Bioconversion of Organic Residues for Rural Communities (UNU, 1979): Nutritional evaluation of bioconversion products for farm animals: Introduction

Bioconversion of Organic Residues for Rural Communities (UNU, 1979)

From the charter of the United Nations University

Foreword

Perspectives on bioconversion of organic residues for rural communities

(introduction...)

Introduction

Sources of available nutrients

The most suitable materials for bioconversion

Characteristics of residues

Bioconversion systems

Physical and chemical treatments

Microbial conversion

The animal conversion phase

Summary

References

Availability of organic residues as a rural resource

(introduction...)

Discussion summary: Papers by van der Wal and Barreveld

Micro-organisms as tools for rural processing of organic residues

(introduction...)

Introduction

Microbial utilization of mono- and di-saccharide residues

Microbial conversion of starchy residues

Microbial conversion of complex mixtures of compounds (Polysaccharides, Proteins, Lipids, etc.)

Microbial utilization of cellulose and ligno-cellulose residues

Algal culture as a source of biomass

Microbial utilization of silviculture biomass

Micro-organisms and marine and freshwater biomass

International studies on processing organic residues

References

Production of feed as an objective for bioconversion systems

(introduction...)

Introduction

General characteristics

Manure as feed

Sewage-grown micro-algae

Conclusion

References

Environmental goals for microbial bioconversion in rural communities

(introduction...)

Introduction

Health and water economy

Fertilizer and energy economy

Concluding remarks

References

Discussion summary: Papers by Porter, Berk and La Rivière

Strategies for developing small-scale fermentation processes in developing countries

(introduction...)

References

Discussion summary

Production of microbial protein foods on edible substrates, food by-products, and ligno-cellulosic wastes

(introduction...)

Preface

Introduction

Contributions to the solution of nutritional problems

Development of protein-rich vegetarian meat substitutes in the western world

References

Discussion summary

The role of ruminants in the bioconversion of tropical byproducts and wastes into food and fuel

(introduction...)

Introduction

Nutritional limitations in the use of tropical by-products and waste

Practical experience with tropical by-products and wastes as feed for ruminants

An integrated system for converting tropical feeds and byproducts into milk, beef, and fuel

References

Discussion summary

Possible applications of enzyme technology in rural areas

(introduction...)

Introduction

Biocatalytic processes

Enzyme hydrolysis of manioc

Whole cell systems

Cellulose degradation and utilization

Transfer of enzyme technology to rural communities

Conclusions

References

Discussion summary

Indian experience with treated straw as feed

(introduction...)

Introduction

Experience with straw treatment

Field testing and demonstration of straw treatment

General considerations

Summary

Annex 1. The energy efficiency of the two-stage, feed-fuel processing of straw in indian villages

Annex 2. Method of calculating the value presented in table 2 for the efficiency of naoh energy usage

Annex 3. Recommendations to farmers on the treatment of straw

Annex 4. Calculated efficiency of milk production by straw-fed village buffaloes

References

Discussion summary

Indian experience with algal ponds

(introduction...)

Introduction

Cultivation of algae in wastes for feed

Problems of contamination

Cultivation of algae for biofertilizer

References

Acknowledgements

Discussion summary

Organic residues in aquaculture

(introduction...)

Introduction

The range of production in aquaculture

The value of organic wastes

Direct feeding

Concluding remarks

References

Discussion summary

Biogas generation: developments. Problems, and tasks - an overview

(introduction...)

Introduction

What is biogas?

Microbiology of CH4, or bio-methanogenesis

The biogas plant-some technical considerations

Environmental and operational considerations

Developments and processes for rural areas

Cost-benefit analyses

Health hazards

Bottlenecks, considerations, and research and development

References

Discussion summary

Mushroom production technology for rural development

(introduction...)

Materials and methods for growing mushrooms under natural or field conditions

Growing mushrooms under semicontrolled conditions

Results and discussion

References

Discussion summary

The combination of algal and anaerobic waste treatment in a bioregenerative farm system

(introduction...)

Introduction

Algae production on organic wastes

The bioregenerative farm

References

Discussion summary

A continuous composting system for disposal and utilization of animal wastes at the village level

(introduction...)

Status of land utilization and disposal of animal wastes

A continuous composting system for land utilization of animal wastes at the village level

References

Bioconversion of fruit and vegetable wastes

(introduction...)

State of the art of bioconversion

Technical transfer

Integrated research on agricultural waste reclamation

(introduction...)

Introduction

Production of yeast from soybean cooking waste at miso factories

Application of soy waste as koji substrate for rice miso manufacturing (5, 6)

Conclusion

References

Discussion summary

Solid state fermentation of starchy substrates

(introduction...)

Introduction

Materials and methods

Agro-economic perspectives

Summary

References

Discussion summary

Production of single-cell protein from cellulose

(introduction...)

Introduction

Experimental results

Discussion

Summary

References

Acknowledgements

Discussion summary

Analysis of energy cost of integrated systems

(introduction...)

Energy cost and energy requirement

Why energy analysis?

Net energy intensity

What criteria are offered by energy analysis?

Conclusion

References

Analysis of bioconversion systems at the village level

(introduction...)

Introduction

Approach to bioconversion analysis

Some results and costs from integrated systems

Future development possibilities

Conclusions

Summary

References

Nutritional evaluation of bioconversion products for farm animals

(introduction...)

Introduction

Testing procedures for determination of nutritional value

Bioconversion products: toxicology - problems and potential

(introduction...)

Summary

References

Nutritional evaluation in humans

(introduction...)

Introduction

Evaluation of products of bioconversion for human consumption

Procedures for nutritional evaluation in humans

The evaluation of various food products

Concept of productivity

Conclusions

References

Discussion summary: Papers by van Weerden, Shacklady, and Bressani

Biomass from organic residues for animal and human feeding

(introduction...)

References

Discussion summary

Appropriate biotechnology - summary remarks

(introduction...)

References

Other UNU Publications

(introduction...)

Books

Introduction

Micro-organisms such as yeast, bacteria, fungi, or algae are the single-cell proteins used for most bioconversion of wastes or other substrates to make food or feed. A crucial question is: What is the nutritional value for man or animals of the final product of the bioconversion process? A second important aspect is the toxicological status of the product. This is the subject of papers by Scrimshaw and Shacklady appearing elsewhere in these proceedings, and my presentation is based on the assumption that the materials are acceptable toxicologically. I will consider some points that must be taken into account when evaluating a bioconversion product for animal feeding.

The main reasons for using micro-organisms in the conversion of agricultural residues are: First, to degrade that part of the residue that is not available for absorption by animals or man when the material is fed as such. In most cases this means that the enzymes secreted in the animal or human gastro-intestinal tract cannot, or are insufficiently able to, break down the material into components that can be absorbed. This pertains to cellulosic, hemicellulosic, and ligno-cellulosic components. The second purpose is to upgrade the nutritional quality of the residue by increasing its protein content, or, for monogastric animals and man, raising its content of essential amino acids.

Of the four categories of micro-organisms involved in bioconversion processes (yeasts, bacteria, fungi, and algae), a considerable amount of information is available about the nutritional value of yeasts. Species of yeast have been used for many years as a valuable component of animal feeds, supplying proteins and certain vitamins. In addition, some of the large-scale industrial SCP processes developed over the past ten years use yeasts that utilize hydrocarbons (i.e., paraffins) as an energy source and carbon and hydrogen for growth and synthesis of cell constituents. The results of extensive evaluation programmes show that these yeasts form a highly valuable source of protein for monogastric animals.

The second category of SCP, the bacteria, have, for many centuries, contributed to food supplies for man in an indirect manner: the protein supply of the ruminant is largely dependent on the bacteria and protozoa abundantly present in the fore-stomach of the animal, which forms, in principle, a large in vivo fermentation vessel.

Bacteria will be used in several large units being constructed for industrial protein production where methane or methanol will provide the energy. The data available show that bacterial material produced in this way also forms a highly valuable protein source.

The last two categories of SCP, the fungi and algae, have until now not been used to any extent in animal feeding, and this is why very little is known about the nutritional value of these products. The scarce data in the literature show variable results and indicate that, for monogastric animals, digestibility may be a problem. ILOB experiments with a fungal product showed reasonable results for digestibility and growth performance in pigs, but the results in poultry were unsatisfactory. Because fungi and algae will most likely be the microorganisms of choice for the small-scale bioconversion units considered in this work shop, a thorough look at the nutritional value of the material produced is essential. I would especially stress the necessity of testing nutritional value at an early stage of process development in order to be able to provide some sort of guidance for that development, for example, the choice of the micro-organism or the relevance of including a special treatment, if possible.