Calculation Methods & Sources

Cow weight

Weight (lb) = heart girth (in)² × body length (in) ÷ 300. Metric: weight (kg) = girth (cm)² × length (cm) ÷ 10,838 (exact unit conversion). Accuracy varies with breed, age, condition and measurements; no universal error range is guaranteed.

Oregon State University Extension; Vikaspedia (use for buffalo); ICAR study on Schaeffer's formula.

Ghee

Ghee (kg) = milk (L) × 1.03 × fat % × fat recovered ÷ 0.995. Fat recovered: cream/malai 88%, desi bilona 80%, cream separator + butter 92%.

NIFTEM ghee processing (desi 80–85%, creamery butter 88–92%, direct cream 90–95%); e-PG Pathshala (desi 78%, creamery 92%, direct cream 88%); AAU Anand measured yields (cow 3.82%, buffalo 5.49%).

Shed size

Per animal, covered + open: cow 3.5 + 7 m², buffalo 4 + 8 m², young calf 1 + 2 m², older calf 2 + 4 m², bull 12 + 24 m², calving pen 12 + 12 m² (about 1 per 10 adults). Manger 60–75 cm per adult, 40–50 cm per calf. Water trough 6–7.5 m per 100 adults.

TNAU Agritech; ICAR table; Teagasc (calving space for 10% of herd).

Feed cost

Cost per animal per day = Σ (kg × price per kg × (1 + local adjustment %)). Month = day × days per month; year = day × 365. Concentrate = maintenance + 1 kg per 2.5 L (cows) or 2 L (buffaloes).

Mineral mixture 65–90 g/day (NDDB ration tables); bypass fat 100–150 g/day in early lactation (Pashu Sandesh). Reference prices and budget estimates: see the tables on the feed cost calculator, each with its source and date.

Silage

Needed (t) = animals × kg/day × days ÷ (1 − loss) ÷ 1000. Volume = tonnes × 1000 ÷ density. Days of supply = volume × density × (1 − loss) ÷ daily use. Bag volume = π × (diameter ÷ 2)² × length. Default density 640 kg/m³ as fed at 35% DM.

UNL CropWatch (14 lb DM/ft³ target); SARE dry matter loss study (5–11% by position).

Farm income

Milk/day = cows × % in milk × litres. Income/month = milk/day × price × 30.4 + other income. Cost/litre = monthly cost ÷ monthly litres.

How prices are kept up to date

Average feed prices are stored in one data file with the date each price was checked and its source. Updates require a manual dataset review and rebuild; there is no live feed or automatic weekly update. Published references, supplier listings and illustrative budget estimates are labelled separately. Users can change any price, and add a local adjustment for their area.

All results are planning estimates. They are not veterinary, nutrition, financial or engineering advice.