Nutrition in Animals – Types, Process of Nutrition in Animals Nutrition in animals depends upon the feeding habits of the animals. Animals derive their nutrition either by eating plants directly (herbivores), or indirectly by eating animals which have consumed plants (carnivores). Some animals feed on both plants and animals; these animals are termed as omnivores.  All organisms require food for their survival and growth.

Nutrition in animals is as important as it is for plants. Plants prepare their own food by the process of photosynthesis but animals cannot prepare their own food, hence they need to depend on plants or other animals for their food. Food has different components, called nutrients, like carbohydrates, fats, minerals, proteins, and vitamins, which are required for the maintenance of the body. These components are complex and cannot be used directly, so they are broken down into simpler components by the process of digestion.

NUTRITION IN ANIMALS WHAT  IS  NUTRITION ? THE PROCESS OF OBTAINING AND UTILISING FOOD BY AN ORGANISM,IS KNOWN AS NUTRITION.NOTE–   THE PROCESS OF OBTAINING FOOD IS NOT SAME IN ALL ORGANISM. ANIMALS EAT COMPLEX FOOD MATERIALS BUT BREAK DOWN INTO SIMPLER FORMS IN THEIR BODIES. THEIR BODY GETS THE REQUIRED NUTRITION THROUGH THE THREE MAIN STEPS-1. MODE OF INTAKE OF FOOD2. FOOD HABIT3. UTILISATION IN THE BODY

MODE OF INTAKE OF FOOD THE METHOD OF TAKING OF FOOD IS DIFFERENT IN DIFFERENT ORGANISMS. THE RELEVANT PARTS OF THEIR BODY GET MODIFIED IN A MANNER THAT MAKES IT EASY FOR THEM TO EAT THEIR FOOD.  SOME EXAMPLE-

FOOD HABITS OF ANIMALS ON THE BASIS OF THEIR FOOD HABITS, ANIMALS HAVE BEEN CATEGORISED INTO THREE DIFFERENT CATEGORIES. THE ANIMALS, LIKE COW AND DEER, THAT EAT ONLY PLANT MATERIALS, ARE CALLED HERBIVORES. THE ANIMALS, LIKE LION AND TIGER, THAT EAT ONLY OTHER ANIMALS, ARE CALLED CARNIVORES. ANIMALS, LIKE BEAR AND HUMAN BEINGS, THAT EAT BOTH ANIMALS AND PLANTS MATERIALS, ARE CALLED OMNIVORES.

UTILISATION  IN  THE  BODY THE NUTRIENTS ENABLE LIVING ORGANISMS TO BUILD THEIR BODIES, TO GROW, TO REPAIR DAMAGED PARTS OF THEIR BODIES AND TO PROVIDE THE ENERGY TO CARRY OUT LIFE PROCESS. MODES OF NUTRITION AS WE KNOW THAT THE MODE OF NUTRITION IN ANIMALS ARE HETEROTROPHIC NUTRITION.HETEROTROPHIC NUTRITION HAS BEEN CATEAGROISED INTO THREE DIFFERENT CATEGORIES-

PROCESS OF NUTRITION IN ANIMALS INGESTION = THE ACT OF GETTING, AND EATIND FOOD IS CALLED INGESTION. DIGESTION = THE PROCESS OF BREAK DOWN, OF COMPLEX MOLECULES INTO SIMPLE SOLUBLE ONES, IS CALLED DIGESTION. ABSORPTION =  THE DIGESTEDFOOD IS ABSORBED BY THE WALLS OF THE SMALL INTESTINE FROM WHERE IT GETS PASSED ON TO THE BLOOD. ASSIMILATION = THE ABSORBED FOOD IS UTILISED BY THE BODY, FOR GROWTH AND FORMATION, OF BODY PARTS KNOWN AS ASSIMILATION. EGESTION = THE ELIMINATION, OF UNDIGESTED FOOD, FROM THE BODY, IS KNOWN AS EGESTION. NOTE-   IN HUMAN BEINGS ALL THESE PROCESS IS HAPPEN IN ALIMENTARY CANAL WHICH IS MADE UP OF DIFFERENT PARTS-

NUTRITION IN SOME COMMON ANIMALS Amoeba – Amoeba ingests its food with the help of pseudopodia. – The food is engulfed by forming a vacuole and is digested with the help of digestive enzymes. – The digested food is absorbed directly into the cytoplasm by the process of diffusion. – Energy is obtained from the absorbed food that helps in its growth. – The undigested food is egested out of the body of amoeba by rupturing the cell wall.

CUD CHEWING Ingestion The food is ingested with the help of the tongue and chewed. Ruminants have sharp incisors and large molars to bite and chew grass. They also have powerful jaw muscles. Digestion After being chewed once, the food passes down the 2 to 3 feet long oesophagus. The oesophagus leads into the stomach. The stomach of ruminants has four chambers: rumen, reticulum, omasum, and abomasum. Rumen: The rumen helps in storing the large quantities of food that has been quickly consumed. The food is partially digested here and is now called the cud. The cud is then brought back to the mouth, re-chewed, and re-swallowed in a process called cud-chewing. The rumen has billions of bacteria and protozoa, which break down the carbohydrate called cellulose found in hay and grass. Reticulum: The reticulum helps in moving the swallowed food back into the mouth for thorough chewing. The reticulum opens into the omasum. Omasum: The omasum absorbs excess water. Abomasum: The walls of the abomasum secrete digestive juices.