Selenium in certain soils may be taken up by plants or through food chain in amounts sufficient to make forage toxic to animals. Selenium can be found in semiarid areas on soils typically derived from Cretaceous geologic material in the World wide. Acute poisoning results from consuming plants containing high selenium concentrations, chronic selenium Poisoning has been described in two forms: alkali disease and blind staggers. Alkali disease results from prolonged ingestion containing, 5-40 ppm selenium in inorganic or organic forms. Alkali disease causes loss or hair, lameness, weight loss and probably reduces reproductive efficiency. Blind staggers causes animals to wander, walk in circles, and to have difficulty in swallowing; in addition, it may cause blindness. Information is presented that questions the attribution of blind staggers to selenium toxicosis. Chronic oral intake of very high levels of selenium (10-20 times more than normal) can produce selenosis in humans, the major effects of which are dermal and neurological.

The heavy metal Chromium has several oxidation states but it occurs predominantly in two forms: trivalent (Cr3]) and hexavalent (Cr6+) states. Unlike trivalent chromium, the hexavalent form rarely exists naturally being originated by anthropogenic sources. Hexavalent chromium (Cr (VI)) is very often an issue in ecotoxicity studies for two main reasons: (i) due to its importance as a pollutant that threats especially aquatic ecosystems and (ii) due to its value as a reference toxicant in standard toxicity tests. Cr (VI) is used in industry (wood preservation, leather tanning, metal finishing, pigments, refractory, etc., Very often wastes from such industries are used as a fill material at numerous locations where Cr (VI) easily reaches groundwater by leaching and seepage from the soils. The tanning industry especially contributes to chromium aquatic pollution, being estimated that in India alone about 2000 to 3200 tone of elemental chromium escape into the environment annually. Generally these works show that Cr (VI) acts as a strong oxidizing agent.

Lectins are sugar-binding proteins that are highly specific for their sugar moieties. They play a role in biological recognition phenomena involving cells and proteins. For example, some viruses use lectins to attach themselves to the cells of the host organism during infection. Lectins may be disabled by specific mono- and oligosaccharides which bind to them and prevent their attachment to cell membranes. Lectins were first discovered more than 100 years ago in plants, but they are now known to be present throughout nature. Lectins are also prevalent in the microbial world, wherein they tend to be called by other names, such as hemagglutinins and adhesions

A book on agriculture microbiology should include a study of the occurrence of microorganisms in the soil, their activities and their role in soil processes. It is this last phase which has been studied least and where the information available is far from satisfactory in explaining what is taking place in the soil. This is due largely to the limitations of the subject which depends for its advance on botany, zoology, bacteriology, chemistry, including biological and physical, and especially upon the advance of our understanding of the physical and chemical conditions of the soil. There are various kinds of audiences to which a book on soil micro-biology may appeal. There is the scientific farmer who may search for a better understanding of the processes taking place in the soil, those processes which control the growth of his crops and indirectly influence the growth of his animals. There is the agronomist, who is interested in the fundamental reactions controlling soil fertility.This book will be useful not only for students, teachers, and researchers but also for those interested in agriculture microbiology, plant pathology, ecology, environmental science, and agronomy.

Biochemistry and biotechnology as any technique that used living organisms to make or modify a product to improve plants, animals or to develop micro organisms for specific use. this book focused mainly developmental and application of modern animal biochemistry and technology based on new enabling techniques of biochemical techniques. this text book is intended for under-graduate and post- graduate students of pure and applied sciences of all veterinary and agricultural universities in India.

Biotechnology as any technique that used to living organisms to make or modify a product, to improve animals or plants or to develop micro-organisms for specific uses. The book focuses on development and modern applications of animal biotechnology.based on newly developed techniques. The book is intended for and post graduates of pure, applied science and veterinary students and also for the non specialists in other disciplines who wish to understand animal biotechnology.