What are the answers to questions 7, 8, and 9 regarding poultry and farm animal husbandry?

Here are the answers to your questions:

7. Newly hatched chicks should be vaccinated against

   • A. Marek's disease.
   • Vaccination against Marek's disease is typically administered to chicks at the hatchery, often on the day of hatching, to provide early protection against this highly contagious viral disease.

8. Sexual maturity in farm animals could be influenced by

   • D. I, II and III.
   • Body weight, breed of animal, and nutrition all play significant roles in determining when a farm animal reaches sexual maturity. Animals need to reach a certain size and receive adequate nutrients, and genetic factors (breed) also dictate the timing.

9. A major advantage of inbreeding in farm animals is that it

   • C. maintains desirable traits.
   • Inbreeding involves mating closely related individuals to increase homozygosity, which helps to fix and maintain desirable traits within a line or breed, making them more consistent across generations.