Theory question 103
Parasites of Farm Animals(a)(i) Describe the life cycle of louse. (ii) State three effects of louse on its host. (iii) State three ways in which louse could be controlled. (iv) Name three farm animals that could be infested by louse. (b) Discuss coccidiosis in farm animals under the following headings: (i) two animals mostly affected; (ii) causal agent; (iii) two symptoms; (iv) two control measures.
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(a)(i) Louse has incomplete metamorphosis on one host: the adult female lays eggs (nits) and glues them to the hairs/feathers; eggs hatch in about 1–2 weeks into nymphs; nymphs moult about three times and become adults in 2–3 weeks; the whole cycle is spent on the host
(ii) Any three: irritation and itching, so animal rubs and loses hair/feathers; sucking lice cause anaemia from blood loss; restlessness, poor feeding and loss of weight; drop in milk/egg production; damaged skin/hide; may carry diseases
(iii) Any three: dipping or spraying with insecticide; dusting with insecticide powder; good sanitation of houses; isolating/treating infested animals; avoiding overcrowding; clipping/shearing
(iv) Any three: cattle; goats; sheep; pigs; poultry; rabbits
(b)(i) Any two: poultry; rabbits; cattle (calves); sheep and goats
(ii) Causal agent: protozoa of the genus Eimeria
(iii) Any two: bloody/watery diarrhoea; ruffled feathers and droopy wings; loss of appetite and weight; dullness/weakness; anaemia; sudden deaths in young
(iv) Any two: coccidiostats in feed or water (e.g. amprolium, sulpha drugs); keep litter dry and clean; avoid overcrowding; clean feeders and drinkers; isolate sick animals; vaccination
Follow the headings in order for (b).