Which of the following diseases is caused by mouldy feed? Semen for artificial insemination should be stored in liquid nitrogen.

Here are the answers to your questions:

39) Which of the following diseases is caused by mouldy feed?
The correct option is A.
A. Aspergillosis
Aspergillosis is a respiratory disease in animals and birds caused by inhaling spores of Aspergillus fungi, which commonly grow on mouldy feed and bedding. Coccidiosis is caused by protozoa, Babesiosis by parasites, and Tuberculosis by bacteria.

40) Semen for artificial insemination should be stored in
The correct option is D.
D. liquid nitrogen.
Semen for artificial insemination is stored at extremely low temperatures, typically around $-196^\circ\text{C}$ ($-321^\circ\text{F}$), using liquid nitrogen to preserve the viability of the sperm for extended periods.