Author: Charles C. Stallings, Extension Dairy Scientist, Nutrition, Virginia Tech
Publication Number 404-105, June 1996
Table 1. Dairy cattle ration specifications for heifers, dry cows, and lactating cows
| Heifers (Age, Mos) | Dry Pregnant Cows | Production Groupa | ||||||
|---|---|---|---|---|---|---|---|---|
| 3-6 | 6-12 | >12 | High | Medium | Low | Maximum | ||
| Crude protein (% dry matter, DM) | 13-16 | 12-13 | 12 12 | 16-18b | 15-16 | 14-15 | 19 | - |
| Acid detergent fiber (% DM) | 22-29 | 29-33 | 33-38 | 35-45 | 19-21 | 21-24 | 24-28 | - |
| Neutral detergent fiber (% DM) | - | - | - | - | 27-32 | 32-40 | 40-48 | - |
| TDN (% DM) | 68-79b | 66-68b | 60-66b | 60-66 | 72-78 | 68-72 | 63-68 | - |
| Net energy (Mcal/lb) | .69-.80 | .67-.69 | .61-.67 | .61 - .67 | .74-.80 | .70-.74 | .64-.70 | - |
| Calcium (% DM) | .52 | .41 | .29 | .50 - .70c | .8-1.0 | .75-.8 | .7-.75 | 2.0 |
| Phosphorus (% DM) | .31 | .30 | .23 | .30 - .35c | .45-.50 | .40-.45 | .35-.40 | 1.0 |
| Magnesium (% DM) | .16 | .16 | .16 | .16 | .30 | .25 | .20 | .5 |
| Potassium (% DM) | .80 | .80 | .80 | .80 | 1.0 | .90 | .90 | 3.0 |
| Sodium (% DM) | .10 | .10 | .10 | .10 | .18 | .18 | .18 | - |
| Sulfur (% DM) | .16 | .16 | .16 | .17 | .25 | .20 | .20 | .4 |
| Iron (ppm) | 50 | 50 | 50 | 50 | 60 | 50 | 50 | 1,000 |
| Cobalt (ppm) | .10 | .10 | .10 | .10 | .10 | .10 | .10 | 10 |
| Copper (ppm) | 10 | 10 | 10 | 10 | 15 | 10 | 10 | 100 |
| Manganese (ppm) | 40 | 40 | 40 | 40 | 50 | 40 | 40 | 1,000 |
| Zinc (ppm) | 40 | 40 | 40 | 40 | 50 | 40 | 40 | 500 |
| Iodine (ppm) | .25 | .25 | .25 | .6 | .6 | .6 | .6 | 50 |
| Selenium (ppm) | .10 | .10 | .10 | .10 | .3 | .3 | .3 | 2.0 |
| Vitamin A (I.U./day) | 10,000 | 15,000 | 20,000 | 40,000 | 100,000 | 80,000 | 60,000 | - |
| Vitamin D (I.U./day) | 5,000 | 7,500 | 10,000 | 20,000 | 50,000 | 40,000 | 30,000 | 50,000 |
| Vitamin E (I.U./day) | 100 | 100 | 200 | 200-1000 | 500 | 400 | 300 | - |
aHigh and low group cows are assumed to be producing 20% above or below herd average; if feeding two groups the medium group specification should be the low group. High group cows would be mature Holsteins producing 80 or more pounds of 4.0% milk, middle group would be 80 to 50 pounds, and low group below 50 pounds. Special consideration should be given to first calf heifers and smaller dairy breeds. Ranges are what would be under normal conditions, but will vary with production level of herd, environmental conditions, etc.
bHeifers reared under confinement may need to have lower levels of energy to prevent deposition of fat in the mammary gland. Limit weight gain to 2 lbs/day or less.
bPregnant dry cows (large breeds) in the last two months of gestation should receive at least 60 grams of calcium per day, but not more than 100 grams. At least 30 grams of phosphorus should be in the ration. Reduce by 20% for Jerseys.
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