eChapters

Abstract

Agriculture is one of the most important factors contributing to the economic growth of India. Out of the 329 million hectares of India’s geographical area, about 114 million hectares are under cultivation. There are 17 essential elements required for proper plant growth. Of the mineral elements, the primary macronutrients (nitrogen, phosphorous, and potassium) are needed in the greatest quantities and are most likely to be in short supply in agricultural soils. Secondary macronutrients are needed in smaller quantities, and are typically found in sufficient quantities in agricultural soil, and therefore do not often limit crop growth. Micronutrients, or trace nutrients, are needed in very small amounts and can be toxic to plants in excess. Silicon (Si) and sodium (Na) are sometimes considered essential plant nutrients, due to their ubiquitous presence in soils.

The economy of India thrives on agriculture, the most practiced occupation in the country. Agricultural fertilizers are essential to enhance proper growth of plants and crop yield. Recently, farmers have been using chemical fertilizers for quicker and better yield. But these fertilizers endanger ecosystems, soil, plants, human and animal lives. In contrast, naturally grown biofertilizers not only give a better yield, but are also harmless to humans. This chapter aims to study the biofertilizers play a key role for enhancing economic development of sustainable agriculture (EDSA) in comparison to chemical fertilizers. Biofertilizers improve the crop yields, plant resistance, soil health, profit to farmers, and the benefit to cost ratio of biofertilizers were higher than chemical fertilizer, proved that the biofertilizers would lead to better sustainable economic development for the farmers and their country.

Abstract

The concern of global food security is growing day by day as the agriculturally available land is reducing each day with the expansion of industrialization and urbanization. During the course of urban and industrial development, crop production is greatly affected by global warming, contamination of hazardous materials, salinity and drought. To combat against such adversities, scientists have taken several additives measurement like development of transgenic crops, application of indigenous plant growth promoting microbes etc. for sustainable agriculture. Use of plant growth promoting microbes is getting popular day-by-day as they occupy a privilege niche with the autochthonous flora of specific environment. For the expanse of food and shelter, the microbes supply a wide range of plant regulators (e.g. auxins, cytokinins, gibberellins, ABA, phenols, NH₃ etc.), antibiotics, alkaloids, steroids, terpenoids, diterpenes, enzymes (e.g. cellulases, lipases, proteinase, esterases etc.) etc. for overall development of the plant. Apart from growth promotion, it also protects the plants against pathogenic invasion creating a competition with pathogens for nutrition and habitat. In near future, formulation of different plant growth promoting bacteria (like alpha- Azorhizobium, Azospirillum, Ancylobacter, Rhizobium, Bradyrhizobium, Sinorhizobium, Novosphingobium sp., beta- Burkholderia sp., gamma- Acinetobacter, Aeromonas, Azotobacter, Enterobacter, Klebsiella, Pantoea, Pseudomonas, Stenotrophomonas sp. Proteobacteria, Bacillus sp., Paenibacillus sp. and Actinobacteria- Microbacterium sp. etc.) and fungus (Aspergillus, Trichoderma, Penicillium etc.) may reduce the use of pesticides and chemical fertilizer to promote greener ways of crop production.

Abstract

Microbes are ubiquitously found in the environment. Their interaction with other living organisms could either be pathogenic or beneficial in nature. Soil as a rich source of microbes, researchers have extensively studied the plant-microbe interactions. The soil microbes supply the nutrients deficit plants with essential growth elements such as nitrogen, phosphorous, potassium, etc. and improve the texture and quality of the soil. Due to the destructive nature of chemical fertilizers to soil and environment, it was required to generate a more ecofriendly means of increasing the soil fertility. This led to the development of microbes based biofertilizers. The primary benefit of biofertilizers is to promote a healthy soil environment along with supplying essential nutrients to the plant. Again, biofertilizers can be tailor-made according to the specific plant or the climatic conditions. Fungal and bacteria based biofertilizers, either alone or in combinations are formulated for the plants. Lately, liquid fertilizers are increasingly finding their use in the biofertilizer industry due to their ease in manufacture and prolonged effect on plant growth. The scope of this chapter lays on the currently popular biofertilizers and recent trends in the biofertilizer industry.

10.1 Introduction

The agriculture sector is also transforming through technological intervention and advancements drastically to improve several processes and crop and livestock production systems. These advancements have resulted in minimizing operation and production costs, reduction of environmental impact and optimization overall production cycle. The major issue in the agriculture sector is human-intensive operation and non-availability of sufficient labor on time. The on-field task like fruit harvesting, intra-row weed control which is supposed to be more difficult to perform by the traditional machinery and manually. This has made to think to introduce the autonomous tractors and robotics platform in field operation. Timely activities and treatment play an important role in agriculture and agriculture production. The farmers generally face many problems in performing the task on the field due to various limitations. The cost is one of the main parameters which need to keep the farmer in a competitive market and reduce the cost of operation as low as possible. Also, the growing population demand more and more food which put pressure on the agriculture sector to raise crop production. In this situation, agriculture robots can play an important role to address the challenges in the farms. A robot can professionally perform the task and can automate the tasks which are difficult for manual labor. These are used in the agricultural lands and they are also completely autonomous. These robots are used in several applications in agriculture and can also work autonomously.

The robotic system has been widely used in industrial production and warehouses in an almost controlled environment. In the early 1960s, the agriculture and forestry sector initiated research into driverless vehicles with a focus on automatic steered system and autonomous tractors. Robotics has made an impact on agriculture and forestry since past few years. The purpose of minimizing the damage to the growing zone of soil tends to cater to the application of automatic vehicle guidance. The interest in the development of robotics system in agriculture has led many experts to explore the possibilities to develop more rational and adaptable vehicles based on a behavioural approach.

9.1 Introduction

The increase in world’s population and respective food demand has brought the global concern. The climate change alone has put a tremendous burden on the farming communities, and has become the major challenge to feed the burgeoning population. It has been estimated that by the end of the year 2050, the global population will be around 10 billion, meanwhile, the food demand will also be increased by 70-100 %. The traditional method of agricultural practices are not sufficient enough to meet the rising food demand. Therefore, to meet the increasing food demand, agriculture is intensified by the use of chemical fertilizer, pesticides, herbicides, which deteriorat the soil health. Thus, new automated/ mechanised systems have been introduced into the agriculture sector to ensure precision farming. These systems are quick in action, and satisfing the requirements along with generation of billions of employment worldwide. In a developing country like India, 65-70 per cent of the total population resides in rural areas, of which, most of the households are dependent on agriculture. The agriculture sector in India accounts for 18 per cent of the country’s GDP, and provide employment to 50 per cent of the total work force. The agriculture sector is one of the most sensitive sectors of Indian economy which supports all other sectors, and spreading its benefit to the far-reaching areas. Therefore, it becomes important for the developing country like India to develop agriculture sector to boost-up the rural economy.

With the advent of technology, a rapid transformation has been occurred in various industries, while agriculture remains the least digitized. Though, the application of aircraft/ drones in agriculture for fertilizer/ pesticides applications, image capturing, access to real-time quality data has adopted in some developed countries like Australia, USA, Japan, and some of the European countries. Moreover, these unmanned aerial vehicles could provide data of soil health, monitor crop health, assist in irrigation scheduling, yield estimation, and weather data analysis too. However, such development in agriculture is still lacking in developing countries. The agriculture development in the modern era could be done by taking the biological information and agricultural knowledge through integration of modern agriculture information technology with traditional agricultural practices. These knowledge integrations with mobile internet, cloud computing, and machine learning could enable to control the agricultural production system over stressed climate condition easily. Thus, Artificial Intelligence (AI), which is a sort of machine intelligence, an inbuilt set of programme and algorithms similar to the human brain in the current world is gaining more attention in agricultural application for precision farming.

8.1 Introduction

In the modern world, the most elementary desire of every common man is to have sufficient food and mental peace. With the increasing world population, pressure on both peace and availability of food are continuously increasing. Advancing agricultural research can explore a possibility to feed to all living beings. Agricultural crops are highly susceptible to climatic conditions and crop productivity which are mainly influenced by extreme weather conditions; including temperature and water availability. In open field conditions, during long dry weather condition, soil moisture reduces and increases the transpiration.

Plants are very important to all forms of life on the earth because they consume carbon dioxide from the atmosphere and produce oxygen. In addition, plants make up the base of the food web. Basically, plants need five things in order to grow and these are: sunlight, proper temperature, moisture, air and nutrients. These five things should be provided by the natural or artificial environments where the plants live. If any of these elements are missing, they can limit plant growth. If any environmental factor is less than ideal, it limits the plant›s growth. People began putting plants indoor to avoid the damage from cold weather and this practice led to development of greenhouse. With the improvement in living standard and upgradation in agricultural technologies, off seasoned cultivation is also possible by providing desired artificial environmental conditions. The environmental stress weakens a plant and makes it more susceptible to disease or insect attack. In the modern engineering era, plant production systems have become more sophisticated. The desired climatic condition to grow plants and its control have changed from manual to automated digital operations and control computers have become faster and more capable.

Environmental control techniques are essential for protected cultivation and are not only for greenhouse’s cultivation but are also applicable to tissue culture and space farming as well. Environmental control in the present protected crop cultivation practices has been profusely supported by computer and sensor developments which is sometimes aslo called controlled environment agriculture.

7.1 Introduction

Agriculture is the backbone of Indian economy and almost 70 per cent of the total population depends on it. After independence, India achieved self-sufficiency in primary agriculture like food grains, fruits, vegetables and milk, etc. Now it is time to think and focus on secondary agriculture. It is assumed that with the adaption of secondary agriculture, India can achieve the goal of doubling the income of farmers. The secondary agriculture can be defined as, value addition to agricultural products, generating basic facilities for primary processing and add value to the basic agro commodities to allow farmers to get better revenues from their farm produce. It also has job creation opportunity in the rural sector to grow rural economy, which is purely based on agriculture. Further, it can also be elaborated that secondary agriculture as a production activity and invented strategy which includes sustainability of production, monetisation of farmer’s produce, straightening of extension service and recognising agriculture as an enterprise. Secondary agriculture can help drive growth of primary agriculture in the three areas i.e. (i) value addition to primary agriculture production, (ii) farmer – industrial linked and (iii) effective utilization of crop residues of primary agriculture.

The value addition to a primary agriculture production can be achieved by establishing direct linkage of farmers with market through grading of agricultural produce, cluster farming, marketing skill and financial literacy. The farmer – industrial linkage is closely associated with rural off-farm activities such as bee keeping, livestock production, etc. it can be promoted as a part of an integrated farming system. The crop residues effectively can be utilized for energy generation. There is scope of establishing rural based agricultural entrepreneurship in the field of biofuel. Agribusiness incubation can help farming community and provide reliable market linkages to improve farmer’s realisations.

6.1 Introduction

Aquaponics represents the relationship between water, aquatic life, bacteria, nutrient dynamics and plants, which grow together in waterways all over the world. Taking cues from nature, aquaponics harnesses the power of bio-integrating these individual components: exchanging the waste by-product from the fish as a food for the bacteria, to be converted into a perfect fertilizer for the plants, to return the water in a clean and safe form to the fish. Just like mother nature does in every aquatic ecosystem.

Aquaponics is basically a combination of aquaculture and hydroponics plant production in a close-loop water system where both vegetables and fish grow simultaneously. This is a closed-loop system and considered as highly efficient, produce more food compared to the traditional farming system. Importantly, it has virtually no waste and with double purpose, aquaponics farming might be an economical viable solution to the low provision of fish and vegetable in some countries. In many cases, aquaponics is advertised as a form of sustainable agriculture because it is water efficient, and has fewer environmental impacts than some forms of aquaculture. That is why, aquaponics is considered as super sustainable and highly efficient because of the healthy symbiotic relationships among the plants, fish and nitrogen-fixing bacteria as illustrated in Fig 6.1. As fish excrete into the water, the water is then pumped up to the plant beds, and bacteria break down the fish excrement so the plants can absorb it.

Aquaponics farming is quite different than hydroponics farming. As discussed in previous chapter, hydroponics is the process of growing plants in a soilless medium where nutrients are added to the water for the plants to absorb. Such systems are not as sustainable and viable as aquaponics because they require the addition of other supplemental nutrients to get desired plants growth. The quality of water decline with time and require proper disposal otherwise, it will contaminate water streams and other water sources. On the other hand, aquaponics incorporates fish to provide the natural fertilizers and nutrients plants need. This simple addition, eliminates the need to add “food” for plants. Best of all, aquaponics has a built in self-cleaning and filtration system that returns clean water to the fish. Aquaponics farming system can be more productive and economically feasible where land and water are limited. No doubt, aquaponics is complicated and requires considerable start-up costs. The production of fish and vegetables is the most visible output of aquaponics farming units. It is essential to understand that aquaponics is the management of a complete ecosystem that includes three major groups of organisms: fish, plants and bacteria.

5.1 Introduction

Hydroponics is a method of growing plants in a nutrient solution rather than in soil. Terrestrial plants may be grown with only their roots exposed to the nutritious liquid.

Traditionally, the soil supports the crop’s roots by helping them remain upright and ensuring the delivery of water and essential nutrients. In hydroponics farming, crops are supported by an inert medium such as perlite, gravel, or other substrates. Therefore, the nutrients are supplied by using various practices that bring mineral nutrient solutions to the crops. In the present situation there excessive use of chemical fertilizers, affecting fertility of soil is badly affected. The fertility of the soil is falling that affects the plants growth but in hydroponics, the plant remains unaffected. Plants grow faster than in soil. Produce better quality of plants and higher yields. It use less water. It is possible to use hydroponics on outdoor crops, but most of the hydroponics production is in greenhouse. Hydroponic farming system has the potential to reduce the problem associated with traditional crop production. Therefore, it could serve to be a turning point in feeding the global population. The greenhouse and its environment control system are the same whether plants are grown conventionally or with hydroponics. The difference comes from the support system and the method of supplying water and nutrients.

The hydroponic farming has been successfully demonstrated by the commercial growers for fast-growing crops such as tomatoes, cucumbers, spinaches, lettuce, radishes, strawberries, bens, spring onions, coriander, and ornamentals. Indeed, hydroponics technology enables a more precise control of micro climatic conditions. In this technique, the vigorous development of a root system is taking place, which enable the uptake of essential nutrients from nutrient solution for better crop yield. The initial investment in hydroponics farming is high and required constant energy input. Owing to this, hydroponics farming is recommended for growing high value crops in developed countries such as the United States, Canada, Europe and Japan.

4.1 Introduction

In the modern era, agricultural productivity seems to have reached a maximum production due to the easy availability of fertilizers and pesticides/insecticide, which are used to improve crop productivity. Excess uses of these products and unawareness about field constraints can decrease the crop productivity and endanger the environmental balance in the cultivation area. Therefore, there is an urgent need to improve agricultural system and efficient utilization of these resources for profitable and environmentally sustainable agriculture.

Government has also an emphasis on effective and efficient use of available resources and farmers are also adopting more scientific approach during crop production such as remote sensing, global positioning system, and new equipment to make their agricultural operation more precise.

Precision agriculture is one of the many advanced farming approaches that make production more efficient. It is basically an approach of farm management with the help of information technology to confirm that the cultivated crops and soil receive desire input for optimum health and productivity. In other words, precision agriculture utilizes different tools and technologies to identify infield soil and crop variability for improving farming practices and optimizing agronomic inputs. To reduce dependency on excessive use of chemical inputs in agriculture, several technologies have been applied to make agricultural products safer and to lower their adverse impacts on the environment and human beings, a goal that is consistent with sustainable agriculture. Precision agriculture has emerged as a valuable component of the framework to achieve this goal. Further, Pierce and Nowak define the precision farming that, the application of technologies and principles to manage spatial and temporal variability associated with all aspects of agricultural production for improving crop performance and environmental quality. Precision agriculture is the combination of many different elements working together in a synchronised way with the help of Geographic Information System (GIS) as shown in Fig 4.1. Precision agriculture is basically an information technology based agricultural management system. In this modern management system, Geography information system (GIS) based analysis is extensively used to get land and crop related data accurately and timely, which help farming community to take correct decision .

3.1 Introduction

The world population will grow by another 2 billion people by 2025 and feeding them will be a big challenge. Rapid industrial development and fast urbanization, the arable lands are continuously shrinking. Many scientists and researchers reported that the Earth had lost a third of its arable lands over the last 40 years¹. In the current scenario, the most challenging task for agricultural sciences is to ensure for continuous and enough supply of food to growing human civilization. Presently, all available arable land on the earth are using extensive pesticides and fertilizers in various ways that are not sustainable as well as harmful to the environment.

There is an urgent need to think about sustainable farming options as arable land for farming is continuously reducing to fulfil the food material demand of growing population. Vertical farming can produce more food from fewer land and water resources. Though it takes out many of the risks inherent in outdoor crop production. With the control of light exposure, indoor temperature, relative humidity and watering levels, growers can grow food very efficiently. Vertical farming has the potential to produce food with less energy, less water, less waste and in less space than traditional methods. It also negates the need for harmful chemical fertilizers and pesticides. Developing and installing vertical farm in those areas where people need good quality healthy food, tackle the shortage of nutritive food material at a local level. Vertical farming can be defined as it is the practice of growing crops in vertically stacked layers where controlled-environment agriculture practices usually incorporated with the aims to optimize plant growth. The soilless farming techniques such as hydroponics, aquaponics, and aeroponics also incorporated in vertical farming as shown in Fig. 3.1. Vertical farming is a very old idea, and indigenous peoples used vertically layered growing techniques like the rice terraces of East Asia. The term vertical farming was coined by American geologist Gilbert Ellis Bailey in 1915. In 1999, Dickson Despommier, a professor at New York’s Columbia University, popularized the modern idea of vertical farming, building upon the idea together with his students.

2.1 Introduction

The great impact of increase in population as well as rapid economic growth has given us cause for concern about the future situation of the earth in recent years. Desertification as well as deforestation is continuously changing the landscape. Irrigated areas are being damaged by salinization. The effect to increase arable lands cannot match with the speed of these deteriorating processes. Weather is also being changed gradually by urbanization. In the new millennium, the challenges in the agricultural sector are very different from those met in the previous decades. The enormous pressure to produce more food from less land with shrinking natural resources is a tough task for the farmers. This calls for special effort to manage the key input without eroding the ecological assets and sound knowledge base to sustain agricultural productivity and profitability.

The maximum crop response depends on the level of the balanced environmental parameters. The natural environment and input availability may not be optimum for a given crop. The environmental factors which affect plant growth includes air temperature, relative humidity, carbon dioxide concentration soil temperature and moisture content to the soil. The micro-climate can be artificially controlled by means of plastic covering structure like greenhouse. The plastic covered greenhouse is the only mechanism, which transmits the useful wavelengths of the light spectrum for photosynthetic activity. Further, it also reduces the air movement, which is of great importance for the plant growth and often used to control the spread of plant diseases.

As far as plant propagation is concerned sunlight provides the primary energy for photosynthesis, the food chain and all human nutrition. The expansion of crop and flower production in various types of greenhouse during the recent years has enabled the growth of agricultural products throughout the year. An agricultural greenhouse consists of frames of metallic or wooden structure covered with a transparent material preferably plastic which provide a suitable environment for the intensive production of various crops. A greenhouse is essentially an enclosed structure, which traps the short wavelength solar radiation and convert and finally stores the long wavelength thermal radiation to create a favorable microclimate for higher productivity. Open field agricultural farming has no control on the environmental parameters such as sunlight, air composition and temperature that influence the plant escalation. Hence, a large number of winter vegetables, flowers and other horticultural crops have to be transported from distant places. Future greenhouse systems in moderate climates will have to be energy efficient. Greenhouses will have decreased transmission for long-wave length radiation and increased transmission for short-wave-radiation compared with common shelters.

1.1 General

Food is basic necessity for the survival of human beings. It is derived from agriculture which traps and transfers solar energy in chemical energy in the form of biomass and end products are processed and utilized for food, feed, fibre, fertilizer, and fuel. Indian’s economic security continues to be foreseen upon agricultural sector. Agriculture supports 52 per cent of population, as against about 75 per cent at the time of dependence. Despite the focus on industrialization, agriculture remains a dominant sector of the Indian economy both in terms of contribution to Gross Domestic Product (GDP) as well as a source of employment to millions across the country. India occupies a leading position in global trade of agricultural products. However, its total agricultural export basket accounts for a little over 2.15 per cent of the world agricultural trade. The major export destinations are USA, Saudi Arabia, Iran, Nepal and Bangladesh. Among agricultural commodities, basmati rice, spices, oil meals, sugar, cotton and castor oil have been leading export commodities.

Agriculture is an essential ingredient in overall development of India economic. The history of Indian agriculture in dates back to Indus Valley Civilization and even before that in some places of Southern India. India ranks second worldwide in farm outputs.

On the eve of Independence, 70 per cent of India’s nation income was from agricultural sector. Before 1947, over 85 per cent of country’s population lives in villages where livelihood completely depended on agriculture, which contributed over 95per cent of country’s income. Agricultural sector was most important sector in Indian economy facing massive stagnation and continuous determination. In the present context, around 60 – 70 per cent of Indian population directly or indirectly depends upon the agricultural sector and currently it contributes to 16 per cent of the Indian gross domestic product.

Hazard Analysis Critical Control Points (HACCP) is an internationally recognized method of identifying and managing food safety related risk and, when central to an active food safety program, can provide customers, the public and regulatory agencies assurance that a food safety program is well managed. HACCP is a management system in which food safety is addressed through the analysis and control of biological, chemical, and physical hazards from raw material production, procurement and handling, to manufacturing, distribution and consumption of the finished product. (FAO, 2003)

Mycotoxin hazard analysis and identification of possible control measures

I. Hazard Analysis

a) Identification of mycotoxin hazard

For a given commodity system in a particular location, the HACCP team need to first consider which, if any, of the mycotoxins known to constitute a food safety hazard are likely to be present. Over 300 mycotoxins are known, but only a relatively few of these are widely accepted as presenting a significant food or animal feed safety risk.

The following mycotoxins have regulatory limits set by one or more countries: the aflatoxins (including aflatoxin M₁), ochratoxin A, zearalenone, patulin, ergot alkaloids, and deoxynivalenol. Guideline limits exist for fumonisin B₁ and regulatory limits are likely to be set in the near future. The regulatory limits are taken as the target levels and should be included in the Product Description table. Mycotoxin limits can also be set by the customer in specific contracts and it is possible that these may include mycotoxins not subject to regulatory limits.

The economic loss in livestock arising due to mycotoxicosis is enormous apart from being a health risk. Indian economy is heavily affected by mycotoxins. It was estimated that 10 million dollars were lost in India’s export within a decade due to groundnut contamination with mycotoxins (Vasanthi and Bhat, 1998). Many developing countries have realized that reducing mycotoxin contamination in foods will not only improve the health and production in animal, but also increase the raw material exports (international trade) to other countries. The following strategies are to be adhered strictly to reduce the mycotoxins contamination of crops in the field.

1. Early harvesting

Early harvesting reduces the fungal infection of crop in the field. Early harvesting and threshing of groundnuts results in lower aflatoxin levels and higher gross returns of 27% than in delayed harvesting (Rachaputi et al., 2002).

Mycotoxins are toxic secondary metabolites produced by different types of moulds which are present in soil, plant and feed ingredients. Ingestion of toxins will result in reduced growth and production performance due to reduced nutrient utilization, illness or death of animals. Analysing the presence of mycotoxin and its concentration in grain and feeds is necessary to eliminate the adverse health effects of mycotoxins in animals. Estimation of mycotoxin in feed ingredients is a challenging task because the concentration of toxin is at µg/kg or parts-per billion levels. At the same time, analysing inappropriate samples is a waste of resources. Mycotoxins are not evenly distributed in feeds or grains. If the specimen collected for analysis includes contaminated grain, the mycotoxin will be detected. If not, the mycotoxin will not be detected.

Sample collection for mycotoxin analysis

The objective of sample collection is to collect the specimen samples from as many parts of the feed lot as possible. The size of the collected specimen depends on the size of the load received. Sample collecting probes can be used to collect the samples from bags.

Different type of mycotoxins commonly present in different feed and fodder crops are produced by mould during cultivation and storage and are specific to certain region according to climatic and environmental conditions. Most of the toxins produced in crops are consumed when fed to animals. Among the mycotoxins, aflatoxin B-1 is present in highest concentration which enters rumen following ingestion of aflatoxin contaminated feed stuffs. In the rumen, AFB-1 is degraded into aflatoxicol and the remaining portion of the aflatoxin is absorbed in the digestive tract by passive diffusion and metabolized in the liver into aflatoxin M-1 (Kuilman et al., 1998). AFM-1 circulates in the blood as a stable compound until excreted in milk, urine and bile. The following are the sources of AFM-1 contamination in milk and milk products and it occurs through two modes of contamination viz., indirect contamination and direct contamination.

Mould growth in raw materials or finished feeds result in production of mycotoxins. Mycotoxins are a large group of toxic chemicals causing wide range of pathological and physiological effects in animals. Symptoms depend on the amount of toxin present in the feed, the period for which the feed is ingested, the nutritional status of the feed and the susceptibility of the animal. Feed efficiency, growth rate and production are affected in animals consuming sub-acute doses.

Ruminants are generally considered less susceptible to mycotoxins than monogastric animals because of degradation of mycotoxin in rumen by rumen microorganism. However, certain mycotoxins resist rumen degradation and cause clinical mycotoxicosis. In high yielding dairy animals, during transition period, animals who are in negative energy balance (NEB), low body condition score and decreased resistance to infectious agents cause adverse effects in animal health with exposure of mycotoxins present in animal diet.

Effect of mycotoxin in ruminants

In cattle during metabolism, mycotoxin present in stored or ensiled feeds produce microbial volatile organic compounds (MVOCs) which are responsible for mouldy odour, reduced feed intake and increased feeding times. This insufficient feed intake further produces negative energy balance (NEB).

The ingestion of mycotoxin-contaminated feedstuffs by animals leads to adverse effect on animal health and the effects are more serious in monogastric animals depending on the species and the susceptibility to toxins within the species. Ruminants are less susceptible to mycotoxins than monogastric animals because of biotransformation of mycotoxins to non-toxic metabolites in rumen by rumen microbiota (Fink-Gremmels, 2008).

Various physical, chemical and biological factors interdependently affect the fungal colonization or production of the mycotoxin. Physical factors such as temperature, relative humidity and insect infestations create ideal environment for fungal colonization and mycotoxin production. Stresses such as drought, an increase in temperature, and an increase in relative humidity may selectively alter colonization and metabolism of mycotoxigenic fungi and thus alter mycotoxin production (Russell et al., 1991). Cool and damp weather favours the germination of the sclerotia and thus ergot alkaloid formation in fescue and ryegrass.

Biological factors are categorized into intrinsic factor such as fungal species, strain specificity, strain variation and instability of toxigenic properties. Interaction between the toxigenic fungal species and substrate affect the fungal colonization and mycotoxin production. Some plant species are more susceptible to colonization and some resistant plant species may also get infestation due to favourable environmental conditions.