Agricultural Science 2015 Jamb Examination

Feed conversion efficiency is measured using the feed conversion ratio (FCR). The lower the FCR, the more efficient the animal is.
For P: \[ FCR = \dfrac{50}{20} = 2.5 \] For Q: \[ FCR = \dfrac{90}{30} = 3.0 \] For R: \[ FCR = \dfrac{100}{25} = 4.0 \] For S: \[ FCR = \dfrac{150}{30} = 5.0 \] P has the lowest FCR value of 2.5, meaning it requires the least feed to produce 1 kg of weight gain. Therefore, P is the most efficient feed converter.

The feed conversion ratio (FCR) is given by:\[ FCR = \dfrac{\text{Feed Consumed}}{\text{Weight Gained}} \]
Weight gained = \( 45 - 25 = 20 \; kg \)

Substitute values:\[ FCR = \dfrac{60}{20} = 3 \]
This shows that 3 kg of feed is required for each 1 kg of weight gained, hence the ratio is 3:1.

Brooding is the stage immediately after chicks hatch, and during this period, they are vulnerable to certain diseases. Yolk sac infection and pullorum are common bacterial infections of chicks. Coccidiosis also occurs early due to poor litter management. Fowlpox, however, is more common at later stages and not typically during brooding. Therefore, yolk sac infection, coccidiosis, and pullorum are the common brooding diseases.

Piglets are born with low iron reserves and sow’s milk does not supply sufficient iron. If left uncorrected, they develop anaemia. To prevent this, iron supplements are given either orally or through intramuscular injections. Sulphur drugs, anthelmintics, and antibiotics do not prevent anaemia in piglets.

Factors such as breed (genetic makeup), sex (male or female differences), and nutrition (adequate feeding) significantly influence the onset of sexual maturity. Weaning age, however, relates to management practices and does not directly affect the physiological timing of sexual maturity in animals.

Oxytocin is a hormone that stimulates milk letdown by causing contraction of the muscles around the mammary alveoli. This helps the sow release milk after farrowing. Antibiotics treat bacterial infections, anthelmintics control worms, and sulphaquinoxaline treats coccidiosis but none of these induce milk production.

Newborn piglets have very little body fat and cannot regulate their body temperature effectively. Without an external heat source, they can easily die from cold stress. Providing warmth prevents chilling, ensuring survival and giving them the chance to suckle and thrive.

A thermostat controls the temperature automatically by switching the heater on or off to maintain a steady range. A thermometer only measures temperature, a hygrometer measures humidity, and a barometer measures air pressure. Therefore, only a thermostat stabilizes heat in an incubator.

Newly-born rabbits are commonly called kits or bunnies. Kids refer to young goats, poults are young turkeys, and lambs are young sheep. Therefore, the correct name for baby rabbits is bunnies.

Area occupied by one tree:\[ 2.5 \times 4.0 = 10 \; m^2 \] Total area of farmland:\[ 2 \; hectares = 2 \times 10,000 = 20,000 \; m^2 \]
Number of seedlings required:\[ \dfrac{20,000}{10} = 2,000 \] Therefore, 2,000 seedlings are needed to plant the farmland.