Age of bird Vaccine Method of administration Day 1 Newcastle disease (first dose) Eye drop Week 2 Infectious bursal disease Drinking water Week 4 Newcastle ...
Question 1 Report
| Age of bird | Vaccine | Method of administration |
|---|---|---|
| Day 1 | Newcastle disease (first dose) | Eye drop |
| Week 2 | Infectious bursal disease | Drinking water |
| Week 4 | Newcastle disease (second dose) | Drinking water |
| Week 6 | Fowl pox | Wing web |
| Week 12 | Newcastle disease (booster) | Injection |
2 A poultry farmer keeps 500 broiler chickens. Table 2.1 shows the vaccination programme that the farmer follows.
Table 2.1
(a) State how many times the birds receive a vaccine against Newcastle disease, according to Table 2.1. [1]
(b) Name two different methods used to administer the vaccines, as shown in Table 2.1. [2]
(c) Suggest one reason why the Newcastle disease vaccine is given more than once during the life of the bird. [1]
(d) Explain why vaccines must be stored at the correct temperature before they are used. [2]
(e) State two signs that a chicken infected with Newcastle disease might show. [2]
(f) Give one reason why newly purchased birds should be kept separate from the existing flock for a period of time before mixing. [1]
(g) Name one disease of poultry, other than those shown in Table 2.1, that can cause high mortality. [1]
Answer Details
(a) According to Table 2.1, the birds receive a vaccine against Newcastle disease three times: on Day 1 (first dose), at Week 4 (second dose), and at Week 12 (booster). [1]
(b) Two different methods of vaccine administration from Table 2.1 (any two):
- Eye drop - used for the Day 1 Newcastle disease dose. [1]
- Drinking water - used for the infectious bursal disease and the Week 4 Newcastle disease dose. [1]
Other acceptable answers from the table: wing web method (fowl pox at Week 6) or injection (Newcastle disease booster at Week 12).
(c) Newcastle disease vaccine is given more than once because immunity from the first dose may decrease over time, and booster doses are needed to maintain a strong level of protection. [1] Young birds may also not develop full immunity from a single dose, as their immune system is still maturing.
(d) Vaccines must be stored at the correct temperature because:
- Many vaccines contain live or weakened organisms that are sensitive to heat and can be killed by high temperatures. [1]
- If the vaccine is not stored correctly it becomes ineffective, meaning the birds will not develop immunity and remain vulnerable to infection. [1]
Most poultry vaccines require refrigeration at 2-8 degrees Celsius and must never be frozen or left in direct sunlight.
(e) Two signs a chicken infected with Newcastle disease might show:
- Twisting of the neck (torticollis) due to the virus attacking the nervous system. [1]
- Greenish diarrhoea, which indicates damage to the digestive tract. [1]
Other acceptable signs: drop in egg production, gasping or difficulty breathing, nasal discharge, drooping wings, loss of appetite, or paralysis.
(f) Newly purchased birds should be quarantined because they may be carrying a disease that has not yet shown symptoms (the incubation period) and could transmit it to the existing healthy flock. [1] The quarantine period allows time to observe the new birds for any developing signs of illness before they are mixed with the main flock.
(g) One poultry disease (other than Newcastle disease, infectious bursal disease, or fowl pox) that can cause high mortality: Marek's disease. [1] Other acceptable answers include avian influenza, coccidiosis, or fowl cholera.
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