ASRB NET Agricultural Structures & Environmental Control: practice questions

Question 1 · hard

In cold weather, a closed poultry house runs minimum ventilation through ceiling inlets that throw a jet of air along the ceiling. What is the purpose of the jet?

1. To blow litter dust out through the inlets and so keep the litter surface clean
2. To keep the ceiling cold so that moisture condenses there instead of on the birds
3. To mix cold incoming air with warm ceiling air before it falls onto the birds
4. To create a draught at bird level that removes heat from the birds directly

Question 2 · medium

In a partly slatted finishing pen, where should drinkers be placed to encourage good dunging behaviour?

1. In the centre of the solid lying area, so that pigs drink where they rest
2. Next to the feeder on the solid floor, so that feed and water are together
3. Over or beside the slatted area, away from the solid lying area and feeder
4. Outside the pen, so pigs are let out to drink at fixed times twice a day

Question 3 · medium

An enriched cage for laying hens in the EU has a total area of 3.0 m². With the minimum of 750 cm² per hen (Directive 1999/74/EC), how many hens may it hold at most?

1. 4
2. 40
3. 400
4. 27

Question 4 · hard

A dairy barn's cows produce 50 kW of latent heat in total. Taking the latent heat of vaporisation as 2.43 MJ/kg, how much water vapour do they produce?

1. 21 kg/h
2. 1.2 kg/h
3. 180 kg/h
4. 74 kg/h

Question 5 · medium

Where should a vapour retarder be placed in an insulated wall of a heated animal house in a cold climate?

1. On the cold (outside) side of the insulation
2. On the warm (inside) side of the insulation
3. In the middle of the insulation layer
4. Outside the cladding, exposed to the weather

Question 6 · hard

A godown must hold 500 t of bagged wheat stacked 4 m high; the stack's effective bulk weight is 0.75 t/m³. If stacks may occupy only 70% of the floor area (the rest is alleys and handling space), what floor area is required?

1. 217 m²
2. 167 m²
3. 667 m²
4. 238 m²

Question 7 · hard

Using Janssen's equation, find the lateral pressure at 12 m depth in a circular bin of 8 m diameter. Grain unit weight 7.8 kN/m³, wall friction coefficient μ′ = 0.4, pressure ratio k = 0.5.

1. 27.3 kPa
2. 35.2 kPa
3. 46.8 kPa
4. 39.0 kPa

Question 8 · medium

Why must a grain bin designed for central discharge never be emptied through an outlet in its side wall?

1. Eccentric discharge gives unsymmetrical pressures that bend and can collapse the wall
2. Side outlets empty the bin far too slowly for any commercial grain-handling operation
3. Grain flowing from a side outlet is always cracked by its impact on the floor below
4. Side outlets lower the lateral pressure everywhere, so the roof becomes overloaded

Question 9 · medium

An anaerobic lagoon is designed on a volatile-solids loading rate of 0.08 kg VS per m³ per day. 1000 pigs each produce 0.45 kg VS per day. What minimum treatment volume is needed?

1. 36 m³
2. 5,625 m³
3. 562 m³
4. 56,250 m³

Question 10 · medium

How does the allowable volatile-solids loading rate for an anaerobic lagoon change from a warm to a cold climate?

1. It is higher in cold climates, because cold air speeds digestion
2. It is the same everywhere, since bacteria ignore temperature
3. It is lower in cold climates, so a larger lagoon is needed
4. It is zero in cold climates, where lagoons cannot be used at all