For what reasons are improved poultry breeds developed?

How do biotic and abiotic factors in stored grains lead to poor marketability? How can these factors be controlled?

Write two examples each of the fishes that are:
$(i)$ Top dwellers
$(ii)$ Middle dwellers
$(iii)$ Bottom dwellers,in composite fish culture.

List two desirable traits for fodder crops.

Sid went to market to buy foodgrains for his home and on returning when his mother found the grains discoloured and of low and poor quality,she returned them back to the vendor. The vendor told Sid's mother that it was due to the storage loss of the grains that resulted in their poor quality and gave her the good quality grains.
$(a)$ What kind of qualities are shown by Sid's mother?
$(b)$ What could be the control measures to prevent this storage loss?

Poultry fowl are susceptible to the following pathogens: