Dairy Cow — Replacement Heifer Feed Requirements
Dairy heifers should reach 55% of mature body weight by breeding at 13-15 months. Target 1.8-2.0 lbs average daily gain. Protein requirement is 16-18% for young heifers, declining to 14-15% as they approach breeding weight. Limit energy to prevent excess fat deposition in the udder.
Replacement Heifer Feeding at Different Body Weights
The daily feed requirements for dairy cow in the replacement heifer 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 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* |
|---|---|---|---|---|---|
| 840 lbs | 29.4 lbs | 5.4 lbs | 20.6 lbs | 882 lbs | $75.17 |
| 980 lbs | 34.3 lbs | 6.3 lbs | 24.0 lbs | 1,029 lbs | $87.70 |
| 1,120 lbs | 39.2 lbs | 7.2 lbs | 27.4 lbs | 1,176 lbs | $100.23 |
| 1,260 lbs | 44.1 lbs | 8.1 lbs | 30.9 lbs | 1,323 lbs | $112.76 |
| 1,400 lbs | 49.0 lbs | 9.0 lbs | 34.3 lbs | 1,470 lbs | $125.28 |
| 1,540 lbs | 53.9 lbs | 9.9 lbs | 37.7 lbs | 1,617 lbs | $137.81 |
| 1,680 lbs | 58.8 lbs | 10.8 lbs | 41.2 lbs | 1,764 lbs | $150.34 |
| 1,820 lbs | 63.7 lbs | 11.7 lbs | 44.6 lbs | 1,911 lbs | $162.87 |
| 2,100 lbs | 73.5 lbs | 13.5 lbs | 51.5 lbs | 2,205 lbs | $187.93 |
*Monthly cost estimated using grass hay at $150/ton.
Feed Options for Dairy Cow (Replacement Heifer)
Different feeds provide varying levels of protein and energy for dairy cow in the replacement heifer stage, which requires a minimum of 18.4% crude protein and 70% 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% | 55.7 lbs | No | No | $125.28 |
| Alfalfa Hay | 18% | 58% | 54.4 lbs | No | No | $204.17 |
| Timothy Hay | 9% | 55% | 55.7 lbs | No | No | $167.05 |
| Bermuda Grass Hay | 10% | 52% | 55.7 lbs | No | No | $133.64 |
| Whole Corn | 9% | 88% | 55.7 lbs | No | Yes | $183.75 |
| Cracked Corn | 9% | 88% | 55.7 lbs | No | Yes | $200.45 |
| Oats | 12% | 70% | 55.1 lbs | No | Yes | $173.43 |
| Barley | 13% | 84% | 55.7 lbs | No | Yes | $192.10 |
| Pasture Grass (Fresh) | 12% | 62% | 196.0 lbs | No | No | $0.00 |
| Layer Pellets | 16% | 70% | 54.4 lbs | No | Yes | $326.67 |
| Broiler Starter | 22% | 78% | 54.4 lbs | Yes | Yes | $367.50 |
| Horse Sweet Feed | 12% | 72% | 55.7 lbs | No | Yes | $292.33 |
| Alfalfa Hay Cubes | 17% | 56% | 54.4 lbs | No | No | $245.00 |
*Cost based on the listed feed as the sole source at current pricing.
Herd Budgets: Dairy Cow Replacement Heifer
For operations managing multiple dairy cow animals in the replacement heifer 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 1400 lbs.
| Head Count | Daily DMI Total | Monthly Tons | Annual Tons | Monthly Cost | Annual Cost |
|---|---|---|---|---|---|
| 1 | 49.0 lbs | 0.74 tons | 8.94 tons | $125.28 | $1,524.29 |
| 5 | 245.0 lbs | 3.68 tons | 44.71 tons | $626.42 | $7,621.45 |
| 10 | 490.0 lbs | 7.35 tons | 89.43 tons | $1,252.84 | $15,242.90 |
| 25 | 1,225.0 lbs | 18.38 tons | 223.56 tons | $3,132.10 | $38,107.24 |
| 50 | 2,450.0 lbs | 36.75 tons | 447.13 tons | $6,264.20 | $76,214.49 |
| 100 | 4,900.0 lbs | 73.50 tons | 894.25 tons | $12,528.41 | $152,428.98 |
Nutritional Management Tips for Replacement Heifer
Proper nutritional management during the replacement heifer phase is critical for dairy cow health, productivity, and profitability. The DMI adjustment factor of 1x reflects the baseline metabolic demands of this production phase compared to maintenance. Similarly, the protein adjustment of 1.15x elevates the dietary crude protein requirement to 18.4% 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 Dairy Cow Life Stages
Compare feed requirements across all dairy cow production phases.