Calculate feed requirements and nutritional needs for livestock including cattle, sheep, goats, pigs, and poultry. Determine daily dry matter intake, protein and energy requirements, and feed conversion ratios for optimal farm management.
Values are estimates based on standard guidelines (NRC, CSIRO, INRA). Actual requirements vary with breed, environment, feed quality, health, and metabolism. Consult a nutritionist or veterinarian for precise ration formulation.
Animal nutrition provides the right balance of nutrients — energy, protein, minerals, vitamins, and water — for optimal health, growth, and production. Daily dry matter intake (DMI) is the most important factor in feed management, expressed as % of body weight.
The weight of feed minus moisture. DMI = BW × DMI% / 100. This is the standard measure for all nutritional calculations and ration formulation.
Feed efficiency = total feed consumed / total weight gain. Lower is better. Poultry: 1.5-2.0, Pigs: 2.5-3.5, Cattle: 6-10.
Usable energy from feed in MJ/kg DM. Roughage: 7-9, Mixed: 9-11, Concentrate: 11-13. Total ME = DMI × density.
Animals need 3-5 L water per kg DMI. Increases with temperature, lactation, and activity. Water is the most critical nutrient.
Maintenance: 1.5-2% BW. Growing: 2.5-3% BW. Finishing: 2-2.5% BW. FCR range: 6-10:1.
Dry cow: 2-2.5% BW. Lactating: 3.5-4% BW. A 650 kg cow producing 30 L/day consumes ~20-24 kg DM/day.
Maintenance: 1.5-2% BW. Lactating: 3-4% BW. Growing lambs consume up to 4% BW. FCR range: 4-6:1.
Grower (20-50 kg): 4-5% BW. Finisher (50-100 kg): 3-4% BW. FCR range: 2.5-3.5:1.
Broilers: ~3-5% BW. Layers: ~100-120 g/bird/day. FCR range: 1.5-2.0:1 for broilers.
Maintenance: 1.5-2% BW. Light work: 2-2.5% BW. Heavy work: 2.5-3% BW. Primarily roughage-based diet.
Scenario: A 450 kg steer in finishing stage is fed TMR over 90 days, consuming 1,200 kg total. Initial weight 350 kg, final weight 500 kg.
Total Weight Gain: 500 - 350 = 150 kg
Daily Feed Intake: 1,200 / 90 = 13.3 kg/day as-fed
DMI (TMR ~55% DM): 13.3 × 0.55 = 7.3 kg DM/day
DMI as % BW: (7.3 / 450) × 100 = 1.6% of body weight
Feed Conversion Ratio: 1,200 / 150 = 8.0:1
Typical FCR for finishing beef cattle ranges from 6:1 to 10:1 depending on genetics, diet, and management.
Scenario: A 650 kg Holstein producing 35 L milk/day, fed TMR with 12 MJ/kg DM energy and 18% CP.
DMI at 3.8% BW: 650 × 0.038 = 24.7 kg DM/day
Metabolizable Energy: 24.7 × 12 = 296 MJ/day
Crude Protein: 24.7 × 0.18 = 4.4 kg CP/day
Water Requirement: 24.7 × 4 = ~99 L/day (plus additional for milk)
High-producing dairy cows require precise balancing to maintain condition and maximize production without metabolic disorders.
Scenario: Ten 35 kg lambs rotationally grazed for 60 days on high-quality pasture. DMI estimated at 3.5% BW.
DMI per Lamb: 35 × 0.035 = 1.23 kg DM/day
Total DMI: 1.23 × 10 = 12.3 kg DM/day
Est. Gain at FCR 5:1: 12.3 / 5 = 2.46 kg/day total (246 g/lamb/day)
Total Gain over 60 Days: 2.46 × 60 = 147.6 kg (~14.8 kg/lamb)
Pasture-fed lambs typically gain 150-250 g/day depending on pasture quality and parasite burden.
Scenario: Grower pigs start at 25 kg, fed concentrate (88% DM) at 2.5 kg/day each for 70 days, reaching 110 kg.
DMI: 2.5 × 0.88 = 2.2 kg DM/day
DMI% at mid-weight (67.5 kg): (2.2 / 67.5) × 100 = 3.3% of BW
Total Feed: 2.5 × 70 = 175 kg | Gain: 110 - 25 = 85 kg
Feed Conversion Ratio: 175 / 85 = 2.06:1
Modern pig genetics with precision nutrition achieve FCRs of 2.0-2.5:1, among the most efficient of livestock.
Scenario: Broilers raised from 45 g to 2.2 kg over 42 days, consuming 3.5 kg total feed per bird.
Weight Gain: 2,200 - 45 = 2.155 kg
Feed Conversion Ratio: 3.5 / 2.155 = 1.62:1
Daily Gain: 2,155 / 42 = 51.3 g/day | Daily Feed: 3,500 / 42 = 83.3 g/day
Broilers have the best FCR of any livestock. Modern strains achieve 1.4-1.6:1 with optimal nutrition.
Animal nutrition provides the right balance of nutrients — energy, protein, minerals, vitamins, and water — for optimal health, growth, and production. Dry matter intake (DMI) is the cornerstone of feed management. Feed conversion ratio (FCR) measures how efficiently animals convert feed into weight gain — poultry (1.5-2.0), pigs (2.5-3.5), cattle (6-10).
Energy (from carbs/fats, measured as MJ/kg DM) is the most limiting nutrient. Protein provides amino acids; ruminants use non-protein nitrogen via rumen microbes. Minerals (Ca, P, Mg, trace elements) support bone and metabolic functions. Vitamins support immunity and metabolism. Water is critical — animals survive weeks without food but only days without water.
Needs vary with body weight, growth rate, milk production, gestation, temperature, activity, and health. Cold increases energy needs; heat reduces feed intake. Working animals need 25-50% more energy.
Our Animal Nutrition Calculator provides three powerful calculation modes. Select the mode that matches your available data for automatic computation with step-by-step explanations.
Select animal type, enter body weight, choose production stage and feed type. Get DMI, metabolizable energy, crude protein, and water estimates.
Enter total feed consumed, feeding period, and initial/final weights. Get FCR, daily intake, daily gain, and feed efficiency.
Select animal type, enter body weight, choose production stage. Get DMI, energy, protein, calcium, phosphorus, and water estimates.
View a detailed breakdown of each calculation step — DMI formulas, nutrient estimates, and final values — for transparency and education.