Eggs and milk are small calorie sources for a community but valuable protein and fat sources: 40-60 laying hens at 15-20 eggs a day supply about 0.4-0.5% of a community of 100’s daily 280,000 kcal, and 1-2 dairy cows at 10-20 litres a day each supply about 2-9%. The hens’ grain is the larger cost, 10-15 lb a day if they were fed grain alone.
Part of Caloric Budget for a Community
Dairy and egg calorie efficiency is the food energy a laying flock or milking herd returns relative to the feed it eats and to the community’s total need.
Eggs And Milk Do Not Cost An Animal’s Life, But They Do Cost Feed
The caloric guide’s livestock count for 100 people includes 40-60 laying hens (15-20 eggs a day) and 2-4 dairy goats or 1-2 dairy cows. The corpus husbandry guides add yields: a dairy cow gives 10-20 litres a day (Dairy Processing), a dairy goat 2-4 litres a day on browse (Goat Raising). The sums below use those figures and standard food energies recalled from food-composition tables: a large egg about 72 kcal (143 kcal per 100 g, 50 g); cow’s milk about 61 kcal per 100 g, so about 628 kcal per litre at 1.03 kg per litre; goat’s milk about 69 per 100 g, about 711 per litre.
Worked Example: Eggs
- Energy: 15 × 72 = 1,080 kcal a day and 20 × 72 = 1,440 kcal a day.
- Share of the community’s 280,000 kcal: 1,080 ÷ 280,000 = 0.39% and 1,440 ÷ 280,000 = 0.51%, or about 0.4-0.5%.
- The guide’s output is low for the flock size. The corpus says six hens produce roughly 1,500 eggs a year (Poultry Keeping), which is 1,500 ÷ 6 ÷ 365 = 0.68 eggs per hen per day, so 40-60 hens would lay 27-41 eggs a day, giving 1,970-2,960 kcal, or 0.7-1.1% of demand.
- Feed, if the hens ate a full ration of grain: a laying hen eats about 0.25 lb of feed a day (recalled, a typical figure), so 40-60 hens eat 10-15 lb a day, 3,650-5,475 lb a year. At corn’s 1,500-3,000 lb per acre that is 3,650 ÷ 3,000 = 1.2 acres to 5,475 ÷ 1,500 = 3.7 acres of corn. At 1,650 kcal per lb the feed is 16,500-24,750 kcal a day.
- Efficiency under the guide’s output: 1,080 ÷ 24,750 = 4.4% to 1,440 ÷ 16,500 = 8.7%, below the guide’s stated 20-25%. Hens that forage insects and weeds eat less grain, so real efficiency lies between the two.
Worked Example: Milk
- One cow at 10 litres: 10 × 628 = 6,280 kcal a day. At 20 litres: 12,560 kcal.
- One or two cows: 6,280 to 25,120 kcal a day, which is about 2% to 9% of 280,000 (6,280 ÷ 280,000 = 2.2%; 25,120 ÷ 280,000 = 8.97%).
- Goats: 2-4 goats at 2-4 litres each gives 4-16 litres a day, 4 × 711 = 2,844 to 16 × 711 = 11,376 kcal a day, or 1.0% to 4.1% of demand.
What They Are Really For
Eggs and milk are efficient protein and fat sources and the main animal foods that do not require slaughter, so their value for a community’s nutrition is larger than their share of calories suggests. Dairy products also store: salted butter and hard cheese keep for weeks to months (Dairy Processing, Dairy Production at Scale), which helps the winter gap. The land cost is the feed and pasture.
Method: Plan A Flock And Herd
Step 1: Choose animals for the land you have, goats for browse, cows for pasture, hens for scraps and screenings. Step 2: Record eggs and milk daily for a season. Step 3: Record feed, and the grain acres it required. Step 4: Compare the real totals with this page’s, and keep the species that pay for their feed.
Common Mistakes
- Counting eggs as calories. They are a protein and fat source.
- Forgetting winter. Laying drops with short days unless lit, and cows need hay.
- Feeding grain freely. It is the cost the table hides.
Safety
Raw milk is a disease route
Milk must be cooled within 1 to 2 hours of milking to below 40 F or it risks spreading tuberculosis and other disease, according to the corpus dairy guide (Dairy Production at Scale). Keep milkers’ hands and utensils clean and apply the kitchen’s hygiene rules to dairy.
What’s Next
- Learn next: Acres per Person by Diet Type — adding animals to the land budget
- Combine with: Winter Calorie Gap Planning — using stored dairy