Nutrition in Animals

Nutrition in Animals

Nutrition, Nutrition in animals, Modes of nutrition in animals, Process of nutrition in animals, Types of animals based on nutrition.

The process of obtaining food and then using it to generate energy, grow, and heal the body is known as nutrition. As we already know, plants make their own food through photosynthesis. Animals, on the other hand, are heterotrophs, meaning they eat other organisms. 

In this article, we will further read about “what is nutrition in animals?”

What is Nutrition in Animals?

It is the process of consuming various nutrients such as carbs, vitamins, minerals, proteins, and so on in order to support various biological processes such as development and repair. Nutrients provide energy for a variety of metabolic processes.

The food we eat is derived from either plants or other animals. We eat grains, pulses, vegetables, and other plant-based meals, as well as animal-based goods such as milk, eggs, poultry, and fish.

Nutrients Absorbed By Animals

  • Carbohydrates: They give you energy, particularly for your brain controlling blood glucose levels.  
  • Proteins: Proteins are required for the production and growth of cells, tissues, and organs, as well as for the development and repair of body tissue. 
  • Fats: They provide energy and protect the organs from harm.  
  • Vitamins: Vitamins are classified into two categories based on their solubility. Vitamins B and C are both water and fat-soluble (vitamin A D E and K). Vitamin deficiency can cause disorders including night blindness, scurvy, and rickets, among others. 
  • Minerals: Minerals include sodium, which regulates electrolytes and muscular contractions in our bodies, chlorine, which is required for healthy fluid balance, and potassium, which maintains fluid balance, Calcium and phosphorus are minerals that help strengthen bones and teeth, iron that helps in the formation of hemoglobin in red blood cells, etc. 

Nutrition in Animals Process

The following steps are included in the nutrition in animal process:

Ingestion: The act of ingesting food is known as ingestion.

Digestion: The large food particles are broken down into smaller, water-soluble bits during this process. Food digestion can be physical or chemical. Physical methods include chewing the food in the mouth while the chemical method includes the digestive juices that are secreted inside the body. 

Mouth and Oesophagus: Digestion begins in the mouth, where the salivary gland secretes the saliva, which contains two types of enzymes: ptyalin and maltase. Saliva contains an enzyme called salivary amylase, which starts the process of converting starches in food to maltose. On an average day, humans secrete about 1.5 liters of saliva, which is acidic in nature (pH 6.8).

Digestion in the Stomach: This acidic environment in the stomach aids in the breaking down of food particles and the absorption of essential nutrients. Gastric glands secrete gastric juice which has the enzymes Pepsin and Renin. Pepsin degrades proteins into peptones, while Renin degrades Caseinogen to Casein. Hydrochloric acid is present.

Digestion in Duodenum: The duodenum gets partially digested food (chyme) from the stomach. The gallbladder secretes bile, which is made by the liver and aids in the breakdown of lipids into a form that can be absorbed by the intestines. Bile juice’s primary role is to convert acidic foods to alkaline.

Pancreatic juice mixes with food and contains the following enzymes:

  • Trypsin is a digestive enzyme that breaks down proteins and peptones into polypeptides and amino acids.
  • Amylase is an enzyme that transforms starch into soluble sugar. 
  • Lipase is a digestive enzyme that breaks down emulsified lipids into glycerol and fatty acids.

Digestion in the Small Intestine: The process of digestion is completed in the small intestine, and the absorption of digested meals begins. Intestinal juices that have erepsin, maltase, sucrase, lactase, and lipase are secreted in the small intestine and are alkaline in nature. Approximately 2 liters of intestinal juice are secreted per day. 

  • Absorption: In this step, the digested food is absorbed into the bloodstream through the gut wall. 
  • Assimilation: Food is taken and utilized by the body’s cells for energy, growth, and repair.
  • Egestion: Food that has not been digested is excreted in the feces. Egestion is the term for this procedure.

Types of Animals Based on Nutrition

  • Holozoic: This type of animal will consume, digest, and absorb the food. There are three varieties of these animals:
  • Herbivores are animals that only eat plants (e.g. Cow, Goat, etc.)
  • Carnivores (animals that devour other animals) are the second type of animal (e.g. Tiger, Viper, Spiders, etc.)
  • Animals that eat both animals and plants are known as omnivores (e.g. Human Beings, Ants, etc.)
  • Parasites: These are parasitic organisms that live on or inside other living things. This species of animal is reliant on the sustenance of other animals. The parasitic animal is known as a parasite, and the animal on which it is dependent is known as a host.
  • Saprozoic: It is a type of animal that feeds on dead and decaying organic debris. These organisms eat rotting wood from dead and decaying trees, rotten leaves, dead animals, rotten bread, and other rotting materials.


Nutrition in animals is just as vital as plant nutrition. Plants manufacture their own food through the process of photosynthesis, but animals are unable to do so and must rely on plants or other animals for their nourishment. Different modes for heterotrophic nutrition in animals include holozoic, parasitic, and saprophytic.