Breeding pigs form the foundation of pig production and are the key to maintaining a stable and efficient breeding system. Since the productive lifespan of breeding animals is limited, boars typically do not exceed 2 years in natural mating, while sows usually have a maximum of 8 litters. In commercial settings, boars may be used for up to 3–4 years, but sows generally do not go beyond 8 litters. Moreover, there is significant variation in the performance of individual pigs. Therefore, implementing a scientifically sound and reasonable breeding and replacement strategy is essential to maintain or improve breeding productivity and ultimately enhance the farm’s economic efficiency.
So, how should breeders be removed and replaced?
To calculate the data needed for the elimination and renewal of breeding pigs, let's take an example of 100 basic sows with a farrowing rate of 2.3. Here's how it works:
**Boars:** Under natural mating conditions, the male-to-female ratio should not exceed 1:20. Therefore, 100 sows would require 5 boars (100 ÷ 20 = 5). Each year, about 2.5 boars need to be replaced, meaning 2 or 3 per year.
**Sows:** With an effective lifespan of 8 litters and an average of 2.3 litters per sow annually, the average service life is approximately 3.5 years (8 ÷ 2.3 ≈ 3.48). The annual culling rate is around 28.6%, which we can round up to 30%. For 100 sows, this means 30 sows need to be culled and replaced each year, or about 2.5 per month. In large-scale farms, this number should be adjusted weekly to ensure smooth operation.
**Principles for Breeding Replacement:**
The above calculations are theoretical. In practice, the culling and replacement of breeding pigs should follow certain guidelines.
**For sows:**
1. Remove sows that have reached breeding age and weight but continue to show no signs of estrus after 2–3 heat cycles.
2. Eliminate sows that do not come into heat within 60 days post-weaning.
3. Cull sows that return to estrus 3–4 times consecutively without successful breeding.
4. Remove sows that have fewer than 6 litters, experience stillbirths, or have poor litter quality.
5. Eliminate sows with less than 6 functional teats, abnormal udder development, inverted teats, or poor milk production.
6. Remove sows with weak maternal instincts, aggressive behavior, or low survival rates among piglets.
7. Cull sows that are slow to eat, overweight, lethargic, or show poor physical condition.
8. Eliminate sows that produce deformed offspring.
9. Remove sows suffering from diseases, disabilities, old age, or declining performance.
**For boars:**
Boars are generally culled based on their age, but those with poor semen quality, poor mating behavior, or aggressive temperaments should also be removed promptly.
After culling, it's important to replace them immediately with high-quality replacement breeding stock to maintain production levels and genetic improvement. This process ensures continuous breeding performance and long-term farm profitability.
Product Dimensions: Customized
Casting General Tolerance: Grade GBT6414-CT8
Flow Processes: Die casting, Degating to remove the residual of the gate, Polishing and Deburring to remove the burrs, Polishing to remove the parting line, flash,CNC Turning, Cleaning, Packaging, Storaging, Shipping
Control Measure: Incoming Material Test, First Article inspection, Routing inspection, Final item inspection, and Outgoing quality control
Inspection Equipment: CMM, Caliper, Plug Gage, Screw Gauge
Application: Machinery Parts
Certificate: IATF16949:2016,ISO14001:2015,ISO45001:2018
Lead Time: 30-35 days
Trade Term: FOB Ningbo
This classification mainly includes the aluminum low-pressure casting Machinery Parts using in motor area.
Normal raw material: A356.ZL101A.ZL101.AlSi7Mg
The pressure on the surface of the molten metal is 0.06~0.12Mpa.This processing has good shrinkage, casting tissue is dense, easy to produce the large thin-walled complex parts, the casting head is not needed , metal yield can be up to 95%.
Product Dimensions: Customized
Casting General Tolerance: Grade GBT6414-CT8
Flow Processes: Die casting, Degating to remove the residual of the gate, Polishing and Deburring to remove the burrs, Polishing to remove the parting line, flash,CNC Turning, Cleaning, Packaging, Storaging, Shipping
Control Measure: Incoming Material Test, First Article inspection, Routing inspection, Final item inspection, and Outgoing quality control
Inspection Equipment: CMM, Caliper, Plug Gage, Screw Gauge
Application: Machinery Parts
Certificate: IATF16949:2016,ISO14001:2015,ISO45001:2018
Lead Time: 30-35 days
Trade Term: FOB Ningbo
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