by building exercise yards for sows to increase their amount of exercise, so as to improve reproductive capacity. Second, fattening and growing black pigs must not be mixed with other pig breeds, to avoid growth falling behind due to the poor competitive feeding ability of Yuxi black pigs.

3. Purposeful Development and Utilization

The intramuscular fat content of straight-faced long-snout black pigs is higher than that of concave-faced short-snout black pigs, and their backfat thickness is smaller, indicating that the meat quality of straight-faced long-snout black pigs better meets people's consumption requirements. Therefore, in development and utilization, straight-faced long-snout black pigs should be focused on as the priority target for development and utilization.

The black pig is a very popular pig breed, its meat is much liked by consumers, and it has low farming costs and simple farming methods, with good farming prospects, and is worth raising by all farmers. The above is about the methods and precautions for large-scale black pig farming, and everyone can use it for reference.