What is dry matter (DM) and why does it matter?
Dry matter refers to the weight of forage after all moisture has been removed. Animals consume forage on a dry matter basis, so stocking rate calculations use DM rather than fresh weight. Typical pastures produce 1,000–4,000 lbs of dry matter per acre per growing season, depending on rainfall, soil fertility, and grass species.
Why should I only allow animals to graze a percentage of available forage?
Leaving 40–60% of forage ungrazed is critical for plant recovery and long-term pasture health. Overgrazing removes too much leaf area, reducing the plant's ability to photosynthesize and regrow. Most rangeland specialists recommend a 50% utilization rate as a conservative starting point.
What daily dry matter intake values does this calculator use?
The calculator uses widely accepted estimates: mature horses ~26 lbs/day, donkeys ~18 lbs/day, mules ~22 lbs/day, mature sheep ~3.5 lbs/day, yearling sheep ~2.5 lbs/day, mature goats ~3.0 lbs/day, yearling goats ~2.0 lbs/day, llamas ~6.0 lbs/day, and alpacas ~3.0 lbs/day. These are approximate and may vary with body weight and condition.
How do I determine how much dry matter my pasture produces?
The most accurate method is to clip and weigh sample plots, then dry them to remove moisture. Many county extension offices or agricultural agencies offer forage testing. As a rough guide, improved pastures under good management often yield 2,000–3,500 lbs of dry matter per acre per season in temperate climates.
What is an Agricultural Acre Footprint?
An agricultural acre footprint quantifies the land area needed to produce food — whether crop or livestock — accounting for yield, conversion efficiency, and land use intensity. For grazing animals, this includes the pasture area consumed per animal over a defined period, which is exactly what this calculator estimates.
Can I use this calculator for cattle?
This version focuses on horses, donkeys, mules, sheep, goats, llamas, and alpacas. Cattle calculations follow the same principle — divide total available dry matter by the animal's daily intake multiplied by the number of grazing days. A mature beef cow typically consumes around 26–30 lbs of dry matter per day.