A 200-Bird Layer Shed Beside a Flood Nullah
A farmer in Puri district has a 6 m x 3 m layer shed: 1 m brick wall, chicken wire above, asbestos-cement sheet roof at 2.4 m, mud floor, and a tin sheet closing the west side. There are four tube feeders, three round waterers and about 5 cm of litter. He keeps 200 layers and wants to add 50 growers under the same roof. The plot is beside a seasonal nullah. In July water enters to 15 cm; annual rainfall is about 1,400 mm. In May, with 38°C heat, six birds died panting. In July, litter became wet, ammonia was strong, and egg production fell about 20%. The prevailing wind is east-west. He has limited cash and wants a practical retrofit, not a new building.
1. Calculate the floor area and stocking density of the existing shed and show whether 200 layers plus 50 growers can be housed. Identify the heat, ventilation and flood faults.
Read the worked answer
Area: 6 m x 3 m = 18 m².
Current stocking: 200 layers ÷ 18 m² = 11.1 birds/m². That is well above the usual deep-litter layer allowance of about 6–8 birds/m² (0.13–0.15 m² per bird). Adding 50 growers makes it worse.
Space needed:
- 200 layers at 0.15 m²/bird = 30 m².
- 50 growers at about 0.10 m²/bird = 5 m².
- Total about 35 m², plus feed store and egg handling space.
The existing shed cannot hold both groups. Even 200 layers alone need roughly 30 m², so the present 18 m² is overcrowded by about 40%.
Faults
- Heat: the west tin sheet radiates heat into the shed in May; a 2.4 m eaves height gives little hot-air cushion; the roof has no ridge vent or insulation.
- Ventilation: wire mesh above 1 m is useful, but with the west side closed and no ridge outlet, ammonia and moisture build up. Strong ammonia in July confirms poor air exchange and wet litter.
- Flood: mud floor at ground level, 15 cm water entry, no plinth or apron. Wet litter and faecal contamination follow.
- Roof: dark asbestos-cement sheet absorbs heat; no overhang to keep rain out.
- Equipment: four tube feeders and three waterers are too few for 200 birds.
A practical conclusion: reduce to about 120–130 layers in the existing shed until it is extended or a second shed is built.
2. Redesign the shed and site layout for 200 layers and a separate 50-bird grower pen, giving dimensions, plinth, roof and opening specifications.
Read the worked answer
Keep the long axis east-west so the roof shades the sides. A workable low-cost layout is a 10 m x 4 m shed (40 m²): 30 m² for 200 layers, 5 m² for 50 growers, and 5 m² for feed, eggs and a small store. If cash is tight, extend the existing shed to 10 m x 4 m rather than build a second unit.
Site and floor
- Raise the plinth at least 0.6 m above ground level and above the highest recorded flood level; 0.6–0.9 m is safer beside the nullah. Alternatively move the shed to higher ground.
- Concrete or stabilized floor with a 1:100 slope to a drain, and a 1 m concrete apron around the shed.
- Dig a diversion drain on the uphill side so rainwater does not pond against the plinth.
Roof and openings
- Eaves 2.4–2.7 m, ridge 3.6–4.0 m.
- Continuous ridge vent of about 30–45 cm for a 4 m width, with a rain cap.
- Side openings of at least 1.2 m height, wire mesh with adjustable curtains.
- Roof overhang of 0.9 m; insulate under the sheet with thatch, grass or a reflective layer; shade the west side with trees or a shade net instead of tin.
Internal separation
- A wire partition with a solid lower panel separates the 50 growers from the layers. Never mix age groups freely.
- Provide a small feed store with a raised pallet and a closed egg tray area.
Stocking check: 200 layers in 30 m² = 6.7 birds/m², acceptable for deep litter; 50 growers in 5 m² = 10 birds/m², acceptable for young growers.
3. Prepare an equipment, litter and water-management plan for the redesigned unit.
Read the worked answer
Equipment for 200 layers
- Feeder space: about 10 cm per bird = 20 m of linear trough, or roughly 8–10 tube feeders of the size that each serves 25–30 birds. Four feeders are not enough.
- Water space: about 2 cm per bird = 4 m linear, or 6–8 bell waterers; place them so a bird does not have to walk more than 2–3 m.
- Nests: one nest box per 5 hens = about 40 nest spaces, in a dark, ventilated bank.
- Perches: 15–20 cm per bird = 30–40 m of perch, fixed at 60–90 cm height with removable droppings boards.
- Feeders and waterers on stands or slats to keep litter dry; never place waterers directly on litter without a drip tray.
Litter and water
- Use dry paddy husk or clean straw, 5–8 cm deep. Do not use wet or mouldy material.
- Stir litter daily and remove wet cappings around waterers. Top up with dry litter rather than merely turning wet litter.
- Keep ammonia below about 20 ppm; if the eyes water on entry, ventilation is inadequate.
- Clean waterers twice daily, scrub weekly, and keep water cool and shaded. Test the well or tap water for coliforms and excess iron.
- During monsoon, raise feeders and waterers on platforms, check the drain daily, and replace any litter that becomes sodden. Do not let birds stand in mud.
- Keep a simple daily record of mortality, feed intake, water intake and egg number; a sudden change in water intake is an early warning of heat or disease.