ADEQUACY OF PROTEIN IN SWINE RATIONS IN ILLINOIS As related to areas within the state, phases of production, size of enter- prise, share of income from swine sales, soil association, tenure, and the market for protein supplements By R. J. MUTTI Bulletin 599 UNIVERSITY OF ILLINOIS AGRICULTURAL EXPERIMENT STATION CONTENTS PAGE PART 1: FEEDING PRACTICES AND ADEQUACY OF PROTEIN IN SWINE RATIONS 5 Protein Supplements Fed 5 Comparisons of Methods of Feeding Protein Supplements 6 Differences in Use of Pasture Among Areas and Phases of Production 8 Adequacy of Crude Protein in Rations 10 Amount of Protein Supplement Required to Eliminate Protein Inadequacy 16 Relation of Pasture Use to the Amount of Commercial Protein Supplement Needed 18 Number of Brands of Feed Used 19 PART 2: DIFFERENCES IN ADEQUACY OF CRUDE PROTEIN IN SWINE RATIONS AS RE- LATED TO CERTAIN FACTORS (size of enterprise, share of income from swine sales, soil association, and tenure) 20 SUMMARY 27 APPLICATION OF FINDINGS 30 ACKNOWLEDGMENTS.. .31 Urbana, Illinois February, 1956 Publications in the Bulletin series report the results of investigations made or sponsored by the Experiment Station ADEQUACY OF PROTEIN IN SWINE RATIONS IN ILLINOIS By R. J. MUTTI, Associate Professor of Agricultural Marketing THE OBJECTIVES OF THIS STUDY WERE TWOFOLD. The first was to determine how much protein supplement would be required to bring rations fed swine by Illinois farmers up to recom- mended levels and how deficiency of protein in swine rations differed among areas and phases of production. The second was to determine whether deficiency of protein was associated with size of enterprise, percentage of income from swine sales, soil association, and tenure. Earlier studies for the United States had shown that rations fed swine were more deficient in protein than rations fed other classes of live- stock. 1 Information secured in personal interviews with farmers covered: 1. The quantities of different feeds grain, commercially mixed feeds, protein ingredients or supplements, pasture, hay, skimmilk, and whey that they fed in each phase of production (bred sows, 2 nursing sows, and growing hogs). 3 2. The number of swine fed during each phase of production. 3. The estimated percentage that swine sales were of the operator's gross cash income. 4. The tenure status of each farm operator. Most of the records covered the calendar year of 1951, but in some cases a 12-month production period for which data were secured began in the fall of 1950, and in some cases it ended in the spring of 1952. Farms from which information was secured were located in areas representative of four important type-of-farming areas in the state (Fig. 1). 1 These studies, made by R. D. Jennings and published by the U. S. Department of Agriculture Bureau of Agricultural Economics, are: The deficit in protein for livestock: a quantitative estimate of needs based on feeding standards (mimeo- graph, April, 1946) ; Consumption of feed by livestock, 1909-47 : relation between feed, livestock, and food at the national level (Cir. 836, Dec., 1949); A look at the protein situation for livestock (mimeographs, March, 1950, and Sept., 1952). 2 In this study, bred gilts were included with bred sows. 3 Estimates of quantities fed during each phase of production were based on the most accurate data available, whether those data covered a day, a week, a month, or the entire phase. Feeding practices over a 12-month period were analyzed to include both spring and fall feeding programs. BULLETIN No. 599 NORTHWESTERN (MIXED LIVESTOCK) NORTHEASTERN (MIXED LIVESTOCK) WESTERN (LIVESTOCK AND GRAIN) SOUTH-CENTRAL (GENERAL FARMING) Areas from which records were secured. (Fig. 1) The western area has the greatest density of swine in the state; the northwestern and northeastern areas have densities well above that of the state average; the eastern area is below the state average in density; and the south-central area much below that of the state average. In all areas except the northeastern, the farms visited were located in sections chosen at random. Only sections of land lying entirely within a given soil association 1 were included in the universe from which the sample was drawn. In the northeastern area, the northeast corner farm in every third section was visited, irrespective of soil association, and only data cover- ing the spring production period were secured. 1 In the western and northwestern areas, sections were selected from soil associations K and L ; in the eastern area, from soil association H ; and in the south-central area, from soil associations O and P. These five soil associations comprise 46 percent of the total farmland in the state. The productivity ratings in each of these areas under a low level of management ranged as follows: H: 65- 100; K: 45-100; L: 5-45; O: 5-25; P: 20-35. For further information on soils, see Illinois soil type descriptions, by H. L. Wascher, J. B. Fehrenbacher, R. T. Odell, and P. T. Veale (111. Agr. Exp. Sta. AG-1443, 1950). 1956] ADEQUACY OF PROTEIN IN SWINE RATIONS The number of records obtained from each area was as follows: western, 54; northwestern, 26; northeastern, 50; eastern, 24; and south- central, 78. PART 1: FEEDING PRACTICES AND ADEQUACY OF PROTEIN IN SWINE RATIONS Protein Supplements Fed A protein supplement was fed at least part of the time on nearly all farms. About 5 out of every 11 farms used commercially mixed supplements only; 1 out of every 8 used ingredient supplements only; Table 1. Percentage of Farms in Five Areas Feeding Various Types of Protein Supplements and Pasture to Swine, 1951 Types of protein supplements fed Western No " h - N rth - Eastern Sou f th - western eastern central Commercially mixed supplement only 52 Commercially mixed supplement and: one ingredient supplement 24 two ingredient supplements 7 three or more ingredient supplements 6 Subtotal (37) Ingredient supplements only one ingredient supplement 3 two ingredient supplements 2 three or more ingredient supplements 2 Subtotal (7) No supplements 4 Total (100) Ingredient supplements Alfalfa meal 18 Bran or shorts 2 Condensed buttermilk Cottonseed meal Fish meal 2 Linseed meal 7 Meat scraps or tankage 11 Skimmilk 17 Soybean meal 20 Whey Pasture Legume pasture only 52 Legume and grass pasture 26 Grass pasture only 15 Drylot only 7 (percent of farms) 31 76 33 19 12 15 (46) (100) 10 4 2 (16) 62 6 8 2 2 14 4 24 70 22 42 8 4 (54) (100) (100) 12 25 4 29 12 50 38 4 40 29 12 5 (46) 12 13 9 7604 4201 (23) (8) (12) (14) (100) 9 15 3 10 31 17 1 13 29 45 13 6 BULLETIN No. 599 [February, and 2 out of every 5 used a commercially mixed supplement together with one or more ingredient supplements (Table 1). About 7 out of every 8 farms used commercially mixed protein supplements. The northeastern and western areas had the highest per- centages of farms feeding commercially mixed supplements only. The northwestern area had the highest percentage of farms using ingredient supplements only. Alfalfa meal, meat scraps or tankage, skimmilk, and soybean meal were ingredient supplements fed in every area. The northeastern area had the highest percentage of farms using alfalfa meal, the northwest- ern area the highest using meat scraps or tankage, the eastern and south-central areas the highest using skimmilk, and the western and northeastern areas slightly higher percentages using soybean meal. Of other ingredient supplements, these areas had the highest per- centage of farms using them: Bran or shorts northwestern and south-central Condensed buttermilk eastern Linseed meal northwestern Whey northwestern These variations reflect the availability and price of ingredient sup- plements in different parts of the state. Comparisons of Methods of Feeding Protein Supplements General comparisons Comparisons in this section are based on averages computed from combined percentages for the phases of production shown in Table 2. Comparison of spring and fall production periods does not include the northeastern area, for which no fall data were secured. This exception applies to all subsequent discussion in which fall data are analyzed. Entire production period. Free-choice feeding 1 of protein supple- ments was practiced by over three- fourths of the farms in the north- eastern area, by over a half in the northwestern area, and by nearly a half in the eastern area. Rationing supplements fed (limiting the amount) was practiced by 1 Rations were considered as fed free choice if both grain and protein supple- ments were available so that the swine could choose as much of each as they wanted. Nearly all rations included as free choice were those put in self-feeders. 1956] ADEQUACY OF PROTEIN IN SWINE RATIONS Table 2. Percentage of Farms in Five Areas Using Different Methods of Feeding Protein Supplements to Swine, 1951 (By phases of production) Spring Fall* iviernoas 01 - feeding West- supplements ern North- west- ern North- east- ern East- ern S ?e U n h " ^rn^ North- west- ern East- ern South- cen- tral Bred sows No supplements 4 Rationed .... 82 9 46 45 4 32 64 44 56 2 13 85 36 64 16 84 (percent of farms) 10 18 8 40 73 80 50 9 12 002 39 82 57 61 18 41 005 50 57 56 50 43 39 33 34 33 14 14 72 10 50 40 25 31 44 14 39 47 6 59 35 18 77 5 7 76 17 2 57 41 Free choice. ... 14 Nursing sows No supplements 2 Rationed 56 Free choice .... 42 Growing hogs No supplements 6 Rationed 49 Free choice .... 45 No data for the fall production period were secured in the northeastern area. Differences shown in the northwestern area are less significant than in the other three areas because only a few records were obtained. over two-thirds of the farms in the south-central area, and by five out of every eight in the western area. Feeding no supplements was practiced by less than 12 percent of the farms in all areas. The range was from less than 1 percent in the northeastern area to 11.7 percent in the northwestern area. Spring and fall production periods. A higher percentage of farms fed no supplements in the fall than in the spring. Conversely, a higher percentage fed free choice in the spring than in the fall. About equal proportions of farms rationed supplements in the spring and fall. This was also true for each phase of production bred sows, nursing sows, and growing hogs. Phases of production. A greater percentage of farms fed no sup- plements to bred sows than to either nursing sows or growing hogs. A slightly greater percentage also rationed supplements to bred sows than to either nursing sows or growing hogs. A greater percentage fed supplements free choice to growing hogs than to bred sows. The aver- age difference in the percentages of farms using these methods of feeding supplements to nursing sows and growing hogs was slight. 8 BULLETIN No. 599 [February, Comparison of areas by phase of production Sows bred for spring farrowing. The south-central area had the highest percentage of farms feeding no supplements, the northeastern area for feeding free choice, and the western and south-central areas for rationing supplements (see Table 2). Sows bred for fall farrowing. The northwestern and eastern areas had the highest percentages of farms both for feeding no supplements and for free choice. The western area had the lowest for feeding no supplements, the south-central area the lowest for feeding free choice. About equally high percentages of farms in the western and south- central areas rationed supplements. Nursing sows, spring. A much higher percentage of farms in the eastern and two northern areas fed free choice than in the south- central or western areas. The south-central area had the highest per- centage rationing supplements. Few farms in any area fed no supple- ments. Nursing sows, fall. The south-central area again had the lowest percentage of farms feeding free choice as well as the highest for rationing supplements. The northwestern and eastern areas had the highest percentages both for feeding no supplements and for free choice. Growing hogs, spring and fall. The percentages of farms feeding in different ways were similar in the western, northwestern, eastern, and south-central areas in both spring and fall. Differences in feeding between spring and fall were less for growing hogs than for either bred or nursing sows. The northeastern area in spring had by far the highest percentage of farms feeding free choice. Differences in Use of Pasture Among Areas and Phases of Production Data in Table 1 show that the south-central and northwestern areas had the highest percentage of farms feeding swine in drylot the entire year. Table 3 shows the differences among areas in availability of pasture within the year. A higher percentage of farms had no pasture available for sows bred to farrow in the spring than for any other phase of production. For these sows, none of the farms in the northwestern area had pas- ture, and only about two-fifths of the farms in the western, eastern, and south-central area had pasture for them. 1956] ADEQUACY OF PROTEIN IN SWINE RATIONS Table 3. Percentage of Farms With Different Kinds of Pasture Avail- able, by Areas and Phases of Production, 1951 Area and kind of pasture Spring Fall Bred sows Nursing Grow- sows ing hogs Bred sows Nursing Grow- so ws ing hogs (percent of farms) Western Alfalfa 12 26 25 25 12 5 Ladino clover 2 4 4 2 Red clover 6 21 21 12 14 7 Mixed legumes 266 15 12 Mixed legumes and grasses" 10 26 21 10 9 4 Bluegrass 6 11 15 18 16 14 Other grasses 2 2 No pasture 60 6 8 18 35 70 Northwestern Alfalfa 18 20 30 34 9 Red clover 23 20 000 Mixed legumes 4 4 10 11 Alfalfa-bromegrass 9 16 10 11 27 Alfalfa-bromegrass-Ladino.. 14 12 10 11 9 Mixed legumes and grasses* 054 000 Bluegrass 9 12 No pasture 100 18 12 40 33 55 Eastern Alfalfa 550 000 Ladino clover 4 4 6 6 6 Red clover 059 16 12 11 Mixed legumes 048 560 Alfalfa-bromegrass 6 Mixed legumes and grasses* 5 14 35 17 12 6 Bluegrass 28 36 31 39 41 22 Other grasses 5 18 9 11 5 No pasture 57 14 4 6 12 55 South-central Alfalfa 2 Ladino clover 2 14 10 8 7 10 Red clover 3 6 Mixed legumes 335 473 Mixed legumes and grasses* 8 20 24 32 28 19 Bluegrass 16 17 16 12 14 12 Other grasses 5 15 13 16 14 16 Woods 673 433 No pasture 60 24 27 24 24 31 Northeastern Alfalfa 24 Ladino clover 2 Red clover (data not secured) 16 (data not secured) Mixed legumes 28 Alfalfa-bromegrass 4 Mixed legumes and grasses* 18 Bluegrass 4 Other grasses 4 No pasture 76 22 Not alfalfa-bromegrass or alfalfa-bromegrass-Ladino 10 BULLETIN No. 599 [February, Another phase of production for which a high percentage of the farms had no pasture was growing hogs farrowed in the fall. Just as for sows bred to farrow in the spring, a big share of the feeding period occurs during winter. The percentage of farms having pasture for fall- farrowed hogs was higher in the south-central area than in other areas, a result in part of a little longer growing season and earlier farrowing. A greater share of the farms had pasture available for hogs far- rowed in the spring and for sows nursing in the spring than for other phases of production. For these two phases, the percentage of farms having no pasture was slightly higher in the south-central area than in the other areas. Legumes as well as mixtures containing legumes were, according to the percentage of farms using them, much more important than grass pastures in the two northern areas. In the western area legumes alone were more important than either grasses alone or mixed legumes and grasses in five phases of production. In both the eastern and south- central areas a greater percentage of farms had grass pasture only than legume pasture only in all phases of production. In the western area the most commonly used pasture was alfalfa, followed by mixed legumes and grasses and red clover. In the northern areas alfalfa or a mixture including alfalfa was the dominant pasture, with red clover next in importance. In the eastern area bluegrass was the most common pasture, fol- lowed by mixed legumes and grasses, other legumes, and other grasses. As shown in Table 1, this area had the highest percentage of farms using a mixture of legumes and grasses. In the south-central area, bluegrass and other grasses combined were slightly more common than mixed legumes and grasses. Adequacy of Crude Protein in Rations The adequacy of rations fed to sows in gestation and lactation, and to growing hogs of different weights, was measured by determining to what extent the crude protein content of the rations fed differed from recommendations (shown in Table 4) 1 for swine in these classes. In 1 No attempt was made to adjust these recommendations to changing price relationships between protein supplements and grain. Since swine producers are primarily concerned with maximizing their returns from the swine enterprise, the feeding of these levels of protein would not be most desirable under all swine and feed-ingredient price relationships. It may be noted here that the period which these data covered was normal. During that period, for example, the average ratio of corn to soybean meal prices was almost the same as the average for the 7-year period, 1947-1953. 1956] ADEQUACY OF PROTEIN IN SWINE RATIONS 11 making these calculations, the kind, condition, and amount of pasture available were taken into account, as well as the grains and supple- ments produced on the farm. Among other things, it was recognized that grass pastures were lower in protein content than legumes except in their early growth period, and that weather and the number of animals using a pasture affect its condition. Table 4. Recommended Percentages of Crude Protein in Swine Rations for Certain Classes and Weights of Swine" Class and weight of swine Percentage recommended for Drylot or poor pasture Fair pasture Good pasture Bred sows 14 13 14 13 14 15 13 12 11 10 12.5 12 13 12 13 14 12 11 10 9 11.5 Bred gilts . 15 Nursing sows Young females . . . . 14 Mature sows 15 Growing hogs Weaning to 75 pounds 16 75 to 125 pounds 14 125 to 175 pounds . . 13 175 to 225 pounds 12 225 to 275 pounds 11 Average for growing hogs (125 pounds) . 13 5 Adapted from data in Your hog business, by S. W. Terrill (111. Agr. Ext. Cir. 719, page 11, 1955 printing). For farms that fed in self-feeders complete rations containing the recommended percentages of crude protein, or that made available all the protein supplement that swine could consume, no attempt was made to ascertain the quantity fed nor to determine whether more protein supplement was used than the recommendations called for. The assumption was made, in effect, that swine were able to balance their own rations if adequate supplement and grain were made avail- able. 1 Nor was any attempt made to determine the adequacy of the rations in other nutritional requirements besides protein, or to estab- 1 This assumption departs from the actual situation whenever swine did not in fact have access to adequate quantities of supplement, which might occur, for example, when the farmer neglected to keep the feeders supplied at all times, or when there was overcrowding of animals, or when feed did not flow from the feeders properly. Recent nutrition studies indicate that swine will not always balance their own rations properly. 12 BULLETIN No. 599 [February, lish deficiencies related to the quality of the purchased protein sup- plements fed. All areas. Considering rations fed in all phases of production and in all areas, an average of about half the farms fed adequate rations, nearly one-third fed moderately inadequate rations, and nearly one- sixth inadequate rations. 1 The range for farms feeding adequate rations was from only 25 percent in the south-central area (for sows bred to farrow in the spring) to 81 percent in the eastern area (for sows nursing in the spring). (See Table 5.) Comparison of the same production phases in spring and fall. Each area had a higher percentage of farms feeding adequate rations to growing hogs in the spring than in the fall, and all but the north- western area had slightly higher percentages for nursing sows in the spring than in the fall. The western and south-central areas had higher percentages of farms feeding adequate rations to sows bred to farrow in the fall than in the spring, but the northwestern and eastern areas had higher percentages for sows bred to farrow in the spring. Comparison of phases in the spring production period. All areas except the northeastern area had higher percentages of farms feeding adequate rations to nursing sows than to either bred sows or growing hogs. The western, south-central, and northeastern areas had higher percentages feeding adequately to growing hogs than to bred sows. Comparison of phases in the fall production period. All areas except the western area had higher percentages of farms feeding adequately to nursing sows than to either bred sows or growing hogs. 1 Rations were considered adequate if they contained sufficient crude protein to meet or exceed the standards recommended; moderately ina>dequate if they were within 3 percentage points of these standards ; and inadequate if they were below 3 percentage points. For example, if the percentage recommended as ade- quate was 14 and the percentage fed was 13, a deficiency of 1 percentage point was recorded. a Variance in mean deficiency among areas was significant at the 0.1 -percent level for bred sows and growing hogs farrowed in the spring, at the 1-percent level for bred sows in the fall, at the 20-percent level for nursing sows in the spring, but not at the 20-percent level for either growing hogs or nursing sows in the fall. Variance in mean deficiency among each phase of production within each area was significant at the 0.1-percent level in the northeast and the south-central areas in the spring, at the 5-percent level in the western area in the fall, and at the 20-percent level in the eastern (both spring and fall) and in the south-central areas. Varia- tions within each phase of production were so great in the other areas (northwestern, spring and fall, and western, spring) that differences among them were not significant at the 20- percent level. b Bred to farrow in thjs period. c Farrowed in this period. d Weighted by the number of swine on each farm. e Differences shown in the northwestern area for the fall production period are less signifi- cant than in the other three areas because only a few records were obtained. 1956] ADEQUACY OF PROTEIN IN SWINE RATIONS 13 Table 5. Percentage of Farms in Five Areas With Different Levels of Deficiency of Crude Protein in Swine Rations, 1951" (By phases of production) Deficiency of crude protein in rations Spring Fall Bred Nursing Growing sows b sows hogs c Bred Nursing Growing sows b sows hogs c (percent of farms) (Percentage points below recommended percentages) Western area None 37 54 49 50 .1-1.5 22 17 21 24 1.6-3.0 23 19 20 14 3.1-4.5 16 6 8 10 4.6 or more 242 2 Average weighted deficiency* 1.20 .97 1.03 .78 Northwestern area 6 None 55 71 54 43 .1-1.5 18 10 17 1.6-3.0 18 5 25 14 3.1-4.5 9 14 4 43 4.6 or more 000 Average weighted deficiency 11 86 .64 .54 2.51 Eastern area None 65 81 59 56 .1-1.5 10 14 9 19 1.6-3.0 15 23 6 3.1-4.5 059 19 4.6 or more 10 Average weighted deficiency* 1 93 .26 .82 .47 South-central area None 25 54 48 32 .1-1.5 8 17 12 8 1.6-3.0 19 20 13 25 3.1-4.5 21 7 16 15 4.6 or more 27 2 11 20 Average weighted deficiency 11 2.28 1.00 1.12 1.51 Northeastern area None 26 56 72 .1-1.5 38 28 28 1.6-3.0 30 14 3.1-4.5 420 4.6 or more 2 Average weighted deficiency* 1 1.07 .51 .13 43 16 21 18 2 1.32 75 13 12 .69 73 14 13 .63 50 5 26 17 2 1.55 33 14 23 19 11 1.71 45 19 18 18 1.20 47 6 6 35 6 1.65 44 11 16 20 9 1.21 (data not secured) (Footnotes appear on opposite page) 14 BULLETIN* No. 599 [February, The western and eastern areas had higher percentages of farms feed- ing adequately to bred sows than to growing hogs, but in the south- central area the converse was true. In the northwestern area the difference was negligible. Comparison of weighted deficiencies. When protein deficiencies in rations were weighted by the number of swine on each farm, the south- central area was found to be most inadequate in four of the six production phases, with the northwestern and western areas most in- adequate in one phase each (Table 5). The average deficiency for the year was greatest in the south-central area, followed closely by the western area (Table 6). If the estimates of weighted deficiency shown in Table 6 are repre- sentative of the entire state, there was an inadequacy of approximately 1 percentage point below recommended standards in Illinois in 1951. Comparison of weighted deficiencies in fall and spring. The aver- age weighted deficiency in each of the areas was greater for nursing sows and growing hogs in the fall than in the spring (Table 5). In three areas, rations fed sows bred to farrow in the spring were more inadequate than for sows bred to farrow in the fall. These differences can be attributed primarily to pasture: in periods when good pasture was unavailable, insufficient amounts of supplement were added. Comparison of the same farms within the year. Data in Table 5 show the variations in inadequacy of rations in different phases of Table 6. Average Deficiency of Crude Protein in Swine Rations in Five Areas, 1951" (For spring, fall, and yearly production) Area Spring Fall Year Western (I 1.04 percentage points) 1.56 1.25 1.29 .80 1.41 1.03 1.30 1.28 (data not (data not secured) secured 6 ) Northwestern .59 Kastern 77 South-central 1.27 Northeastern 28 B Percentage points below recommended percentages weighted by the number of swine on each farm and by the amount of feed required for bred sows, nursing sows, and growing hogs. The yearly average was determined by assuming the following weights for spring and fall : western and eastern: 0.6 for spring and 0.4 for fall; northwestern: 0.7 for spring and 0.3 for fall; south-central: 0.5 for spring and 0.5 for fall. No attempt was made to adjust rations with respect to the quality or excess of protein fed (note in Table 1 the various types of supplements used). b If deficiency in the fall production period was 0.98 (assuming the same difference between spring and fall as in the northwestern area), the year's deficiency would be 0.49. 1956] ADEQUACY OF PROTEIN IN SWINE RATIONS 15 production for a group of farms. However, the same farms were not included in each group, because some farms did not have swine in all phases. Table 7 presents the results of an analysis of feeding on each farm for the phases of production which were carried out on that farm. Nearly one-fourth of these farms fed adequate rations in every phase, over one-fifth had inadequate rations in every phase, and over one-half of the farms fed adequate rations only part of the time. Table 7. Proportion of Phases of Production in Which Farms in Five Areas Fed Inadequate Protein in Swine Rations, 1951 Proportion of All West- North- North- East- South- production phase" areas 1 ' ern western eastern ern central (percent of farms in each group) Not inadequate in any phase .. 24 17 31 18 37 17 Inadequate in less than half the phases 25 23 23 25 18 Inadequate in half or more, but not in all phases . . . 29 38 31 24 17 36 20 21 29 Inadequate in all phases 21 22 15 The number of production phases varied from farm one production phase; many had the entire six production to farm. A few farms had only- phases. The proportion for each farm was determined from the number of production phases which that farm had. For example, a farm feeding adequate rations in all phases of production in which it had swine was included in the category, not inadeqiiatc in any phase. b Arithmetic average of the percentages given for the five areas. The northwestern area had the lowest proportion of farms feeding inadequate rations in all phases, and the eastern area had the highest proportion feeding adequate rations in all phases. The percentage of farms in each area which had swine in all six phases of production was as follows: Western 74 Eastern 58 South-central 41 Northwestern 15 Northeastern (fall data not secured) In the western area, a higher percentage of the farms were on a two-litter-a-year program; of those that were not, many purchased feeder pigs and had no sows to feed while others were on a one-litter- a-year program. A two-litter-a-year program also dominated the east- 16 BULLETIN No. 599 [February, ern area, whereas farms in the northwestern area were mainly on a one-litter-a-year program. In the south-central area there was no clear-cut pattern; nearly one- fourth of the farms produced hogs in only one or two phases of production, and one-fifth had hogs in only three phases. Several farms in the south-central area sold weanling pigs. Amount of Protein Supplement Required to Eliminate Protein Inadequacy The extent of the additional market for protein supplements among swine feeders can be estimated by calculating the percentage increases that would be required if all farms fed the amounts of crude protein recommended. Assuming an overall inadequacy of 1 percentage point (based on data shown in Table 6) below a recommended protein level of 12.7 percent, 1 about 27 percent more supplement containing 35-percent protein would be required to reach the recommended level. Within each area the estimated increase needed was approximately as follows: South-central 38 percent Western 36 percent Eastern 28 percent Northwestern 21 percent Northeastern 6 percent 2 An inadequacy of 2 percentage points below a recommended level of 13-percent protein would require 67 percent more supplement to make up the deficiency, whereas an inadequacy of 1 percentage point at that level would require only 25 percent more supplement (see Table 8). It should be noted that on a percentage basis much more supplement is required to make up a given amount in adequacy when the recommended level is at 11 percent than when at 18 percent. This difference becomes especially noticeable as the level of inadequacy increases. Table 9 shows the additional quantities of supplement needed to meet recommended levels in each phase of production in each of the areas from which samples were taken. These data show that the greatest need for more supplement was generally for growing hogs farrowed in the fall. 1 Approximate average of recommendations for bred sows, nursing sows, and growing hogs on fair pasture. 2 For spring production period only. 1956] ADEQUACY OF PROTEIN IN SWINE RATIONS 17 Table 8. Percentage Increases in 35-Percent Protein Supplement Required to Meet Recommended Protein Levels in Swine Rations When protein fed is this percentage point below recom- mended levels Percentage increase required when level of protein in ration" recommended is 11% 12% 13% 13.5% 14% 14.5% 15% 16% 18% .2 7 5 11 18 25 33 43 54 67 82 100 122 150 300 700 ( b ) ( b ) 4 9 14 19 25 32 39 47 56 67 79 92 150 233 400 900 4 8 12 17 22 28 34 41 49 57 67 77 120 175 267 450 3 7 11 15 20 25 30 36 43 50 58 67 100 140 200 300 3 6 10 14 18 23 27 33 38 44 51 59 86 117 160 225 3 6 9 13 17 21 25 30 35 40 46 52 75 100 133 180 3 5 8 11 14 18 21 25 29 33 38 43 60 78 100 129 2 4 6 9 11 14 16 19 22 25 28 32 43 54 67 82 .4 . 15 .6 . 25 .8 . 36 1.0 . 50 1.2 67 14 88 1.6 . 114 1.8 . 150 2.0 . 200 2.2 . 275 2.4 . . . . . 400 3.0 (b) 3.5 ( b ) 4.0 ( b ) 4.5 . (b) a Rations assumed to consist of corn with 8-percent protein and supplement with 35-percent protein. To make 100 pounds of a ration containing 9-percent protein, 96.3 pounds of 8-percent corn and 3.7 pounds of 35-percent supplement are required. Thus a change of 3.7 pounds in supplement in 100 pounds of feed occurs with each change of 1 percentage point in crude protein content of the ration. b Infinity since no supplement supplied. Table 9. Percentage Increases in 35-Percent Protein Supplement Required to Meet Recommended Protein Levels in Swine Rations in Five Areas, 1951" (By phases of production) Spring Fall Area Bred sows Nursing sows Growing Bred Nursing hogs sows sows Growing hogs Western 28 23 13 5 22 11 (percentage points) 30 17 31 63 14 84 15 37 23 10 13 60 34 38 40 38 2 (data not secured) Northwestern ... 19 Eastern ... 21 South-central ... 72 Northeastern ... 25 Interpolated from Table 8, using average weighted deficiencies shown in Table 5 and assuming the required protein level for bred sows and nursing sows to be 13.5 percent, and that for growing hogs, 12.5 percent. 18 BULLETIN No. 599 [February, Relation of Pasture Use to the Amount of Commercial Protein Supplement Needed The use of pasture has a tremendous effect on the amount of protein supplement required to feed swine. The Illinois Plan for Swine Feed- ing recommends rations in which the crude protein content can be 2 percentage points lower when swine are on good pasture than when they are in dry lot. 1 Assuming a ration, as was assumed in Table 8, in which corn with 8-percent protein is mixed with a 35-percent protein supplement, the following percentage increases in 35-percent supplement are required to bring a ration up 2 percentage points: Crude protein content of Percentage increases in ration increased from supplement required 14 to 16 (pigs up to 75 pounds) 33 13 to 15 (gilts and young females) 40 12 to 14 (hogs, 75 to 125 pounds, and mature sows). . 50 10 to 12 (hogs, 125 pounds, to market) 100 These figures also indicate the percentage increases in supplement needed by a farmer who had good pasture which is no longer available. The percentage increases required might be even greater than those shown above, because many recommended pasture supplements contain 40-percent protein. For example, an increase of 58 percent in amount of supplement would be required if 60- pound pigs fed 40-percent protein pasture supplement in a 14-percent protein ration were put in drylot and fed 35-percent protein supplement in a 16-percent protein ration. 2 On the other hand, a farmer who fed a recommended drylot protein ration of 16, 15, 14, and 12 percent could reduce his protein supple- ment requirements by 25, 29, 33, and 50 percent respectively when he began to use good pasture. The availability and use of good pasture represent, therefore, a key factor in trying to ascertain the potential market for protein supple- ments among swine producers. Tables 1 and 3 show that many farmers did not have good pasture.. One of the main causes for deficiency in rations fed to swine has been the failure to use adequate supplements when pasture was not available or when it was of poor quality. 1 This plan appears in Your hog business, by S. W. Terrill (111. Agr. Ext. Cir. 719, 1955 printing). 2 If the protein content of corn is taken at 8.5 percent, an increase of 36 per- cent in amount of 35-percent protein supplement would be required if used in both pasture and drylot, and an increase of 62 percent in amount of supplement would be needed if the shift were from a 40- to a 35-percent protein supplement. 7956] ADEQUACY OF PROTEIN Table 10. Number of Brands of Interviewed in the IN SWINE RATIONS Swine Feed Used Five Areas, 1951 on the 19 Farms Number of brands used in specified area and Total number used in each area Area No other area One other area Two other areas Three other areas Four other areas Western 7 1 1 1 1 5 4 3 3 3 1 1 1 1 5 5 5 5 5 19 14 13 16 15 Northwestern 4 Northeastern 3 Eastern 6 South-central 6 Number of brands used in One area . . 26 Two areas 2 Three areas 6 Four areas 1 Five areas 5 All areas 40 Number of Brands of Feed Used An indication of the nature of competition in feed distribution in Illinois is disclosed by an analysis of the brands of commercially mixed feeds used by the farms in this study. Of the forty commercially prepared brands fed on the farms sur- veyed, twelve (or 30 percent) were fed in three or more of the five areas (Table 10). However, within each of the five areas, these twelve brands (produced by the larger feed manufacturers and distributed more widely) represented about three-fifths of all the brands sold. Two brands of feed were distributed in two of the five areas. Twenty-six brands (65 percent of all those fed) were fed in only one of the five areas surveyed, but in the aggregate they accounted for a substantial tonnage of feed sold. These brands, distributed only in one area, averaged about one-third of all the brands fed in the indi- vidual areas. In some cases such brands were those of local feed mixers, but in other cases they were brands of larger feed mixers, some out- of-state, who serve only certain areas of Illinois. This analysis does not disclose the relative volume of the different brands sold, for quantities of each brand of feed fed were not secured. The percentage of farms in each of the five areas using only one, two, or three and more commercial brands is shown below: Number of commercial North- North- South- brands used One Two Three and more . Western western eastern Eastern central 61 50 88 79 70 24 23 4 8 13 44003 20 BULLETIN No. 599 [February, The higher percentages of farms using only one brand in the eastern and south-central areas than in the western and northwestern areas is related to the fact that these areas had lower densities of swine and many dealers there handled only one brand of feed. 1 The very high percentage of farms in the northeastern area (smaller and with fewer dealers) using only one brand suggests a hjgh degree of satisfaction with the feed used and the service received from dealers. The data above show that in the northwestern area 77 percent of the farms used commercial brands of feed compared with 92, 89, 87, and 86 percent in the northeastern, western, eastern, and south-central areas respectively. However, the northwestern area had the highest percentage of farms using straight protein ingredient supplements ( Table 1 , page 5 ) . PART 2: DIFFERENCES IN ADEQUACY OF CRUDE PROTEIN IN SWINE RATIONS AS RELATED TO CERTAIN FACTORS Differences in the adequacy of protein in swine rations among phases of production and by areas have already been pointed out. Here, several other factors said to affect the use of protein supplements are analyzed. Differences among areas with the least and most swine. Do areas with the most swine meet feeding standards for crude protein more closely than areas with the least swine? Only by a small extent. The area with the most swine (western) had about the same level of in- adequacy as the area with the least swine (south-central). The eastern area showed only slightly more inadequacy than the northwestern area (Table 6). Differences between farms with the least and most swine within the same area. The same question that was asked about areas applies to farms as well. To answer this question, farms in each area were arrayed according to the number of swine on each farm and then di- vided equally into three groups. A comparison of inadequacy of rations fed in the group with the most swine and the group with the least swine is given in Table 11. (The third or intermediate group was not used in this analysis.) About the same percentage of farms in the two groups was found in several 1 As shown in The retail distribution of feed to Illinois fanners, by R. J. Mutti and G. W. Stone (111. Agr. Exp. Sta. AE2953, page 5, March, 1954). 1956] ADEQUACY OF PROTEIN IN SWINE RATIONS 21 Table 11. Comparison of the Inadequacy of Protein in Rations Between Farms With the Least Swine and Farms With the Most Swine, 1951" (By phases of production) Percentage points below recommended percentages of protein Phase of production None .1-1.5 1.6-3.0 3.1-4.5 4 ' 6 and over Spring (percent ol r farms in e; ich group) Bred sows Farms with most 38 15 29 12 6 Farms with least 40 17 10 16 17 Nursing sows Farms with most 61 17 14 4 4 Farms with least 51 19 20 10 Growing hogs Farms with most . . . 59 17 11 9 4 Farms with least 36 23 21 11 9 Fall Bred sows Farms with most . . 54 14 23 9 Farms with least 35 14 17 17 17 Nursing sows Farms with most . 40 17 24 16 3 Farms with least 40 14 19 22 5 Growing hogs Farms with most . . . . 51 10 13 23 3 Farms with least 20 23 26 23 8 a Excludes farms in the northeastern area and one-third of the farms the intermediate group - in the other four areas. of the sorts. In all phases of production the group with the least swine had a higher percentage of farms with inadequacies of over 3 percent- age points and in only one phase a higher percentage of farms feeding adequate rations. However, there was a wider variation within each group of farms than between them. 1 While the farms with the least swine generally had higher inade- quacies of protein in their rations, potential increases in sales of protein supplements on a tonnage basis are greater on farms with the most swine simply because they have far more swine to feed. Differences among farms varying in number of swine. Farms with the most swine in the south-central and eastern areas often had no 1 An analysis of variance in average deficiency of protein fed growing hogs (spring and fall) disclosed that the higher deficiency of the group with the least hogs was not significant in the western area, but was significant in the south- central area at the S-percent level. 22 BULLETIN No. 599 [February, more swine than farms with the least swine in the western and north- western areas. For this reason another analysis of deficiency, limited to spring data, was made, based on the actual number of swine on each farm (Table 12). In each phase of production, a greater percentage of farms with 25 or more sows or 125 or more hogs had adequate rations than farms with less than 4 sows or 25 hogs. However, for nursing sows a higher per- centage of the farms with 25 or more sows had rations 3 or more percentage points below recommendations than farms with fewer sows. In all four size groups shown in Table 12, the percentage of farms Table 12. Comparison of Inadequacy of Protein in Swine Rations According to Actual Size of Enterprise, Spring, 1951 Number of swine Percentage points below recom- mended percentages of protein None Less ^ an Ove - r 3.1 points 3.0 points (percent of farms in each group in eastern, northwestern, south-central, and western areas, combined) Bred sows 1 to 3 22 25 53 4 to 12 46 35 19 13 to 24 48 40 12 25 and over 36 55 9 Nursing sows 1 to 3 48 43 9 4 to 12 63 29 8 13 to 24 71 19 10 25 and over 64 18 18 Growing hogs 3 to 24 46 33 21 25 to 74 46 37 17 75 to 124 57 33 10 125 and over 68 28 4 (percent of farms in each group in the northeastern area) Bred sows 1-10 20 70 10 11-20 12 76 12 21 and over 39 61 Nursing sows 1-10 20 70 10 11-20 59 41 21 and over 70 30 Growing hogs 1-10 50 50 11-20 65 35 21 and over.. 87 13 1956] ADEQUACY OF PROTEIN IN SWINE RATIONS 23 feeding rations from 0.1 to 3 percentage points below recommendations to growing hogs was similar. A slightly higher percentage of farms with 13 to 24 sows fed ade- quate rations to both bred and nursing sows than farms having 25 or more sows. In the northeastern area (from which data were secured on a slightly different sorting basis), a much higher percentage of farms with the largest swine enterprises fed adequate rations. As shown below, farms with less than 11 sows had a slightly lower weighted deficiency than farms with 11 to 20 sows for bred sows and growing hogs, but a much higher deficiency for nursing sows. Size of enterprise 1-10 11-20 21 and over. . Bred sows . 1.59 . 1.75 .73 Nursing sows Growing hogs All phases 1.32 .39 .49 .20 .31 .04 1.04 .82 .42 The differences in average deficiency among these phases were sig- nificant at the 1-percent level. Differences related to income from swine. Data for the spring production period were analyzed to compare differences in feeding ac- Table 13. Comparison of Inadequacy of Protein in Swine Rations According to the Percentage That Swine Sales Were of Operator's Gross Cash Income, Four Areas,* Spring, 1951 Percent of operator's gross cash income from swine sales Percentage points below recom- mended percentages of protein None Less than 3.1 points Over 3.0 points (percent of farms in each group) Bred sows Under 20 29 23 48 20 to 44 45 28 27 45 and over 29 55 16 Nursing sows Under 20 51 34 15 20 to 44 64 29 7 45 and over 59 32 9 Growing hogs Under 20 40 30 30 20 to 44 49 37 14 45 and over 63 32 5 The northeastern area is not included because no data on swine sales were secured there. 24 BULLETIN No. 599 [February, cording to the percentage that swine sales were of the operator's gross cash income (Table 13). A smaller percentage of farms whose swine sales accounted for less than 20 percent of the operator's income fed adequate rations in two of the three phases of production. A greater share of farms with 45 percent or more of the operator's income from swine sales fed adequate rations to growing hogs but a smaller share of them fed adequate rations to bred sows and nursing sows than farms whose swine sales accounted for 20 to 44 percent of the operator's income. As in the other analyses of differences in adequacy of rations, vari- ations in feeding practices within a given group were more noticeable than differences among different groups. The variations among indi- vidual farms in adequacy of protein in rations fed growing hogs far- rowed in spring is shown in Fig. 2. Farms without any protein deficiency were located throughout the range of percentage of income from swine sales. 5.5 5.0 z "c/> 45 Q^ 40 LJ cr ziu 3.5 ui z 1* O w 30 w - ^S 2.5 Ife yp 2.0 85 1.0 0.5 o - 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 PERCENT THAT SWINE SALES WERE OF OPERATOR'S GROSS CASH FARM INCOME 85 90 There was extensive variation among individual farms (each represented here by a dot) in feeding adequate quantities of protein to growing hogs farrowed in the spring. Adequate rations were fed by a substantial num- ber of farms on which swine sales accounted for relatively small percent- ages of the operators' gross cash income, and several farms whose swine sales accounted for half or more of the operators' gross cash income fed inadequate rations. (Fig. 2) 7956] ADEQUACY OF PROTEIN IN SWINE RATIONS 25 Table 14. Comparison of Inadequacy of Protein in Swine Rations Between Farms on Prairie and Timber Soils, Western and South-Central Areas, 1951 Percentage points below recommended percentages of protein" Bred sows Nursing sows Growing hogs Prairie soils b Timber soils Prairie soils b Timber soils Prairie soils b Timber soils (percent of farms in each group) Western area, spring None 42 33 59 48 50 48 .1-1.5 15 27 15 16 23 20 1.6-3.0 27 20 18 16 15 24 3.1-4.5 12 20 4 12 88 4.6 and over 40 48 40 Western area, fall None 56 46 45 42 25 39 .1-1.5 22 25 25 8 15 13 1.6-3.0 16 12 10 29 20 26 3.1-4.5 6 13 20 17 35 4 4.6 and over 04 04 5 18 South-central area, spring None 23 29 59 48 55 37 .1-1.5 14 16 19 14 11 1.6-3.0 23 14 22 18 6 22 3.1-4.5 20 21 15 17 15 4.6 and over 20 36 30 8 15 South-central area, fall None 35 29 60 35 53 29 .1-1.5 13 12 11 12 1.6-3.0 22 35 24 23 11 24 3.1-4.5 13 12 16 24 14 29 4.6 and over 17 24 6 11 6 * Average deficiency for all phases of production was as follows: western circa, prairie soils: 1.2; timber soils: 1.4; south-central area, prairie soils: 1.5; timber soils: 2.1. b Soil association K in western Illinois and P in southern Illinois. c Soil association L in western Illinois and O in southern Illinois. Differences related to soil association. Approximately the same number of farms were selected from each of the two major soil associ- ations in the western and south-central areas. 1 A summary of the differences in adequacy between these farms is given in Table 14. 2 In the south-central area fewer farms on timber soils fed adequate rations in all but one phase of production than farms on prairie soils. 3 In the western area differences between rations fed on farms with 1 See footnote on page 4 for identification of these soils. 2 When records in both the south-central and western areas were analyzed, it was found that the average deficiency for farms on timber soil was significantly higher (at the 5-percent level) than for farms on prairie soil. 3 The difference in average deficiency for all production periods was signifi- cant at the 1-percent level. 26 BULLETIN No. 599 [February, Table 15. Comparison of Inadequacy of Protein in Swine Rations Between Farms Operated by Owners and by Tenants, Western and South-Central Areas, 1951 Percentage points Bred sows Nursing sows Growing hogs below recommended percentages of protein Tenants Owners Tenants Owners Tenants Owners (percent of farms in each group) Western area, spring None 44 32 52 55 50 48 .1-1.5 13 29 13 21 23 21 1.6-3.0 30 18 26 14 18 21 3.1-4.5 9 21 93 5 10 4. 6 and over 40 07 40 Western area, fall None 52 47 43 44 43 23 .1-1.5 24 24 14 17 9 18 1.6-3.0 14 14 14 26 15 32 3.1-4.5 10 10 29 9 19 18 4.6 and over 05 4 14 9 South-central area, spring None 30 24 69 46 53 44 .1-1.5 69 12 18 17 12 1.6-3.0 23 16 19 23 6 16 3.1-4.5 6 28 10 12 19 4.6 and over 35 23 3 12 9 South-central area, fall None 39 30 79 36 59 40 .1-1.5 15 4 7 8 12 1.6-3.0 15 29 14 32 8 18 3.1-4.5 23 11 7 21 17 21 4. 6 and over.. 8 26 04 89 prairie and timber soils were less distinct. 1 About the same number of farms on both these soils fed the same level of inadequate rations to growing hogs in the spring production period. Slightly fewer farms on timber soils than on prairie soils fed adequate rations to nursing sows and to bred sows in both spring and fall, but the reverse was true for growing hogs in the fall. Differences related to tenure. In the western area approximately the same number of farms in the sample were owner-operated and tenant-operated. In this area, in four of the six phases of production, slightly more tenant-operated farms fed adequate rations than owner- operated farms. The greatest differences between tenants and owners occurred in the rations fed sows bred to farrow in the spring and growing hogs in the fall (Table 15). 1 Differences of 0.2 percentage points in average deficiency were not statisti- cally significant. 1956] ADEQUACY OF PROTEIN IN SWINE RATIONS 27 In the south-central area over twice as many farms in the sample were owner-operated as tenant-operated. A greater percentage of the tenant-operated farms fed adequate rations and a lower percentage fed rations whose inadequacy exceeded 3.0 points in all six phases of production. Differences between farms on prairie and timber soils with the same type of tenure. Since differences in feeding in an area, asso- ciated with differences in soil, might be associated with differences in tenure status, a further analysis was made of the differences between owner-operated farms on prairie soils and owner-operated farms on timber soils, as well as between tenant-operated farms on prairie soils and tenant-operated farms on timber soils. The average inadequacy of protein in rations in each of these groups was as follows: Owner-operators on Tenant-operators on Area Prairie soils Timber soils Prairie soils Timber soils South-central.. 1.60 2.25 1.47 1.27 Western 85 1.55 1.38 1.06 The major points of these statistics are: 1. In both the western and south-central areas, the average defici- ency 1 was lower for owners on prairie soils than for owners on timber soils. 2. The average deficiency was lower in both areas for tenants on timber soil than for tenants on prairie soil, but the variation among tenants was so great that the variation due to soil differences was not statistically significant at the 20-percent level. 3. In both areas owners on timber soils averaged a higher deficiency than tenants on timber soils. 2 4. On prairie soils in the western area, owners had a lower deficiency than tenants,* but in the south-central area the mean deficiencies were about the same and the difference was not statistically significant. The reasons for these differences might, in turn, be traced to differ- ences in the financial position of operators on land of different pro- ductivity. This possibility, however, was not tested. SUMMARY This study appraised the protein content of rations fed to swine on individual farms in 1951 in relation to recommendations of the Illinois Plan for Swine Feeding. Differences in the adequacy of protein fed 1 Differences were significant at the 1-percent level. 2 The difference was statistically significant in both areas at the 20-percent level and almost at the 5-percent level. 3 The difference was statistically significant at the 5-percent level. 28 BULLETIN No. 599 [February, swine were determined within five areas in Illinois western, north- western, northeastern, eastern, and south-central selected because they represent varying levels in intensity of swine production. The amount of protein supplement required to eliminate protein deficiency in each phase of production was determined, as were differ- ences in deficiencies occurring among groups of farms varying in size of swine enterprise, proportion of operator's income from swine sales, soil association, and tenure. Major findings with respect to the adequacy of protein fed were: 1. Nearly all farms fed a protein supplement at least part of the time. 2. About 7 out of every 8 farms used some commercially mixed pro- tein supplement. 3. Alfalfa meal, meat scraps or tankage, skimmilk, and soybean meal were the ingredient supplements fed in every area. The percentage of farms using a given ingredient varied considerably from area to area, reflecting differences in the availability and price of that ingredient. 4. A higher percentage of farms omitted protein supplements when feeding bred sows than when feeding either nursing sows or growing hogs. 5. The south-central and northwestern areas had the highest per- centages of farms feeding swine in clrylot one-eighth of the farms in each area. Among phases of production in every area, the percentage of farms not making pasture available was higher for sows bred to farrow in the spring and for growing hogs farrowed in the fall. 6. The northeastern area had the highest percentage of farms making legume pasture available to swine; the south-central and eastern areas had the highest percentages making grass pasture available to swine. 7. About one-fourth of the farms fed rations containing the recom- mended level of protein in every phase of production conducted on those particular farms. However, among all areas in all phases of production, an average of half the farms fed rations that met the recommended levels for protein adequacy. 8. Among the five areas, the most significant differences in protein deficiency occurred in two phases of production: sows bred to farrow in the spring and growing hogs farrowed in the spring. 9. Among phases in the spring production period, differences in pro- tein deficiency were most significant in the northeastern and south- central areas. Among phases in the fall production period, differences were most significant in the western area. 10. Within areas, rations were most and least deficient as follows: Area Most deficient Least deficient Western Growing hogs, fall Bred sows, fall Eastern Growing hogs, fall Nursing sows, spring South-central Bred sows, spring Nursing sows, spring Northeastern Bred sows, spring Growing hogs, spring Northwestern Bred sows, fall Growing hogs, spring 1956] ADEQUACY OF PROTEIN IN SWINE RATIONS 29 11. Farms in the northeastern and northwestern areas fed rations averaging a lower protein deficiency than rations fed in the eastern area, and considerably lower than rations fed in the western and south-central areas. 12. The average deficiency for all areas was about 1 percentage point below the recommended protein level. If this deficiency were to be elim- inated by the use of a 35-percent protein supplement, a 27-percent in- crease in the amount of protein supplement used would be required. 13. Within areas, the percentage increases in protein supplement needed to eliminate deficiency ranged from only 2 percent (in the north- eastern area for growing hogs farrowed in the spring) to over 59 percent (in the south-central area for sows bred to farrow in the spring, in the western and eastern areas for growing hogs farrowed in the fall, and in the northwestern area for sows bred to farrow in the fall). 14. Nearly two-thirds of all the brands of commercially mixed feed used were fed in only one of the five areas. One-eighth of the brands used were fed in all five areas. Major findings as related to certain factors were: 1. In all phases of production the group with the least swine had a higher percentage of farms with protein inadequacies of over 3 percent- age points. In only one of the six phases did the group with the least swine have a higher percentage of farms feeding adequate rations than the group with the most swine. Differences in average deficiency between these two groups were significant in the south-central and northeastern areas, but not in the western area. 2. A higher percentage of farms on which the operator's sales of swine represented 45 percent or more of his gross cash farm income fed adequate rations in the spring production period than farms on which the operator's sales of swine represented less than 20 percent of his gross cash farm income. 3. In the south-central area, farms located on timber soils averaged 0.6 percentage points higher deficiency than farms on prairie soils, but in the western area farms on timber soils averaged only 0.2 percentage points higher deficiency than farms on prairie soils. These differences were significant only in the south-central area. 4. A greater share of tenant-operators fed adequate amounts of pro- tein in the south-central and western areas than owner-operators in those areas. 5. In both the south-central and western areas, owner-operators on prairie soils fed rations averaging less protein deficiency than owner- operators on timber soils. However, tenant-operators on prairie soils in these areas averaged more deficient rations than those on timber soils. Rations fed by owners on timber soils averaged a higher deficiency in protein than those fed by tenants on timber soils. 30 BULLETIN No. 599 [February, APPLICATION OF FINDINGS This study, dealing with matters pertinent to manufacturers and distributors of protein supplements, as well as to others who advise and serve farmers, showed a wide variation in swine- feeding practices among individual farms and within and among areas. Because of such variation, those who advise farmers must find out the specific feeding practices and conditions on individual farms in order to make the soundest recommendations. Their educational and advertising programs should point out those times when farmers are apt to feed deficient amounts of protein, such as when pasture deteri- orates or becomes unavailable, and when pigs weigh less than 75 pounds. The 27-percent increase in protein supplement required in the areas studied to meet recommended levels provides only a reference point today in appraising the additional market for commercially mixed protein supplements. Current appraisals must consider changes in many factors, of which these are major: 1. Number of swine produced. 2. Protein content of formula feeds sold. 3. Use of pasture. 4. Seasonal distribution of swine farrowings. 5. Feeding and management practices such as earlier weaning, more extensive practice of creep feeding, and disease control. 6. Nutritional requirements of swine as determined by research studies. 7. Protein content of corn and other feedstuffs used. 8. Amount of home-mixed rations. The findings of this study suggest that a greater use of protein supplement per animal will occur if the proportion of enterprises with 1 to 3 sows declines, for this size enterprise averaged somewhat higher protein deficiency than the large ones. Likewise, as the size of the swine enterprise increases on a given farm, supplement may need to be pur- chased because the availability per animal of pasture and of farm- produced grains and skimmilk may be reduced. Therefore, changes in the size of swine enterprises are of concern to the feed industry. The individual feed dealer is also affected by such changes because farmers with large swine enterprises tend to attract other dealers and more of these farmers may purchase straight protein ingredients to mix themselves or have mixed locally. Illinois farm records 1 show that the more profitable swine enter- 1 "Summary of farm business records on Illinois farms for 1953," b3' A. G. Alueller, in Illinois farm economics, No. 221, p. 1543, Nov., 1954. 1956] ADEQUACY OF PROTEIN IN SWINE RATIONS 31 prises (upper sixth of records) have used on the average about 20 per- cent less protein supplement per pound of pork produced than the less profitable swine enterprises (lower sixth of records). Thus it would seem that if farmers as a group improve the management of their swine enterprises they will tend to use less protein per animal. At the same time, it should be recognized that some farmers who have less profitable swine enterprises may be able to increase their net income by using more protein. Continual study of farmers' feeding practices is needed. Particular attention should be given to finding out under what conditions limiting the amount of protein supplement is more profitable than free-choice feeding, which, many farmers contend, is the case on their farms. Further research on input-output relationships arising from feeding swine rations of different levels of protein will help answer this ques- tion, for the expected returns under varying price relationships be- tween high-protein feeds and other feeds could then be determined. Other research determining how different feeding practices affect the use of labor and other farm resources would also be helpful in estab- lishing the most profitable feeding plan on a given farm. ACKNOWLEDGMENTS The author acknowledges the assistance of the following persons in making this study: For visiting farms to secure information from farmers: T. W. ANDERSON, northeastern area; R. E. CAIN, northwestern area; W. C. HARRIS, western area; C. R. SMITH, eastern area; and W. E. WILLIAMS, south-central area. For help in summarizing and analyzing data: V. I. WEST, Associate Professor of Agricultural Economics, University of Illinois ; T. W. ANDERSON, Vocational Agriculture Teacher, Maple Park, Illinois; and R. E. ROGERS, W. L. RUBLE, and G. W. STONE, former assistants in agri- cultural economics, University of Illinois. For suggestions in establishing standards of feeding adequacy: S. W. TERRILL, head of the swine division, University of Illinois. This study was supported in part by funds authorized by the Research and Marketing Act of 1946. 5M 2-56 59272