Analysis of the causes of sows giving birth to few piglets and solutions

In pigs, any female pig of any age that has given birth to piglets is called a sow. In actual production, analyzing the causes of low litter size in sows and proposing countermeasures to increase sow litter size is an urgent problem that needs to be solved, and it is of great significance for improving the economic benefits of pig farming. Let us take a look below at the causes of and solutions for sows giving birth to few piglets!

Breed reasons

Some sow breeds themselves have low reproductive capacity, resulting in a small litter size. For example, Pietrain, Duroc, etc., because of breed reasons, it is very difficult to increase litter size. In the process of maternal line selection for commercial pig production, one should not only focus on the pig breed's body type and lean meat rate while neglecting reproductive capacity. Try to avoid the bloodlines of breeds with small litter size, and it is recommended to choose Landrace or Large White pigs.

Age reasons

The age and parity of pigs affect the number of piglets born, and also affect the number of live piglets born. Sows in their 1st to 2nd gestation have low reproductive performance, few ovulations, and a small litter size. The 3rd to 5th parities have the best reproductive performance, with the highest litter size and number of live piglets born. After the 6th to 7th parities, the reproductive performance of sows declines somewhat, and the litter size and number of live piglets born decrease. Moreover, due to the influence of physical strength, fatigue is likely to occur during the farrowing process, and the time is too long, causing an excessively large proportion of stillbirths. In production, assistance during farrowing should be strengthened for pigs of low parity and high parity to reduce the interval between births.

Feeding reasons

1. Not providing sows with nutritious, complete compound feed: Some producers believe that sows do not need additives or need fewer of them, so as to avoid excessive obesity in sows. This idea is incorrect and must be corrected.

2. Feeding moldy and deteriorated feed ingredients: Corn with excessive mycotoxins, soybean meal with high urease, neglect of bran quality, and sows' weak digestion of minerals causing inability to absorb calcium and phosphorus, excessive fluoride content, etc., all affect the litter size and number of live piglets born of sows.

Management reasons

1. Management before mating: Because current pig breeds grow too fast, mating too early, before reaching sexual maturity, causes a reduction in litter size. The mating age of replacement gilts should be above 7 months of age and around 120 kg body weight.

2. Failure to control body condition before mating: Replacement gilts are not restrict-fed, resulting in too large and too fat body weight at mating, reducing litter size. Base sows are too thin after weaning, and sows that have aborted or returned to estrus are too fat, affecting the number of ovulations in sows, thereby affecting litter size.

3. No short-term flushing before mating: In order to increase the number of ovulations, replacement gilts should be flush-fed 3 to 4 weeks before mating, and weaned sows should be flush-fed for a short period after weaning, feeding high-quality complete feed and increasing the feeding amount to increase the number of ovulations.

4. Unreasonable feeding amount during gestation: In the early stage of gestation, feed 2 kg per day; in the middle stage, feed an appropriate amount of 2 to 2.5 kg per day; in the late stage, feed 3 to 3.5 kg per day. At the same time, the feeding amount should be adjusted at any time according to the individual body condition of the sow.

5. Excessive stress in sows: Such as whipping, fright, fighting, sudden climate changes, cold and heat stress, etc., can all cause a reduction in the number of fetal implantations.

Other reasons

1. Unreasonable vaccination timing: During gestation, vaccination of sows should be minimized to reduce the impact of vaccination on the fetuses.

2. Impact of diseases: Many diseases can cause reproductive disorders and lead to a decline in litter size and an increase in the proportion of stillbirths and mummified fetuses, such as porcine reproductive and respiratory syndrome and swine fever.

Precautions

1. Strengthen epidemic prevention work and reduce infection from external wild viruses.

2. Reduce the number of introductions and do not introduce breeding stock from epidemic areas.

3. After introduction, isolate and inspect to prevent the introduction of infectious diseases.

4. Regularly conduct serological testing on the sow herd, and carry out immunization with various vaccines according to the health status of the pig herd.

5. Strengthen feeding management to reduce the reduction in litter size caused by management reasons.

6. When introducing breeding stock, choose pig breeds with high reproductive performance to improve the production efficiency of sows.