🐷 Pig Pregnancy Calculator: Farrowing Date & Care Timeline

Pig Pregnancy Calculator

Breeding/Artificial Insemination Date

Pregnancy Summary

Breeding Date:

Expected Farrowing Date:

Current Gestation Stage:

Days Pregnant: days (of 114 total)

Days Remaining: days

Pregnancy Progress

Breeding Farrowing

Pregnancy Milestones

Care Recommendations

1. Standard Gestation Period & Calculation Methodology

Core Formula:
Swine gestation is 114 days (3 months, 3 weeks, 3 days), with natural variations of 111–117 days depending on breed, litter size, and environmental factors.
- Mini Pigs: 112–114 days.
- Commercial Breeds (Yorkshire, Landrace): Strictly 114 days.
- Heritage Breeds (Duroc, Berkshire): 113–115 days.
Key Input: Breeding or artificial insemination (AI) date. For multiple matings, use the first service date for accuracy

2. Scientific Backing: Genetic & Physiological Insights

Gestation Stability:
Genetic studies confirm gestation length (GP) has medium heritability (0.251–0.430), making it predictable across breeds. Larger litters may farrow 1–2 days early, while smaller litters extend to 117 days.
Critical Milestones:
- Day 12–18: Embryo implantation.
- Day 25–35: Organ formation (ultrasound confirmation possible).
- Day 80+: Rapid fetal weight gain (70% of birth weight)

3. Essential Features for Real-Time Calculation

Inputs:

Breeding/AI date (calendar picker).

Outputs:

Farrowing Date: Highlighted in bold (e.g., “June 15, 2025”).
Progress Tracking:
- Days pregnant & remaining (e.g., “Day 60 of 114”).
- Visual progress bar (color-coded by trimester).
Milestone Alerts:
“Day 70: Fetal skeletons visible via ultrasound. Schedule a vet scan!”.

Care Recommendations by Stage:

Stage	Nutrition	Management
Early (0–30d)	High-quality gestation feed (2–2.5kg/day)	Minimize stress; no pen moves
Mid (31–80d)	Increase feed to 2.5–3kg/day; add protein	Vaccinations; space allocation (16–18 ft²/sow)
Late (81–114d)	Lactation diet (3–3.5kg/day)	Move to farrowing pen; provide nesting materials

4. Tips for Reproductive Success

Boost Litter Survival:
Altrenogest supplementation (Days 6–12 of pregnancy) increases piglets born alive by 5.4% and reduces stillbirths by 22%.
Nutrition Tweaks:
- Parity 2–3 sows: Higher protein (SID Lys: 5g/kg) maximizes body protein gain .
- Avoid excess protein for older sows (Parity 4+) to prevent oxidation.
Farrowing Prep:
- Disinfect pens 1–2 weeks pre-farrowing.
- Provide heat lamps (32–35°C) for piglets

5. When to Seek Veterinary Help

Critical Checkpoints:
Timeline Vet Action
Day 28–35 Ultrasound to confirm pregnancy & fetal count
Day 115+ Emergency intervention if farrowing delayed
Labor signs Assist if no piglets in 2 hours

Timeline	Vet Action
Day 28–35	Ultrasound to confirm pregnancy & fetal count
Day 115+	Emergency intervention if farrowing delayed
Labor signs	Assist if no piglets in 2 hours

6. Breed-Specific Nuances

Litter Size Trends:
- Yorkshire/Landrace: 12–16 piglets.
- Duroc: Smaller litters (8–12) but higher stillbirth risk.
Gestation Variations:
- Mini Pigs: Shorter (112 days) vs. Duroc: Longer (115 days)

7. FAQs

Q: Can sows hide pregnancy symptoms?
A: Yes! 20% show no signs until late stage. Confirm via ultrasound.

Q: Why did my sow farrow early?
A: Large litters (>14 piglets) often deliver 1–2 days early.

Q: How does heat stress impact pregnancy?
A: Reduces embryo implantation. Keep barns <25°C in summer

Q: What’s the 3-3-3 rule in pig pregnancy?
A: The 3-3-3 rule (3 months, 3 weeks, 3 days = 114 days) is a standard gestation estimate. However, research shows actual gestation varies between 111-117 days based on litter size and breed. Always confirm with ultrasound.

Q: Can pigs have false pregnancies?
A: Yes, 10-15% of sows show pseudopregnancy (hormonal imbalance). Key indicators: no weight gain by Day 50, absence of mammary development. Confirm via progesterone testing.

Q: How soon after breeding can you test pig pregnancy?
A:

Day 18-22: Ultrasound (95% accuracy)
Day 25+: Doppler heartbeat detection
Day 30: Rectal palpation by vet
Avoid stress-inducing methods before Day 18.

Q: Why is my pregnant pig not eating?
A: Common causes:

Heat stress (keep barn <24°C)
Parasites (deworm quarterly)
Lameness (check flooring)
If lasting >24hrs, consult a vet immediately.

Q: Do pigs need vaccinations during pregnancy?
A: Critical vaccines:

Parvovirus (Day 60 & 90)
E. coli (Day 100)
ERYSENGEL® (pre-breeding)
Always consult your herd veterinarian.

Q: How many piglets do first-time sows have?
A:

Breed	Avg. First Litter
Yorkshire	10-12 piglets
Duroc	6-8 piglets
Vietnamese	4-6 piglets
Litter size increases by 1-2 piglets per subsequent pregnancy.

Q: Can you transport pregnant pigs?
A: Only during mid-gestation (Days 35-80). Avoid:

Early gestation (embryo loss risk)
Last 3 weeks (premature farrowing risk)
Max 2hrs travel with non-slip flooring.

Q: What temperature should a farrowing room be?
A:

Sow zone: 18-20°C (64-68°F)
Piglet zone: 32-35°C (90-95°F) for Week 1
Use heat lamps with guards to prevent burns.

Q: How long after pigs mate do they show signs?
A: Visible signs appear at:

Day 30: Abdominal enlargement
Day 70: Udder development
Day 100: “Dropping” of belly
Early detection requires professional methods.

Q: Why do pigs eat their babies after birth?
A: Causes include:

Stress from overcrowding
Nutritional deficiency (provide 18% protein)
Stillborn removal (natural instinct)
Ensure 20 sq ft/sow in farrowing pens.

Q: How much water do pregnant pigs drink daily?
A: Consumption increases by stage:

Stage	Liters/Day
Early	8-10L
Mid	12-15L
Late	20-25L
Install nipple drinkers with 2L/min flow rate.

Q: Can pigs have miscarriages?
A: Yes, 5-10% pregnancy loss causes:

Infectious (PRRS, leptospirosis)
Thermal stress (>28°C)
Toxins (mycotoxins in feed)
Blood tests confirm cause.

Q: When do pregnant pigs start nesting?
A: Nesting behaviors peak 12-24hrs pre-farrowing:

Pawing bedding
Rooting materials
Restlessness
Provide straw 2 days before due date.

Q: Do pigs need vitamins during pregnancy?
A: Critical supplements:

Folic acid (5mg/kg feed): Redovers stillbirths
Vitamin E (50 IU/kg): Boosts immunity
Selenium (0.3ppm): Prevents MMA syndrome
Avoid excess Vitamin A (birth defect risk).

Q: How to increase piglet survival rate?
A: Evidence-based methods:

Split suckling (rotate piglets)
Iron dextran injections (Day 3)
Cross-fostering (<48hrs post-birth)
Supplemental milk for litters >14

Cite Recent Studies:

*”Altrenogest supplementation (Days 6–12) increases litter size by 4.2% and reduces low-birth-weight piglets by 17.5%”* 8.

Study Sources:
University of São Paulo Research, Frontiers in Veterinary Science.