Bison — Bull Feed Requirements
Bison bulls are massive animals reaching 2,000+ lbs. Nutritional requirements increase during the breeding season (rut) in July-September when bulls may lose 10-15% of body weight. Provide good quality hay and minimal grain before and after the rut to maintain condition.
Bull Feeding at Different Body Weights
The daily feed requirements for bison in the bull 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* |
|---|---|---|---|---|---|
| 1,080 lbs | 23.8 lbs | 1.8 lbs | 12.4 lbs | 713 lbs | $60.75 |
| 1,260 lbs | 27.7 lbs | 2.1 lbs | 14.4 lbs | 832 lbs | $70.88 |
| 1,440 lbs | 31.7 lbs | 2.4 lbs | 16.5 lbs | 950 lbs | $81.00 |
| 1,620 lbs | 35.6 lbs | 2.7 lbs | 18.5 lbs | 1,069 lbs | $91.13 |
| 1,800 lbs | 39.6 lbs | 3.1 lbs | 20.6 lbs | 1,188 lbs | $101.25 |
| 1,980 lbs | 43.6 lbs | 3.4 lbs | 22.7 lbs | 1,307 lbs | $111.38 |
| 2,160 lbs | 47.5 lbs | 3.7 lbs | 24.7 lbs | 1,426 lbs | $121.50 |
| 2,340 lbs | 51.5 lbs | 4.0 lbs | 26.8 lbs | 1,544 lbs | $131.63 |
| 2,700 lbs | 59.4 lbs | 4.6 lbs | 30.9 lbs | 1,782 lbs | $151.88 |
*Monthly cost estimated using grass hay at $150/ton.
Feed Options for Bison (Bull)
Different feeds provide varying levels of protein and energy for bison in the bull stage, which requires a minimum of 7.7% crude protein and 52% 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% | 45.0 lbs | Yes | Yes | $101.25 |
| Alfalfa Hay | 18% | 58% | 44.0 lbs | Yes | Yes | $165.00 |
| Timothy Hay | 9% | 55% | 45.0 lbs | Yes | Yes | $135.00 |
| Bermuda Grass Hay | 10% | 52% | 45.0 lbs | Yes | Yes | $108.00 |
| Whole Corn | 9% | 88% | 45.0 lbs | Yes | Yes | $148.50 |
| Cracked Corn | 9% | 88% | 45.0 lbs | Yes | Yes | $162.00 |
| Oats | 12% | 70% | 44.5 lbs | Yes | Yes | $140.16 |
| Barley | 13% | 84% | 45.0 lbs | Yes | Yes | $155.25 |
| Pasture Grass (Fresh) | 12% | 62% | 158.4 lbs | Yes | Yes | $0.00 |
| Layer Pellets | 16% | 70% | 44.0 lbs | Yes | Yes | $264.00 |
| Broiler Starter | 22% | 78% | 44.0 lbs | Yes | Yes | $297.00 |
| Horse Sweet Feed | 12% | 72% | 45.0 lbs | Yes | Yes | $236.25 |
| Alfalfa Hay Cubes | 17% | 56% | 44.0 lbs | Yes | Yes | $198.00 |
*Cost based on the listed feed as the sole source at current pricing.
Herd Budgets: Bison Bull
For operations managing multiple bison animals in the bull 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 1800 lbs.
| Head Count | Daily DMI Total | Monthly Tons | Annual Tons | Monthly Cost | Annual Cost |
|---|---|---|---|---|---|
| 1 | 39.6 lbs | 0.59 tons | 7.23 tons | $101.25 | $1,231.88 |
| 5 | 198.0 lbs | 2.97 tons | 36.14 tons | $506.25 | $6,159.38 |
| 10 | 396.0 lbs | 5.94 tons | 72.27 tons | $1,012.50 | $12,318.75 |
| 25 | 990.0 lbs | 14.85 tons | 180.68 tons | $2,531.25 | $30,796.88 |
| 50 | 1,980.0 lbs | 29.70 tons | 361.35 tons | $5,062.50 | $61,593.75 |
| 100 | 3,960.0 lbs | 59.40 tons | 722.70 tons | $10,125.00 | $123,187.50 |
Nutritional Management Tips for Bull
Proper nutritional management during the bull phase is critical for bison 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 1.1x elevates the dietary crude protein requirement to 7.7% 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 Bison Life Stages
Compare feed requirements across all bison production phases.