Agricultural Science 2020 Jamb Examination

The oestrus cycle in goats, also called the heat cycle, typically spans 18 to 21 days. This cycle length ensures regularity in reproduction and allows farmers to plan breeding effectively. Shorter cycles such as 16–17 days and longer ranges like 20–22 days are less accurate and may occur due to irregularities. The most biologically correct and widely accepted range for goats is 18–21 days.

Daily management in poultry focuses on tasks that must be performed every day, such as providing feed and water, collecting eggs, and observing general health. Debeaking, however, is not a daily routine but an occasional management practice to reduce pecking and cannibalism. Therefore, it is not considered part of daily poultry management routines.

Castration of a young male chicken, or cockerel, results in what is known as a capon. Caponisation reduces aggressive behaviour and improves meat quality by making it more tender and juicy. This practice is used to improve the market value of poultry meat. A broiler refers to a chicken bred specifically for meat, a cock is a mature male, and a layer is a hen that produces eggs.

Pigs are prolific breeders, efficient feed converters, and an important source of meat such as pork, bacon, and ham. They are not, however, a source of land. Land is a natural resource independent of livestock. Therefore, the statement describing pigs as a source of land is incorrect.

Rinderpest is a viral disease of cattle characterised by high fever, nasal discharge, and diarrhoea. Since it is caused by a virus, antibiotics are ineffective. Sanitation reduces disease spread but cannot stop outbreaks. Vaccination provides immunity and is the most reliable control method. Eradication of infected stock may help but is not as effective as widespread immunisation programmes.

Drip irrigation is highly efficient because it delivers water directly to the root zone, allows for fertiliser application through fertigation, reduces salt accumulation, and operates under low pressure compared to sprinklers. However, one limitation is its poor efficiency on steep slopes, where water distribution becomes uneven. Thus, this is not an advantage but rather a disadvantage.

Windmills harness wind energy to produce mechanical power, which is commonly used for pumping water from wells. They are not used for soil drainage, ridging, or erosion control. The main agricultural benefit of windmills is their ability to provide a renewable and sustainable energy source for water lifting in farming operations.

Breaking soil involves turning and loosening it for planting. The plough is the most suitable implement for this purpose, as it cuts, lifts, and inverts the soil. A harrow is used after ploughing to refine the soil structure, while a ridger shapes soil into ridges. A tractor provides the power to operate these implements but is not itself a soil-breaking tool.

Farm mechanisation improves efficiency, increases yields, and reduces labour needs. However, one limitation is that heavy machinery disturbs the soil structure, leaving it exposed to climatic factors such as erosion, drought, or compaction. This environmental risk makes soil exposure a significant drawback of mechanised farming practices.

Soil physical properties are characteristics that can be observed and measured without chemical testing. These include colour, texture, moisture content, and porosity. pH, however, refers to the soil’s acidity or alkalinity, which is a chemical property. Thus, pH is not considered a physical property of soil.