What replaced the animal drawn farm implements

Cultivator.

Explanation:

Instruments such as cultivator replaced the animal drawn farm implements because these instruments works quickly and more efficiently. This cultivator has long teeth which soften the soil for better root penetration and aeration of the soil. This instrument works with high speed and finished its work in hours not days which make it more preferable in agriculture than animals.

answer: 20 percent

the fish culture has become a developing commercial practice in developing countries which is already prominent in developed countries of the world. the major fish protein demand is being supplemented in developing countries is   fishing to meet the needs of the growing population. therefore, in some developing nations, the percentage of animal protein from fish in the diet can be as high as 20 percent.