Livestock Shelter

Animals in open sun take on heat faster than they can shed it; animals in cold wind lose it faster than they can make it. A livestock shelter is an open-sided structure - a raised roof, a solid wall, or both, but never four walls - that changes the weather around grazing animals without shutting them in, so they stay alive and keep eating through the part of the year that would otherwise stop both. It has a second effect too: animals go where the shade is, so the shelter decides where the herd spends its idle hours, making siting it a grazing decision as much as a welfare one.

Height is what separates shade from a hot box: the roof or cloth sits at least 2.4 m (8 ft) up so air keeps moving underneath, over roughly 2 to 3.7 square metres (20 to 40 sq ft) per head. A cover that blocks sun and wind together makes things worse, and water must be within reach and sized for the crowd the shade creates. Orientation is a trade-off with no free answer: east and west keeps the same patch shaded, so it stays cooler but turns to mud, while north and south lets the shade travel across the ground through the day, sparing it at the cost of a less consistently cool patch.

Almost everything that goes wrong follows from one thing: the shelter gathers animals into one place. Traffic at the shade, the water and the feed kills the plants and packs the soil, and 20 cm (8 in) of mud cuts feed intake by 15 percent, 25 cm (10 in) by 30. The same worn ring is where parasite larvae climb the grass, 5 to 8 cm (2 to 3 in) up the leaf, which is the height short grass gets grazed at. Every hour spent loafing under a fixed shelter is also manure taken off the pasture and banked in one spot - fertility moved rather than made. A shelter on skids moved with the herd every 3 or 4 days, on ground then rested 4 to 6 weeks, turns all three into an advantage; where it must stay put, the ground beneath it is hardened.