By-products generated during rectification of bio ethanol is utilized as

The correct option is "dog feed".

Bioethanol production via the fermentation of biomass generates several by-products, primarily distillers grains and solubles (often referred to as DDGS or Condensed Distillers Solubles). During the rectification and purification processes of bioethanol, these nutrient-rich by-products are recovered. Because they contain high levels of protein, fiber, and essential nutrients, they are processed and utilized as animal feed, specifically formulated for canine nutrition as dog feed.