Fig. 1 shows a cross-section of a building used to house livestock on a farm. (a) Name the building material labelled X used for the roof. [1] (b) State two...

Labelled answer diagram:

(a) The building material labelled X used for the roof is corrugated iron (galvanised iron sheeting) [1]. This is a common, durable, and waterproof roofing material for livestock housing in tropical and subtropical regions.

(b) Two functions of the open eaves labelled Y (any two) [2]:

• Allow air to enter the building for ventilation, providing fresh air to the livestock.
• Provide shelter and shade from direct sunlight at the edges of the building.
• Allow rainwater to drip clear of the walls, preventing water from running down and entering the building.

(c) The building provides ventilation through a stack effect (natural convection):

1. Cool, fresh air enters through the open eaves on both sides of the building at a low level [1].
2. Warm, stale air rises naturally (because warm air is less dense) and escapes through the ridge vent at the top of the roof, creating a continuous flow of fresh air through the building [1].

(d) Good ventilation is important for livestock health for the following reasons (any three) [3]:

1. It removes stale, humid air that can encourage respiratory diseases such as pneumonia [1].
2. It reduces the build-up of ammonia from animal waste. Ammonia irritates the lungs and eyes of livestock and workers [1].
3. It helps regulate temperature and prevent heat stress, which reduces feed intake and productivity (e.g. milk yield or weight gain) [1].

Other valid points include: reducing moisture levels to lower the risk of fungal infections, and maintaining good air quality to improve overall animal welfare and growth rates.