Pig (Sow/Boar) — Gilt Development Feed Requirements
Replacement gilts should reach 280-300 lbs by first breeding at 7-8 months. Protein requirement is 15-16% for continued lean growth. Limit-feed after 250 lbs to prevent excess fat deposition. Begin feeding a gestation diet with added vitamins and minerals 2 weeks before expected estrus.
Gilt Development Feeding at Different Body Weights
The daily feed requirements for pig (sow/boar) in the gilt development stage vary directly with body weight. The table below shows how dry matter intake, protein needs, and monthly feed costs change across a range of body weights. The DMI adjustment of 1.1x is applied at every weight level, reflecting the consistent metabolic demands of this production phase regardless of the individual animal's size.
| Body Weight | Daily DMI | Daily Protein | Daily TDN | Monthly Feed | Monthly Cost* |
|---|---|---|---|---|---|
| 240 lbs | 7.9 lbs | 1.3 lbs | 5.9 lbs | 238 lbs | $20.25 |
| 280 lbs | 9.2 lbs | 1.5 lbs | 6.9 lbs | 277 lbs | $23.63 |
| 320 lbs | 10.6 lbs | 1.7 lbs | 7.9 lbs | 317 lbs | $27.00 |
| 360 lbs | 11.9 lbs | 1.9 lbs | 8.9 lbs | 356 lbs | $30.37 |
| 400 lbs | 13.2 lbs | 2.1 lbs | 9.9 lbs | 396 lbs | $33.75 |
| 440 lbs | 14.5 lbs | 2.3 lbs | 10.9 lbs | 436 lbs | $37.13 |
| 480 lbs | 15.8 lbs | 2.6 lbs | 11.9 lbs | 475 lbs | $40.50 |
| 520 lbs | 17.2 lbs | 2.8 lbs | 12.9 lbs | 515 lbs | $43.88 |
| 600 lbs | 19.8 lbs | 3.2 lbs | 14.9 lbs | 594 lbs | $50.63 |
*Monthly cost estimated using grass hay at $150/ton.
Feed Options for Pig (Sow/Boar) (Gilt Development)
Different feeds provide varying levels of protein and energy for pig (sow/boar) in the gilt development stage, which requires a minimum of 16.1% crude protein and 75% TDN. The table below compares common feeds, showing the as-fed daily quantity needed to meet the dry matter requirement and whether each feed meets the protein and TDN thresholds as a sole feed source.
| Feed | CP % | TDN % | As-Fed/Day | Protein OK? | TDN OK? | Monthly Cost* |
|---|---|---|---|---|---|---|
| Grass Hay | 8% | 52% | 15.0 lbs | No | No | $33.75 |
| Alfalfa Hay | 18% | 58% | 14.7 lbs | Yes | No | $55.00 |
| Timothy Hay | 9% | 55% | 15.0 lbs | No | No | $45.00 |
| Bermuda Grass Hay | 10% | 52% | 15.0 lbs | No | No | $36.00 |
| Whole Corn | 9% | 88% | 15.0 lbs | No | Yes | $49.50 |
| Cracked Corn | 9% | 88% | 15.0 lbs | No | Yes | $54.00 |
| Oats | 12% | 70% | 14.8 lbs | No | No | $46.72 |
| Barley | 13% | 84% | 15.0 lbs | No | Yes | $51.75 |
| Pasture Grass (Fresh) | 12% | 62% | 52.8 lbs | No | No | $0.00 |
| Layer Pellets | 16% | 70% | 14.7 lbs | No | No | $88.00 |
| Broiler Starter | 22% | 78% | 14.7 lbs | Yes | Yes | $99.00 |
| Horse Sweet Feed | 12% | 72% | 15.0 lbs | No | No | $78.75 |
| Alfalfa Hay Cubes | 17% | 56% | 14.7 lbs | Yes | No | $66.00 |
*Cost based on the listed feed as the sole source at current pricing.
Herd Budgets: Pig (Sow/Boar) Gilt Development
For operations managing multiple pig (sow/boar) animals in the gilt development stage, the following table projects total feed requirements and costs for various herd sizes. These projections use grass hay pricing and assume all animals are at the average body weight of 400 lbs.
| Head Count | Daily DMI Total | Monthly Tons | Annual Tons | Monthly Cost | Annual Cost |
|---|---|---|---|---|---|
| 1 | 13.2 lbs | 0.20 tons | 2.41 tons | $33.75 | $410.63 |
| 5 | 66.0 lbs | 0.99 tons | 12.05 tons | $168.75 | $2,053.13 |
| 10 | 132.0 lbs | 1.98 tons | 24.09 tons | $337.50 | $4,106.25 |
| 25 | 330.0 lbs | 4.95 tons | 60.23 tons | $843.75 | $10,265.63 |
| 50 | 660.0 lbs | 9.90 tons | 120.45 tons | $1,687.50 | $20,531.25 |
| 100 | 1,320.0 lbs | 19.80 tons | 240.90 tons | $3,375.00 | $41,062.50 |
Nutritional Management Tips for Gilt Development
Proper nutritional management during the gilt development phase is critical for pig (sow/boar) health, productivity, and profitability. The DMI adjustment factor of 1.1x reflects the increased metabolic demands of this production phase compared to maintenance. Similarly, the protein adjustment of 1.15x elevates the dietary crude protein requirement to 16.1% of dry matter.
When formulating rations for this stage, start with the forage base and determine how much of the protein and energy requirements it provides. If the forage alone does not meet the protein or TDN requirements shown in the feed comparison table above, supplement with protein concentrates (soybean meal, cottonseed meal) or energy sources (corn, barley, fat supplements) to fill the gap. Always make dietary changes gradually over 7-14 days to allow the digestive microbiome to adapt, particularly for ruminant species where sudden changes can cause acidosis, bloat, or other digestive disturbances.
Water intake is closely linked to dry matter intake and is often overlooked in feeding calculations. As a general rule, livestock consume 2-4 lbs of water per lb of dry matter consumed, with lactating animals at the high end of this range. Ensure that clean, fresh water is available at all times, as even mild dehydration reduces feed intake and animal performance. During winter, heated water sources prevent freezing and maintain intake. During summer heat, shade and ventilation reduce heat stress that can depress feed intake by 10-20%.
Monitor body condition scoring (BCS) regularly to verify that the feeding program is achieving the desired results. Animals gaining or losing condition outside the expected range indicate that feed quality or quantity needs adjustment. Laboratory analysis of forage samples ($15-$30 per sample) provides accurate protein and energy values for your specific hay or silage, which may differ significantly from the book values used in this calculator. Hay quality varies by cutting, maturity at harvest, storage conditions, and weather during the curing process, making testing the most reliable basis for ration formulation.
Other Pig (Sow/Boar) Life Stages
Compare feed requirements across all pig (sow/boar) production phases.