FAO ANIMAL PRODUCTION AND HEALTH PAPER   18

feed from animal wastes: state of knowledge Table of contents

by
z. o. müller

The designations employed and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries.

M-23
ISBN 92-5-100946-5

The copyright in this book is vested in the Food and Agriculture Organization of the United Nations. The book may not be reproduced, in whole or in part, by any method or process, without written permission from the copyright holder. Applications for such permission, with a statement of the purpose and extent of the reproduction desired, should be addressed to the Director, Publications Division, Food and Agriculture Organization of the United Nations, Via delle Terme di Caracalla, 00100 Rome, Italy.

ABSTRACT

This study describes the potential of nutrient recovery from animal wastes in integrated animal feeding systems. The philosophy behind feeding processed animal wastes is based on the fact that coprophagy within the same or other animal species has always existed in nature. The nutritive value of individual animal wastes, with and without various bedding materials, is described in detail.

Individual classes of livestock, levels of nutrition, housing, management, environment and other factors that play a significant role in the chemical and nutritive value of animal wastes are examined.

Health hazards and safety considerations are discussed in the light of the presence of accumulations of minerals, antimicrobial drugs, pesticides, mycotoxins and hormonal residues, the danger of disease transmission, and problems associated with other xenobiotics that may affect the performance and health of animals fed waste-based rations. The human consumption of products derived from waste-fed animals is also envisaged from the health and safety standpoint.

Numerous processing methods, technologies and systems (including dehydration, ensilling, chemical and mechanical treatments, composting, biodegradation via insect and earthworm cultures, and other complex recycling systems) are described and evaluated with respect to their development status, reliability, applicability and other considerations.

Industrial processes involving the conversion of animal wastes into protein biomass by aerobic, anaerobic, thermophilic and other processes are described briefly. A separate chapter is devoted to the photosynthetic recovery of nutrients by higher and lower plants (water hyacinth, Lemnacae, algae and others).

The most recent results of feeding cattle waste to livestock are presented. Recent advances in feeding pig waste to pigs and other livestock species are documented. The latest developments in feeding animal wastes to fish are described briefly in terms of their integration with other livestock activities.

Circularly-integrated feeding systems involving a closed cycle with zero pollution discharge are evaluated in economic terms and illustrated graphically.

ACKNOWLEDGEMENTS

The author is greatly indebted to all those individuals and organizations who assisted him during the course of the collection of research findings, results from practical application and other data necessary for the completion of this report. He particularly thanks Prof. W.B. Anthony of Auburn University, Auburn, Ohio, USA; Prof. J.P. Fontenot and the most excellent research team (J. Berger, J. Duque, J. Gerken, W.D. Lamm, E.T. Kornegay, K.E. Webb and others) of the Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA; Prof. A. Henning of the University of Jena, GDR; Dr. G.R. Pearce of the University of Melbourne, Australia; Dr. L. W. Smith of the United States Department of Agriculture, Washington, D.C., USA; Dr. J.C. Taylor of the Food and Drug Administraton, Washington, D.C., USA; Prof. R.L. Vetter of the lowa State University, Ames, lowa, USA; and Associate Prof. T.W. Westing, California State Polytechnic University, Pomona, California, USA.

Sincere gratitude is also expressed to government officials, university scholars, scientists and others, too numerous to mention, who provided much necessary data and information.

Last but not least, gratitude is expressed to my secretary, Mrs. Rosy Chin, for typing and processing this report.

FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS
Rome © FAO 1980

Hyperlinks to non-FAO Internet sites do not imply any official endorsement of or responsibility for the opinions, ideas, data or products presented at these locations, or guarantee the validity of the information provided. The sole purpose of links to non-FAO sites is to indicate further information available on related topics.

TABLE OF CONTENTS

ABSTRACT
ACKNOWLEDGEMENTS
TABLE OF CONTENTS
LIST OF TABLES
LIST OF FIGURES

INTRODUCTION

Chapter I NUTRIENTS IN LIVESTOCK WASTES

1.0 General
1.1 Poultry-house Litter

1.1.1 Bedding material
1.1.2 Broiler litter
1.1.3 Replacement bird litter
1.1.4 Laying house litter

1.2 Poultry-battery Manure
1.3 Cattle Manure

1.3.1 Cattle litter
1.3.2 Feedlot manure

1.4 Pig Waste

Chapter 2 FEEDING ANIMAL WASTES

2.0 General
2.1 Feeding Poultry Waste to Cattle

2.1.1 Energy-rich wastes as potential counterpart ingredients of poultry waste
2.1.2 Pineapple cannery waste/poultry waste cattle project
2.1.3 Advantages of poultry litter ensiling with forage
2.1.4 Feeding to beef cattle

2.1.4.1 Feeding broiler litter
2.1.4.2 Broiler litter for winter feeding of beef cows
2.1.4.3 Feeding litter from replacement birds
2.1.4.4 Feeding layer litter
2.1.4.5 Feeding turkey litter
2.1.4.6 Feeding poultry manure
2.1.4.7 Effect of feeding poultry waste on carcass quality
2.1.4.8 Concluding remarks on the feeding of poultry wastes to beef cattle

2.1.5 Feeding to dairy cattle

2.1.5.1 Feeding poultry litter
2.1.5.2 Feeding poultry manure

2.2 Feeding Poultry Waste to Sheep
2.3 Feeding Poultry Waste to Pigs
2.4 Feeding Poultry Waste to Poultry

2.4.1 Refeeding layer manure to layers
2.4.2 Feeding poultry waste to other classes of poultry
2.4.3 Feeding poultry manure to turkey breeders

2.5 Feeding Cattle Waste

2.5.1 Feeding cattle manure to cattle
2.5.2 Feeding cattle manure to pigs
2.5.3 Feeding cattle manure to poultry

2.6 Feeding Pig Waste
2.7 Feeding Animal Wastes to Fish

Chapter 3 HEALTH HAZARDS AND SAFETY CONSIDERATIONS

3.0 General
3.1 Accumulation of Minerals
3.2 Antimicrobial Drugs
3.3 Pesticides
3.4 Mycotoxins
3.5 Hormone Residues
3.6 Disease Transmission

Chapter 4 PROCESSING METHODS

4.1 Dehydration

4.1.1 Mechanical drying
4.1.2 In-house drying
4.1.3 Solar drying

4.2 Ensiling
4.3 Processing of Litter by Stacking
4.4 Chemical Treatments
4.5 Mechanical Treatments
4.6 Oxidation Ditch
4.7 Activated Sludge
4.8 Compost for Feeding
4.9 Insect Cultures
4.10 Earthworms and Beetles

Chapter 5 COMMERCIAL RECYCLING PROCESSES

5.1 The Feed Recycle Process
5.2 Biochemical Recycle Process
5.3 The Cereco Process
5.4 The Corral System
5.5 Kaplan's “Closed-loop” Cycle
5.6 The “Closed Ecological Cycle”
5.7 The Chemical Extraction Process
5.8 The Midwest Process
5.9 The Grazon Process
5.10 The Organiform Process
5.11 Poultry Waste Processing Systems

Chapter 6 CONVERSION OF MANURE INTO PROTEIN BIOMASS BY FERMENTATION

6.0 General
6.1 Aerobic Fermentation Processes
6.2 Anaerobic Fermentation Processes
6.3 Thermophilic Process
6.4 Fungi and Moulds

Chapter 7 PHOTOSYNTHETIC RECLAMATION OF NUTRIENTS FROM ANIMAL WASTES

7.0 General
7.1 Water hyacinth and other higher plants
7.2 Lemnacae
7.3 Algae
7.4 Algae + Bacterial Biomass

Chapter 8 CIRCULARLY INTEGRATED FARMS UTILIZING ANIMAL WASTES

REFERENCES

LIST OF TABLES

Table 1 Animal wastes: Estimated recovery value by various modes of conversion
Table 2 Animal wastes: Total collectable
Table 3 Estimated production of crude protein and TDN from collectable faecal waste of livestock
Table 4 Animal wastes: Collectable TDN
Table 5 Estimated annual production of nutrients in various animal wastes
Table 6 Animal wastes: Structural carbohydrates and other critical nutrients
Table 7 Distribution of nitrogen in faeces and urine
Table 8 Animal wastes: Mean cattle feed energy values
Table 9 Animal wastes: Mean calcium and phosphorus content
Table 10 Poultry litter from broilers, replacement birds and layers: Nutritive and economic value
Table 11 Properties of bedding materials
Table 12 Broiler mortality: Effect of new and old litter
Table 13 Effect of bedding material upon nutritive value of deep litter for cattle
Table 14 Influence of quantity of bedding material on content of nutrients in deep litter
Table 15 Influnce of lime supplement to bedding material upon nitrogen losses
Table 16 Effect of phosphate supplementation on the feeding value of broiler litter
Table 17 Mineral elements in deep litter based on different bedding materials
Table 18 Effect of bedding material on vitamin content of litter
Table 19 Tocopherol isomers in broiler feed and deep litter
Table 20 Effect of bedding material on chlortetracycline level in deep litter
Table 21 Broiler litter: Nutrient composition
Table 22 Composition of litter from replacement birds
Table 23 Quantity of hen manure produced by various breeds
Table 24 Estimated losses of organic matter and other critical nutrients in poultry manure during storage
Table 25 Ammonia content of composite hen excreta samples
Table 26 Dried layer waste (DLW): Amino acid composition
Table 27 Manure composition of cows fed different diets
Table 28 Cattle manure: Nitrogen components
Table 29 Influence of diet on digestibility and composition of excreta
Table 30 Cattle manure and its separated fractions: Chemical composition
Table 31 Cattle litter: Chemical composition
Table 32 Feedlot wastes: Composition
Table 33 Pig waste: Effect of weight category on quantity
Table 34 Pig faeces: Composition
Table 35 Pig feed and faeces: Composition
Table 36 Pig faeces: Amino acid composition
Table 37 Effect of continuous closed recycling of manure on digestibility and manure production
Table 38 Estimated production of poultry waste
Table 39 Broiler litter contribution to protein requirements of beef cattle
Table 40 Combination of poultry wastes with fruit/vegetable wastes for ruminant rations
Table 41 Cattle formulas based on pineapple pulps and poultry waste
Table 42 Summary of experiments with feeding poultry litter to beef cattle
Table 43 Effect of feeding broiler litter on performance of finishing steers
Table 44 Beef cows: Calving performance
Table 45 Cattle fed on poultry wastes: Carcass quality
Table 46 Contribution of protein and energy from poultry litter fed to dairy cows
Table 47 Summary of feeding broiler litter to dairy cows
Table 48 Dairy cow feeds: Poultry waste/cassava-based silages
Table 49 Dairy cow feeding: Complete formulas based on poultry waste/cassava silage
Table 50 Contribution of protein and energy from poultry manures fed to dairy cows
Table 51 Milk production of cows fed rations containing DPE
Table 52 Results of ewes fed on 63% poultry litter
Table 53 Performance of wethers fed poultry litter
Table 54 Effects of feeding broiler litter to ewes
Table 55 Performance of lambs fed different protein sources
Table 56 Layer manure contribution to feed cost and profit of growing pigs
Table 57 Performance of young sows on rations containing litter of different bedding origins
Table 58 Performance of layers on various rations
Table 59 Recycled DLM: Influence on egg production, feed efficiency and total mortality
Table 60 Proximate analyses of manure from hens fed their own manure
Table 61 Utilization of DPM to feed growing chicks and broilers
Table 62 Performance of turkey breeder hens fed DLM
Table 63 Feedlot manure: Heifer feeding trial results
Table 64 Feeding dairy and beef manure to pigs
Table 65 Feeding cattle manure to layers
Table 66 Recycling cattle waste to poultry
Table 67 Refeeding pig manure
Table 68 Digestibility for lambs of nutrients in dried pig faeces
Table 69 Feeding dried pig faeces to finishing bulls
Table 70 Pig manure hay silages: Fermentation characteristics
Table 71 Ensiled pig waste and ground maize grain fed to gilts: Apparent digestibility
Table 72 Recycling pig waste to cattle and pigs
Table 73 Growth of fish in manured ponds
Table 74 Nutrient requirements of broilers and catfish, and nutrients in animal wastes
Table 75 Critical minerals: Dietary and faecal levels
Table 76 Mineral profiles in liver from steers fed broiler litter and beef feedlot waste
Table 77 Antimicrobial drugs in broiler litter
Table 78 Effect of feeding broiler litter on pesticide residues in steer liver and omental fat
Table 79 Poultry manure drying costs
Table 80 Commercial manure dryer capacity
Table 81 Effects of drying and fermentation methods on crude protein levels
Table 82 Effect of time on moisture content of manure on slats
Table 83 Animal wastes: Effect of ensiling on nitrogen composition
Table 84 Effect of moisture level on nutritional value and fermentation characteristics of ensiled litter
Table 85 Effect of moisture level on distribution of nitrogen in silages
Table 86 Ensiled broiler litter with maize forage: Nutritional and feeding value
Table 87 Faecal wastes ensiled with forage maize: Composition and fermentation characteristics
Table 88 Deep-stacked broiler litter: Temperature, DM, pH and lactic acid changes
Table 89 Orchardgrass faeces in sheep rations: Digestion coefficients
Table 90 Apparent digestibility of rations containing basal and steer faecal wastes
Table 91 Fresh animal wastes: Particle sizes
Table 92 Effect of processing screened manure solids on intake and digestibility
Table 93 Feedlot manure: Composition of coarse and fine fractions
Table 94 Effect of ration on content of fractions of beef manure
Table 95 Aerobically treated animal wastes: Amino acid content
Table 96 Dried ground fly pupae: Composition
Table 97 Cereco System: Projected statement of net income
Table 98 Corral System: Estimated recovery
Table 99 Corral System: Summary of economic data
Table 100 Manure: Composition change by fermentation
Table 101 Dried fermenter effluent, dried centrifuge cake, lucerne hay and soybean meal: Essential amino acid composition
Table 102 Blue-green algae production: Prospective costs
Table 103 Layer-Pig-Fish integration
Table 104 Broiler-Dairy Cow-Fish integration
Table 105 Layer-Dairy-Fish integration
Table 106 Layer-Pig-Dairy-Fish-Crop integration
Table 107 Broiler-Dairy-Biogas-Fish-Crop integration
Table 108 Pig-Biogas-Fish-Crop integration
Table 109 Pig-Dairy-Biogas-Fish-Crop integration
Table 110 Layer-Pig, Broiler-Dairy, Biogas-Fish-Crop integration

LIST OF FIGURES

Figure 1 Flow diagram of agro-industrial project
Figure 2 Schematic flow sheet for feed processing plants
Figure 3 Manure-fish recycling
Figure 4 Separating raw slurry into liquid and solid wastes
Figure 5 Oxidation ditch mass balance of a steer
Figure 6 System for feeding ODML to pigs
Figure 7 Activated sludge
Figure 8 Device for separating negatively phototactic house-fly larvae from chicken hen excreta
Figure 9 The Biochemical Recycle Process
Figure 10 The Cereco Process
Figure 11 The Corral system
Figure 12 The “Closed Ecological Cycle”
Figure 13 Chemical Extraction
Figure 14 Algae production from poultry waste
Figure 15 Fuel, Feed and Fertilizer Production and Pollution Control Through Recycling Maya Farms

INTRODUCTION

“Every great scientific truth goes through three stages.
First, people say it conflicts with the Bible.
Next, they say it has been discovered before.
Lastly, they say they have always believed it”.

Louis Agassiz

Food and wastes, like Siamese twins, are closely interconnected. Since the beginning of this century, the flow of food into cities has increased fivefold. By the end of the century, about 80% of the world's population will be living in urban centres. The rate of disappearance of farmland is alarming. This irreversible trend, with inputs of foods and outputs of wastes occurring in an ever-accelerating cycle, will directly affect waste disposal problems in cities, and will indirectly create the same problems in peripheral rural areas.

One of the results on the countryside of a growing urban population is the expansion of the livestock industry, which produces an enormous volume of its own wastes in confined areas. Thus, municipalities are becoming increasingly burdened with garbage disposal, and some rural areas are already having disposal problems with animal wastes. Both problems are essentially the same in that they interfere with the human environment.

The attitude towards overcoming these problems is usually quite negative: either nothing is done to remedy the damage to the environment and to the population or, if action is taken, it is motivated only by sheer necessity, and it is undertaken only with reluctance because it is an additional drain on the public purse.

It was not until recently that some people became aware that these problems could be converted into assets.

Feeding of animal wastes results in reducing feed cost and a lower price of animal products; it contributes to self-sufficiency in protein, phosphorus and other expensive nutrients in ruminant rations. In addition, the system makes possible a vertical, mutually complemented integration of animal production among individual species which can, in return, solve some problems of waste disposal and thus some problems of pollution.

The traditional method of disposing animal wastes has been to spread them on the land because of their excellent fertilizing properties. In the classical era of Justus von Liebig, this use of animal wastes represented an essential branch of agricultural science, but since the advent of chemical fertilizers, there has been a significant decline in the use of organic fertilizer, mainly due to the cost of transport compared with that of more concentrated chemical fertilizers. The value of animal wastes as feeds appears to be far superior to their other uses, as appears in Table 1.

Table 1
ANIMAL WASTES: ESTIMATED RECOVERY VALUE BY VARIOUS MODES OF CONVERSION

¹ Levels in different countries may vary considerably.
² Wide range, as values may be influenced by the cost of feed, energy and chemical fertilizers from conventional sources.
³ Based on several pre-investment studies and financial analyses and related to profit margins. The range inevitably varies with the size of operation, country and other variables.
⁴ Low estimates adopted from Jones and Dale (undated); higher estimates by the present author.
⁵ Varies with the nature of the waste and its physical properties; includes tractor, spreader or honey wagon, etc.
⁶ Involves thermophilic fermentation yielding protein biomass, press cake and methane.

Global information (see Table 3) obtained through a comprehensive questionnaire provides an estimate of the total animal waste produced and collectable in developed, developing and centrally planned countries.

The global volume of faecal wastes from broilers, laying hens and breeding chickens (excluding turkeys) is estimated to be over 46 billion tonnes; from turkeys about 2.6 billion tonnes; from cattle almost 932 billion tonnes; from buffaloes almost 100 billion tonnes and from pigs nearly 109 billion tonnes, for a total of 1,188 billion tonnes of animal wastes. Nevertheless, from these enormous quantities of faecal wastes only about 25%, i.e. 302 billion tonnes, are collectable, and thus potentially available for feed or other recovery processes. The breakdown by species and groups of countries is given in Table 2.

Table 2
ANIMAL WASTES: TOTAL COLLECTABLE

The estimates indicate that poultry (including turkeys) contribute to the total collectable faecal protein by 15.4%, ruminants by 53.7% and pigs by 30.9%. Developed and centrally-planned countries represent about 82.1% of the total global protein derived from collectable animal wastes, while developing countries represent only 17.9%. Since crude protein in the faecal waste of poultry is utilizable at a level comparable to that of conventional protein feedstuffs, it is reasonable to assume that this quantity of faecal protein is equivalent to 17.22 million tonnes of soybean meal (44% crude protein at 89.6% DM). Although the faecal nitrogen in cattle, buffalo and pig waste appears to be utilized less efficiently than protein in conventional feedstuffs, the potential of this protein contribution to the nutrition of ruminants is enormous, representing an equivalent of almost 95 million tonnes of soybean meal. In practical terms, the collectable faecal waste from poultry could totally cover the protein requirement of 61.5 million dairy cows (assuming 800 kg crude protein annual consumption by one high-yielding cow) or 289 million finishing cattle.

Table 3
ESTIMATED PRODUCTION OF CRUDE PROTEIN AND TDN FROM COLLECTABLE FAECAL WASTE OF LIVESTOCK

¹ Excluding turkey, ducks, geese.
² There are vast differences between the degree of cattle confinement in Europe and other developed countries (USA, Australia, New Zealand).
³ From compiled estimates, about 27% (includes mainly overnight time spent in paddocks).

Assumptions:

(DC = developed countries; LD = developing countries; CP = centrally planned countries).
Poultry Waste: Participation of individual classes of poultry in the total of poultry waste (on DM basis) is in DC:broilers(82%)= 3.28 kg; layers (9.7%)= 1.16 kg; replacement birds (8.3%) = 0.83 kg, for an average 5.27 kg per poultry unit; LD: broilers (24%) = 0.96 kg; layers (55%) = 0.6 kg; replacement birds (21%) = 2.10 kg, for an average 9.66 kg per poultry unit. CP: broilers (65%) = 2.6 kg; layers (18%) = 2.2 kg; replacement birds (27%) = 2.7 kg; for an average 7.5 kg per poultry unit. Turkey Waste: an average of 32 kg per turkey unit per annum; Cattle Waste: DC: dairy cow 334 kg; followers 678 kg; average 784 kg; CP: dairy cow 370 kg; followers 381 kg; average 751 kg; Buffalo Waste: 750 kg average for all countries; Pig Waste: DC: 161 kg; LD: 178 kg; CP: 168 kg.

Table 4
ANIMAL WASTES: COLLECTABLE TDN

Table 4 shows quantities of TDN in collectable manure.

Although livestock wastes (except wastes from broilers and non-laying birds) are generally low in energy, the recovery of feed energy from collectable animal wastes is striking. It is estimated that almost 212 billion tonnes of TDN in faecal waste is left practically unutilized, poultry (including turkeys) contributing 6.5%, large ruminants 42.1% and pigs 51.4%. Developed and centrallyplanned countries represent 78.9% of the total TDN value discarded in animal wastes, while developing countries represent 21.1%.

In recent years it has been shown that these figures should no longer be regarded as a potential, but as a reality. Poultry waste is being widely used by farmers in the United States, Europe, Asia and other areas of the world. The trend will continue with other livestock wastes with the growth of integrated animal production. In such a recycling situation of the near future, circularly integrated farms will theoretically be able to offer about 15–20% more animal products without additional land and feed requirements.