Food Chain
The land mass, water bodies and atmosphere are the three endowments of nature on which the living beings have to depend for their nourishment and sustenance. The inter-dependence of various living species to derive their food materials has resulted in the transfer of energy and nutrients from one to another, thus setting up a process of ‘Food chain’.
Biological Recycling Solar energy is the primary energy on which the entire living system on the earth depends. The plants conserve and build up nutrients and energy, while the animals degrade and utilize them. Microbes form side links in the food chain. Soil microorganisms involved in the decaying process of organic matter in the soil help the release of nutrients in utilizable forms to assist their uptake by the plants. Rhizobial organisms in the root nodules of leguminous plants fix the atmospheric nitrogen in the soil for the utilization of plants. Micro-organisms inhabiting the complex stomach of ruminants help in the digestion of fibrous feed materials and synthesize high quality microbial proteins and B-complex vitamins to be utilized by the host animal. Materials shed and voided by plants and animals are food materials for a wide variety of lower forms of life. It is noteworthy that the skill of micro-organisms like yeasts and fungi for utilizing even petroleum products is exploited biotechnologically to produce edible food material like single cell proteins.
Livestock and Food Chain
Livestock form a vital link in the food chain. Energy needs of the human diet are mostly met by the foods of plant origin, especially cereals which are abundant in carbohydrates. Foods of animal origin lack carbohydrates, with the exception of milk.
Animal proteins are of superior quality possessing the required amino acids in balanced proportions as needed by the human body. Livestock production has a special role to play in situations where crop production has unavoidable limitations. Ruminant stock such as cattle, buffaloes, sheep and goats are capable of utilizing the residues of crops which are not directly utilizable by man. They also utilize simple non-protein nitrogenous substances for meeting their protein requirements partly, through rumen microbial synthesis.
It is being increasingly recognized that the maintenance of soil-plant-animal-microbe food chain is essential for sustaining life on this planet. Biodiversity and ecological balance are areas of great concern in the present context of depleting natural resources. Adoption of eco-friendly animal rearing systems and feeding strategies can be of enormous value in this direction.