Disease Predisposing Factors
Aperçu
Two poultry farms near Oyo keep the same breed of bird, buy feed from the same market and sit less than a kilometre apart. When Newcastle disease reaches the area, one farm loses a third of its flock and the other loses almost nothing. The birds are not different, and the pathogen is not different. What is different is everything that made one flock's defences weaker and one flock's exposure higher long before the virus ever arrived. Those conditions are called disease predisposing factors, and they explain more about who falls sick on a farm than the pathogen itself ever does.
In this lesson you will learn what a predisposing factor is and how it differs from the actual cause of a disease, then work through six factors examiners return to every year: nutrition, housing, stress, hygiene, genetics and age, and the absence of vaccination or parasite control. For each one you will learn not just its name but the mechanism, exactly how it tips an animal toward disease, and the practical steps a farmer takes to close that door.
Objectifs
- Define disease predisposing factors
- State the factors that predispose farm animals to disease
- Explain how poor nutrition predisposes animals to disease
- Explain how poor housing and management predispose animals to disease
- Suggest ways of reducing disease predisposing factors on a farm
Note de cours
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Évaluation de la leçon
Félicitations, vous avez terminé la leçon sur Disease Predisposing Factors. Maintenant que vous avez exploré le concepts et idées clés, il est temps de mettre vos connaissances à lépreuve. Cette section propose une variété de pratiques des questions conçues pour renforcer votre compréhension et vous aider à évaluer votre compréhension de la matière.
Vous rencontrerez un mélange de types de questions, y compris des questions à choix multiple, des questions à réponse courte et des questions de rédaction. Chaque question est soigneusement conçue pour évaluer différents aspects de vos connaissances et de vos compétences en pensée critique.
Utilisez cette section d'évaluation comme une occasion de renforcer votre compréhension du sujet et d'identifier les domaines où vous pourriez avoir besoin d'étudier davantage. Ne soyez pas découragé par les défis que vous rencontrez ; considérez-les plutôt comme des opportunités de croissance et d'amélioration.
- Which of the following is a disease predisposing factor rather than the actual cause of disease? A. A bacterium B. A virus C. An overcrowded, poorly ventilated house D. A parasitic worm Answer: C
- Sustained stress increases an animal's susceptibility to disease mainly by: A. Increasing its appetite B. Raising a hormone level that suppresses immune function C. Improving its body temperature regulation D. Strengthening its skin Answer: B
- Day old chicks are more susceptible to disease than adult birds chiefly because: A. They eat more feed B. Their immune system is not yet fully developed C. They have thicker feathers D. They are kept in larger numbers Answer: B
- Which management practice would most directly reduce disease spread caused by poor hygiene? A. Reducing stocking density only B. Regular cleaning and disinfection of drinking troughs and pens C. Feeding a higher energy ration D. Selecting a hardier breed Answer: B
- An unvaccinated flock is at greater risk from a disease outbreak chiefly because: A. It has no trained immunity against that specific pathogen B. It eats more feed than a vaccinated flock C. It grows faster than a vaccinated flock D. Vaccination has no effect on immunity Answer: A
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Créez un compte gratuit pour accéder à toutes les ressources d'apprentissage, aux questions d'entraînement et suivre votre progression.
Inscrivez-vous pour continuer
Créez un compte gratuit pour accéder à toutes les ressources d'apprentissage, aux questions d'entraînement et suivre votre progression.
