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# 
 
 iL-e- 
 
 THE ECONOMIC VALUE OF MANURE 
 FROM CONFINEMENT FINISHING OF HOGS 
 
 Roy N. Van Arsdall 
 
 . .. 
 
 .- 
 
 V 
 
 Bulletin 687 
 
 VERSITY OF ILLINOIS AGRICULTURAL EXPERIMENT STATION 
 
CONTENTS 
 
 Method of Study 4 
 
 Built-up Litter Systems 4 
 
 Liquid-Manure Systems 5 
 
 Cleaning Methods 6 
 
 Frequency of Cleaning 6 
 
 Storage Facilities 6 
 
 Pumping from Storage 7 
 
 Liquid Applicators 8 
 
 Frequency of Hauling 8 
 
 Disadvantages of Liquid-Manure Systems 9 
 
 Initial and Annual Costs of Liquid-Manure Systems 9 
 
 Cost of Storage Facilities 9 
 
 Cost of Disposal Lagoons 11 
 
 Value of Liquid Hog Manure 13 
 
 Losses in Fertility Value 15 
 
 Availability of Fertility Elements 16 
 
 Other Economic Factors 18 
 
 Summary 19 
 
 This bulletin was prepared by ROY N. VAN 
 ARSDALL, Agricultural Economist, Economic Re- 
 search Service, United States Department of 
 Agriculture, and Professor of Agricultural Eco- 
 nomics, University of Illinois. Published in co- 
 operation with the Farm Economics Division, 
 Economic Research Service, United States De- 
 partment of Agriculture. 
 
 Urbana, Illinois May, 1962 
 
 Publications in the Bulletin series report the results of investigations made 
 or sponsored by the Experiment Station 
 
MANURE HAS BEEN CALLED the most valuable byproduct of Illinois 
 agriculture. 1 Approximately 13 million hogs are produced on Illinois 
 farms each year. The manure byproduct from this branch of the state's 
 livestock industry yields plant nutrients that would cost many millions 
 of dollars if purchased at prevailing prices for chemical fertilizers. 
 
 Collection and use of this manure, however, constitute an increas- 
 ingly heavy expense for the farmer. Probably as much as half of all 
 hog manure is now dropped at the farmstead, and the trend toward 
 confinement raising of hogs will increase this amount still further. 
 Many farmers who change from pasture to confinement production of 
 hogs to eliminate such jobs as fence building, and hauling feed and 
 water, soon find that the manure-handling chore more than offsets the 
 labor saved in other parts of the operation. 
 
 Manure handling in confinement systems has been taking an average 
 of three- fourths of the total labor input used to grow and finish hogs. 
 Loaders, spreaders, tractors, and other manure-handling equipment, 
 and the bedding used to keep the hogs clean and comfortable and to 
 conserve the liquid in the manure have added to production costs. 
 
 The handling of manure has always been accepted as a necessary 
 and unavoidable cost of livestock production. Because the manure had 
 to be loaded on a vehicle and hauled from the premises in any case, 
 the profitability of spreading it on cropland was not questioned. The 
 fertility value thus obtained was simply a bonus return to the enterprise. 
 
 The valuable plant nutrients in manure are perhaps present in 
 greater quantity now than formerly because of the increased use of 
 high-protein feeds. Spreading solid manure on cropland rather than 
 dumping it in a disposal area is still a profitable practice because there 
 is little difference between spreading and disposal costs. 
 
 Technological improvements in housing and equipment, however, 
 have changed hog production methods, and also the cost situation. In a 
 properly designed building, hogs can do without bedding, and water 
 can be used to clean the floors, converting the manure into a fluid that 
 can be removed with pumps or by gravity. Under this system it is 
 easy and relatively inexpensive to discard the manure in a lagoon or 
 other kind of disposal system. 
 
 These new developments raised the question of whether the value 
 of liquid hog manure justifies the added expense of providing storage 
 for it and applying it to cropland, or whether it is more economical to 
 
 1 Thompson, W. N., Manure Multimillion Dollar Byproduct. Farm Mgt. 
 Letter 41, Agr. Econ. Dept., Univ. 111., July, 1953. 
 
4 BULLETIN No. 687 [May, 
 
 buy chemical fertilizers and consider liquid manure a waste product 
 to be removed in the least expensive way. 
 
 Method of Study 
 
 A study to provide information for an economic evaluation of 
 confinement systems of hog production on Illinois farms was initiated 
 by agricultural economists of the Farm Economics Division, Economic 
 Research Service, U. S. Department of Agriculture, and the Illinois 
 Agricultural Experiment Station. The study covered 72 farms on 
 which hogs were grown and finished in confinement during 1959 and 
 1960. Operators of these farms furnished information by answering 
 questions, permitting researchers to observe their operations, and keep- 
 ing production and labor records. 
 
 The problem of manure handling was selected for special considera- 
 tion because it is a laborious, disagreeable, and time-consuming job 
 that has probably caused more concern than any other aspect of con- 
 finement raising of hogs. Three methods of handling hog manure 
 were studied: (1) the use of straw or other dry bedding material and 
 the subsequent handling of manure as a solid; (2) the confinement of 
 hogs on a bare concrete floor and the handling of manure as a liquid, 
 to be stored and later applied to cropland; (3) the handling of manure 
 as a liquid to be discarded in a manure lagoon. The chief concern of 
 this study was to compare costs and benefits of methods (2) and (3) 
 for enterprises ranging in capacity from 250 to 2,500 hogs in terms of 
 annual production. 
 
 Data from the records of the 1959-1960 hog enterprises are used 
 throughout this bulletin to describe systems of handling manure, and 
 as a partial basis for estimating or calculating the capital requirements 
 and annual costs cited in the tables. Values for the soil fertility ele- 
 ments in hog manure and the probable fertility losses in handling, 
 storage, and application to cropland were obtained from research data 
 as noted. 
 
 Built-up Litter Systems 
 
 Most confinement producers have followed the conventional method 
 of bedding their buildings with straw or similar material and period- 
 ically removing the bedding and manure in solid form with tractor- 
 powered equipment. Previous experience with pasture systems of 
 producing hogs, the use of bedding with other classes of livestock, and 
 the availability of tractor-powered loaders, scrapers, and spreaders led 
 
1962] VALUE OF MANURE IN CONFINEMENT FINISHING OF HOGS 5 
 
 farmers to continue with conventional methods. Also, it was seldom 
 possible to provide the drainage necessary for successful operation of 
 a liquid system in buildings converted into finishing barns from other 
 uses. Even on farms with new buildings designed for handling liquid 
 manure, farmers have sometimes been forced to revert to handling 
 manure as a solid during part of the year because of freezing tempera- 
 tures and inadequate drainage. 
 
 All farmers in the study who handled manure as a solid used tractor- 
 mounted loaders for putting manure into spreaders. Only a third of 
 the operators, however, were able to clean their facilities entirely with 
 tractor equipment. A similar proportion relied about equally on hand 
 labor and tractor-powered equipment. The remaining third did 
 all of their cleaning by hand because their buildings could not be 
 entered with a tractor. Most of the units in the last group housed fewer 
 than 200 head of hogs. 
 
 As a year-round average, the built-up litter systems were cleaned 
 once a week. Some operators, however, simply added straw two or 
 three times a week, or as needed, to keep the bedded area clean, and 
 removed manure from the buildings no oftener than once a month. 
 
 Systems with built-up litter were usually cleaned only when the 
 manure could be spread directly on the fields. Sometimes, however, 
 the manure was stored in piles to await spreading under suitable condi- 
 tions. A slab or wide gutter outside the lot fence was the extent of 
 storage structures and none of the storage areas was roofed. Losses, 
 inadequate drainage, odors, and flies usually made such storage 
 unsatisfactory. 
 
 Liquid-Manure Systems 
 
 Systems designed for handling manure as a liquid are drawing in- 
 creasing interest from hog producers in the Midwest. A few of the 
 early users of such systems disposed of the manure by flushing it into 
 some type of drainage system. Most producers, however, built storage 
 tanks and arranged for spreading the liquid manure on cropland. 
 
 Unlike the common European practice of providing storage for the 
 highly concentrated urine only, the practice of midwestern hog pro- 
 ducers is to store and handle all of the hog excrement plus all water 
 used in the cleaning operation. The problem of handling such large 
 volumes of liquid has aroused interest in the lagoon system in which 
 the manure is flushed into a lagoon or pond, where it is stabilized by 
 bacterial action. This disposal method wastes the fertility value of the 
 manure, but saves considerable labor and equipment expense. 
 
6 BULLETIN No. 687 [May, 
 
 Cleaning methods. Units for handling manure as a liquid are 
 cleaned either with hand scrapers or with water under pressures of 
 100 to 120 pounds per square inch. In the manual systems, water is 
 used as a carrying agent to move the manure to storage or a disposal 
 area. Units equipped with high-pressure water systems use water both 
 for cleaning the floors and for carrying away the manure. The opera- 
 tor works from a center or side alley and flushes the manure to a gutter 
 on the opposite side of the pen. 
 
 An experimental unit on the Moorman Swine Breeding Research 
 Farm at the University of Illinois holds promise for reducing the labor 
 of manure removal. A growing-finishing building has been con- 
 structed with a slotted (or slatted) floor so that the excrement passes 
 through the slots and is pooled in water beneath the building and 
 periodically flushed into a lagoon for disposal. It is expected that the 
 slotted floor will be virtually self -cleaning. 1 Researchers hope also that 
 the contents of the holding pool can be flushed into the lagoon without 
 difficulty the year around or, if necessary, retained beneath the build- 
 ing for extended periods without ill effects. 
 
 Frequency of cleaning. Farmers who do not use bedding in their 
 growing-finishing facilities usually consider daily cleaning a necessity. 
 A few producers scrape or flush their floors twice daily, while others 
 clean them as infrequently as once each week. Floors are usually 
 cleaned more often when the hogs are large, and during wet, cool 
 weather. 
 
 Research to date has not provided an answer to the question of what 
 constitutes optimum cleanliness in hog buildings. Among the factors 
 to be considered are the effect of manure accumulation on the animals, 
 and the attitude of the operator. If manure accumulation does not 
 constitute a costly stress on the animals, then fewer cleanings would 
 reduce unit costs. The farmer's satisfaction in having a neat, clean 
 operation, and the desire to forestall offensive odors from manure 
 accumulation have so far tended to encourage the practice of daily 
 cleaning. 
 
 Storage facilities. Tanks for conserving liquid manure for use on 
 cropland are commonly constructed of either concrete block or cast- 
 in-place concrete. Most are built on the farm, but prefabricated tanks 
 are sometimes used in small operations. Tanks for storing liquid 
 
 1 Spillman, C. K., "Slatted Floors for Raising Swine," Illinois Research, 
 Vol. 3, No. 3, 111. Agr. Exp. Sta., 1961. 
 
1962] 
 
 VALUE OF MANURE IN CONFINEMENT FINISHING OF HOGS 
 
 manure should be designed to handle 2 gallons of liquid per hog per 
 day for at least 2 weeks if floors are washed with water. 1 
 
 Capacity of the tanks on the farms in the study ranged from less 
 than 2-day up to 4- week accumulations (Table 1). Differences in 
 cleaning practices and amount of water used account for part of the 
 variation in capacity. For the most part, tank capacities approached 
 
 Table 1. Characteristics of Facilities for Storing Hog Manure 
 as a Liquid in Confinement Finishing Systems 
 
 
 
 
 Producers' 
 
 estimates 
 
 
 Actual tank 
 
 Farm 
 No. 
 
 Type of 
 layout 
 
 Maxi- 
 mum 
 number 
 of hogs 
 
 Tank 
 capacity 
 in terms 
 of volume 
 
 Tank 
 capacity 
 in terms 
 of time 
 
 Tank 
 capacity 
 per hog 
 per day* 
 
 capacity at 
 2 gallons 
 per hog 
 per day 
 
 1 
 
 . . . roofed 
 
 600 
 
 gallons 
 10,000 
 
 days 
 30 
 
 gallons 
 .56 
 
 days 
 8.3 
 
 2 
 
 roofed 
 
 200 
 
 3,200 
 
 21 
 
 .76 
 
 8.0 
 
 3 
 
 roofed 
 
 200 
 
 3,400 
 
 7 
 
 2.43 
 
 8.5 
 
 4 
 
 roofed 
 
 200 
 
 4,000 
 
 14 
 
 1.43 
 
 10.0 
 
 5 b 
 
 . . roofed 
 
 500 
 
 25,000 
 
 30 
 
 1.67 
 
 25.0 
 
 6 . 
 
 . . open c 
 
 225 
 
 1,500 
 
 3 
 
 2.22 
 
 3.3 
 
 7 
 
 open 
 
 420 
 
 12,000 
 
 12 
 
 2.38 
 
 14.3 
 
 8 
 
 . . . open" 
 
 400 
 
 9,000 
 
 14 
 
 1.61 
 
 11.2 
 
 9 
 
 . . . open c 
 
 850 
 
 3,000 
 
 7 
 
 .50 
 
 1.8 
 
 10 
 
 . . . open d 
 
 400 
 
 3,600 
 
 ( e ) 
 
 ( e ) 
 
 4.5 
 
 
 
 
 
 
 
 
 * Based on maximum number of hogs that could be put into the buildings as estimated 
 by the producer. 
 
 b This unit was cleaned with water under high pressure. All other producers scraped 
 their floors by hand, and used water to flush the manure into storage but not to clean the floors. 
 
 f Roof guttered or sloping away from the open lot, thus not draining into the storage tank. 
 
 d Roof drained into the storage tank. 
 
 e No estimate. 
 
 the recommended levels on the basis of length of storage period esti- 
 mated by the farmer, but few were large enough to hold a minimum 
 2- week accumulation based on a daily rate of 2 gallons per hog with 
 the house stocked to capacity. Some tanks had as little as one- fourth 
 the storage space necessary to handle a liquid system. Overflow from 
 storage tanks was frequent on these farms, and it was particularly 
 serious when barn roofs and open lots drained into them. 
 
 Pumping from storage. Electric- and gasoline-powered diaphragm 
 pumps, tractor-powered vacuum pumps, and electrically driven augers 
 were used to remove liquid manure from storage on the farms in the 
 
 1 Jedele, D. G., and Hansen, E. L., Handling Hog Manure as a Liquid, 111. 
 Agr. Ext. Serv. Cir. 820, April, 1960. 
 
8 BULLETIN No. 687 [May, 
 
 study. The diaphragm and vacuum pumps normally produced at a 
 higher rate than the auger units, but they required relatively large 
 power units, and initial costs were high usually from $350 to $500 
 excluding the power unit. 
 
 The typical system was equipped with an auger to move the liquid 
 from storage to an applicator tank. Four-inch enclosed augers, 16 to 
 20 feet long, powered by a 1/3- to 1 -horsepower electric motor, were 
 used by most producers. These units cost $100 to $150 depending upon 
 motor size and quality of the auger. 
 
 Chief difficulties encountered by the early users of auger pumps 
 were low rate of output, and rapid deterioration of the unit. Under- 
 powered augers often required as much as 1 hour to move 500 gallons 
 of liquid from storage to the applicator tank, causing considerable 
 waste of labor on many farms. 
 
 Tests conducted at the University of Illinois indicate that a 4-inch 
 auger will pump about 50 gallons per minute when operated at 1,600 
 r.p.m. using a 1 -horsepower motor. 1 This rate is sufficient to fill the 
 usual applicator tank in a reasonable amount of time. 
 
 Liquid applicators. There has been a lack of effective equipment 
 designed specifically for spreading liquid manure onto cropland. Be- 
 cause of the relatively small number of potential customers, the main- 
 line equipment manufacturers were not producing liquid spreaders in 
 quantity during the period of study. Most farmers were and still 
 are using custom-made units mounted on a running gear and pulled 
 by a tractor, or mounted permanently on a truck frame. Attachments 
 usually consist of a fan-shaped or rotating spreader, and an agitator 
 to prevent the solids from settling. 
 
 Tank sizes used by most producers range from 500 to 1,000 gallons. 
 Economy of travel encourages farmers to use large tanks, but weight 
 places the practical limit at about 1,000-gallon capacity for most situa- 
 tions. Cost ranges up to $1,000 for a 1,000-gallon unit. Mounting the 
 tank on a truck frame instead of using tractor power adds considerably 
 to the initial cost, but some farmers prefer this method in order to 
 .free the tractor for other jobs. 
 
 Some commercial equipment for application of liquid manure is 
 now available at about the same cost as custom-built units. 
 
 Frequency of hauling. On the study farms the frequency of haul- 
 ing varied from almost once a day for operators with small storage 
 
 1 Illinois Circular 820. 
 
1962] VALUE OF MANURE IN CONFINEMENT FINISHING OF HOGS 9 
 
 tanks, to once a month at the other extreme. Storage capacity and 
 volume of water moving into storage were the chief factors affecting 
 frequency of hauling. Condition of the fields, availability of a place 
 to spread the liquid, and demands of other jobs were other factors. 
 
 Disadvantages of liquid-manure systems. None of the producers 
 included in the study was completely satisfied with the liquid cleaning 
 system he was using. Frequent criticisms included the large amount 
 of time and hand labor necessary to scrape or hose down the buildings, 
 and the time and expense involved in hauling the huge quantities of 
 liquid accumulated in water-cleaned systems. The hogs were incon- 
 sistent in their use of the dunging alley, intensifying the cleaning prob- 
 lem so that building designs did not function as expected. In the 
 open- front buildings, freezing during winter compelled some operators 
 to abandon the liquid system temporarily and to use bedding to protect 
 the hogs. Such combination systems created operational problems. 
 The need to haul liquid regularly and frequently sometimes forced 
 farmers to travel over wet fields or, particularly during the crop- 
 growing season, to dump manure on wasteland. During the summer, 
 odors and flies constituted serious nuisances on many farms. 
 
 Initial and Annual Costs of Liquid-Manure Systems 
 
 There is some variation in the cost of systems designed to store 
 liquid manure and preserve its fertility value for use on cropland. 
 Factors that influence cost of facilities include locality, type of mate- 
 rials, kind of equipment, and the farmer's ability for carpentry and 
 shopwork. Key factors in establishing operating costs include avail- 
 ability of tractor power for hauling the liquid, location of areas on 
 which the liquid is to be spread, and value placed on the operator's time. 
 
 Cost of storage facilities. Storage is of first concern in planning a 
 system when the liquid manure is to be used on the land. It is advisable 
 to plan for holding at least 2 weeks' production from the full capacity 
 of the system. A good rule-of-thumb for determining the necessary 
 volume of storage facilities is to multiply the number of hogs at maxi- 
 mum capacity times 2 gallons of liquid times days of storage desired. 
 A unit designed for 125 hogs, therefore, would require a 3,500-gallon 
 storage tank to handle a 2-week accumulation. Storage space for 
 35,000 gallons would be needed for an operation handling 1,250 hogs 
 at one time. 
 
 Storage tanks can be constructed from several materials, but cast- 
 in-place concrete or core-filled concrete blocks are best for most areas 
 
10 BULLETIN No. 687 [May, 
 
 Table 2. Calculated Initial and Annual Cost of Concrete Tanks 
 for Storing Liquid Hog Manure 
 
 Size of tank 8 
 
 Capacity in 
 gallons' 5 
 
 First cost 6 
 
 Annual cost d 
 
 10' x 4' 
 
 1 500 
 
 $ 276 
 
 $ 28 
 
 10' x 6' 
 
 2,250 
 
 324 
 
 32 
 
 10' x 8' 
 
 3,000 
 
 394 
 
 39 
 
 20' x 4'.. 
 
 3,000 
 
 462 , 
 
 46 
 
 20' x 6' 
 
 4,500 
 
 576 
 
 58 
 
 20' x 8' 
 
 6,000 
 
 676 
 
 68 
 
 30' x 4' 
 
 .... 4 500 
 
 668 
 
 67 
 
 30' x 6' 
 
 6 750 
 
 812 
 
 81 
 
 30' x 8' 
 
 9 000 
 
 962 
 
 96 
 
 40' x 4' 
 
 6 000 
 
 876 
 
 88 
 
 40' x 6' 
 
 9,000 
 
 1,062 
 
 106 
 
 40' x 8' 
 
 12,000 
 
 31,244 
 
 ?124 
 
 
 
 
 
 a Inside dimensions. 
 
 b Assuming the level of liquid to be 1 foot below the top of 6-foot-deep tank. 
 
 c Tank is constructed of cast-in-place concrete walls and floor, 6 inches thick, reinforced 
 with 6-by-6-inch welded-wire mesh. Top is wood frame covered with sheet metal. Material 
 prices are typical for central Illinois in 1960. Labor for construction is charged at 100 percent 
 of material cost. Concrete-block tanks, core-filled and reinforced, can be constructed at similar 
 costs. (For construction details see Illinois Circular 820.) 
 
 d Includes 5 percent for depreciation and 5 percent for interest, maintenance, and taxes. 
 
 in Illinois. Calculated initial costs of tanks per 1,000 gallons of capacity 
 range from $104 for 12,000-gallon tanks to $184 for 1,500-gallon tanks 
 (Table 2). These costs include a labor charge equal to 100 percent of 
 the material cost. One or more of these tanks, as required to supply 
 needed capacity, form the basis of the storage-investment estimates 
 appearing in Table 3. 
 
 Some economy is achieved with the larger storage tanks. Size of 
 operation is even more important, however, in cutting unit investments 
 in pumping and spreading equipment because essentially the same 
 equipment is needed for handling liquid manure whether the operation 
 is small or large. Estimates indicate that a tenfold increase in output 
 necessitates less than a threefold increase in investment for manure 
 storage and handling facilities (Table 3). 
 
 Annual calculated costs of storing, pumping, hauling, and spreading 
 liquid manure range from about $320 for 250 hogs to $1,550 for 2,500 
 hogs (Table 4). The unit cost advantage remains with the larger 
 operations, but it is not so pronounced as with investments because 
 labor and tractor inputs comprise a substantial part of the total annual 
 cost. These two inputs, which account for 30 percent of the total cost 
 for 250 hogs and 60 percent of the total cost for 2,500 hogs, cost about 
 the same per unit regardless of size of operation. Producers with large 
 
1962} VALUE OF MANURE IN CONFINEMENT FINISHING OF HOGS 11 
 
 Table 3. Calculated Capital Outlay for New Facilities for Storing, 
 Pumping, Hauling, and Spreading Liquid Hog Manure 
 
 Hogs 
 produced 
 annually 
 
 Investments 
 
 Storage 
 tank(s) 
 
 Auger 
 pump a 
 
 Applicator 
 tank b 
 
 Total 
 
 250 
 
 $ 460 
 
 $130 
 130 
 130 
 130 
 130 
 130 
 130 
 $130 
 
 $1 ,000 
 1,000 
 1,000 
 1,000 
 1,000 
 1,000 
 1,000 
 $1,000 
 
 $1,590 
 1,972 
 2,472 
 2,814 
 3,002 
 3,336 
 4,124 
 $4,756 
 
 500 
 
 842 
 
 750 
 
 1,342 
 
 1,000 
 
 1,684 
 
 1,250 
 
 1,872 
 
 1,500 
 
 2,206 
 
 2,000 
 
 2,994 
 
 2,500 
 
 $3,626 
 
 
 
 8 A heavy-duty 4-inch by 20-foot auger with 1-horsepower motor. 
 
 b A 1,000-gallon tank with agitator and fan spreader mounted on four-wheel running 
 gear. Assuming availability of a tractor to pull applicator tank. In large operations an addi- 
 tional tractor may be required. 
 
 operations, however, may experience a considerable increase in unit 
 labor and tractor costs if they are forced to go farther and farther 
 from the production center to find areas on which to apply the manure 
 profitably. Thus as size of operation increases, the cost estimates in 
 Table 4 actually become increasingly conservative. 
 
 Cost of disposal lagoons. The task of getting liquid manure from 
 feedlot to cropland has caused increased interest in lagoons for manure 
 
 Table 4. Calculated Annual Labor, Equipment, and Structure Costs 
 for Storing, Pumping, Hauling, and Spreading Liquid Hog Manure 
 
 Labor d Tractor 8 Total 
 
 annually 
 
 tank" 
 
 pump b 
 
 tank 
 
 Hours 
 
 Cost 
 
 Hours 
 
 Cost 
 
 costs 
 
 250.. 
 
 $ 46 
 
 $31 
 
 $147 
 
 46 
 
 $ 55 
 
 34 
 
 $ 40 
 
 $319 
 
 500 
 
 84 
 
 32 
 
 154 
 
 90 
 
 108 
 
 68 
 
 80 
 
 458 
 
 750 
 
 134 
 
 34 
 
 161 
 
 135 
 
 162 
 
 101 
 
 118 
 
 609 
 
 1,000 
 
 168 
 
 35 
 
 168 
 
 181 
 
 217 
 
 135 
 
 158 
 
 746 
 
 1,250 
 
 187 
 
 36 
 
 174 
 
 226 
 
 271 
 
 169 
 
 198 
 
 866 
 
 1,500 
 
 221 
 
 38 
 
 181 
 
 271 
 
 325 
 
 202 
 
 236 
 
 1,001 
 
 2,000 
 
 299 
 
 41 
 
 195 
 
 362 
 
 434 
 
 270 
 
 316 
 
 1,285 
 
 2,500 
 
 $363 
 
 $44 
 
 $208 
 
 452 
 
 $542 
 
 338 
 
 $395 
 
 $1,552 
 
 
 
 
 
 
 
 
 
 
 a Ten percent of initial cost to cover annual costs of depreciation, interest, taxes, insur- 
 ance, maintenance, and repairs. 
 
 b A 5-year or 1,500-hour life with lifetime repairs equaling 50 percent of initial cost of 
 machine; electricity use charged at 2 cents per horsepower hour. 
 
 c A 5-year life with lifetime repairs equalling 30 percent of initial cost. 
 
 d Twenty minutes to pump, 15 minutes to spread, and 5 minutes for preparatory work in 
 handling a 1,000-gallon tank of manure. Wage rate, $1.20 per hour. 
 
 8 Tractor time is 30 minutes per load at $1.17 per hour, the 1958 average cost of using 
 25- to 36-horsepower tractors for 500 or more hours per year. Agr. Econ. Res. Rep. 32, 
 Detailed Cost Report for Heavy Till Soils, Central Illinois, 1958. Agr. Econ. Dept., Univ. of 
 
12 BULLETIN No. 687 [May, 
 
 disposal. Under this system, manure is flushed from the buildings and 
 lots into a lagoon or pond where it is stabilized by bacterial action. 
 Cities and factories have used this method of waste disposal for many 
 years, but only limited data are available concerning the use of lagoons 
 in animal production. 
 
 Early attempts at using lagoons for handling liquid hog manure 
 have been encouraging. Experience shows that a lagoon that is con- 
 structed, used, and maintained according to recommended procedures, 1 
 remains serviceable for at least 5 years. A more exact determination 
 of useful life and of the costs of rejuvenating a lagoon will require 
 study of the rate of sediment accumulation, and longer and more 
 extensive experience under operating conditions. 
 
 Experimental lagoons at the University of Illinois swine farm are 
 designed to provide from 20 to 60 square feet of water surface area 
 per hog. These trials are incomplete, but 20 square feet are presently 
 considered adequate. On this basis, the land area needed for a lagoon 
 is rather small, amounting to less than 1 acre for an operation produc- 
 ing 2,500 hogs per year (Table 5). 
 
 Table 5. Calculated Size of Lagoon for Handling Liquid Manure 
 for Selected Sizes of Hog Operations 
 
 Hogs 
 
 produced 
 
 Water area 
 needed* 
 
 Fencing 
 needed 6 
 
 Each year 
 
 Maximum on hand 
 
 
 
 square feet 
 
 feet 
 
 250 
 
 125 
 
 2,500 
 
 320 
 
 500 
 
 250 
 
 5,000 
 
 404 
 
 750 
 
 375 
 
 7,500 
 
 468 
 
 1,000 
 
 500 
 
 10,000 
 
 520 
 
 1,250 
 
 625 
 
 12,500 
 
 568 
 
 1,500 
 
 750 
 
 15,000 
 
 608 
 
 2,000 
 
 1,000 
 
 20,000 
 
 684 
 
 2,500 
 
 1,250 
 
 25,000 
 
 752 
 
 Based on 20 square feet per head and the maximum expected to be on hand at one time. 
 b Lagoon is assumed to be square with the fence 15 feet from the shoreline. 
 
 The cost of building a lagoon is affected greatly by its site and by 
 custom rates for earth moving, and the like. The average farmer can 
 expect to invest from $30 to $80 per 100 hogs produced annually, 
 depending upon size of operation, if he hires all of the work done 
 (Table 6). 
 
 1 For specific recommendations, see Illinois Circular 820. 
 
1962] VALUE OF MANURE IN CONFINEMENT FINISHING OF HOGS 13 
 
 Table 6. Calculated Initial and Annual Costs of Liquid-Manure 
 Lagoons to Service Selected Sizes of Hog Operations 
 
 Hogs 
 produced 
 annually 
 
 Earth 
 moving* 
 
 Fencing 13 
 
 Tile" 
 
 Total 
 invest- 
 ment 
 
 Total 
 annual 
 costs d 
 
 250.. 
 
 . $ 56 
 
 27 
 
 3120 
 
 #203 
 
 $ 51 
 
 500 
 
 111 
 
 36 
 
 120 
 
 267 
 
 67 
 
 750 
 
 166 
 
 43 
 
 120 
 
 329 
 
 82 
 
 1,000 
 
 222 
 
 48 
 
 120 
 
 390 
 
 98 
 
 1,250 
 
 278 
 
 53 
 
 120 
 
 451 
 
 113 
 
 1,500 
 
 333 
 
 58 
 
 120 
 
 511 
 
 128 
 
 2 000 
 
 . . . 444 
 
 66 
 
 120 
 
 630 
 
 158 
 
 2 500 
 
 #555 
 
 $72 
 
 #120 
 
 3747 
 
 3187 
 
 
 
 
 
 
 
 A 45-horsepower bulldozer moving earth an average of 100 feet at a rate of 50 cubic 
 yards per hour. Lagoon averages 2 feet of earth removal. Fifteen dollars per hour for an 
 operator and machine. 
 
 b A 3-strand barbed-wire and steel-post fence around the lagoon 15 feet from the shoreline. 
 
 c An 8-inch tile to carry liquid from buildings to the lagoon 100 feet away. 
 
 d Allowing 20 percent for depreciation and S percent for maintenance and interest on 
 investment. 
 
 Value of Liquid Hog Manure 
 
 Moving liquid manure from buildings and lots is essentially the 
 same operation whether the liquid is stored for later use on cropland 
 or flushed into a lagoon for disposal. Thus if profit is the chief objec- 
 tive in selecting a system, the fertility value of the manure saved must 
 more than offset the added costs of a storage and handling system. 
 Computations based on standard data show that the annual cost of 
 storing and spreading liquid manure in a 250-hog operation is $268 
 greater than the annual cost of using a lagoon (Table 7). The difference 
 
 Table 7. Annual Cost of Storing and Spreading Liquid Manure 
 Compared With Disposal in a Liquid-Manure Lagoon 
 
 
 
 Annual cost! 
 
 3 
 
 produced 
 annually 
 
 Storage and 
 spreading* 
 
 Lagoon 
 system" 5 
 
 Additional cost 
 of storage 
 and spreading 
 
 250.. 
 
 $ 319 
 
 $ 51 
 
 3 268 
 
 500 
 
 458 
 
 67 
 
 391 
 
 750 
 
 609 
 
 82 
 
 527 
 
 1,000 
 
 746 
 
 98 
 
 648 
 
 1,250 
 
 866 
 
 113 
 
 753 
 
 1,500 
 
 1,001 
 
 128 
 
 873 
 
 2,000 
 
 1,285 
 
 158 
 
 1,127 
 
 2,500 
 
 31,552 
 
 3187 
 
 31,365 
 
 
 
 
 
 Data from Table 4. 
 b Data from Table 6. 
 
 
 
 
14 BULLETIN No. 687 [May, 
 
 increases to $1,365 on farms that have an output of 2,500 hogs a year. 
 These costs must be equaled or exceeded by the fertility value of liquid 
 manure if a storage and spreading system is to be more profitable than 
 a lagoon system. 
 
 Corn and soybean meal, the main constituents of growing-finishing 
 rations for hogs in the Midwest, contain quantities of nitrogen, phos- 
 phorus, and potassium the chief elements needed for plant growth 
 (Table 8). Seventy-two to 90 percent of each of these elements passes 
 through hogs into the excreta (Table 9). At this rate, the value of the 
 soil fertility elements excreted by one hog while growing from 50 to 
 220 pounds averages $1.62 based on 1960 prices for the same elements 
 in straight commercial fertilizer materials. Total value could run as 
 
 Table 8. Percentage of Specified Soil Fertility Elements 
 in Selected Feedstuffs* 
 
 Content of fertility elements 
 Feedstuff 
 
 Nitrogen Phosphorus PaOs Potassium K 2 O 
 
 Corn, dent No 2 
 
 1 39 
 
 27 
 
 percent 
 62 
 
 29 
 
 35 
 
 Soybean meal, 
 solvent, 44-percent- 
 protein guarantee 
 
 7.31 
 
 0.63 
 
 1.44 
 
 1.92 
 
 2.31 
 
 
 
 
 
 
 
 Morrison, F. B., Feeds and Feeding, 22nd ed., 1956. 
 
 Table 9. Amount and Value of the Chief Soil Fertility Elements 
 Present In and Excreted From a Swine Growing Ration' 
 
 Feed 
 
 Fertility elements 
 
 N 
 
 P 2 5 
 
 K 2 O 
 
 Corn, Ib 512 
 
 7.12 
 6.07 
 13.19 
 
 72 
 9.50 
 
 0.12 
 31.14 
 
 3.17 
 1.20 
 4.37 
 
 83 
 3.63 
 
 #0.09 
 0.33 
 
 1.79 
 1.92 
 3.71 
 
 90 
 3.34 
 
 0.044 
 0.15 
 
 Soybean meal, Ib. 83 
 
 Total 595 
 
 Percent excreted* 5 
 
 Pounds excreted 
 
 Value per pound 
 
 Total value of fertility 
 elements excreted 
 
 
 The rate of feed conversion is assumed to be 3.5 pounds of feed per pound of gain. The 
 ration, for growing a pig from 50 to 220 pounds, is composed of 8-percent-protein corn and 
 44-percent-protein soybean meal, plus necessary fortifying agents. The ration averages 13 per- 
 cent protein over the feeding period. 
 
 b Salter, R. M., and Schollenberger, C. J., op. cit., p. 8. 
 
 c Typical 1960 Illinois prices for commercially prepared N in ammonium nitrate, PsOs 
 in super phosphate, and KjO in muriate of potash. See Agricultural Prices, Agr. Mkt. Ser., 
 USDA, Sept., 1960. 
 
1962] VALUE OF MANURE IN CONFINEMENT FINISHING OF HOGS 15 
 
 much as one- fourth greater if based on the cost of the ingredients in 
 higher-priced mixed fertilizers. Quantities of organic matter in liquid 
 manure are considered too small to be significant. 
 
 Losses in fertility value. Manure loses part of its fertility value 
 while lying on the feeding floor and in storage. 1 The amount of loss 
 depends upon many factors, chief of which are temperature, amount 
 of surface exposed to air, delay in removal to storage, method of 
 storage, and length of storage period. 
 
 Nitrogen is both the most valuable and most unstable of the soil 
 fertility elements in manure. In the early period following excretion, 
 manure is quite rapidly attacked by bacterial action. Changes are 
 especially rapid in the soluble nitrogenous compounds such as urea. 
 Unless liquid manure is quickly moved into storage that provides 
 anaerobic conditions, loss of nitrogen by volatilization of ammonia and 
 evolution of nitrogen gas is quite high. With the best handling facilities, 
 researchers have been able to reduce losses under farm experimental 
 conditions to about one-sixth of the nitrogen in the manure. Further 
 losses can be largely avoided by immediate storage of manure under 
 strictly anaerobic conditions such as are provided by a tightly covered 
 tank and a thin film of tar or oil floating on the surface of the liquid. 2 
 However, the nitrogen loss may easily amount to 50 percent or more 
 under typical farm practices of storing manure in open vats as is now 
 done on many farms in Illinois. 3 
 
 Loss of fertility value also occurs when manure is spread at other 
 than optimum times and on crops other than those that can best use 
 the fertility constituents. The ideal time to spread manure on the land 
 is in the spring or fall, immediately before plowing. Even under opti- 
 mum conditions, the nitrogen loss may be heavy. Plots under con- 
 tinuous wheat production at Rothamsted, England, received 14 tons 
 
 1 Salter, R. M., and Schollenberger, C. J., Farm Manures, Ohio Agr. Exp. 
 Sta. Bui. 605, Sept., 1939. 
 
 2 Ibid., pp. 31-32. 
 
 *For comprehensive discussions of the fertility value of manures, see Hall, 
 A. D., Fertilizers and Manures, 3rd ed., John Murray, London, 1929; Morrison, 
 F. B., op. cit., Chap. 24; Smith, A. M., Manures and Fertilizers, T. Nelson and 
 Sons, Ltd., London, 1952. For analyses of soil fertility elements in solid hog 
 manure produced under specified conditions, see Bauman, R. H., and Fitzpatrick, 
 J. M., Production, Composition, and Costs of Handling Farm Manures on 
 Indiana Farms, Purdue Agr. Exp. Sta., July, 1953. Generally, the fertility values 
 reported by Bauman and Fitzpatrick range from $1.90 to $3.08 per ton of manure 
 based on 1960 prices. 
 
16 BULLETIN No. 687 [May, 
 
 of farmyard manure per acre per year over a 50-year period. Only 
 26 percent of the nitrogen in the manure was recovered by the crops. 
 Seventeen percent was lost in handling and storage of the manure and 
 57 percent was apparently lost in the field, as it could be accounted for 
 neither in the crops nor in the soil. 1 
 
 Tests on the Danish State Experimental Farms show that manure 
 loses nearly half of its yield-increasing potential after lying on the land 
 for only four days before being plowed under, as cpmpared with 
 immediate plowdown. 2 
 
 Availability of fertility elements. Evidence also suggests that, be- 
 cause of variation in availability, a pound of organic nitrogen as found 
 in manure may not be worth as much for some purposes as a pound of 
 inorganic nitrogen in mineral fertilizer. While nitrogen in urine is as 
 readily available as that of such mineral fertilizers as sulfate of 
 ammonia or nitrate of soda, the nitrogen of dung is of very low grade. 3 
 Much of the nitrogen in dung and in bedding materials, which are 
 sometimes used, is in forms that are either unavailable to crops or 
 only slowly available, sometimes requiring years before being totally 
 converted into available forms. Such slow release of nitrogen is 
 advantageous for some crops, but others may suffer by not being able 
 to get nitrogen when it is needed. Test plots in England showed that 
 rapidly growing mangolds did not get as much nitrogen from farmyard 
 manure containing 200 pounds of nitrogen as they did from nitrate of 
 soda containing 86 pounds of nitrogen. 4 On the other hand, the phos- 
 phoric acid and potash in manures are practically equal in availability 
 to the same elements in mineral fertilizers. 5 
 
 In year-round hog confinement operations, manure needs to be 
 removed regularly and frequently. Since applications must often be 
 made at inappropriate times in the crop cycle, manure must sometimes 
 be spread on land devoted to low-value crops, or even on wasteland. 
 Corn, corn, small grain, meadow a four-year rotation common on 
 livestock farms in the corn belt provides for optimum application of 
 liquid manure for only a limited period of time during the year. Little 
 more than half of the manure can be placed on ground to be used for 
 second-year corn. Most of the remainder must be spread on old rota- 
 
 1 Hall, A. D., op. cit. 
 
 2 Salter, R. M., and Schollenberger, C. J., op. cit., p. 35. 
 1 Ibid., p. 41. 
 
 4 Hall, A. D., op. cit. 
 
 5 Salter, R. M., and Schollenberger, C. J., op. cit., pp. 42-43. 
 
1962] VALUE OF MANURE IN CONFINEMENT FINISHING OF HOGS 17 
 
 tion meadow and new seeding which benefit little, if at all, from the 
 application of manure. The carryover value of the nitrogen in such 
 applications for the first-year crop is unknown. 
 
 Management practices and facilities for storing and handling liquid 
 hog manure differ greatly among farms. Research evidence suggests, 
 however, that even under the most favorable conditions the loss of fer- 
 tility elements will amount to at least 25 percent of the original values 
 in the manure, and a much greater loss is likely on many farms. Un- 
 timely applications and applications to low-value crops reduce the 
 realized value still further. 
 
 The calculated value of soil fertility elements in the manure from 
 different sizes of hog operations is shown in Table 10. Comparison 
 of these data with the cost of saving and spreading the manure (Table 
 7) provides a guide as to the economy of lagoons versus storage 
 systems. 
 
 Table 10. Calculated Value" of Soil Fertility Elements 
 in Liquid Hog Manure at Specified Rates of Recovery 
 
 Value of fertility elements 
 
 by percentage recovered b 
 
 Hogs c 
 
 100 percent 
 initially 
 present 
 
 At 
 75-percent 
 recovery 
 
 At 
 50-percent 
 recovery 
 
 At 
 25-percent 
 recovery 
 
 250.. 
 
 . 3 405 
 
 3 304 
 608 
 911 
 1,215 
 1,519 
 1,822 
 2,430 
 33,038 
 
 3 202 
 405 
 608 
 810 
 1,012 
 1,215 
 1,620 
 32,025 
 
 3 101 
 202 
 304 
 405 
 506 
 608 
 810 
 31,012 
 
 500 
 
 810 
 
 750 
 
 1,215 
 
 1 ,000 
 
 1,620 
 
 1 250 
 
 2,025 
 
 1,500 
 
 2,430 
 
 2,000 
 
 3,240 
 
 2,500 
 
 34,050 
 
 
 
 a Based on 1960 prices for nitrogen, phosphorus, and potassium. 
 
 b Based on the following values for fertility elements in manure from one hog: nitrogen, 
 $1.14; phosphorus, 33 cents; potassium, 15 cents; total value, $1.62. (See Table 9.) 
 c Market hogs grown from 50 to 220 pounds. 
 
 Two-thirds of the value of the fertility elements in manure must be 
 saved just to cover costs in a 250-hog operation. The break-even point 
 gradually declines to one-third of the original fertility value as annual 
 output increases to 2,500 hogs because of economies in use of equip- 
 ment and storage facilities. There will be a tendency for the break-even 
 point to remain above this level, however, because greater hauling costs 
 are often encountered as size of operation increases. 
 
 If a producer could achieve a 75-percent rate of recovery, storage 
 and spreading of liquid manure would be profitable, especially for large 
 
18 
 
 BULLETIN No. 687 
 
 [May, 
 
 operations (Fig. 1). High fixed costs of equipment and storage facil- 
 ities cut the margin for the producer with a small output. Storage of 
 manure for use on cropland presents almost a break-even situation if 
 half the value of the manure is recovered. Benefits do not cover costs 
 at any size of operation if losses are as high as three-fourths of the 
 total. In all of these situations, spreading manure has provided the 
 farmer with a market for his labor at $1.20 per hour. 
 
 12,000 - 
 
 ft 1,500 - 
 
 ft 1,000 - 
 
 $500 - 
 
 ADDITIONAL COST OF STORING AND 
 SPREADING LIQUID MANURE, COMPARED 
 WITH DISPOSAL IN A LAGOON 
 
 250 
 
 500 
 
 750 
 
 1,000 1,250 1,500 
 HOGS PRODUCED ANNUALLY 
 
 2,000 
 
 2,500 
 
 Net cost of storing and spreading liquid hog manure compared with value 
 of the manure at different rates of recovery for fertility constituents. 
 (Fig. 1) 
 
 A producer should not rate himself above the 50-percent recovery 
 mark unless he is particularly well equipped to handle manure, or has 
 a quantitative measure (such as chemical analysis of manure, or com- 
 parative yield data) of the effectiveness of his operation. Evidence 
 from research suggests that most producers will probably be below this 
 level. 
 
 Other economic factors. The relative economic position of the 
 storage method versus lagoon disposal of liquid manure may be in- 
 fluenced by factors other than the value of the soil fertility elements 
 
1962} VALUE OF MANURE IN CONFINEMENT FINISHING OF HOGS 19 
 
 and the cost of getting them on the cropland. Among the items worth 
 considering are: the probable imbalance of the nitrogen, phosphorus, 
 and potassium in manure, making it necessary to supplement manure 
 with purchased fertilizers; the possibility of reaching a buildup of 
 plant nutrients in the soil on small farms with large livestock enter- 
 prises, to the point where additional manure gives little or no response; 
 and compaction of the soil and damage to plants by heavy equipment 
 during the spreading operation. Another consideration is the lessening 
 of odors, flies, disagreeable working conditions, and unattractive ap- 
 pearance when manure is disposed of in a lagoon rather than stored 
 and later spread on the land. 
 
 Summary 
 
 Confinement hog systems designed for storing liquid manure for 
 later use on cropland present at best a break-even situation for the 
 typical hog producer raising 500 to 750 hogs, with only a small chance 
 that the manure is worth more than the additional costs involved in 
 saving rather than disposing of it. The most profitable practice for the 
 average farmer who raises hogs in confinement is to dispose of the 
 liquid manure in a lagoon and use commercial fertilizers on his fields. 
 This economic choice is reinforced by esthetic considerations. 
 
 These conclusions are drawn from facts observed in a 1959-1960 
 economic study of confinement hog production on 72 Illinois farms. 
 Most operators in the study used bedding in their barns and re- 
 moved the solid manure with tractor-powered equipment. Some farms, 
 however, had newly-designed finishing buildings which provided for 
 handling manure as a liquid. Manure was scraped or flushed from the 
 feeding floor each day and carried by water to a storage tank for later 
 use on the land, or to a lagoon for disposal. 
 
 Findings of the study indicate that the various operations involved 
 in manure removal take about three-fourths of the total labor input 
 used in confinment growing and finishing of hogs on the average Illinois 
 farm. Much of this labor is used to move the manure from storage onto 
 the land. Slotted floors in newly designed buildings offer promise for 
 reducing the work of cleaning. 
 
 Adequate facilities for storing and spreading liquid manure consist 
 of a cast-in-place concrete storage tank, an electrically driven auger 
 to pump the manure from storage, and a tractor-drawn 500- to 1,000- 
 gallon applicator tank. Calculated initial capital requirements range 
 from around $2 per hog for equipping a unit with an annual capacity 
 
20 BULLETIN No. 687 
 
 of 2,500 head to more than $6 per hog for a 250-hog unit. Annual costs 
 for storing, pumping, hauling, and spreading liquid manure drop from 
 $1.28 per hog in small operations to 62 cents per hog in units producing 
 2,500 head annually. 
 
 Lagoons for disposing of liquid manure can be constructed on an 
 average site for 30 to 80 cents per hog, depending upon size of opera- 
 tion. Lagoons have low maintenance costs, and they eliminate the 
 expensive and disagreeable task of pumping, hauling, and spreading 
 manure throughout the year. All of the fertility value of the manure, 
 however, must be sacrificed to gain these cost advantages. 
 
 Fresh hog manure is a valuable source of nitrogen, phosphorus, and 
 potassium. The quantity of these elements excreted by one hog while 
 growing from 50 to 220 pounds is worth about $1.62 at 1960 prices for 
 the same elements in commercial fertilizers. Producers could realize 
 up to nearly $1 per hog above costs if they could preserve all of this 
 fertility value and use it on crops as they would normally use com- 
 mercial fertilizers. 
 
 A high proportion of the fertility value of liquid manure can be 
 utilized if the manure is stored under anaerobic conditions, and if it is 
 plowed under immediately after it is spread on the land. Ideal condi- 
 tions, however, are seldom possible. Fertility losses, especially of the 
 highly unstable nitrogen, begin on the feeding floor and continue while 
 the manure is in storage and lying on the fields. Much potential value 
 is wasted when manure must be spread on low- value crops or wasteland. 
 
 The typical producer will probably lose one-half to three-fourths of 
 the fertility value in hog manure that is handled as a liquid. If a pro- 
 ducer has an effective manure-handling system and thus manages to 
 recover as much as half the original fertility value, he can pay the 
 additional costs of storing the manure and spreading it on cropland, 
 including a $1.20 an hour charge for labor. Some additional return 
 may be realized in the larger operations, which afford some economies 
 to scale in the use of equipment. If losses are greater than 50 percent, 
 the value of the manure will not pay for the additional costs of getting 
 it on the land. 
 
 6M 5-62 76755 
 
UNIVERSITY OF ILLINOIS-URBANA