Key Technical Points for the Feeding and Management of Replacement Gilts

Replacement gilt is a term in swine production science, generally referring to a female pig that has been selected and retained but has not yet been mated. They are used to replace sows culled due to older age, poor reproductive performance, or disease, thereby maintaining a herd structure of production sows composed mainly of young and prime-aged animals.

1. Full-feeding stage: 20-60 kg is the stage for promoting full physical development of replacement gilts. They should be fed a nutritionally complete, full-price diet according to the corresponding feeding standards.

2. Restricted-feeding stage: Lean-type sows generally begin restricted feeding at 90-110 kg, while meat-fat type and fat-type sows can begin restricted feeding at 70 kg. The daily feed allowance is about 2%-2.5% of body weight. Restricted feeding for replacement gilts ends two weeks before mating, when supplementary feeding is implemented to stimulate estrus, so as to increase the number of ovulations.

3. Reasonable grouping and moderate exercise. To ensure good growth and development of replacement gilts, they should be divided into small groups according to body weight. Before reaching 60 kg body weight, 4-6 pigs can be kept per pen; after 60 kg, they should be divided again by body weight into small groups of 2-3 pigs each, which is conducive to early estrus and mating. Replacement gilt barns should have an outdoor exercise yard to strengthen their physique and enhance the flexibility and firmness of their limbs.

4. Timely training. Replacement gilts should receive strengthened training and management from a young age to build a harmonious relationship between humans and pigs and train the pigs to develop good living habits. After being raised to a certain age in months, they will reach sexual maturity and show periodic estrus, but at this time their physical development is not yet fully mature. When gilts are 150-180 days old, it is best to use adult boars for contact-induced estrus stimulation to promote estrus in the gilts.

5. Daily management. The suitable temperature for replacement gilt barns is 19-21°C. In summer, attention should be paid to heat prevention and cooling. Once the room temperature exceeds 30°C, it will inhibit the secretion of sex hormones in the body of replacement gilts, leading to absence of estrus or abnormal estrus. In winter, ventilation and air exchange in the pig barn should be strengthened, and the contradiction between temperature and ventilation must be handled well, maintaining both a suitable temperature and fresh air. The pen environment and facilities and equipment should be disinfected regularly, the pigs' bodies should be brushed frequently, and regular deworming should be carried out.

6. Strictly implement the immunization program. Carry out timely vaccination against diseases such as foot-and-mouth disease, swine fever, porcine parvovirus disease, pseudorabies, Japanese encephalitis, and porcine reproductive and respiratory syndrome according to the immunization program.