eChapters

Samples for toxicological analysis are usually taken during post-mortem examination. In suspected cases of poisoning the following specimens should be sent for chemical analysis.

Bone marrow biopsy
Indications
    •    In blood abnormalities in which it is impossible to confirm a diagnosis by means of peripheral blood examination.
    •    In conditions like leucopenia, non-regenerative anaemia and thrombocytopenia.
    •    As a confirmatory diagnosis of leukaemia and differentiating it from leukemoid reactions.

Cerebrospinal fluid is found in the ventricles, cistern of brain, canal of spinal cord and in space between piamater and arachnoid. The main source of CSF is choroids plexus in the ventricles of brain. CSF is derived from the blood plasma and therefore, it has qualitatively the same composition. But the discrepancies between the ionic concentrations in cerebrospinal fluid and blood plasma indicate that the fluid is not a simple filtrate but a product of active secretary mechanism. Functionally, CSF protects and nourishes the parenchyma and maintains homeostasis. Diagnosis of diseases of CNS posses a challenge to the clinician and confirmation of tentative diagnosis based on clinical manifestations requires cytological and biochemical examination of CSF. Removal and laboratory examination of CSF are indicated whenever there is clinical evidence suggesting CNS disease.

Transfusion therapy is basically an attempt to replace blood or its components when the life is threatened. Blood transfusion plays a life saving role in general mostly to shorten the recovery time during any severe blood loss conditions arising due to accidents, major surgical interference, haemoprotozoan diseases especially in canines during anaemic conditions due to sever helminthic infestions, tick infectation, haemophilia etc.

In livestock, diversity of blood and lack of commercially available blood typing reagents, make blood group matching and typing difficult, which results in reduced importance in veterinary practice. Blood or individual blood component is to be transferred during the following conditions-

The daily nutrient requirements of animals varies for various stages of life i.e. maintenance ration, growing, working, pregnant, lactating, dry and diseased animals ration. Maintenance ration contains the vitamins and mineral only for life without any other production, while during pregnancy and lactation their requirements changed drastically from the maintenance ration. If not supply the standard amount of vitamins and minerals during these stages may disturb the metabolism and ultimately cause the production or metabolic disease. Therefore, the proper and sufficient (as per standard requirements) supplementation of vitamins and minerals can help in the prevention and control of production diseases in livestock.

Increased ketone bodies level in blood, known as ketonemia and condition is ketosis. The disease respond readily to treatment with glucogenic substances which can be one of the test therapy to differentiate this condition from milk fever and hypomagnesemia. The efficacy of this therapy can be estimates through estimation.

Collection of blood samples

Collection of blood sample is already discussed in exercise no. 4.

The concentration of essential elements must be maintained within quite narrow limits if the growth, health and productivity of the animal are to be maintained. Soil-plant-animal relationship is based on micro-mineral profile in animal blood, plant (fodder) and the soil is of paramount importance to identify dietary requirements of animals maintained under different husbandry practices of various agro-climatic zones. The soil occupies a strategic position in the chain of nutrition flow to plant, animal and eventually to man. The soil is the principal source of trace elements entering the food chain. The influence of the chemical composition of soil on the trace element contents of pant is well known.

Trace minerals have long been identified as essential components in the diets of domestic livestock species. Trace minerals exist in cells and tissues of the animal body in a variety of chemical combinations, and in characteristic concentrations, depending on the trace mineral consumed and the tissue in which it is metabolized. Concentrations of trace minerals must be maintained within narrow limits if the functional and structural integrity of the tissue is to be maintained and the growth, health, and productivity of the animal are to remain unimpaired. Minerals are as vital to cattle as grass, water or air.

Total protein: (Biuret method)

There are several methods of estimating protein, in food, agricultural and clinical samples, each of them varying in sensitivity and applicability.

Principle
Biuret method is highly specific for protein and is based on the formation of the blue peptide-copper complex in alkaline solution. It is a method of choice in the clinical laboratory because of the simplicity accuracy and precision. The major limitation of the method is its poor sensitivity for many dilute solutions. The principle of this method is that the peptide bonds in protein react with biuret reagent to give a violet colored complex known as cupric potassium biuret. The colour intensity of which is proportional to protein concentration.

Sodium and potassium are the most important electrolytes of the body fluid. The sodium as sodium chloride is contained in body fluids. The potassium is also essential in body fluids and its concentration is controlled by the kidneys. The estimation of sodium-potassium balance makes an important contribution as component of metabolic profile test. Low level of Na occurs in early lactation of low grazing on summer pasture and also increasing age, depraved appetite, polydipsia and polyurea.

The levels of calcium (Ca), inorganic phosphorus (P) and magnesium (Mg) may help in early diagnosis of metabolic and deficiency disorders and for monitoring the herd health status of dairy cattle to maintain production and reproduction.

Estimation of Serum calcium

Calcium is present in 2 forms – inorganic and organic forms. Most of the functions of the calcium depend upon the ionized form. For estimation of serum calcium the most commonly used method is Clark and Collip method.

Urea is the detoxification product of the ammonia derived from the deamination of amino acids. Urea is therefore the most common nitrogen-containing end product of protein catabolism. Its synthesis from ammonia occurs in the liver (via the urea cycle), and it is then excreted by the kidneys. The concentration of urea inside red cells is slightly less than in plasma due to the presence of large amounts of hemoglobin inside the cells. Whole blood urea concentration is therefore slightly less than plasma (or serum) urea. Therefore, usually serum is used instead of whole blood for the determination of urea. The familiar term BUN (blood urea nitrogen) persists in spite of the fact that it is serum urea nitrogen which is usually measured.

The glucose is utilized in the body for immediate energy requirements. The utilization of glucose depends on the integrated activity of digestive system metabolism and endocrine system of the body. Glucose tolerance is referred as the capacity of animal to regulate elevated blood glucose on ingestion or infusion, gradually. The level of glucose that can be tolerated by an animal without producing glucosurea is indicative of tolerance. Glucose load challenges the pancreas to release insulin which in turn regulates blood glucose level. If the insulin release is adequate and target cells have healthy receptors, elevated blood glucose level return to base value within 2 hours and glucose does not appear in urine. An increased glucose tolerance means limited rise and rapid fall in blood glucose in short span than the normal rate of utilization.

Carbohydrates are constituents of all living cells. Animal as well as plant cells use carbohydrates as source of energy. Blood glucose is a useful indicator of energy metabolism and fertility status. Under certain clinical circumstances, estimation of carbohydrates becomes essential. Sugar levels (particularly glucose) in blood or urine are used as an important parameter for diagnosis of ketosis and diabetes mellitus.

The main aim of blood testing is to ascertain the adequacy of each new diet in relation to the herd’s requirements, i.e. what the cows think of their rations. So blood sampling should be carried out as soon as possible after major changes in dietary constituents. But two weeks must elapse after the changes to allow the rumen to become fully adapted. The metabolic profile is based on the concept that the laboratory measurement of certain components of the blood will reflect the nutritional status of the animal with or without the manifestation of clinical abnormalities. The values of Hb, PCV, TEC, TLC, DLC and erythrocytic indices are useful indicator of health status of the animal.

Examination of rumen fluid was introduced for clinical diagnosis during the 1950’s. The stomach of ruminant harbor beneficial microbes required for digestion of feed consumed. Stomach maintains an ideal environment (pH 6.8 to 7.2 and temperature 39-40°C) for growth and proliferation of these microfloras. In any of the ruminal disorder this homeostasis get upset resulting in shifting of microbial population (Gram negative to Gram positive) and formation and accumulation of toxic products of abnormal metabolism. This further leads to an array of pathologic process in the body. Hence physical, microbial and biochemical examination of rumen fluid can be considered as an important diagnostic tool for wide variety of disorders.

Metabolic profile testing (MPT) refers to the use of a battery of tests for the diagnosis of subclinical nutritional and metabolic disease in dairy cows on a herd basis. Typically, blood samples from 5-7 animals per production group are tested for various analytes. MPT is most useful in the diagnosis and management of periparturient disease. Specific nutrient imbalances, either deficiency or excess, in the diet of late-gestation cows have been related to increased prevalence of milk fever, hypomagnesemia, retained placentas, downer cow syndrome, mastitis, udder edema, ketosis, hepatic lipidosis, and displaced abomasums.

The purpose of the clinical examination is to identify the clinical abnormalities that are present and the risk factors that determine the occurrence of the disease in the individual or population. The focal point of any investigation of animal disease is the making of diagnosis and the critical part in making that decision is the clinical examination of the animal or group of animals. Without a proficient clinical examination and an accurate diagnosis it is unlikely that the treatment, control, prognosis and welfare of animals will be optimized.  The level of examination set out is sufficient to enable the clinician to determine the nature of the abnormality and the system involved.

Abstract

Human Resource Management (HRM) is an essential function of every organization. Information Technology (IT) application has made such ‘human resource management’ function easy, to a great extent. Now a day, IT has been used widely across the organizations to perform different functions like, Recruitment, training, maintenance and development etc. Human Resource Information System (HRIS) is one of the latest contributions of IT to the area of human resource management, which is going to revolutionise management in 21st Century. Technology has brought changes in the existing working styles of organisations. By the introduction of HRIS, it enhances the efficiency of the organisation by changing the traditional way of working. In Human Resource Information Systems, many organizations use employee data in traditional ways. These can create conflict with the rights and interests of employees, with external stakeholders, and with society at large. The present paper discusses such issues. Other soft issues like, challenges and possible solutions are also discussed.

Abstract

Training is essential but expensive. Hence, training impact is a crucial measure. National Agricultural Research System (NARS), India employs about 30000 scientists. To effectively manage such huge scientific-capital, Indian Council of Agricultural Research (ICAR) establishedCentres for Advanced Faculty Training (CAFT) and National Academy of Agricultural Research Management (NAARM). CAFT train faculty of State Agricultural Universities (SAUs), while NAARM trains scientists of ICAR institutes and SAUs. Assessing impact of these training programmes becomes essential. Application of knowledge, skills and attitude (KSA) acquired during training back at job environment is training-transfer that addresses learning, behaviour and results levels of training impact. This chapter critically analyses training-transfer of NAARM and CAFT programmes, suggests empirical framework to enhance impact of NAARM and CAFT programmes and thus contributes to literature. Policy strategies suggested in this paper hold wider applicability.

Introduction

Training is the crucial and expensive component of HRD, intended to improve the efficiency and effectiveness of performance of the members of organization through planned learning efforts, transfer of such learning at work place and in turn improvement of the organizational performance. Given such objectives, most of the training programmes fail to inculcate the transfer component in trainees (Subedi 2004). Hence, there is an increasing concern over training transfer at work place and the resultant improved organizational performance in terms of productivity, efficiency, effectiveness and turn over etc (Howard 1995, Huselid 1995, Martocchio and Baldwin 1997 and Salas et al.. 2000, Thayer1997).

Improving the skill set of individuals is an important agenda of any development organization. The individuals may be anyone in the system who is directly or indirectly connected to the system.  Agriculture System is a complex and multi-stakeholder system with farmers as the axis of the wheel with other stakeholders’ forms part of spokes of the wheel. The scope for capacity building or training of every stakeholder has been peaking tremendously given the ever changing nature of the profession. The public and private training Institutions are vying with each other for conducting trainings in order to sustain the existence of the Institutions. Though a few institutions are really trying hard to take the technologies in real terms to the farming community, the following observations are very difficult to be masked.

1. Introduction

With the advent of globalization and subsequent economic liberalization, the focus of Indian agriculture is shifting from “subsistence” to “commercial” mode, where farming is viewed as a “business” rather than “life-support” system of poor farmers. Enabling farmers “decision-making” capacity is a primary driver of success in the market-oriented agriculture. This “commercial focus” has brought tremendous changes in the “nature” and “mode” of extension work. On the other hand, extension work organizations in developing countries like India, are being impacted by sharp decline in public sector funding, rapid technological innovations especially in the Information and Communication Technologies (ICTs), and the shift to a knowledge-based workforce. These developments created new opportunities for the extension workers to perform the information dissemination, capacity building and technology application more effectively. 

Agricultural colleges and universities were first formed in the belief that farm production could be increased as a result of the systematic application of current technology and agricultural research findings. The mission of these early educational institutions was to scientifically study agriculture with the participation of the farming community; to carry the results to a broad range of farmers who could use them; and to train farmers, extension workers, agricultural teachers and researchers so that agricultural production could continue to be increased on a sustained basis. In many of the developing countries, agricultural education and training have failed to adapt and respond to the realities of rural societies. In response to the urgent need to review and adjust teaching and training in agriculture at all levels. The training is an important tool to overcome the problem faced by the rural people all over the world. The availability of the resource is the crucial determining factors to strengthen the training Programme for the needy people.

In India’s National Extension Programme, professional workers constitute the link between the people and the institute created to advance economic and social change upon the character philosophy, technical knowledge and compliance of these workers largely rests for the success of the programme. Hence the quality of these workers and their training is the important element to be dealt with properly and guided wisely.

In early fifties, the Gramsevak / Village Level Workers (VLW’s) served as a key-man in Community Development Programme and therefore, the Government of India aimed at imparting him by better training and supervisory assistance. As a step in this direction, Gramsevak Training Centers were started to impart training to GramSevaks / VLW’s and Extension Officers were appointed in block for better supervisory assistance.

Training helps people to become qualified and proficient in doing some jobs (Dahama, 1979). Usually an organization facilitates the employees’ learning through training so that their modified behaviour contributes to the attainment of the organization’s goals and objectives.
 
Training needs refer to the gaps between desired and expected levels of performance. Needs may be numerous. Besides they also need group, affection, recognition and fulfilment of their talents.

Training need may be defined as difference between existing and desired performance of person(s). In other words it is a gap between job requirement and job performance. That means it is gap between the existing and desired level of competency. Thus, the attitude, knowledge and skills of a person are lower than desired if the gap is significant there is a need for training.

Introduction

Today we are part of a highly complex and dynamic society. The complexity and dynamism are primarily due to the chain of changes induced by the scientific and industrial developments. The impetus provided by the information explosion coupled with scientific and technological developments to human life has triggered several unimaginable developments in the number, structure and functions of formal organizations. Realization of the supremacy of human mind over the tangible and exhaustible organizational resources like money, material and machine has led to the concept of ‘human capital’, which is now being considered as the most critical organizational resource to ensure organizational effectiveness and efficiency. Analogously huge investments are going in towards servicing and developing this critical resource of human capital in organizations. In this context, the concepts of human resource development (HRD) and training assume greater significance. In fact, training has been considered as a potential tool for HRD since ages. However, as a distinct profession, and also as a critical management tool, training is still in its early years. At the same time, there have been significant changes in the way training is conceived, understood and practiced.

Introduction

Pollution is the introduction of contaminants into an environment that causes instability, disorder, harm or discomfort to the physical systems or living organisms they are in.
 
Pollution can take the form of chemical substances, or energy, such as noise, heat, or light energy.
 
Pollutants, the elements of pollution, can be foreign substances or energies, or naturally occurring; when naturally occurring, they are considered contaminants when they exceed natural levels. Sometimes the term pollution is extended to include any substance when it occurs at such unnaturally high concentration within a system that it endangers the stability of that system. For example, water is innocuous and essential for life, and yet at very high concentration, it could be considered a pollutant.

Definition
 
Radiation poisoning, also called “radiation sickness” or a “creeping dose” is a form of damage to organ tissue due to excessive exposure to radiation. The term is generally used to refer to acute problems caused by a large dosage of radiation in a short period, though this also has occurred with long term exposure to low level radiation. Many of the symptoms of radiation poisoning occur as ionizing radiation interferes with cell division.
 
The clinical name for “radiation sickness” is acute radiation syndrome. A short exposure can result in acute radiation syndrome; chronic radiation syndrome requires a prolonged high level of exposure. A chronic radiation syndrome does exist but is very uncommon;

Introduction

Chemical warfare involves using the toxic properties of chemical substances to kill, injure or incapacitate an enemy.

Chemical warfare is different from the use of conventional weapons or nuclear weapons because the destructive effects of chemical weapons are not primarily due to any explosive force. The offensive use of living organisms (such as anthrax) is considered to be biological warfare rather than chemical warfare; the use of nonliving toxic products produced by living organisms (e.g., toxins such as botulinum toxin, ricin, or saxitoxin) is considered chemical warfare under the provisions of the Chemical Weapons Convention. Under this Convention, any toxic chemical, regardless of its origin, is considered as a chemical weapon unless it is used for purposes that are not prohibited (an important legal definition, known as the General Purpose Criterion)

Introduction
The major conditions described under this heading are as follows :
    1.    Snakebite 
    2.    Scorpion bite 
    3.    Black widow spider sting 
    4.    Toad poisoning

Snake Bite
Poisonous snakes mainly belong to three categories

Introduction

A toxin (Greek: ôïîéêüí, toxikon, lit. (poison) for use on arrows) is a poisonous substance produced by living cells or organisms that is active at very low concentrations. Toxins can be small molecules, peptides, or proteins and are capable of causing disease on contact or absorption with body tissues by interacting with biological macromolecules such as enzymes or cellular receptors. Toxins vary greatly in their severity, ranging from usually minor and acute (as in a bee sting) to almost immediately deadly (as in botulinum toxin)

Introduction

In the thirst of modernization and industrialization man has contributed pollution to the life and ecology of plants, animals and microbes. Increased demand for food and fiber has lead to the chemicalization of agriculture and we have reached on such a stage that modern agriculture is dependent on high yielding varieties, which can only be grown under the influence of fertilizers and pesticides. Pesticides are the man made chemicals which are being used to produce enough cheap food. In India, 90,000 MT of technical grade pesticides are used annually to control pests and plant diseases. The pesticides are classified as insecticides, fungicides, weedicides, herbicides, nematodicides and rodenticides; of which insecticides constitutes 77% of the total pesticides used in different agricultural and animal husbandry practices and in public health operations.

Introduction

The word mycotoxin is derived from myco, meaning mold and toxin, a poison. A great number of mold metabolites have been identified as mycotoxins. Thus mycotoxins are secondary fungal metabolites (i.e., metabolites not essential to the normal growth and reproduction of the fungus) which cause pathologic, physiologic, and/or biochemical lesions in other species (may include animals, plants, other microbes, etc.).

Introduction

Plants are the main source of nutrition to farm animals for their maintenance and production. But, under certain conditions, plants intoxicate farm animal life due to the presence of some deleterious substances called phytotoxins. Such plants include a variety of fodder plants (Jowar, wheat straw, Lucerne), grasses (Millet grass), ornamental or fencing plants (Crotons, Nerium sps) and weeds (Tribulis) in the farm premises.

Nitrate - Nitrite Poisoning
Sources
Accidental ingestion/grazing of Plants which are Nitrate accumulators 

Arsenic
General Information
    1.    Exists in elemental form (-3), trivalent As⁺³ and pentavalent As⁺⁵ oxidation states
    2.    Arsenic is an essential element for rats, chicks, mini-pigs and goats
    3.    The second most important pollutant for livestock. 

Source
    1.    Inorganic form is used in paints.
    2.    Pasture near smelters may be contaminated. 
    3.    Industrial effluents released into nearby water body
    4.    Insecticides (Arsenic trioxide, lead arsenate).
    5.    Herbicides (Sodium arsenite, lead arsenate)

Definitions

        Toxicology: Knowledge (or science) of poisons, including their chemical properties, identification, biological effects, and the treatment of conditions they cause.

        Poison: Any solid, liquid, or gas that, when introduced into or applied to the body, can interfere with the life processes of cells of the organism - by its own inherent chemical properties - without acting mechanically and regardless of temperature.

Analyzing feeds for nutrient content is essential for proper balancing of livestock rations. This is especially essential for those feeds that have undergone the fermentation process. Silage samples should be analysed for dry matter, protein fractions (degradable and undegradable protein, soluble protein, and heat damaged protein), ADF, NDF, mineral content and energy. In addition to these components, lactic, acetic, and butyric and propionic acids, pH, ammonia nitrogen, ethanol, and yeast and mold counts are also quantified.

Haylage or baleage or round bale silage, is a somewhat newer method of preserving forage. Haylage is simply forage that is baled at higher moisture content than dry hay and then stored in a sealed plastic wrap. Because of the high moisture level and air-tight environment, the forage ferments and is preserved by acid production during fermentation. The higher pH values associated with baleage are related to a slower fermentation process. During the respiration stage of the ensiling process the oxygen that is trapped in storage is rapidly consumed by aerobic bacteria. Anaerobic bacteria, which survive in the absence of oxygen, begin to grow and multiply in the fermentation stage and convert the plant sugars into organic acids- mainly lactic acid and acetic acid. With production of acids, the pH of the silage is reduced from an original level of 7.0 to a final ideal pH of 4–5. Typical large bale haylage has a pH of 4.5–5.5. Fermentation ceases when bacteria growth is stopped by the accumulation of acids. The haylage will then remain at a stable pH with no bacterial growth and can be preserved for a long time, providing there is no exposure to air. Harvesting forages with a long fiber usually results in a slow release of the plant nutrients necessary for the growth of acid producing bacteria. This generally results in less fermentation in the baleage than in chopped silage.

Storage of hay at higher moisture contents may lead to some heating due to the activity of aerobic micro-organisms and possibly some plant respiration. The warm, moist conditions in hay will provide the ideal environment for growth of spoilage bacteria, e.g. Bacilli and yeasts, moulds and fungi. These organisms utilize the energy and protein of the hay and can lead to a substantial increase in their respective populations. Their action leads to the following reaction:- 

Hay (plant sugars) + oxygen ® Carbon dioxide + water + heat
 
The resultant heating causes a reaction between the carbohydrates and proteins rendering both less digestible as temperatures continue to increase. The best opportunity to reduce hay-harvesting losses is by shortening curing time. A combination of mechanical conditioning, chemical conditioning and high-moisture baling help accomplish this goal (Collins, 1988; Mahanna, 1994).

Hay quality really means feed value. The ultimate test of hay quality is animal performance. Quality can be considered satisfactory when animals consuming the hay give the desired performance.
 
Characteristics of Good Quality Hay

    1.    Hay should be nutritious therefore prepared form plants cut at an appropriate stage of maturity when it has the maximum nutrients.
 
    2.    Good hay should be leafy. The leaves are generally richer in proteins, minerals and vitamins then other parts of the plant.

    3.    Hay should be green in colour. The green colour indicates the amount of carotene which is precursor of vitamin A. The green colour should be preserved by minimizing the bleaching, leaching arid fermentation losses.

Feeding of green and succulent fodder is of utmost importance to farm animals. Grazing fresh forage year round at the optimal stage of maturity would supply the highest quality and most palatable form of feed in any livestock operation. In most part of the world, green fodder is limited to a particular season only. Because of fluctuations in seasonal growth and plant maturity, excessive biomass in the spring, it is necessary to harvest and store forages to maximize both quality and productivity. One of the important form of conservation practiced on a wide scale is hay making. Hay making is an art in which the fodder is kept for future use in lean period. Since it contains large quantity of moisture it is to be dried properly to increase its keeping quality without reducing its nutritive value. The objective of hay making is to achieve a rapid moisture loss after cutting so that the forage can be romoved from the field with minimum losses from weathering and microbial degradation (Bareebam, 1992).

Forage preservation as silage is a key component of high input (zero-grazing) systems (Mannetje, 1999). It has allowed producers to intensify the productivity of the land and the productivity of the livestock. Large quantities of forage can be conserved in a short time, forage conservation is less weather dependent and thirdly, silage is well suited to mechanization. However, a major disadvantage associated with silage making is that the feeding value of the resultant forage is reduced relative to that of the original crop. Ensiling offers many advantages over haymaking.

Feeding silage is also an important part of the process. Silage can be fed to all kinds of animals. Silage is suitable for feeding 6-7 weeks after ensiling. Purposes of silage feeding are drought feeding, production increases, an aid to pasture or crop management, utilization of excess growth, balancing nutrients in the diet, and the storage of wet feed products. Silage is most likely to be profitable when used to increase productivity or balance nutrient content of the diet.
 
Feeding value of silage is defined as the product of the nutritive value and potential voluntary intake of the forage (Wheeler and Corbett, 1989).

Objective of the conservation of forage is to preserve as much as of the crop nutrient as possible. However, during ensilage loss of nutrients occurs. There are five sources of loss. Theses are:
 
    (a)    Field losses 
    (b)    Oxidation or respiration losses 
     (c)    Fermentation losses
    (d)    Effluent losses 
    (f)    Aerobic deterioration

It is recognized in developed countries that the production of silage of high quality cultivated forage can be a valuable component for the development of a high-performing and low-cost system of animal production, using a relatively low level of purchased concentrates. However, this appears inappropriate for smallholders in tropical countries, primarily due to lack or high cost, or both, of equipment for harvesting and conservation and production of cultivated forage being often limited due to lack of available land. Many agricultural, agro-industrial and fishery by-products have potential as animal feeds. Most farmers in developing countries rely for their food security on the cultivation of cereals, root crops and high-value crops such as fruits and vegetables, which understandably take priority in the allocation of land. Fruit, vegetables and root crops are increasingly integrated in the farming system and play a key role as staples in the human diet in most developing countries.

Silage fermentation is a dynamic process involving interactions among the forage, microbial populations and the ensiling environment. A good fermentation process is not only dependent on the type and quality of the forage crop, but also on the harvesting and ensiling technique. There are various factors that influence the fermentation process and ultimately the nutrient composition and quality of ensiled feed. These are as follows:

1. Plant Factors

Forage characteristics at the time of ensiling are the predominant factor which determines the final quality of silage. Factors such as type of forage to be ensiled, maturity, DM content and WSC content of that forage, all influence the ease of ensiling and ultimately the quality of silage that is produced.

Quality of silage is determined by nutrients content and intake potential of the silage. High quality silage is a stable feed, made from high quality pasture, which is preserved in the absence of oxygen by a high quality fermentation, to minimize any loss of feeding value. It is not possible to produce high quality silage from low quality pasture, no matter how good the fermentation is. The silage quality is generally used to indicate the success of fermentation and not to evaluate the feeding value of the silage. However, the fermentation quality and nutritional value of the silage are usually highly correlated because a poor fermentation can result in great loss of the digestible nutrients (Sutoh et al., 1970; Uchida and Sutoh, 1973). Therefore, both the quality of the ensiled pasture and the quality of the fermentation must be considered.

Silage fermentation is a dynamic process that is affected by variety of factors. The primary goal of making silage is to maximize the preservation of original nutrients in the forage crop for feeding at a later date. Unfortunately, fermentation in the silo is a much uncontrolled process usually leading to less than optimal preservation of nutrients. In order to assist in the fermentation process, various silage additives have been used to improve the nutrient and energy recovery in silage, often with subsequent improvements in animal performance (Henderson, 1993; Bolsen et al., 1996; Muck and Kung, 1997; Kung and Muck, 1997; Muhlbach, 2000). Their main functions are to either increase nutritional value of silage or improve fermentation so that storage losses are reduced. The benefits obtained from silage additives depend upon their influence on the silage fermentation process. These benefits are usually measured by the reduction in fermentation losses and/or improvement in silage quality and feeding value.