The animal’s body derives all the nutrients for its – physiological functions like growth, milk, wool and egg production from the digestion of food, most of which consist of grasses, forages, hays and concentrate. In utilizing the nutrients present. In the food to the nutrients present in the animal body to transform the nutrients present in the food to the nutrients present in animal body. It is therefore, essential to know the chemical composition of the plants and animals which may give general information regarding the relationship. In the subsequent article the detailed aspects of the various nutritional processes involved in the animal body would be discussed.
COMPOSITION OF PLANTS
In the case of ruminants like cattle, buffaloes, sheep and goats, plants and their by – products from the majors
portion of their diet. The same is true for the monogastric animals like pigs , poultry and pre – ruminant calf but to these animals on a limited scale, foods of animal origin are also fed namely, fish meal, meat meal , meat offal’s and milk products. Plants and animals contain similar types of chemical substances but the relative amount present is different.
Most of the nutrients present in the plants and animals have been grouped together into different classes like water, proteins, fat, carbohydrates and ash. Plants and their by-products show much larger differences in the
chemical compositions then do the animals. The chemical composition of the plants is affected by the physiological stage and the species.
The water content in the plant decreases with the progressive maturity and so is the case with the animal body .the new born baby has got about 75% of water and about 55% in mature animal
THE main component of organic matter in the plants is carbohydrate whereas in animal’s body the carbohydrate content is very low. The carbohydrates serve as both structural and reserve material in the plants whereas in animals proteins reserve as the structural material and fats serve as the reserve.
Fats are important components of plants and animals. The liquid content in the plants is very low and contribute little towards energy availability to the animals whereas in the animal body, though variable, fat increases with age.
Proteins are the major nitrogen containing compounds present in both plants and animal. In young plants protein content is high. Leaves are richer than the stem. In animals muscles hairs, feather, wool, etc are composed of proteins.
The ash content which contains both micro and macro element in plants is highly variable depending upon soil conditions.
Vitamins are present in plants and animals in small quantities. Plants can synthesize all the vitamins required
for their tissue metabolism whereas animals can’t synthesize all the vitamins which they require as a component of various enzyme systems.