Feeding and Management Key Points for Large Yorkshire Sows During Their High-Production Period
1. The age structure of the sow herd must be reasonable. According to a survey of 150 litters from parities 1-10 at a certain pig breeding farm in Jining, sow production performance varies with age (parity).
The Large Yorkshire sow is a fine breed with relatively stable genetic traits, a long high-production period, strong reproductive capacity, and sustained high and stable production over many years. According to a survey of 150 litters from parities 1-10 at a certain pig breeding farm in Jining, adult sows (parities 4-7) averaged 12.4 live piglets born per litter, 1.6 more per litter than young sows (parities 1-3), and 1.09 more per litter than old sows (parities 8-10). At 20 days of age, the average weight per piglet was 0.37 and 0.44 kg higher than that of young sows and old sows respectively; at 60 days of age, the average weight per piglet was also 1.24 and 1.84 kg higher than that of young sows and old sows respectively.
Therefore, in the age structure of the sow herd, the more adult sows there are, the more piglets are produced and the higher the economic benefits. Large-scale pig farms should raise as many adult sows as possible, promptly supplement young sows, and cull old sows. For purebreeding farms, the suitable structural ratio is the "three-thirds system," which is relatively reasonable, that is, supplementing 1/3 young sows and culling 1/3 old sows each year. Cull low-producing sows and those with physiological defects and bad habits at any time.
2. Increase the selection intensity of breeding pigs and the quality of the herd. Through strict mating plans and the methods of selection and mating, select, breed and make full use of outstanding middle-aged individuals to mate with each other, produce more outstanding offspring, continuously improve the overall quality of the pig herd, and gradually narrow individual differences.
According to the survey, the reason why sows of parities 1-3 at a certain pig breeding farm in Jining showed relatively high production performance is that, in addition to better breed, individual quality and feeding conditions, a very important factor is giving first-litter sows appropriate "late marriage." Generally, after 2-3 estrous cycles, at 8-11 months of age and 90-100 kg body weight, adult boars are used for first mating. Repeat mating is practiced, generally 3 matings. Therefore, the differences in piglet birth weight and body weight at 20 and 60 days of age are relatively small, uniformity is better, and growth and development are also relatively consistent. Compared with sows of other breeds, they can enter the high-production period 1 parity earlier.
At present, special attention should be paid to correcting the phenomena in some areas of "keeping every sow," early mating and random uncontrolled mating, which cause fewer piglets born, weak and small piglets, poor vitality, low survival rate, and breed degeneration, and affect the growth and development of young sows, delay the arrival of the high-production period, and other adverse consequences.
3. Early weaning to increase the number of litters per year. A lactating sow weighing 150 kg usually consumes about 5 kg of mixed feed per day. If weaning can be advanced to 21 days of age, 200 kg of sow feed can be saved. One farrowing cycle can be reduced to about 135 days, and 0.5-0.6 more litters can be produced. Based on 10 piglets per litter, 5-6 more piglets can be produced. The lactation period is shortened, the sow is in good body condition, and it is easier to come into estrus and mate, which both improves feed utilization and increases the number of piglets born, better tapping the potential of the sow's high-production period.
For piglets weaned early, full-price pellet feed for suckling piglets should be used to attract them to eat or manual forced feeding should begin at 5 days of age. Around 20 days of age, eating until 70-80% full generally will not affect the growth, development and survival of piglets, and can also reduce the occurrence of piglet diseases (transmitted from sows to piglets). Early weaning can also extend the service life of sows, and outstanding individuals can still show production performance when they produce up to 10 parities. Practice has proved that the more piglets born and the higher the lactation ability of high-producing sows, the more obvious the sow's weight loss after 35 days of age. If weaned at 60 days of age, some sows are skin and bones, and the anestrous period lasts about 1 month. If it occurs in a high-temperature season, anestrus often appears, affecting production in the next cycle.
4. Prevent abortion and ensure survival. Most infectious diseases can cause abortion in pregnant sows. In particular, reproductive disorder diseases such as Japanese B encephalitis, parvovirus pseudorabies, and porcine reproductive and respiratory syndrome. Vaccination should be carried out on time for prevention. At the same time, management of pregnant sows should be strengthened: prohibit feeding moldy feed, prohibit drinking cold water, and prevent chasing, fighting, whipping, frightening, jumping ditches, crowding, slipping on the ground and falling, etc. If there are signs of abortion, 15-25 mg of progesterone can be injected immediately to prevent miscarriage.
5. Scientific feeding of sows. During the high-production period, sows have more requirements for feed nutrition. Full-price compound feed should be consistently fed, especially protein, minerals, calcium, phosphorus, vitamins, trace elements, etc., which must be supplied in balance. During gestation, each kg of feed should contain about 11.5 megajoules of digestible energy and about 13% crude protein; during lactation, each kg of feed should contain 12.5 megajoules of digestible energy and about 15%-16% crude protein. Green feed should be kept available all year round. Let sows exercise properly and bask in the sun every day, and maintain good body condition all year round.
The feed intake of high-producing sows has a great relationship with the daily weight gain of weaned piglets, the weight loss of sows during lactation, the length of the anestrous period after weaning, and the number of ovulations. According to experiments, sows fed 2.9 kg of mixed feed per day had piglets with a daily weight gain of 189.8 g, lactation weight loss of 27.4 kg, anestrous period of 21.2 days, and ovulation number of 10.9; sows fed 4.83 kg of mixed feed per day had piglets with a daily weight gain of 192.8 g, lactation weight loss of 9 kg, anestrous period of 7.8 days, and ovulation number of 12.
In short, to make sows produce more piglets, every possible means should be used to make good use of the sow's high-production period and fully give play to and improve its production performance. This is an important way to increase @#@227@#@ economic benefits.