Effect of sewage sludge diets fed swine on nutrient digestibility, reproduction, growth and minerals in tissues

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Title:
Effect of sewage sludge diets fed swine on nutrient digestibility, reproduction, growth and minerals in tissues
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vii, 59 leaves : ; 28 cm.
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English
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Beaudouin, J. Jean ( Joseph Jean ), 1938-
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Swine -- Feeding and feeds   ( lcsh )
Sewage sludge as feed   ( lcsh )
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bibliography   ( marcgt )
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non-fiction   ( marcgt )

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Thesis:
Thesis (Ph. D.)--University of Florida, 1981.
Bibliography:
Includes bibliographical references (leaves 50-58).
Statement of Responsibility:
by J. Jean Beaudouin.
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Typescript.
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Vita.

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University of Florida
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EFFECT OF SEWAGE SLUDGE DIETS FED SWINE ON NUTRIENT
DIGESTIBILITY, REPRODUCTION, GROWTH AND MINERALS IN TISSUES










BY


J. JEAN BEAUDOUIN


A DISSERTATION PRESENTED TO THE GRADUATE COUNCIL
OF THE UNIVERSITY OF FLORIDA IN
PARTIAL FULFILLMENT OF THE REQUIREMENTS
FOR THE DEGREE OF DOCTOR OF PHILOSOPHY

UNIVERSITY OF FLORIDA


1981



























This dissertation is dedicated to my wife

Winie, for her love, understanding, and patience

during the course of endeavour, and to my

Mother for her faith in my potential.













ACKNOWLEDGEMENTS


The author owes a most sincere debt of gratitude to Dr. R. L.

Shirley of the Graduate Supervisory Committee, for his continuous

support and guidance during the course of this endeavor. The writer

thanks Drs. H. D. Wallace and G. E. Combs for providing facilities to

carry out the metabolism trial, and Dr. D. L. Hammell, formerly of the

Agricultural Research Center in Live Oak, where most of the experiments

were conducted, for his cooperation and great aid in conducting this

study. Special thanks are extended to Drs. D. S. Anthony, G. T. Edds,

A. Z. Palmer and P. H. Smith for serving as members of the Graduate

Supervisory Committee and to Professor J. F. Easley and Dr. H. Breland

(Soil Science Department) for their aid in carrying out many laboratory

analyses.

The writer greatly appreciates the help and cooperation of Mr.

Stacey Geiger, in charge of the University of Florida Sewage Plant, for

providing the sewage utilized in the investigation. The manuscript was

typed by Ms. Patricia Beville, to whom the author is sincerely grateful.









TABLE OF CONTENTS

Page

ACKNOWLEDGEMENTS ............................ ...... .............. iii

LIST OF TABLES .................................................. v

ABSTRACT .................................................... vi

INTRODUCTION ................................................... 1

REVIEW OF LITERATURE ........................................... 3

Methods of waste disposal .................................. 3
Sanitary landfill .......................................... 4
Incineration ............................................... 4
Pyrolysis .............................. ................... 5
Ocean dumping ........................................... 5
Composting ............................................... 6
Land application of sewage sludge .......................... 7
Metal uptake by plants grown on sludge amended soil ........ 9
Use of sludge as a fertilizer ............................. 12
Nutritive value of sewage sludge as a feed ingredient ...... 14
Mineral uptake in tissues when animals are fed sludge ...... 15
Effect of sludge-containing diets on animal performance .... 16
Indirect effect of sludge on animal feeding ................ 17

MATERIALS AND METHODS ........................................... 19

Metabolism Trial ................................. ..* *...... 19
Data Collection .......................................... 21
Reproduction and Weanling Pig Performance .................. 24
Growing and Finishing Trial ................................ 25
Procedure for Mineral Analyses in Tissues .................. 26
Statistical Analysis ...................................... 27

RESULTS AND DISCUSSION ....................................... 28

Digestibility Trial ........................................ 28
Mineral Concentration in Tissues .......................... 30
Reproductive Performance of Gilts Fed University of
Florida Sewage Sludge .................................... 31
Growing-Finishing Swine Performance ........................ 35
Mineral Accumulation in Milk and Tissues of Sows ........... 35
Minerals in Weanling Pig Tissues ........................... 38
Minerals in Growing-Finishing Swine ........................ 41
Adverse Effect of Some Minerals in Tissues ................. 45

SUMMARY AND CONCLUSIONS ........................................ 48

BIBLIOGRAPHY ............................ ................ 50

BIOGRAPHICAL SKETCH ....................................... 59
iv











LIST OF TABLES


TABLE PAGE

1 BASAL DIETS FED DURING METABOLISM TRIAL, GESTATION-
LACTATION, GROWING AND FINISHING PERIODS ......................... 20

2 PROXIMATE ANALYSES OF SEWAGE SLUDGE AND DIETS .................... 22

3 MINERAL COMPOSITION OF SLUDGE AND DIETS .......................... 23

4 DIGESTIBILITY OF DRY MATTER, ORGANIC MATTER, CRUDE PROTEIN,
ETHER EXTRACT, CRUDE FIBER, NITROGEN-FREE-EXTRACT (NFE),
TOTAL DIGESTIBILE NUTRIENTS (TDN), METABOLIZABLE ENERGY (ME),
AND NITROGEN RETAINED IN SEWAGE SLUDGE DIETS FED SWINE ........... 29

5 MINERALS IN TISSUES OF PIGS IN METABOLISM TRIAL .................. 32

6 REPRODUCTIVE PERFORMANCE OF SOWS DURING FIRST AND SECOND
LITTERS ON DIETS CONTAINING 0, 10 AND 20 PERCENT SEWAGE
SLUDGE ...................................................... .. 34

7 PERFORMANCE OF FIRST AND SECOND LITTER OFFSPRING FED
GROWING AND FINISHING DIETS THAT CONTAINED 0, 10 AND 20
PERCENT SEWAGE SLUDGE ............................................ 36

8 EFFECT OF SEWAGE SLUDGE IN DIETS FED SOWS ON CONCENTRATION
OF MINERALS IN MILK AND SELECTED TISSUES WHEN THEY WERE
SLAUGHTERED ................................................... 37

9 MINERALS IN WEANLING PIG TISSUES OF FIRST AND SECOND LITTERS ..... 39

10 MINERALS IN TISSUES OF GROWING-FINISHING SWINE FROM FIRST
AND SECOND LITTERS FED DIETS CONTAINING SEWAGE SLUDGE (SIX
PER TREATMENT) .................................................. 42










Abstract of Dissertation Presented to the Graduate Council
of the University of Florida in Partial Fulfillment of the Requirements
for the Degree of Doctor of Philosophy


EFFECT OF SEWAGE SLUDGE DIETS FED SWINE ON NUTRIENT
DIGESTIBILITY, REPRODUCTION, GROWTH AND MINERALS IN TISSUES

By


J. JEAN BEAUDOUIN


March 1981



Chairman: Dr. R. L. Shirley
Major Department: Animal Science

Twelve female swine were fed in a 3X4 crossover design metabolism

trial corn-soybean grower diets that contained 0, 10 or 20% sewage

sludge over three 19-day periods. The mean values for total digestible

nutrients were 79.4, 73.7 and 55%; those for metabolizable energy were

3.36, 2.25 and 1.15 Mcal/kg diet; and those for nitrogen retained were

42.8, 44.0 and 25.3%, respectively. Sewage sludge (0, 10, 20%) diets

were fed to 31 sows approximately equally divided into the dietary

groups during their first two pregnancies, and to their offspring from

weaning until market weight. More live pigs were farrowed and weaned

per litter from sows fed 20% sludge diets than from the control group.

However, 21-day weaning weights of pigs were lower from sows fed the

sludge-containing diets. Offspring of both first and second litters fed

growing and finishing diets containing sludge from weaning until market

weight had decreased daily weight gains and feed efficiency. There were








no increases in nine elements (lead, cadmium, nickel, zinc, chromium,

manganese, iron, copper and aluminum) in sow's milk or blood. Offspring

of sows fed sludge diets showed increases of several elements in selected

tissues at weaning and after consuming sludge diets until market weight.













INTRODUCTION


The explosive increase in world population especially in urban

areas is responsible for the increasing problem of sewage sludge dis-

posal which is a major ecological and economic burden. Concern for

quality of the environment has significantly increased the economic cost

of traditional disposal options (Smith et al., 1979). With the growing

concern over land, stream or ocean disposal, of sludges, alternate

methods of disposal warrant evaluation (Farrel, 1974). One of these

methods is recycling of wastes thereby reclaiming the nutrients they

contain for animal production.

Sewage sludge consists of organic and inorganic matter from human

and industrial sources and needs to be evaluated for its possible effects

if consumed by livestock and wild animals when disposed of on grazing

fields and timberlands. While nutrient organic matter and minerals

present in sewage sludge may be utilized by livestock, it is suggested

that microorganisms, heavy metals and other toxic compounds occurring in

municipal sewage might pose health hazards to animals consuming them.

Much concern about accumulation of heavy metals in animal products had

been expressed (Hackler et al. 1957). Pal (1980) suggested a complete

characterization of sewage solids for toxic metals, individual drugs,

pesticides and other organic chemicals as well as pathogenic agents to

assess the health risk associated with continuous application of sewage

sludge on farms and forests.







Sewage sludge utilization on land is considered by many to be the

best solution to the municipal sludge problem. Chaney (1975) reported

that sewage solids appeared to be very valuable in revegetation and

reclamation of land disturbed by urban development, mining and road con-

struction and that, if properly used, the sludge can transform these

disturbed lands into an environment suitable for plant growth.

Sludge from sewage plants has commonly been used in landfill

(Engelbrecht and Amirhor, 1976). It can also be put back into the soil,

fertilizing crops needed to feed livestock (Cambel, 1971; Decker et al.,

1980; Manning and Spitko, 1980). However, sewage sludge may be a source

of nutrients that would be more valuable if used directly as animal feed

rather than as fertilizer (Smith et al., 1980).

Sewage sludge has been fed to rats (Kindzell et al., 1976; Smith

and Staples, 1976), fish (Natarajan and Varghese, 1978; Sing and Ferns,

1978), laying hens (Damron et al., 1980), sheep (Smith et al., 1976a;

Smith et al., 1977a), cattle (Kienholz et al., 1976a; Smith et al.,

1979; Bertrand et al., 1980; Smith et al., 1980) and swine (Beaudouin et

al., 1977; White et al., 1980; Edds et al., 1980).

The objectives of the present experiments were to evaluate the

effect of sewage sludge in diets fed swine on:

a) reproductive performance

b) rate of growth

c) total digestible nutrients (TDN), metabolizable energy (ME)

and nitrogen balance in a metabolism trial

d) accumulation of potentially toxic minerals in tissue of swine

consuming sludge-containing diets












REVIEW OF LITERATURE


Sewage sludge can be defined as the total organic and inorganic

wastes generated by human and commercial sources and removed from waste-

water at treatment plants. The waste treatment is based on the need to

remove objectionable substances in the wastewater prior to its release

in the general environment (Waller, 1976). It is estimated (Bastian,

1977) that close to 5 million dry tons of sewage sludge are produced

each year and the amount might double in the next five years. Land

available for landfill disposal of the solid waste material is diminish-

ing. With new federal regulations in water management and air pollution

control, the disposal of sewage waste in a manner consistent with environ-

mental criteria has become urgent and difficult.

Methods of waste disposal: The most popular methods of sludge

disposal in the United States are landfilling, ocean dumping, incin-

eration, pyrolysis, composting and landspreading. All methods of dis-

posal are costly and Montague (1975) reported some comparative costs

of sludge disposal. Costs for incineration and heat dried sludges are

approximately $50/ton; drying for fertilizer, $5/ton; disposal at sea,

$32/ton; landfilling, $25/ton; liquid sludge spreading and stripmine

reclamation $15 and $16/ton, respectively. Landspreading of the liquid

sludge is one of the most attractive alternatives from an economical and

hopefully from the environmental standpoint. Montague (1975) compared

its cost of disposal in this manner with the cost of ocean disposal by







the coastal megalopoli and the "out of sight out of mind" philosophy

associated with this practice.

Sanitary landfill: This procedure is defined by the American

Society of Civil Engineers (1959) as a method of disposing refuse on

land without creating nuisances or hazards to public health or safety.

The refuse should be confined to the smallest practical area, reduced to

the smallest practical volume and it should be covered with a layer of

earth at the end of each day of operation or at more frequent intervals

if necessary. Objectionable materials like toxic metals, toxic organic

chemicals, and pathogenic microorganisms may be present in sufficient

concentration to be hazardous (Farrell, 1974).

High concentration of pathogens and chemicals in the raw sewage

sludge may prohibit disposal in landfill or to agricultural land. The

landfill should be in a site above the highest seasonal level of the

water table and should not be subject to flooding (Clayton and Huie,

1973). The site should be located where groundwater contamination is not

possible, and any leachate should be collected and treated (Farrell,

1974).

Incineration: As a disposal method, incineration is the process of

reduction of combustible waste to inert residues by high temperature

burning. The rapid increase in the production of solid waste and the

steady exhaustion of available land within practical distance from

population centers had generated a trend toward incineration as a major

method of waste disposal, particularly in large communities. In recent

years, the trend to incinerate waste in the United States rapidly in-

creased and it was projected that by 1985, as much as 35% of the sludge

would be disposed of in this manner (Farrell, 1974). But energy scarcity





5

and air pollution equipment with high operation expense required in most

communities make incineration less attractive. However, Roesler (1977)

reported that manufacturers of incinerators recognized this problem and

have developed automated and semi-automated incinerators with the

potential for improving performance, enhancing safety and saving fuel.

Incineration also presents the problem of a residue which must be

buried or otherwise disposed of. The ash resulting from the burning of

sewage sludge can be converted into an environmentally acceptable mater-

ial while conserving valuable resources. Gabler and Neylan (1977)

reported that various investigators have shown an increasing interest in

both the quantity of metals present in sludge ash and the most efficient

means of extracting them as well as phosphorus. Gabler and Neyland

(1977) concluded that for most cities, recovery costs may only be justi-

fied as part of the disposal cost.

Pyrolysis: This process involves destructive distillation of

organic matter under heat and/or pressure in absence of oxygen and with

a more positive control of the combustion process. But like incin-

eration, it is not a total disposal method since most solid materials

contain non-combustibles and have residual ash (Sittig, 1979; Chaney,

1975). The major difference between incineration and pyrolysis is that

in the latter process three potentially useful energy rich substances

are produced, i.e. a gas (methane), a liquid and a char (Vesilind,

1979).

Ocean dumping: The ocean dumping of sewage sludge has been a way

of disposal in most coastal cities for years. But with environmental

concern over floating materials (oil, grease) floating back to shore and

discouraging recreational fishing and swimming as well as being a health








risk, it is possible that ocean dumping will likely not be allowed in

the future (Vesilind, 1979).

Composting: A major attribute of composts is that it is an es-

thetically pleasing, easily handled material that can be used in urban

environments without odor or nuisance problems (Epstein and Willson,

1974). Proper composting not only dewaters the sludge but also destroys

disease organisms during the compost heating process. Toth (1973)

defines the composting process as the procedure involving microbial

conversion of waste organic residues into lignoprotein (humus) by

thermophilic organisms under optimal condition. Toth (1973) also

observed that compost improves the physical property of soil. It causes

an increased aggregation which results in reductions in surface runoff,

improvement in holding capacity, absorption of heat, aeration and re-

duction of water infiltration in light soil. Addition of sludge compost

to sandy soils increases their ability to retain water and render them

less drought (Willson et al., 1976). Application of sludge or sludge

compost has been found to increase the cation exchange capacity of soils

by as much as threefold (Epstein et al., 1976). Sludge compost, when

added to clay soils, reduces compaction and increases rooting depth.

But the potential use of compost on land is limited to the extent to

which the sludge is contaminated by heavy metals and industrial chemicals.

Willson et al., (1976) pointed out that the chemical composition of

compost depends on the composition of the sludge, which in turn depends

on the extent of the wastewater treatment and particular type of contam-

ination. One difficult problem with sludge is that it is not possible to

guarantee the composition of either the liquid or the dried sludge









because of the varying nature of the sewage received and the treatment

process (Ardern, 1976). In addition to the problem of toxic substances

in composting sewage sludge, it is necessary to add extra nitrogen,

potassium and phosphorus and keep the loading of the soil within a 10 to

20 tons limit. A higher load will allow CO2 accumulation to stop the

decomposition (Cardenas and Varro, 1973; Satriana, 1974).

Hill and Montague (1975) observed that plants grown on compost

plots had significantly lower zinc and cadmium contents than those grown

on sludge treated plots. Composting of sewage sludge appears to be

desirable not only from the standpoint of pathogen reduction (temper-

ature has exceeded 70C for over 14 days as reported by Hill and Montague,

1975) as well as odor control, drying by natural processes, ease of

handling, lowering the nitrate levels, and reduced potential for metal

uptake by plants. According to Willson et al. (1976), composting of

good quality sludge, low in heavy metals, is the most acceptable way of

applying sludge to land.

Land application of sewage sludge: Black (1974), Chaney (1975),

Bastian and Whittington (1977) have reviewed potential hazards and

problems as well as agricultural benefits of land treated with sewage

products. Land application of sewage sludge remains a controversial

area. Most discussions centered on application to agricultural lands

for food crop production. The use of sludge on non-agricultural lands

(stripmine reclamation, park, construction site) or non-food chain crop

production (sod production) can be done without much controversy to

recover nutrient and soil building properties of municipal sludge

(Bastian and Whittington, 1977). Dean and Smith (1973) stated that

for an idea such as recycling of urban sewage or sludge to the land to








be implemented, it must have public acceptance. In fact, public accept-

ance and health effect concerns are the two major impediments to the use

of sewage sludge in agriculture. The ultimate disposal of sewage sludge

by utilization on land is considered by many as the best solution avail-

able to municipal sludge problems. Black (1974) reported the favorable

effect of sewage sludge on soil properties as being that of increased

field moisture capacity, organic matter content and soil aggregation.

Those factors tend to render the soil more suitable to plant growth,

through improved aeration, greater ease of root penetration, increased

rate of water infiltration and improved availability of nutrients.

The sludge can be applied to land as liquid or dried, forms. When

used in liquid form, cost of drying the sludge is avoided. Upon apply-

ing sludge to pasture, Decker et al. (1980) observed excellent plant

growth resulting from both liquid and composted sewage sludge. Forage

quality was not reduced by the sludge fertilizer and forage accept-

ability by grazing animals was excellent. However, disposal or the

application of raw sewage sludge has potential health and aesthetic

problems. The material is odorous, highly biodegradable and bears

pathogenic microorganisms typical of human excreta (Miner and Hazen,

1971). The potential hazard from metals in sludge is the most urgent

problem in sludge utilization on land. There is potential hazard to the

land, to animals that feed on crops, and to humans who eat both the

crops and the animal (Farrell, 1976). There are currently no acceptable

tolerances or limits for heavy metals and other contaminants in sludge

for crops grown on sludge amended soils for human or animal foodstuffs

(Bastian and Whittington, 1977). When sludge is used as an addition to








soil to grow crops in the food chain, it is important to consider the

fact that sludge can contain varying amounts of pathogens, toxic metals,

pesticides and industrial chemicals such as PCB's (polychlorinated

biphenyls), according to Jelinek and Braude (1976). Although the uti-

lization of sewage sludge as a resource to recover nutrients and other

benefits has been encouraged, there are, however, conflicting opinions

on the overall merit versus the potential risks associated with applying

sludges to cropland (Bastian, 1977). Land cultivation of waste is a

disposal technique by which wastes are mixed with the surface soil to

promote microbial decomposition of the organic fraction (Bauer et al.,

1977). Miller (1973) observed that frequent large applications of sewage

sludge or a single massive application could result in an accumulation

of organic matter which would adversely affect ion solubility and avail-

ability, plant growth or environmental quality.

Metal uptake by plants grown on sludge amended soil: Lutrick and

Cornell (1980) observed that metal uptake by corn grown on sludge treat-

ed soil was proportional to the quantity added from the sludge and was

directly associated with soil pH. When liquefied, irradiated, digested

sludge was applied to soil, Manning and Spitko (1980) found that with

the exception of lead, which exceeded normal concentration only in

lettuce, concentrations of all other metals were within normal range

observed for plants grown without sludge. Naylor et al. (1980) showed

that uptake of cadmium into corn grain grown on sludge amended soil was

only slightly greater than that of corn grown on a control site. How-

ever, there was a significant increase in the cadmium content of the corn

leaves over the control plants. No contamination of surface water or

ground water was detected. Corn grown on a sludge fertilized field had








significantly more Ca, P, K, Mg, Zn, Cd, Ni, Cu, and Fe, and less Mn

than a standard corn (Hansen et al., 1976). Loehr et al. (1979) con-

cluded that aluminum, iron and manganese levels in sludge were usually

of no environmental concern. They are not toxic as long as low pH is

avoided and good aeration of the soil is maintained. Lead toxicity in

sludge was found to decrease when incorporated into a neutral soil.

Loehr et al. (1979) suggested, that a good management practice designed

to prevent production of crops with toxic cadmium concentration, would

be to maintain a 1:100 cadmium to zinc ratio. The Food and Drug Admin-

istration (FDA) has set some limitations on the application of sludge to

land used to grow human and animal foods in order to protect public

health. The sludge should not contain more than 20 ppm of cadmium,

1,000 ppm of lead or 10 ppm of PCB (polychlorinated biphenyl) on a dry

weight basis (Jelinek and Braude, 1976). Goldstein (1979) suggested

these heavy metal limits for croplands: zinc, 1,500 ppm; copper, 750

ppm; lead, 500 ppm; chromium, 500 ppm; nickel, 150 ppm; and cadmium, 50
ppm. The heavy metals occurring in amounts that are significant to

agriculture include zinc, copper, nickel, cadmium, mercury and lead. It

has been proven (Otte and Laconde, 1977) that repeated sludge applications

result in increased surface accumulation of cadmium, copper, nickel and

zinc in sludge treated fields. In fact, Jelinek and Braude (1976)

observed a cadmium increase in grains and soybeans as a result of re-
peated applications of cadmium-containing sludge. Chaney (1975) re-

ported some concerns by agronomists who feared that the disposal of some

sludges on agricultural land may impair crop growth because of their

heavy metals content or may endanger the food chain through excessive

accumulation of these metals in the crop's edible portion. Metals such








as copper, zinc, nickel can be toxic to vegetation if they are applied

in excessive concentration. Other metals, cadmium for instance, may

accumulate in animals and humans, where they act as cumulative toxins

(Sidle, 1977). The toxicology of cadmium is recognized as a serious

cumulative disease in man, first described in Japan as Itai-Itai or

Ouch-Ouch disease and characterized by deformities, muscular atrophy and

excruciating pain (Stevens, 1976). Sludge disposal in forested areas

seems a viable alternative to farmland application since the vegetation

is generally not harvested as edible crops (Sidle, 1977). The only means

of food chain transfer would be through wildlife feeding on vegetation

in the sludge treated areas and through the ground water recharge.

Incidentally, nitrogen in the nitrate form is implicated in methemo-

globinemia, a current condition in infants in areas with high nitrate

drinking water (Waller, 1976). But according to Dean and Smith (1973),

a long history of successful use of sludge as a soil amendment in agri-

culture indicated that hazards are slight and probably are easily con-

trolled by appropriate farm practices. Results of experiments on using

sludge on calcareous soils did not differ whether the sewage products

are thermoradiation treated or untreated. However, thermoradiation

treatment greatly facilitates handling of the raw sewage for experi-

mentation because pathogens are eliminated and objectionable odors

almost completely eliminated (McCaslin and Titman, 1977). Adrian (1973)

reported that when digested sludge is dried on sand beds, it takes many

weeks to months to provide time for a significant die-off of pathogens.

However, one has to be cautious. Hoffmann and Bertrand (1980) identi-

fied non-lactose fermenting, gram negative bacteria from dry University

of Florida sludge. They also isolated two groups of Salmonella enteritidis








from feces of animals fed on a sludge amended diet. Mineral toxicity is

also a serious problem. For example, cumulative cadmium ingestion

causes renal tubular dysfunction (Franconi syndrome) in man (Chaney,

1980). Ryan (1978) indicated that cadmium toxicity could occur in

animals consuming food and feed crops produced on soil treated with

large amounts of sewage sludge, high in cadmium, the metal adhering to

the edible plant surface. But Schauer et al. (1978) estimated that food

chain accumulations of many heavy metals, with the exception of cadmium,

do not appear to present a problem because they are toxic to plants in

lower concentrations than those detrimental to animal or human health.

Use of sludge as a fertilizer: Liquid sludge, as applied to land,

contains major fertilizer elements, mainly nitrogen, potassium and phos-

phorus. The dry weight percentage of each depends on the sewage and the

sludge treatment plant operation (Hill and Montague, 1975). Peterson et

al., (1973) found the following amounts of mineral nutrients in sludge:

Mineral nutrient percentages of dry sludge solids.

Total N 3.5 6.4% Organic N 2.0 4.5%

Total P .3 3.9% P205 1.8 3.7%

Total K .2 .7% K20 .24 .84%


Micronutrients such as iron, manganese, copper, zinc and boron were also

determined. Dried sludge can be a very good fertilizer and soil con-

ditioner but the cost of drying the sludge is high and the end-product

must be sold to make the operation economical (Vesilind, 1979). Blok

(1976) reported that in 1975, a total of 160,000 tons of dried sludge

were produced in Houston, Chicago, Milwaukee and Winston-Salem. Most of

them were used in Florida for turfgrass, citrus industry, nurseries and








vegetable industry. Blok (1976) even mentioned that citrus groves on an

organic versus synthetic fertilizer program are better able to withstand

freeze and droughts. Some cities sell the sludge to fertilizer manu-

facturers who incorporate it into specialty products and handle the

marketing of the product (Styers, 1973). The value of the heat dried

sludge is directly related to its nutrient content and its character-

istics as a soil conditioner. Plant growth on calcareous soils in

greenhouse was stimulated by digested sludge in comparison with nitro-

gen-phosphorus chemical fertilizers (Smith et al., 1976b). It is dif-

ficult to estimate the economic benefit of sludge application with that

of commercial fertilizer (Reisner and Christensen, 1977), because of the

varying chemical composition of the sludge as well as fluctuation of

nutrient price. These authors estimated that one ton of dried sludge

provides about 100 Ibs each of nitrogen and phosphate and 5 pounds of

potash. But to produce a marketable fertilizer, it is necessary to keep

the nitrogen content as high as possible and minimize the moisture, ash,

grease and cellulose (Garrett, 1974). Heat dried activated sludge must

compete with other sources of organic nitrogen such as dried blood, fish

scraps, tankage and cottonseed meal. Sewage sludge is often used in

commercial fertilizers as an organic source or as a cheap bulking agent

(Chaney, 1973). Digested sludge contains all the nutrients and trace

elements required for plant growth. Three to four tons of sludge per

acre provide adequate nitrogen and phosphorus for a healthy crop of corn

(Black, 1974). But according to Martin and Baxter (1976), nitrogen,

heavy metals, salts, and pathogen transmission are possible limitations

to using sludge as a fertilizer. Excess nitrogen can be converted to

nitrates contaminating surface or ground water supplies (Dean and Smith,








1973; Martin and Baxter, 1976). The shortage of fossil fuels used in the

manufacturing of nitrogen fertilizer has tremendously increased the cost

of commercial fertilizer. Savings from using sludge will likely increase

as the cost of commercial fertilizers increases.

Nutritive value of sewage sludge as a feed ingredient: In an

experiment using dried activated sewage sludge as a source of nitrogen

for sheep, Hackler et al., (1957) found that sewage sludge has good

nutritive value for animal feeding and presents little problems from

pathogens. But the hazards of chemical toxicants, cultural stigma and

low economic incentive precluded practical application. Nutrients in

sewage solids are potentially more valuable as animal feed than as

fertilizer, especially when fed to ruminants (Smith et al., 1979).

Undigested sewage solids fed as a supplement in a fibrous diet to sheep

and compared to one containing cottonseed meal had 40-60% digestible

energy and approximately 50% digestible nitrogen (Smith et al., 1976a).

Sewage solids had about 65 to 75% as much supplemental energy and nitrogen

as cottonseed meal when fed in approximately isonitrogenous diets to

sheep. In short-term trials with sheep and cattle, Smith et al. (1979)

demonstrated that irradiated sewage solids from primary sludge provided

nutritive energy and nitrogen worth at least half the value of cotton-

seed meal when fed with poor quality, fibrous feeds. Smith et al.

(1980) concluded that raw sewage could be recycled as supplemental feed

for ruminants subsisting on poor quality roughage at substantial nutritive

benefits, without incurring undue risk from accumulation of heavy metals

or halogenated hydrocarbons. Hackler et al. (1957) fed sheep a ration

in which 18% of the nitrogen was supplied as dried activated sludge and








found nitrogen retention equivalent to that obtained with soybean meal

and urea-containing rations of similar crude protein content (11-12%).

The total nitrogen of the sludge-containing ration had a significantly

lower apparent digestibility but a higher biological value.

In a feeding trial with three groups of lambs (basal versus 10%

cottonseed meal (CSM) versus 20% thermoradiated, centrifuged undigested

sewage solids), Smith et al. (1977b) observed that the amount of digested

energy and digested nitrogen were greater for lambs fed 20% sludge than

those fed the 10% cottonseed meal diet. The diets, when fed to steers,

showed that both CSM and TRUS-C (thermoradiated, centrifuged, undigested

sewage solids) tended to increase digestible energy and nitrogen over

that of the basal diet.

Mineral uptake in tissues when animals are fed sludge: In long

term feeding of diets that contained 20 or 30% of irradiated dried

sewage sludge to sheep, tissue retention of selected trace minerals

lightly increased over the control groups (Smith et al., 1979). How-

ever, only the increase in iron was considered biologically important.

Bertrand et al. (1980) fed 500 g/head/day of dried Pensacola sludge to

steers and observed a consistent decrease of liver tissue concentration

of copper and some accumulation of lead in both liver and kidney.

Accumulation of cadmium and lead in liver and kidney tissues were also

observed when dried Chicago digested sludge replaced the Pensacola

sludge in the diets. These authors found no significant increases in

concentration of selected metals in liver and kidney of beef steers fed

a diet that contained corn grain grown on land pretreated with a Pensacola

liquid sludge. Kienholz et al. (1976a) fed steers feedlot diets that

contained 15% dried sewage sludge for 95 days and observed a 10-fold








increase in lead and mercury and a 2-fold increase in cadmium and copper

in their liver and kidney. In another experiment, Kienholz et al.

(1976b) found that by adding 3.7 or 11.6% sludge to a diet, cadmium and

lead increased in the kidney but there was a significant decrease in

copper when 11.6% sludge was present in the diets. The sludge-containing

diets significantly increased copper, cadmium and lead in liver tissues,

but had no effect on zinc contents. Edds ed al. (1978) fed a 50% dried

sewage sludge diet to pigs and observed an increase in cadmium and lead

in the kidney and liver. However, copper and zinc decreased in both

tissues when sludge was fed. Accumulation of chromium, iron, nickel and

lead in rainbow trout maintained on a diet containing 30% activated

sludge was observed by Sing and Ferns (1978).

Effect of sludge-containing diets on animal performance: Smith et

al. (1976b) fed rats sewage solids during growth periods and found no

detrimental effect on subsequent reproductive performance. No recogniz-

able lesions that were due to the dietary sludge were found in rats upon

post-mortem examinations. However, the feed efficiency decreased with

increasing levels of dietary sludge (0, 12.5, 25 and 50% sewage sludge).

Bertrand et al. (1980) fed Chicago sewage sludge to steers at levels of

6% of the dry diet for 141 days and found, however, no differences in

growth, feed efficiency or carcass quality measurements. Firth and

Johnson (1955) included 5% dry activated sewage sludge in the diet of

baby pigs without adverse effects on growth. However, 10% sludge inhibit-

ed growth and feed efficiency. These authors fed 10% sewage sludge in

diets to baby chicks for a month without any evidence of adverse effects.

Damron et al. (1980) fed Leghorn hens rations containing 0, 3.5 and 7%








dried Chicago sludge and found neither egg production, egg weights,

daily feed intake, feed efficiency nor body weights significantly

affected.

Indirect effect of sludge on animal feeding: Stoewsand et al.

(1980) found hepatic necrosis in lambs fed corn silage grown on land

covered with municipal sludge and cadmium and zinc were found to be

higher in kidney and liver. Steers consuming forages produced on land

covered with dried Pensacola sludge had a decrease in copper and zinc in

liver (Edds et al., 1980). When these authors used corn grain harvested

from soils previously amended with Pensacola liquid sludge to replace

either 50% or 100% of corn from plots fertilized with commercial ferti-

lizer in diets fed chicks, they found, with one exception, no signifi-

cant differences in growth performance in three experimental groups.

These diets had no detrimental effects on egg laying or hatchability

when fed to hens. When freeze dried liver from swine that had been fed

diets that contained 0, 10 or 20% dried University of Florida sewage

sludge was included in diets fed mice, an increase in the lead content

of the mice liver and muscle occurred with the 20% dried sewage sludge

treatment (Kelley et al., 1980). Such tests are called relay feeding

trials and are defined (Robens, 1980) as ones in which edible tissues

obtained from animals fed potentially toxic feed ingredients, are

subsequently fed to laboratory animals which are then observed for

effect of accumulated toxicants on survival, lesions, reproduction or

other parameters.

This review of the literature indicates that sewage sludge can be

valuable as a fertilizing agent for crops as well as a feed ingredient






18

for animals. The potential for human or animal disease due to patho-

genic organisms being transmitted in unprocessed or improperly managed

sludge and the danger from heavy metal accumulation in some vital tissues

limits its general acceptance.













MATERIALS AND METHODS


Metabolism Trial


This experiment was conducted at the Swine Research Unit of the

University of Florida at Gainesville in order to study the effect of

sewage sludge diets fed swine on total digestible nutrients (TDN),

metabolizable energy (ME), nitrogen balance and minerals accumulation in

tissues. Twelve crossbred gilts averaging 28 Kg in body weight were

eoually divided into three groups of four and fed corn-soybean grower

diets (table 1) containing either 0, 10 or 20% sewage sludge over three

nineteen-day periods in a crossover design metabolism trial. The pigs

were randomly selected from several litters of the same age and weight

that had not previously been fed sewage sludge diets. The sludge,

aerobically digested in the University of Florida sewage plant and sun-

air dried replaced corn grain in diets on an equal air-dry weight basis.

Diets were marked with chromic oxide (.1% Cr2 03), a reference substance

used to calculate fecal output according to the equation:


Fecal output = Total chromium intake, g
gram chromium/gram dry matter of feces


The swine were adapted to the diets for nine days in pens and then

confined to individual metabolism cages where feed intake was recorded

and feces and urine collected for seven days. Determination of chromic

oxide in swine feed and feces was done by the method of Christian and

Coup (1954).


















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Proximate analysis constituents were determined in the sludge,

diets (table 2), feces and urine by the AOAC (1975) procedures. Diets,

sludge, feces and urine were analyzed for selected mineral concentration

by atomic absorption spectrophotometry (Perkin Elmer Corporation, 1973).

Gross energy was determined in an oxygen bomb calorimeter (Parr Instru-

ment Company, 1960). The mineral composition of sludge and diets are

presented on Table 3.


Data Collection


The pigs were weighed at the beginning and at the end of each fecal

collection period. During the seven day period in the metabolism cages

about 300 grams of feces were obtained each day per animal and kept in a

sterile plastic bag. Feces was air-dried for four days, ground in a

Wiley mill to pass a 10 mesh stainless steel screen. Approximately 300

grams of ground feces from each pig were saved for analyses. The urine

was collected in bottles that contained 10 ml of toluene and 15 ml of

concentrated hydrochloric acid and measured each day. An aliquot of 100

ml was saved from each animal and stored in a refrigerator until analyses

were completed. All animals were allowed a 12-day adjustment period to

the new diets before feces or urine collection were made in each period.

Pigs fed the control diet in the last period were slaughtered one day

after the conclusion of the experiment while corresponding ones fed the

10 or 20% sludge diets were fed the control diet for one or two weeks
















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respectively before slaughter. This was done to decrease the residual

material of the sludge diets. Kidney, liver, spleen and skeletal muscle

samples were cut with a stainless steel knife and frozen until analyzed

for potentially toxic minerals. Blood was also collected in heparinized

tubes and kept at 340C until analyzed. Tissues and blood were analyzed

for lead, mercury, cadmium, nickel, zinc, chromium, copper, manganese,

iron, aluminum and magnesium by atomic absorption spectrophotometry

(Perkin Elmer Corporation, 1973). Mercury was similarly analyzed in

feed, feces and urine.


Reproduction and Weanling Pig Performance


An experiment was conducted at the swine unit of the Agricultural

Research Center in Live Oak, Florida, that involved thirty-three York-

shire-Hampshire crossbred gilts. The gilts weighed initially approx-

imately 60 kg each and were allowed randomly and equally to corn-soybean

gestation-lactation diets (table 1) that contained either 0, 10 or 20%

sewage sludge. The sludge was air and sun-dried. Analysis values for

protein and selected minerals are presented in tables 2 and 3, respect-

ively. The added sludge replaced the ground corn in the diets on a dry

weight basis. Feed and sludge samples were taken at each mixing of

diets and analyzed for selected mineral content. During approximately

twelve months of feeding the diets, two litters were obtained from each

of the sows. The sows were fed from troughs in open pens on the ground

except just prior to farrowing and during lactation until weaning when

they were kept on concrete in farrowing pens and hand-fed. Ad libitum

feed consumption by sows was not determined. After weaning, the sows








were returned to open pens on the ground. On day 7 of the first lacta-

tion, three sows randomly chosen from each dietary group were milked by

hand after being injected with 1 ml of oxytocin. The milk was dried on

a steam bath and ashed at 4800C overnight. Subsequently, the ash was

dissolved in .1% HC1 and analyzed for nine selected elements: lead,

cadmium, copper, chromium, nickel, manganese, aluminum, iron and zinc.

Six weanling pigs (three male, three female) of each dietary group from

both first and second litters were killed by severing the jugular vein,

and blood was collected in heparinized tubes. In addition, liver,

kidney, spleen and muscle tissues were secured with a stainless steel

blade and frozen immediately at -100C. Samples were partially oxidized

with nitric acid followed by dry ashing at 4800C. The ash was dissolved

in aqueous hydrochloric acid and filtered through a No. 43 acid washed

Whatman filter paper. The filtrate was volumetrically diluted to 100 ml

with distilled water and analyzed for Pb, Cd, Cu, Cr, Ni, Mn, Al, Fe and

Zn. At the conclusion of the reproduction phase, 18 sows, 6 from each

dietary group, were randomly selected and slaughtered. Blood, liver,

kidney, spleen and muscle were obtained and handled as above prior to

analysis of the nine elements.


Growing and Finishing Trial


This trial was also conducted at the Agricultural Research Center

in Live Oak, Florida. Seventy-two weanling pigs from each of the first

and second litters were randomly selected and allotted to 18 pens accord-

to weight, sex and litter number. There were two barrows and two gilts

in each pen, none littermates. They were successively fed starter,








grower and finisher diets until they reached market weight (80 to 90

kg). All diets contained either 0, 10 or 20% sewage sludge. Individual

weights and pen feed consumption data were obtained every two weeks for

calculation of the average daily gain (ADG) and feed efficiency. The

pens were equipped with wooden self-feeders and automatic drinking

fountains. At market weight, 18 pigs (nine barrows, nine gilts), one

from each pen, were randomly selected, and slaughtered. Blood, liver,

kidney, spleen and muscle were secured and handled as described above

prior to analyses of selected elements.


Procedure for Mineral Analyses in Tissues


Five to ten grams of tissue were dried overnight in an oven at

1100C for dry matter determination. The dried tissue was predigested

with concentrated nitric acid on a hot plate until completely carbonized,

then placed in a furnace where the temperature was gradually raised to

4800C and ashed overnight. The crucibles were allowed to cool in a

dessicator and weighed. The ash was dissolved in concentrated nitric

acid, filtered into a 100 ml volumetric flask and diluted to volume with

distilled water according to the AOAC (1975). Selected elements were

analyzed as described above. Feed, sludge and feces samples were air

dried for three or four days in an oven at 600C and ground in a stain-

less steel Wiley mill. Dry matter was then determined at 1000C followed

by ashing at 4800C. The ash was dissolved in concentrated HC1 and

minerals analyzed by atomic absorption spectrophotometry as described

above.





27


Statistical Analysis


In the metabolism trial significance of variation in values due to

treatments were analyzed using the least significant difference (LSD)

method of Steel and Torrie (1960). The data in all other treatments

were tested for significance of variance by the SAS computer method

(Barr et al., 1976). Duplicate analyses were made for each element in

the various tissues.













RESULTS AND DISCUSSION


Digestibility Trial


Digestibility of crude protein, crude fiber, ash, ether extract and

nitrogen-free extract as well as total digestible nutrients (TDN),

metabolizable energy (ME) and nitrogen balance data are presented in

table 4. Daily feed intake was slightly greater with the 20% sludge

diet. Organic matter, TDN, ME, nitrogen retained and all proximate

analyses nutrient values except for ether extract were decreased (P<.05)

in digestibility when 20% sludge was included in the diet. However,

values for dry matter, organic matter, crude protein and NFE digest-

ibility as well as TDN, ME and N retained with the 10% sludge-containing

diet were equivalent to those of the control diet. It is not apparent

why more ether extractable material was present in the feces than in the

diet; the diet ranged from .3 to 1.1% (table 2). The increased fecal

lipid must have been of metabolic origin. The two sludge-containing

diets did not differ significantly in digestibility of dry matter, crude

protein, crude fiber or ME. The nutritive value of the sludge diets may

have been influenced by the high level (23.8%) of ash present, which was

largely sand from the sand-based drying beds of the sewage plant. The

ash decreased the organic matter in the 20% sludge-containing diets by

approximately 5%.

Average daily weight gains of swine were .69, .60 and .63 Kg with

corresponding feed/gain ratio of 2.31, 2.62 and 2.77 for the 0, 10 and









TABLE 4. DIGESTIBILITY OF DRY MATTER, ORGANIC MATTER, CRUDE PROTEIN,
ETHER EXTRACT, CRUDE FIBER, NITROGEN-FREE EXTRACT (NFE), TOTAL
DIGESTIBLE NUTRIENTS (TDN), METABOLIZABLE ENERGY (ME), AND
NITROGEN RETAINEDIN SEWAGE SLUDGE DIETS FED SWINEa


Diets
Item Control Sludge, 10% Sludge, 20%


No. swine 12 12 12

Daily feed intake, kg, d.m. 1.59 1.57 1.74

Gain, kg/day .69 .60 .63

Feed efficiency 2.31 2.62 2.77

Digestibility, %

Dry matter 76.4b 68.3b 49.8c

Organic matter 79.7b 72.5b 56.5C

Crude protein 77.8b 68.6bc 58.2c

Ether extract -63.6b -42.9c -112.5d

Crude fiber 69.7 70.3 63.9

NFE 82.8b 78.2b 61.7c

TDN, % 64.7b 62.3b 53.6c

ME, Mcal/kg 3.74b 2.74bc 1.88c

Nitrogen retained, % 50.9b 51.4b 35.6c

Nitrogen intake, g/day 19.1 18.4 24.05

Nitrogen in feces, g/day 4.02 5.7 10.0

Nitrogen in urine, g/day 5.2 3.3 4.6


a
All values on dry weight basis.

b,c,d
Values on lines that vary significantly have different superscript
letters (P<.05).








20% sludge dietary groups, respectively. While weight gain and feed

efficiency were not significantly different, there was a trend to poorer

utilization of the sludge-containing diets. Kienholz et al. (1976a) fed

steers 5 or 15% dried sewage sludge in a finishing ration for 94 days

and found that they gained respectively 32 and 63 Ibs less than the

control group. Edds et al. (1980) fed diets that contained 50% sewage

sludge to swine and found gain significantly depressed as well as leukemia

and lower PCV (packed cell volume) value in the animals. The toxicity,

they observed was associated with increased levels of cadmium and lead

and low concentration of copper and zinc as well as low protein content

of the sludge ration (9.0% versus 17.2% in the control).


Mineral Concentraiton in Tissues


The data on mineral analyses of liver, kidney, spleen and muscle

showed no increase in Pb, Cd, Cu, Cr, Zn, Mn, Al or Mg due to sludge in

the diets. However, swine fed the 20% sludge-containing diet had a

significant increase in the blood of Ni, Cu, Cr and Al. Iron was elevated

in the liver with the 20% sludge level and Ni was higher in liver,

kidney and muscle at the 10% level of dietary sludge. Only traces of Cr

appeared in the tissues except in blood of swine fed the 20% sludge diet

which indicated that Cr used as a feed and fecal marker was very un-

absorbable in the alimentary tract. Kienholz et al. (1976a) found that

a diet fed feedlot steers for 84 days and containing 15% sewage sludge

resulted in liver and kidney concentrations of lead and mercury that were

approximately ten-fold greater and cadmium and copper levels that were

twice that of the controls. However, they observed no histological or








pathological lesions in the steer carcass or tissues that could be

attributed to the sludge diet. During a ten day trial with rats re-

ceiving 0, 10 or 20% dietary sludge, Kindzell et al. (1976) observed

that urinary excretion of iron and zinc significantly increased with

addition of sewage solids. In the present study, urinary excretion of

iron and zinc in swine also increased when sludge-containing diets were

fed (table 5).


Reproductive Performance of Gilts Fed University of Florida Sewage Sludge

The reproductive performance of sows fed 10 and 20% sewage sludge

diets was not adversely affected during their first and second preg-

nancies compared to controls. There were apparent linear decreasing

weights of pigs from dams fed 10 and 20% sewage sludge diets (table 6).

Gestation weight gain of sows decreased (P<.05) with the diets that

contained 20% sewage sludge in both litters. These results are in

agreement with those of Hammell and Edds (1977) when they fed equivalent

amounts of Chicago sludge in diets to sows. There were no significant

difference in number of pigs farrowed per sow, birth or weaning weight

of pigs in either the first or second litters with the three dietary

levels of sewage sludge. Approximately one to two more live pigs were

farrowed on the average and slightly more (.45 Vs. .25) pigs were weaned

per litter with diets that contained 20% sludge. However, the 21-day-

old weaning weights were depressed by dietary sludge. Dams fed the 20%

sludge diets had weaning weights of offspring that averaged .53 and 1.45

kg less (nonsignificant) than controls for the first and second litters,

respectively. The slightly slower gaining pigs appeared to be normal in

vigor and health.

















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Growing-Finishing Swine Performance


Performance data on first and second litter offspring fed growing-

fattening diets that contained 0, 10 or 20% sewage sludge are presented

in table 7. Pigs from the second litters fed the sludge-containing

diets had lower (P<.05) daily weight gains and a greater (P<.05) feed to

gain ratio than the controls. First litter swine fed diets with sludge

increased their feed intake over controls and made similar weight-gains.

They had greater (P<.05) feed to gain ratios. The failure of the second

litter swine to consume more of the sludge-containing diets than the

controls as was observed for the corresponding first litter groups may

have been due to the stress of summer temperatures, as they were born in

June and the first litters were born in January. Similar weight gain

depression to that observed with the second litter groups was reported

by Kienholz et al. (1976a) for feedlot steers fed 5 or 15% dried sewage

sludge diets. Baxter et al. (1980) also observed that cattle ingesting

sludge gained less weight than the control group. The feed to gain

ratio of their sludge-fed steers averaged 2.2 and 2.0% for the 4 and 12%

sludge diets, which was better than the 2.6% observed with the controls.


Mineral Accumulation in Milk and Tissues of Sows


Data obtained on mineral present in milk and tissues of sows slaugh-

tered after weaning their second litters are presented in table 8. The

sludge diets resulted in no increase in concentration of selected elements

in milk or blood of the sows. However, sows fed the 10 or 20% sludge-

containing diets had an increase in cadmium in the kidney and muscle












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TABLE 8. EFFECT OF SEWAGE SLUDGE IN DIETS FED SOWS
OF MINERALS IN MILK AND SELECTED TISSUES WHEN THEY


ON CONCENTRATION
WERE SLAUGHTEREDab


Diet Pb Cd Ni Cu Cr Zn Mn Al Fe


Milk, mg/liter


1.0 .06
1.3 .06
1.0 .05


1.0 <.01c
1.1 <.01
1.2 <.01


Liver, mg/kg dry wt


Control
Sludge, 10%
Sludge, 20%


<.01
2
<.01


3d
14e
23e


39d
64e
51e


1d 231
11e 243
12e 209


Kidney, mg/kg dry wt


Control
Sludge,
Sludge,


<.01
<.01
<.01


4d
17e
24f


1d
8e
15f


5d
10e
20e


122d
123d
147e


Spleen, mg/kg dry wt


Control
Sludge,
Sludge,


Control
Sludge, 10%
Sludge, 20%


<.01
<.01
<.01


<.01
<.01
<.01


.4
2
<.03



1
2e
<.03d


8d
17e
19e


<.01d 128
15e 127
16e 123


<.05
<.05
<.05


259d
763e
873e



397d
1952e
1069e



483d
1123e
1062e


Muscle, mg/kg dry wt


4d
11e
21e


<.01d 113
12e 111
14e 90


2
.6
<.05


485d 689
836de 304
1006e 125


Blood, mg/liter


Control
Sludge, 10%
Sludge, 20%


2
<.01
<.01


13d
12d
7e


.5
<.05
<.05


7d
<.01e
I


384 2051
139 2289
374 2181


a
Milk from three sows/treatment during seventh day of the first lactation
period.
b
Tissues from six sows/treatment slaughtered after second pregnancy and
lactation period.
c
The < symbol denotes limit of measurement by procedure.
d,e,f
Means in columns with unlike superscript letters differ significantly
(P<.05).


Control
Sludge,
Sludge,


1217
1133
1126


3030d
4736e
5104f








(10% sludge only); nickel in the liver, kidney (20% sludge only), spleen

and muscle; copper in the liver; chromium in the liver, kidney, spleen

and muscle; zinc in the kidney (20% sludge only); manganese in the

liver, and aluminum in the liver, kidney, spleen and muscle. Similar

concentrations of several elements in swine liver to those found in the

present study have been reported (Liebholz et al., 1962; Hedges and

Kornegay, 1973; Gipp et al., 1974; Skutches et al., 1974).


Minerals in Weanling Pig Tissues


Concentrations of various elements in selected tissues of weanling

offspring from the first and second litters of sows fed diets that

contained 0, 10 or 20% sewage sludge are presented in table 9. The

liver of pigs fed sludge-containing diets had more (P<.05) lead, cad-

mium, and iron in the first litter pigs, but not in those of the second

litter. Aluminum was increased in pigs fed the 20% sludge level in the

second litters but not in the first litter pigs. Nickel was increased

with the 10% sludge diet but not at the 20% level with the first litter

pigs. The sludge diets had no effect on chromium, zinc and manganese in

the liver. Kidney concentrations of lead, cadmium, nickel, copper,

chromium, zinc, aluminum and iron were increased in weanling pigs from

the first litters of dams fed 20% sludge diets, and the same was true of

cadmium, nickel and chromium with the corresponding second litter pigs.

Manganese concentration in the kidney was not affected by dietary sludge.

In the spleen, nickel, copper and manganese at higher concentration with

weanling pigs of the first litters of dams fed diets that contained 20%

sewage sludge. Manganese levels were was also higher in the spleen of

pigs from dams fed sewage sludge at the 10% and 20% level, in the first





















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litters. Chromium was higher in the spleen of corresponding pigs of the

second litters of dams fed 20% sludge diets. Concentrations of lead,

cadmium, zinc, aluminum and iron in the spleen were not affected by the

sludge-containing diets. In skeletal muscle, cadmium, nickel, chromium,

zinc and manganese were higher in the first litter pigs of dams fed 20%

sludge diets, but, all except cadmium which was less, were not changed

in the second litter pigs. Manganese was also less at the 10% sludge

level in the second litter pigs. The sludge-containing diets had no

effect on lead, copper, aluminum and iron in muscle.

Lead and chromium were less concentrated in the blood of offspring

of second litters of dams fed 20% sludge diets. Nickel was less in the

blood of the corresponding first litter offspring. Chromium was higher

in first litter pigs of dams fed 20% sludge diets. Dietary treatments

had no effect on copper, zinc, manganese, iron and aluminum concentrations

in the blood.


Minerals in Growing-Finishing Swine


Concentration of selected elements in various tissues at time of

slaughter of the growing-finishing offspring fed diets that contained 0,

10 or 20% sewage sludge are presented in table 10. The sludge-contain-

ing diets fed the first litter offspring had no effect on concentrations

of any of the nine elements in the liver. However, in the second litter

pigs cadmium of the 20% sludge group and zinc of both sludge groups were

higher than controls. The kidney of the first litters was not affected

by the sludge diets. But the kidneys of the second litter swine had more

cadmium with both sludge levels. The sludge diets had no influence on

mineral deposition in the spleen of pigs from either the first or the















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second litters. Lead was greater in the muscle of the second litter

pigs fed the 20% sludge-containing diet, while zinc was lower in muscle

of second litter offspring that consumed 10 or 20% sludge diets. None

of the minerals were increased in blood due to the dietary sludge.

Statistical analyses of the data revealed more significant differences

between the two litters studied than between the treatments used. A

significant interaction between treatment and litter was observed only

for cadmium in the liver.

Smith et al. (1977a) reported that heavy metals and potentially

toxic trace elements tend to accumulate in the liver and kidney of rats

fed sludge-containing diets. These tissues had higher levels than

muscle tissue. They stated that levels of these elements in liver and

kidney can be regarded as indicators of potential hazards in the human

food chain. Baxter et al. (1980) fed cattle diets containing 0, 4, or

12% digested Denver or Fort Collins sludge for approximately three

months and found increases of cadmium, copper and lead in the kidney and

liver. The concentration of cadmium in kidneys increased with age of the

animal while liver copper concentration appeared to be limited by the

dietary intake. A four-month withdrawal period after feeding the sludge

for three months did not change the cadmium tissue concentration but

copper and lead declined. They concluded that sludge does not appear to

have any positive or negative effects on animal health or performance

other than to act as diet diluent. The accumulation in kidney of zinc

and cadmium was postulated to be due to sequestering by the kidney of

metallothionein, which tends to bind both metals in equimolar amounts.








Adverse Effect of Some Minerals in Tissues


Neathery and Miller (1975) reported that young calves are extremely

susceptible to lead toxicity. Lead inhibits the utilization of iron and

the biosynthesis of heme leading to anemia. It is believed to displace

other elements from enzymes. It inhibits lipoamide dehydrogenase in the

synthesis of acetyl Co-A and succinyl Co-A from pyruvate and a-ketoglu-

tarate. In dairy cows, Neathery and Miller (1975) also reported that

relatively little of the absorbed cadmium, inorganic mercury or lead are

secreted in milk or deposited in muscle. In the present study with

swine, dietary sludge did not affect cadmium concentration in milk or

muscle, but pigs fed sewage sludge had increased (P<.05) cadmium in the

kidney of sows, and level of the element in the sludge-containing diets

had no effect on the amount excreted. Very little cadmium was secreted

into milk. In rats, Neathery and Miller (1975) found that a cadmium

binding protein limits cadmium transfer to milk. Cadmium, in general,

was low in all the.tissues analyzed in the present experiment. But

according to Doyle (1977), when expreimental animals are fed low levels

of cadmium, a significant amount can accumulate in the liver, kidney,

small intestines and spleen. Dry University of Florida sewage sludge

fed to swine at 10 or 20% of the diets produced no obvious toxic effects.

However, with high intake levels, Edds et al. (1980) reported that a

toxicity may occur due to a deficiency of available protein and other

nutrients, or from the accumulation of hazardous chemical residues,

or was due to exposures to pathogenic micro-organisms or parasites.

Edds et al. (1980) also fed swine Chicago sewage sludge (high in cadmium

content) at 50% of dry weight of the diet for 42 days and observed a








cadmium toxicity. The metal blocked the microsomal enzyme system in

liver. They also observed depressed growth and feed consumption in pigs

fed 83 mg of cadmium per kilogram of feed. Kline et al. (1972) fed

pigs 250 ppm dietary copper and observed improved gains and feed effi-

ciency, but 500 ppm copper dietary levels depressed gains and showed no

effect on feed efficiency. No mortality or morbidity was observed at

the elevated copper levels. Popp et al. (1980) reported that swine

receiving 10 or 20% University of Florida sludge in their ration had

greater serum transaminase levels plus parenchymal liver disease and

degeneration, cellular infiltration with multiple foci of lymphocytes

and eosinophils as well as necrosis of the kidney. Kienholz et al.

(1976b) reported some adverse effects of heavy metals frequently found

in sludge. Cadmium was linked to hypertension, renal dysfunction and

Itai-Itai disease. Sheep are especially sensitive to elevated levels of

copper. High concentration of copper in the liver may cause liver

damage. Copper deficiency as well as toxicity in amimals is believed to

be caused by a copper-molybdenum imbalance. Diets containing 900 ppm of

zinc can cause deleterious effects in sheep and cattle. Lepple (1973)

reported that grain treated with mercurials for seed purposes led to

outbreak of human poisoning in Guatemala, Iran and Pakistan. In the

review, it was pointed out that a New Mexico family became ill after

they consumed pork from animals fed seed coated with an organic mer-

curial called panogen. The grain contained 32 ppm mercury compared to

28 ppm in the pork. Three children became delirious, blind and even-

tually comatose. On a New York farm, pigs fed wheat grain that had been

coated with panogen exhibited symptoms of minamata disease for 3 to 5





47


days before dying in a coma. Toxicological tests confirmed that the

problem was due to mercury poisoning.












SUMMARY AND CONCLUSIONS


The reproductive, growth and metabolism trials of the present study

demonstrated the relative health safety and nutritive value of sewage

sludge. Reasonable safety to health of swine was indicated by the

observations that young sows could be fed 10 and 20% sewage sludge-

containing diets and weaned two apparently healthy litters of pigs over

approximately one year. There was no secretion in milk or accumulation

of hazardous levels of metals in the tissues of the sows or their wean-

ling offspring. The offspring, when grown to market weight on the

sludge-containing diets grew normally and did not accumulate hazardous

levels of potentially toxic minerals. Feed intake increased with sludge

addition to the diets, probably due to a relative high ash (sand) level

in the sludge. There was some depression in growth rate and feed effi-

ciency with the sludge-containing diets, especially at the 20% sludge

level. However, no mortality or morbidity was observed in any swine

that consumed the diets. In the metabolism trial, ME, TDN and nitrogen

retention were significantly depressed in the 20% sludge-containing diets.

The 10% sludge levels also tended to decrease the availability of these

nutrient factors. Feed efficiency was significantly depressed at both

10 and 20% levels of sludge in the growing-finishing diets. Overall,

no significant nutritional benefit in reproduction and growth was observed

when sludge was included in swine diets. However, the sludge in this

study did not demonstrate the presence of any especially hazardous





49


pathogens, parasites, chemical contaminants or other material that

affect the health of the animal consuming it. However, further research

would be necessary before recommendations can be made.













BIBLIOGRAPHY


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Engineering Progress Symposium Series. pp. 188-191.

American Society of Civil Engineers. 1959. Committee on sanitary
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AOAC. 1975. Official methods of analysis (12th Ed.). Association of
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Ardern,D. A. 1976. The agricultural use of municipal sludge. In
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Barr, A. J., J. H. Goodnight, J. P. Sall and J. T. Hellwig. 1976. A
user's guide to SAS 76. Sparks Press, Raleigh, N.C.

Bastian, R. K. 1977. Guidance on land application of municipal sludge.
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Fertilizer and Agricultural Residues. Ann Arbor Science. Ann
Arbor, MI. pp. 125-136.

Bastian, R. K. and W. A. Whittington. 1977. EPA guidance on disposal
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Bauer, D. H., D. E. Ross and E. T. Ross. 1977. Land cultivation of
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Baxter, J. C., D. E. Johnson and E. W. Kienholz. 1980. Uptake of trace
metals and persistent organic into bovine tissues from sewage
sludge Denver Project. In Proceedings of the Conference on
Evaluation of Health Risks Associated with Animal Feeding and/or
Land Application of Municipal Sludge. G. Bitton, B. L. Damron,
G. T. Edds and J. M. Davidson, eds. Ann Arbor Science. Ann Arbor,
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Beaudouin, J., D. L. Hammell and R. L. Shirley. 1977. Sewage sludge
diets fed swine Vs. reproduction, growth and tissue minerals. In
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Animal Science. University of Wisconsin, Madison, WI. Abstract
No. 199.








Bertrand, J. E., M. C. Lutrick, H. L. Breland and R. L. West. 1980.
Effects of dried digested sludge on performance, carcass quality
and tissue residues in beef steers. J. Anim. Sci. 50(1):35-40.

Black, S. A. 1974. Utilization of digested chemical sewage sludges on
agricultural lands in Ontario. In Proceedings of the National
Conference on Municipal Sludge Management. Pittsburg, PA. pp.
107-113.

Blok, A. 1976. Pelletized sludge: resource recovery product. In
procedure of the 3rd National Conference on Sludge Management,
disposal and utilization. Miami Beach, FL. pp. 81-83.

Cambel, P. 1971. Improved control of animal waste. In Animal Waste
Management Proceeding of the National Symposium on Animal Waste.
Airlie House, Warrenton, VA. p. 7.

Cardenas, R. R. and S. Varro. 1973. Disposal of urban wastes by compost-
ing. In G. E. Inlett ed. The Avi Publishing Co. Inc., Westport,
CT. pp. 183-204.

Chaney, R. L. 1973. Crop and food chain effects of toxic elements in
sludges and effluents. In Proceedings of the Joint Conference on
recycling municipal sludges and effluents on land. Champaign, IL
pp. 129-143.

Chaney, R. L. 1975. Plant uptake of heavy metals from sewage sludge
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BIOGRAPHICAL SKETCH


Joseph Jean Beaudouin was born March 16, 1938, in Les Cayes, Haiti.

In July 1963, he graduated from the State University of Haiti with a

B.S. degree in Agronomy. From August 1963 to September 1966, he worked

for the Haitian Department of Agriculture as an extension agent. In

April 1968, he obtained his Master of Science in Agriculture from the

Interamerican Institute of Agricultural Sciences of the Organization of

American States (OAS) in Turrialba, Costa Rica. At present, he is a

candidate for the Ph.D. degree in Animal Science at the University of

Florida. He is married to the former Winie Bernard, who is also from

Haiti.

He is a member of the Latinamerican Association of Animal Pro-

duction and the American Society of Animal Science.








I certify that I have read this study and that in my opinion it
.conforms to acceptable standards of scholarly presentation and is fully
adequate, in scope and quality, as a dissertation for the degree of
Doctor of Philosophy.




Dr. R. L. Shirley, Chairmar/
Professor of Animal Science


I certify that I have read this study and that in my opinion it
conforms to acceptable standards of scholarly presentation and is fully
adequate, in scope and quality, as a dissertation for the degree of
Doctor of Philosophy.




Dr. A. Z./Palmer
Professor of Animal Science


I certify that I have read this study and that in my opinion it
conforms to acceptable standards of scholarly presentation and is fully
adequate, in scope and quality, as a dissertation for the degree of
Doctor of Philosophy.


/I


Dr. G. T.
Professor


> j ;*
Edds
of Veterinary Science


I certify that I have read this study and that in my opinion it
conforms to acceptable standards of scholarly presentation and is fully
adequate, in scope and quality, as a dissertation for the degree of
Doctor of Philosophy.


Dr. D. S.
Professor


Anthony
of Botany








I certify that I have read this study and that in my opinion it
*conforms to acceptable standards of scholarly presentation and is fully
adequate, in scope and quality, as a dissertation for the degree of
Doctor of Philosophy.




Dr. P. H. Smith
Professor of Microbiology and Cell
Science


This dissertation was submitted to the Graduate Faculty of the
College of Agriculture and to the Graduate Council, and was accepted
as partial fulfillment of the requirements for the degree of Doctor
of Philosophy.


March 1981




Dean,/ 11ege of Agri eture


Dean, Graduate School











































UNIVERSITY OF FLORIDA
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