SB 191 .M2 S52 Copy 1 SB 191 .M2 S52 Copy 1 FNITED STATES DEPARTMENT OF AGRICULTURE €E1 bulletin No. 953 •^Mk^^--l|K5? Contribution from the Bureau of Animal Industry ^^'^^^ JOHN R. MOHLER, Chief 'S^i^'^^U Washington, D. C. PROFESSIONAL PAPER May 14, 1921 NITROGEN AND OTHER LOSSES DURING THE ENSILING OF CORN. I' «■ By R. H. Shaw, Chemist, aiul 1'. A. Wuight and K. F. Deyshek, Assistant Chemists, Dairy Division. CONTENTS. Page. Purpose of paper 1 Previous investigations of nitrogen and other losses 1 The experimental work 5 Manner of placing and remov- ing samples 5 Collection of the juice 6 Page. The exi)erlmental work — Continuod. Method of analyzing samples.. C Results of the analyses 6 Discussion of results 9 Conclusions 15 References to literature 15 PURPOSE OF PAPER. The silo is primarily a means for conserving food material. With the preservation through fermentation of the mass of corn or other crops in the silo there is generally the loss of a small amount of food material. Certain losses are ap[)arently necessary in the proper fer- mentation; others are probably unnecessary. For several years the Dairy Division has been studying to find out more definitely what losses incident to the ensiling of corn are neces- sary and what is the proper method of handling the crop to prevent such losses. This bulletin deals with the losses of nitrogen and other elements in corn silage made under ordinary farm conditions. PREVIOUS INVESTIGATIONS. The earliest recorded studies of the loss of nitrogen and othci- elements during the ensiling of corn were made with material very low in dry matter and stored in pit or tub silos. Moser (1)/ at the Vienna Agiicultural Experiment Station, buried bundles of green maize, some wilted and some fresh, at different * The figures in parentheses refer to the citations at the end of this bulletin. ■MiyGir—'M <\ ■^. 2 BULLETIN 5)53, IT. S. DEPARTMEl^rT OF AGEICULTXJRE. depths in a small earth pit silo. Calculating on the basis of the author's tables, one notes losses as high as 74 per cent of the water content and 28 per cent of the crude protein of the original maize in the pit at a depth of 42 centimeters, but at a depth of 170 centi- meters only a 3 per cent loss of water and a 7 per cent loss of the crude protein. His tables indicate a larger loss of nitrogen-free extract in the upper than in the lower layers and a gain in crude fat in the lower layers. The loss in crude fiber is small except in one sample. The change in ash content varies over a wide range. Weiske and Schulze (2) report experiments in which they ensiled maize containing only 12 per cent dry matter. They used two water- tight vats holding 125 kilos and 110 kilos, respectively. The first one, containing maize well packed in, lost 26.1 per cent of its dry matter and 37.8 per cent of its crude protein in 112 days. The second one, containing maize loosely thrown in, lost 35.8 per cent of its dry matter and 54.2 per cent of its crude protein in 115 days. Both tub silos lost heavily in crude fiber and nitrogen-free extract, but gained very markedly in ether extract. Jordan (3) states that in the course of three years' work, using a stone-basement root cellar as a silo, he found only a 5.18 per cent to 11.82 j)er cent loss of organic matter, which appeared to be almost wholly in the carbohydrates other than crude fiber. He notes ap- parent gains in crude fiber in two out of three cases and losses of from per cent to 0.77 per cent in the crude protein present at ensiling. He bases his calculations on the assumption that there is no loss of ash during ensiling. Several years later, at the Pennsylvania Experiment Station, Armsby and Caldwell (4), in connection with a comparative feeding experiment, using silage and dry corn fodder, found a loss of 10.76 per cent of the total dry matter ensiled. Their tables show a large loss in the ash and in the albuminoids; a small loss in crude fiber, and a large loss in the nitrogen-free extract, with a large gain in nonalbuminoids and in the crude fat. Henry and Woll (5) , at the Wisconsin Experiment Station, studied the losses in ensiling green corn by using three different varieties of corn in three square, wooden bay silos, holdin,g from 8| to 12 tons each. They report 22 and 24 per cent losses of the total dry matter ensiled in two of the silos and 31.8 per cent loss in the remaining one, which broke and let in air. They find the largest losses to be in nitrogen-free extract, crude protein, and crude fiber. There was a large gain in ether extract in two of the silos. They also find a small gain of ash in one silo with a large loss in the others, which is explained as a translocation of the mineral matter caused by pressure of the upper layers on the lower ones, by movement of the juices of green fodder or by diffusion. . Liblv/»rp; OF CONGKtS^ MAY26192I J 6^^\^*- .^v NITROGEN AND OTHER LOSSES IN ENSILING CORN Woll (6), in another paper, gives additional data on silago studies taken up at the Wisconsin station. His summary of results for three silos indicates that he found a 37.15 per cent loss in albuminoid nitro- gen and a 46.7 per cent gain in amido nitrogen during ensiling. Short (7), in 1888, at the Wisconsin station finds during the ensil- ing of maize in three silos an average loss of 15.94 per cent of the dry matter and 21.26 per cent of the crude protein ensiled. Woll (8), summarizing three years' work, including 10 experiments in Avhich the comparative losses in ensiling and field-curing green maize were studied, reports that by ensiling there was a loss in the total dry matter of 20.5 per cent and in the crude protein of the green corn a loss of 20.6 per cent. He used silos holding 8 to 12 tons of silage. In the fall of 1890, Woll (9) continued his experiments on the com- parative losses in ensiling and field-curing green corn. He states in the report for the year ended June 30, 1891, that with a large rex:- tangular silo of 80 tons' capacity, he found in the 65 tons of maize ensiled a loss of only 10.3 per cent in the total dry matter, and of 12.5 per cent in the crude protein. He attributes the larger losses of previous years to the smaller quantities of maize ensiled. F. H. King (10), of the Wisconsin Experiment Station, in connec- tion with his experiments to determine the necessary loss of dry mat- ter in maize silage, studied the losses of total green material and total dry matter. Including all material taken out, whether good or spoiled, he finds in one year, in approximately 65 tons of maize ensiled, a loss of 7.35 per cent of the green matter and 4.95 per cent loss of the total drj' matter. In the next year he finds a 5.78 per cent loss of green matter and 9.38 per cent loss of the total dry matter. He concludes that the loss may vary with the maturity of the maize at the time of ensiling. Cooke (11), in the earliest investigations with maize silage reported from the Vermont Experiment Station, describes an investigation with an experimental round stave silo holding about 350 pounds of corn, covered b}^ a follower under a pressure of 50 pounds per square foot. He states that the corn was cut while in the glaze and the silage was in perfect condition when taken out. His tables indicate a loss of 14.67 per cent of total dry matter ; a loss in albuminoids, crude fiber, and nitrogen-free extract ; and a gain in the fat of the maize ensiled. Cooke and Hills (12), in a comparative study of the losses in maize silage and maize fodder, using a square wooden silo holding 12 tons, find a loss during ensiling of 20 per cent of the total dry matter, 13 l)er cent of the all)uminoids, and 31 per cent of the sugars and starch in the maize ensiled. a..,r'^'-^'7 3 J 4 BULLETIN 953, IT. S. DEPARTMENT OF AGRICULTURE. The following year, in a somewhat similar experiment, the same authors (13) find a loss of 18 per cent of the dry matter, 11 per cent of the albuminoids, and 26.5 per cent of the sugars and starch of the green maize during ensiling. Two years later Hills (14) reports a repetition of the investigation of the comparative losses in maize silage and maize fodder and gives a more detailed chemical report. He states that he found losses in the total amounts of the different constituents of the maize from harvest- ing to feeding to be as follows : Dry matter, 20 per cent ; crude pro- tein, 12 per cent ; crude fiber, 5 per cent ; nitrogen-free extract, 30 per cent ; ether extract, 16 per cent ; and a gain of 3 per cent in crude ash. The director of the New York Experiment Station (15) at Geneva reports investigations extending over a period of three years, during which nine bags of green maize and seven bags of green sorghum were buried in a silo 14 by 15 by 30 feet. The bags weighed 50 pounds each at ensiling and, except for one bag of sorghum, were buried in sets of three, one bag at the center and the other two within a foot of opposite walls of the silo. The combined results of the 16 bags show during ensiling the following changes, which are based on the total amounts of each constituent of the maize ensiled : Losses — water, 3.9 per cent ; ash, 0.4 per cent ; albuminoids, 18.5 per cent ; crude fiber, 9.8 per cent; nitrogen- free extract, 15.1 per cent; albuminoid nitrogen, 18.7 per cent ; sugars and starch, 26.6 per cent ; and dry matter, 12.6 per cent; grains — crude fat, 45.4 per cent; and amide nitrogen, 3.7 per cent. Clements and Russell (16) state that they ensiled green maize in a round silo 12 feet in diameter and 17 feet high and examined the silage a few days and also three weeks after ensiling. Tlieir tables show a loss in protein nitrogen and a gain in amide nitrogen, also a slight gain in fiber and in furfurol, and they seem to indicate no trace of sugars remaining even after a few days' ensiling. Russell (17) gives a summary of the investigations undertaken with maize silage over a period of five years at the South-Eastern Agricul- tural College, Wye, England. He concludes that the characteristic silage changes are the disappearing of sugar, of some of the less resistant cellulose, and of a part of the protein. Annett and Russell (18), in a very interesting paper published in the Journal of Agricultural Science in 1908, give a discussion of various phases of silage investigation undertaken at the South- Eastern Agricultural College, Wye, England. They discuss quite thoroughly the losses and changes in the silo. Each year the in- vestigators buried in a 12 by 17 foot round stave silo several sacks of from 10 to 15 kilos of fine-cut corn at different depths, and analyzed the maize when put in and when taken out of the silo. NITROGEN AND OTHER LOSSES IN ENSILING CORN. 5 The maize was cut g:reen. Tn some seasons the dry matter was as high as 20 per cent and in cold, wet seasons as low as 13 per cent. They find practically no loss in crude fiber, but a very great loss in nitrogen- free extract, from wliich the sugar is shown by direct test to disappear almost entirely. The pentosans and protein suffer considerably. They state that the bags in the top half of the silo lost an average of 32 per cent of their original content of ether extract and 17 per cent of their soluble ash constituents, while the bags in the lower half gained over the original amounts 6 per cent in ether extract and 2 per cent in soluble ash constituents. They make note of a downward wash of soluble acids and ash. In a table stating an average of all losses and gains in original constituents present in the green material during the ensiling of maize during the seasons of 1904 and 1905, they give the losses as follows: Dry matter 36 per cent; ether extract, 16 per cent; nitrogen-free extract, 55 per cent; fiber, 8 per cent; total nitrogen, 26 per cent; protein nitrogen, 55 per cent; ash, 14 per cent; furfurol, 32 per cent; and gains, non- protein nitrogen, 83 per cent. Feruglio and Mayer (19) claim to find a loss of only 5 per cent in the food material during the ensiling of maize. They state that this loss falls somewhat on the pure protein and albuminoids, but most strongly on the sugars and pentosans. On the other hand, they find an increase in ether extract and total acidity. THE EXPERIMENTAL WORK. The silo used was a cylindrical concrete silo 42 feet high by 14 feet in diameter inside, holding approximately 150 tons, and located at the Dairy Division Experiment Farm, Beltsville, Md. The floor of the silo was 4 feet below the lowest door, and the silo up to this door was water-tight. Tlie work was carried on for two seasons, 1914-15 and 1915-16. During both seasons the silo used was completely filled with corn. The depth of the silage after settling was approximately 38 feet. MANNER OF PLACING AND REMOVING SAMPLES. Samples of silage in cheesecloth sacks were buried at various depths and positions in the silo. The silo was divided into 8 levels the first season and 6 levels the second season. The first level was near the bottom of the silo and the last one near the top. The distance be- tween levels was approximately the same. When a level was reached in the regular course of filling the silo a sack of the carefully sampled cut corn was weighed and buried at about the center. At the same time another sample was taken for chemical anah'sis. The sacks were numbered according to the level at which they were buried. 6 BULLETIN 953, U. S, DEPARTMENT OF AGRICULTURE. During the fall and winter the silage was fed out as usual, and whenever a level was reached the sack was removed, placed in a closed can, and immediately sent to the laboratory for analysis. COLLECTION OF THE JUICE. The floor of the silo was tapped and a 1-inch pipe conducted the silage juices to a receptacle outside and below the floor level of the silo. During the first season a barrel was used to receive the juice, but this proved unsatisfactory, and during the second season a cov- ered concrete tank was employed. At first daily, later at more extended periods, the juice collected since the previous sampling was thoroughly mixed, and the sample, in an 8-ounce bottle, was immediately sent to the laboratory for analysis. During the collection of a niunber of juice samples in the season of 1914-15 hard rains occurred which caused the barrel in which the juice was collected to overflow or diluted its contents, thus destroy- ing the value of the respective samples. Owing to these facts, the results of this season's work on the juice are of value only as pre- liminary and as indicating the approximate amount of juice lost from the silo and the nitrogen contained therein. METHOD OF ANALYZING SAMPLES. The bags of silage were taken to the laboratory immediately after removal from the silo. After the weights were taken the contents were mixed and a 1-kilogram charge was taken for the gross- moisture determination. The remainder was pulped in a power meat grinder. The pulp was thoroughly mixed and charges for the various nitrogen determinations immediately taken. The charge for the gross-moisture determination was placed in a steam drying closet and dried at a temperature between 50° and 60° C. to a, con- stant weight. It was then exposed to the air for several days and the final weight taken to represent the air-dry condition. The material was then ground in a power mill to a fine flour suitable for analysis. The amino nitrogen was determined by the method of Van Slyke and the ammonia nitrogen by the method of Folin and Macallum. The other determinations were made according to the methods of the Association of Official Agricultural Chemists. RESULTS OP THE ANALYSES. The results of the experimental work are given in the following tables. Table 1 gives the weight and chemical composition of the corn in each sack as it was buried. Table 2 shows the weights and chemical composition of the contents of the sacks as they were re- ISTITKOGElSr AND OTHER LOSSES IN ENSILING CORN. 7 moved from the silo. Table 3 was calculated from the preceding tables and shows the losses or gains in each sack based on the weights ensiled. Tables 4 and 5 give the weights and chemical analyses of the juice. Table 1. — Summary of analyses of cut corn as placed in bags. Season 1914-15. Bag No. Weight. Mois- ture. Total nitrogen. Albu- minoid nitrogen. Ether extract. Crude fiber. Ash. Total sugar. Nonre- ducing sugar. Fur- furol. 1 Grams. 3,350 7,740 5,510 6,220 6,390 6,640 6,620 5,870 Per cent. 68.54 67.18 67.21 66.23 69.13 74.60 69.90 72.19 Per cent. 0.451 .406 .506 .434 .45 .329 .394 .370 Per cent. 0.334 .344 .418 .347 .362 .282 .349 .286 Percent. 0.52 .58 .63 .64 .54 • 42 .58 .47 Per cent. 6.15 6.29 5.65 6.17 5.89 4.55 6.17 5.92 Per cent. 1.33 1.02 1.18 1.18 1.83 1.02 1.56 1.38 Per cent. 4.23 3.93 4.16 3.07 3.67 3.30 2.64 2.46 Percent. 0.39 1.83 1.03 1.30 0.71 0.09 0.68 0.72 Per cent. 3 64 2 3 71 3 4 74 4 3 74 5 3.49 6 2 72 7 3 37 8 3.30 Average. 69.39 .413 .340 .55 5.84 1.31 3.39 1.28 3.56 Season 1915-16. 1 5,615 4,685 7,170 7,180 7,935 7,540 76.95 72.02 76.63 75.18 74.80 73.28 0.398 .434 .360 .374 .416 .344 0.326 .339 .307 .317 .325 .320 1.29 1.91 1.49 1.31 1.13 1.57 2.97 3.57 2.98 3.17 3.23 3.03 0.51 .68 .17 .29 .28 .79 2.33 2 3.03 3 2.47 4 2. 55 5 2 70 6 2. 75 Average. 74.89 .385 .321 1.42 3.14 .46 2.63 Table 2. — Summary of analyses of silage as removed from bags. Season 1914-15. Bag No. Weight. Gain (+)or loss Mois- ture. Total nitro- gen. Al- bumi- noid nitro- gen. Ether ex- tract. Crude fiber. ! Ash '^^^^'^ -^^°- sugar. Non- reduc- ing sugar. Fur- furol. Amino nitro- gen. Am- monia nitro- gen. 1... 2... 3... 4... 5... 6... 7... 8... Grams. 3,800 8,550 6,400 7,920 7,070 6, ,355 7,655 6,560 Grams. +250 +810 +890 + 1,700 + 780 -245 + 1,035 +690 Per cent. 75.14 71.02 73.36 74.48 77.30 75.32 76.83 78.52 Per cent. 0.442 .427 .491 .405 .396 .349 . 331 .312 Per cent. 0.154 .168 .2,37 .155 .149 .106 .110 .114 Per cent. 0.65 .59 .78 .70 .67 .64 .70 .45 Per cent. 5.10 5.58 4.91 4.69 4.40 4.51 4.94 4.74 Per 1 Per cent. cent. 1. 22 0. 12 1. 14' . 08 1.13 .13 1. 16 . 15 1.20 .09 1.13 .74 1.27 .00 1.25 .17 Per cent. None. None. None. None. None. None. None. None. Per cent. 2.68 3.24 2.69 2.62 2.33 2.4-1 2.45 2.49 Parts per million. 1, 530 1,420 1,510 1,300 1,440 1,250 1,880 1,900 Parts per million. 302 264 304 278 246 257 305 105 Avei age 75. 15 .392 . 149 - 65 4.87 1. 19 . 18 2.63 1,538.8 257 6 Season 1915-16. 1 5,510 5,170 6,210 6,870 7,775 7,350 -105 +48.5 -960 -310 -160 -190 78.80 78.12 77.34 75.58 76.98 75.98 0.382 .392 .354 .379 .386 .322 0.139: 1.31 1.72 1.64 1. 23 1.07 1.40| 0.09 .08 .09 None. None. ; 2.28 2.37 2.46 2.39 2.16 1,480 1,320 1,040 1,480 1 440 274 ?. .118 252 8 .1761 ISO 4 .139 217 fl .142 1 .35 .11 None. None. 256 ft .133 1 2.41 1 120 192 ' Avei ■age 77.02 .368 .142 1 1.37J .20 2.34 1,313.3 228.5 1 BULLETIN 953, U. S. DEPARTMENT OF AGRICULTURE. Table 3. — Summary of losses and gains, based on weights ensiled. Season 1914-15. Bag No. Green mat- ter. Mois- ture. Dry mat- ter. Total nitro- Albu- mi- noid nitro- gen. Non- albu- minoid nitro- gen. Ash. Ether ex- tract. Crude fiber. Total sugar. Fur- furo). 1 2 3 4 5 6 7 8 Average of 4 top l)at;s' Average of 4 bottom bags' Average of all bags. . . Per cent. -1-13.43 -1-10.47 -fl6. 15 + 27.33 + 10.64 - 4.29 + 15.63 + 11.75 + 8.31 + 16.87 + 12.35 Per cent. +24. 36 + 16.78 +26. 78 +43. 17 +23. 73 - 3.37 +27. 10 +21. 55 + 16.71 +27. 43 + 21.61 Per cent. -10.36 - 2.46 - 5.63 - 3.78 -18.64 - 7.00 -10.99 -13.69 -12.74 - 4.70 Per cent. + 11.16 + 16.18 + 12.71 + 18.82 - 2.64 + 1.52 - 2.86 - 5.76 - 2.46 + 15.19 + 6.49 Per cent. -47.69 -46.04 -34. 15 -43. 13 -54.47 -64.01 -63.55 -5.3.45 -59.41 -42.18 -50.76 Per cent. + 179.18 +361. 53 +235. 31 + 265.94 +210. 56 +394. 75 +467. 94 + 163.41 +277.24 +264. 33 +270. 36 Per cent. + 4.05 +23.45 + 11.23 +25. 17 -27. 45 + 6.03 - 5, + 1.23 - 8.96 + 17.61 + 2.07 Per cent. +41.79 + 12.37 +43. 82 + 39.26 + 37.26 +45. +39. 56 + 6.99 +33. 31 + 31.92 +32. 59 Per cent. - 5.93 - 2.00 + .94 - 3.21 -17.35 - 5.13 - 7.42 -10.52 -10.29 - 2.26 - 6.34 Per cent. - 96.75 - 97. 73 - 96.37 - 93. 76 - 97.31 - 78.54 -100.00 - 92.31 - 91.65 - 96.35 - 94. 14 Per cent. -16.48 - 3.53 -34.07 -10.80 -26. 13 -14.14 -15.93 -15.67 -18.24 -15.60 -17.07 Season 1915-16. Average of 3 top bags' Average of 3 bottom bags' Average of all bags. . - 1.87 + 10.35 -13.39 - 4.32 - 2.02 - 2.52 - 2.91 - 3.32 - 3.09 + 0.49 + 19.70 -12.59 - 3.81 + .84 + 1.07 - .57 - 9.75 -13.71 -16.01 - 5.86 -10.49 -12.37 - 9.72 - .04-13.41 - .34-11.29 - 5.82 - .33 -14.84 - 3.04 - 9.08 - 8.75 - 7.09 - 7.59 - 7.31 -58. 16 -61.59 -50.34 -58.04 -57. 19 -59. 47 -58.21 -56.08 -57.27 + 231.16 + 136.96 + 190.90 +302. 96 + 162.72 +667. 40 +276. 14 + 184.70 +231. 79 - 0.35 - .63 - 4.67 -10.16 - 7.22 -13.07 -10.43 - 2.16 - 6.54 -97.00 -97.49 -97. 37 -87.91 -89.38 -96. 45 -91. 18 -97. 32 -93.90 - 3.98 -13.68 -13.73 -10.32 -21. 62 -14.57 -15.78 -10.88 -13.68 1 These averages are based on weights obtained rather than on the percentages of the different com- pounds in each bag as shown in this table. Table 4. — Summary of analyses of juice; season 1914 -15. Sample No. Weight. Specific gravity. Acidity.i Total ni- trogen. Albumi- noid ni- trogen. Nonalbu- minoid nitrogen. Total ni- trogen calcu- lated as protein. 1 Pounds. 57 81 84 126 127 128 108 94.75 61 52.5 29.25 59 58.25 28.25 25 28.5 14.25 18 151. 75 131 50.0 38.5 3L5 42.5 22.5 73.25 176. 25 77.25 36.50 140. 00 31.00 127. 00 149. 25 90.00 8.00 23.00 L008 L022 L030 L034 L036 1.039 1.040 1.040 1.040 1.040 L041 1.042 L042 L042 1.042 1.041 1.046 1.047 1.018 1.022 1.026 1.028 1.029 1.029 1.031 1.022 1.013 1.009 1.026 1.014 1.034 1.008 1.015 1.023 1.026 1.009 C.c. 0.59 17.29 24.54 29.12 30.80 32.70 32.66 33.14 33.64 32.45 33.85 33.83 33.08 32.83 32.83 29.69 32. 95 32.45 16.17 20.14 23.06 24.03 24.50 25.45 26.88 21.14 13.31 8.83 26.11 12.53 30.99 7.82 15.03 23.12 19.83 7.06 Per cent. 0.0432 .138 .190 .234 .232 .254 .269 .278 .283 .290 .291 .296 .288 .292 .297 .282 .320 .328 .126 .163 .187 .202 .208 .214 .230 .174 .099 .075 .195 .109 .269 .060 .119 .195 .187 .064 Per cent. 0. 0176 Per cent. 0. 0256 Pounds. 0.1539 2 .6966 3 .9997 4 .0211 .2129 L834 5.. . . 1.842 6 2.035 7 L814 8 .0314 .0295 .0295 .0259 .0259 .0281 .0251 . 0258 .0226 .0306 .0306 .0131 .0170 .0178 .0168 .0191 .0202 .019 .017 .013 .006 .015 .010 .022 .005 .007 .012 .015 .005 .2466 .2535 .2605 .2651 .2701 .2599 .2669 .2792 .2594 .2894 .2974 .1129 .1454 .1692 .1852 .1889 .1938 .211 .151 .086 .069 .180 .099 .247 .055 .112 .183 .172 .059 L700 9 L080 10 .9399 11 .5323 12 L091 13 L048 14 .517 15 .465 16 .502 17 .295 18 .369 19 1.200 20 ... 1.336 21 .585 22 .485 23 .410 24 .570 25 .324 26 .7984 27 1.0928 28 .3631 29 .4453 30 .9520 31 .5208 32 .4826 33 1. 1045 34 .1098 35 .0936 36 .0920 ' The figures in this column represent the number of cubic centimeters of normal alkaU required to neu- tralize the acid in 100 grams of the juice. Total weight of juice, 2,579 pounds. Total weight of nitrogen calculated as protein, 28.88 pounds. NITROGEN AND OTHER LOSSES IN ENSILING CORN. Table 5. — Summary of analyses of juice; season 1915 -16. Sample No. Number of days repre- sented. Weight. Specific gra\'lty. Acidity.' Total nitrogen. Albumi- noid nitrogen. Ammonia nitrogen. Amino nitrogen. Total nitrogen calcu- lated as protein. 1 2 1 2 3 5 4 5 3 6 2 6 4 7 4 4 3 8 8 12 9 8 9 13 10 20 22 14 15 21 30 34 Pounds. 40 81 142.5 166 498.5 655. 5 1,046 650 413 290.7 237. 5 169.5 313 160 250 429 424 262.5 340 172.3 257 147 254 171.5 205 107 107 106 177 115 124 89 68 65 89 58 90 880 49 51 64.5 122 157.5 1.027 1.029 1.030 1.029 1.029 1.029 1.029 1.030 1.030 1.030 1.030 1.030 1.030 1.030 1. 0295 1.029 1.030 1.030 1.030 1.030 1.032 1.032 1.035 1.034 1.035 1.035 1.036 1.036 1.040 1.040 1.040 1.040 1.042 1.046 1.041 1.045 1.045 1.045 1.042 1.039 1.040 1.037 1.030 C.c. 22.8 24.4 21.4 Per cent. 0.139 .168 .184 .195 .208 .211 .227 .240 .245 .246 .245 .254 .251 .250 .258 .251 .258 .266 .262 .251 .277 .262 .291 .290 .280 .285 .288 .290 .298 .302 .306 .304 .315 .320 .299 .315 .322 .323 .299 .274 .275 .267 .219 Per cent. 0.0384 .0384 .0384 Parts per million. 174.2 183.1 171.7 Parts per million. 710.1 850.9 854.5 Pounds. 0.3480 2 .8505 3 1.6388 4 . . 2. 0252 5 21.4 21.4 21.4 29.0 29.0 28.5 29.0 28.5 28.1 28.3 28.3 27.2 28.0 29.7 30.5 31.8 34.1 34.6 36.3 36.8 36.8 37.0 37.5 37.8 38.6 39.5 39.3 38.6 38.5 39.3 35.3 36.2 34.1 32.0 28.2 26.7 24.2 28.3 26.6 .0352 .0368 .0320 .0400 .0496 .0304 .0416 .0400 .0464 .0368 .0464 .0464 .0336 .0384 .0352 .0432 .0384 .0384 .0336 .0384 .0144 .0128 . 01536 .0144 .0160 .0144 .0144 .0112 .0118 . 01328 .01200 .01280 .0182 .0211 .0216 .0151 .0189 .0195 .0158 193.7 190.4 205.4 215.7 224.6 229.2 240.3 232.4 233.4 243.0 248.5 249.8 255.1 295.6 301.7 309.6 316.8 317.9 334.7 332.4 329.4 356.3 374.4 371.2 387.7 394.5 438.3 416.0 429.5 441.6 415.4 416.4 429.6 448.7 416.8 397.1 395.9 419.8 369.3 1,073 1,073 1,133 1,119 1,159 1,203 1,220 1,214 1,240 1,246 1,317 1,285 1,263 1,392 1,401 1,462 1,498 1,503 1,539 1,517 1,558 1,663 1,717 1,757 1,771 1,762 1,959 1,941 1,986 2,139 1,979 1,972 1,962 1,962 1,967 1,657 1,759 1,505 1,318 6.4805 6 8.6526 7 14. 8532 8 9.7500 9 6. 3189 10 4. 4775 11 3.6338 12 13 2.6951 4. 9141 14 2.4960 15 16 4.0250 6. 7353 17 6.8264 IS 19 4. 3575 5.6580 20 2.7033 21 4.4461 22 2. 4108 23 4. 6228 3.1042 25 3.5875 1.9046 27 1. 9260 28 1.9186 29 3.2922 2. 1735 31 2.3684 32 3. 5910 33 1.3396 1.3000 35 1.6643 1.1426 37 1.8090 38 1.6160 39 .9163 .8721 41 1.1094 2. 0374 43 2. 1578 Average . 1. 0345 51.17 .263 .0283 317.9 1,472.9 1 The figures in this column represent the number of cubic centimeters of normal alkali required to neutralize the acids in KM) grams of the juice. Total weight of joico, 9,491. 5 jjounds. Total weight of nitrogen calculated as protein, 150.75 pounds. DISCUSSION OF RESULTS. The investigation was conducted under all the difficulties inherent in practical farm conditions. The silo w^as not in any sense an experimental silo. The burial and removal of the bags took place during the regular course of filling the silo and feeding out the silage. In the sea.son of 1914-15 the filling extended over a period of 17 days and the feeding out took nearly H months from the first bag to the last. In the season of 1915-lG the filling took only 8 days but the feeding out extended over a period of nearly 7 months. In the former season the corn was considered somewhat overmature and for a few minutes during each day's run water was added through the distributer. In the latter season the corn was considered less mature than is desirable for the best quality of silage. 10 BULLETIN 953, U. S. DEPARTMENT OF AGKTCULTURE. TEMPERATURE AND COLOR CHANGES. The changes that occur in corn during fermentation in the silo have been the subject of much study by numerous investigators, both in this country and in Europe. First, there is a more or less rapid rise in temperature of the silage mass, the degree of which depends somewhat upon the temperature of the outside air and more perhaps upon the state of maturity of the corn and the degi-ee of fineness to which it is cut. This is followed by a gradual decline in temperature of the silage and a change of color from the green of the fresh-cut corn to a greenish-brown. These changes in physical appearance are accompanied by a copious evolution of carbon dioxid and the forma- tion of volatile and nonvolatile acids, which have been shown to con- sist largely of acetic and lactic acids. The sugars both of the reduc- ing and nonreducing type which are present in green corn disappear almost completely during the fermentation process. A large part of the albuminoid nitrogen disappears, and there is a great increase in the amount of nonprotein nitrogen, some of which appears as amino acids. The causes which produce these profound changes have been the subject of considerable dispute, some writers taking the ground that bacterial action is entirely responsible, others that bacteria have little if anything to do with them, and still others contend that the changes are due in part to bacterial and in part to enzymatic action. DOWNWASH OF SOLUBLE MATERIAL. The results of the chemical analyses as given in the tables show many evidences of a downwash of soluble material, the upper part of the silo losing and the lower part gaining. In 1914—15 about 2,600 pounds of juice were collected, and in 1915-16 about 10,000 pounds. Doubtless had this juice not been allowed to escape, the analytical re- sults for the bags in the lower part of the silo would have shown a greater loading up with soluble constituents, or at least smaller losses. Especially is it believed that this would have been true in 1915-16 when the loss in juice rose to almost 5 tons. A difficulty in controlling conditions is the impossibility of removing the bags simultaneously so that they would all have been in the silo the same length of time. This factor might be quite important in the 1915-16 work, when from 1 to nearly 3 months elapsed between the recovery of several of the bags. The tables showing losses and gains of green matter and of moisture during ensiling show by comparison the marked effect of adding water when filling the silo. Indeed, the tendency of certain soluble con- stituents to wash downward in the silo, which was probably obscured the second season by the excessive outflow of juice, may have been NITROGEN AND OTHER LOSSES IN ENSILING CORN. 11 enhanced the first season by the addition of water to the corn at en- siling. In the season of 1914^15 the change in amount of green matter varies from a loss of 4.29 per cent in the weight of bag No. 6 to a gain of 27.33 per cent in the weight of bag No. 4. The average gain for all bags is 12.35 per cent. The gain for the bags in the upper half averages 8.31 per cent and for the lower half, 16.87 per cent. That the apparent gain in green matter is only a gain in water which more than offsets any loss in dry matter is shown by a comparison, bag by bag, of the figures for gain in green matter and moisture. In the season of 1915-16, when the corn was somewhat immature and no water was added while filling the silo, there is a loss in green matter in 5 of the 6 bags. The average loss is 3.09 per cent per bag, and the slightl}'- greater loss in the lower than in the upper half prob- ably is due to the large loss of juice that took place. The change in the amount of moisture present, less than 1 per cent, is comparatively unimportant, though it should be noted that the 2 lower bags register gains. LOSS OF DRY MATTER. The great^t loss in dry matter in any bag in 1914-15 is but 18.64 per cent, while the average loss for all the bags is 8.66 per cent. The apparent downwash of the soluble dry matter is illustrated very well that season by a comparison of the losses. The bags in the upper and lower halves show, respectively, 12.74 per cent and 4.70 per cent losses in dry matter. In the season of 1915-16 the figures do not, on their face, bear out this transfusion, there being an increase in loss from 9.72 per cent in the upper half to 13.71 per cent in the lower half. This apparent reversal of the results of the previous season may be and probably is due to the very much larger outflow of juice. The loss in any indi- vidual bag does not run as high as in the previous season, but the average percentage loss of dry matter as ensiled is nearly 3 per cent more, being 11.29 per cent. TOTAL NITROGEN. The figures for total nitrogen in 1914-15 show a gain in 5 out of 8 bags, while in 1915-16 they show a loss in every bag. The fig- ures for the first season show very plainly that there must have been a downwash of nitrogenous material, for while there is a loss of 2.46 per cent in the bags from the top half of the silo, there is a gain of 15.19 per cent over the total nitrogen ensiled in the bags representing the lower half. The fact that this gain in the lower bags raises the average total nitrogen in all the bags may be ac- counted for by irregularities in the downwash by which more nitrog- enous material was washed into the lower bags than was washed out of the upper ones. 12 BULLETIlSr 953, U. S. DEPARTMENT OF AGRICULTURE. In 1915-16 the average figures for total nitrogen show a loss of 7.31 per cent, with almost exactly the same losses for the upper and lower bags. If it were not for the unaccountably high loss of nitro- gen in bag No. 3, the losses for the bags in the lower half would be less than those in the upper half. However, even considering the figure for bag No. 3 as normal, the large loss of nitrogen in the juice would supply a reason Avhy the average figures for total nitrogen show no differences between the bottom and top halves of the silo. The average losses in total nitrogen in all bags for both seasons are very moderate when compared Avith the results of other investi- gators. The smallest loss in albuminoid nitrogen for either season is 34.15 per cent, the largest 64.01 per cent, which also occurs in the same season. The average total loss for 1914-15 is 50.76 per cent and for 1915-16 57.27 per cent. The slightly greater loss in albuminoid nitrogen in the latter season may or may not be due to the less mature condition of the corn when ensiled. The nonalbuminoid nitrogen is, of course, very small in amount in the corn when ensiled, but increases several times its own weight during ensiling in both seasons. The increase is 270.36 per cent the first season and 231.79 per cent the second season. ASH. The figures for loss or gain in ash for both seasons show very plainly the transfusion from the upper half to the lower half of the silo. In 1914-15, 2 of the 4 upper bags gained slightly and the other 2 lost strongly, while all 4 bottom bags gained strongly and consist- ently. The average for the top bags shows a loss of 8.96 per cent and for the bottom bags a gain of 17.61 per cent. The total aver- age gain of 2.07 per cent may be explained in the same way as the gain in total nitrogen. The figures for 1915-16, while showing losses throughout, show plainly that less ash is lost from the bottom bags than from the top bags. The loss for the top bags was 10.43 per cent and for the bottom bags only 2.16 per cent, which latter would probably have been a gain had no juice escaped. SUGARS. The sugars, as has been shown by previous investigators, are the source of much of the actual weight loss of dry matter during en- siling. In both years the nonreducing sugars entirely disappeared and only about 6 per cent of the reducing sugars was left. The loss is slightly greater in the lower bags than in the upper. This is prob- ably due to the fact that fermentation has had a longer time to act on the sugars that remain after the first period of rapid action has taken place. NITEOGEN AND OTHER LOSSES IN ENSILING CORN. 13 FURFUROL. The furfurol-yielding bodies show a loss in both seasons, in 191-^15, 17.07 per cent; in 1915-16, 13.68 per cent. Like the albuminoids they show a smaller loss in the lower than in the upper bags. ETHER EXTRACT AND CRUDE FIBER. The ether extract and crude fiber were determined only for the season 1914—15. The former shows an average gain for all bags of 32.59 per cent, this gain being slightly greater in the upper four bags than in the lower four. This consistent increase, which is quite in harmony with the results of previous investigators, is, no doubt, due to the formation of new ether-soluble bodies during the fermentation process. The crude fiber shows an average loss of 6.34 per cent of its weight at ensiling. Like the albuminoids and furfurol it shows a smaller loss in the lower than in the upper bags. The lower bags lost an average of 2.26 per cent, while the upper bags lost an average of 10.29 per cent. COLLECTION AND ANALYSIS OF JUICE. The total amount of juice collected during the season of 1914^15 was only about one-quarter as much as that collected in the follow- ing season. This is doubtless attributable to the condition of the corn at ensiling, which in the former season had become so mature that water had to be added, and in the latter season was rather too immature. An inspection of the table giving the analyses of the juice for 1915-16 shows that the amount of the solids, as indicated by the specific gravity, the acidity, and the nonalbuminoid nitrogen, seems to follow the same general curve. There appears to be a gradual rise during the first part of the period of juice collection, followed by a gradual fall. The only exception seems to be the albuminoid nitro- gen, which, while showing a slight tendency to follow the specific gravity curve, in amount shows a gradual but continuous decrease from the first sample taken to the last. In percentage it decreases from over one-fourth of the total nitrogen to less than one-nineteenth. AMMONIA NITROGEN AND AMINO NITROGEN. In the season of 1914:-15 the bags contained an average of 257 parts per million of ammonia nitrogen and 1,540 parts per million of amino nitrogen. In the season of 1915-16 the bags contained an average of 228 parts per million of ammonia nitrogen and 1,313 parts per million of amino nitrogen. T5y calculation it is found that in both seasons the ratio of ammonia nitrogen to amino nitrogen is slightly greater in the bags in the lower half than in those in the 14 BULLETIN 953, U. S. DEPARTMENT OF AGRICULTURE. upper half of the silo. This is only what would be expected when it is considered that the ammonia nitrogen is a decomposition prod- uct of the amino bodies and the longer stay in the silo gives more time for such decomposition to take place. The amounts of amino and of ammonia nitrogen, expressed in parts per million, do not follow parallel curves, although there is a general rise and fall throughout the whole period of juice collec- tion. The proportionate increase in the amount of amino nitrogen is greater, as is also the later decrease. The ammonia nitrogen in the first sample is nearly one-fourth as much as the amino nitrogen, but as the amount of amino nitrogen increases much more rapidly than the ammonia nitrogen it drops in the fifth sample to less than one-fifth. The proportion remains at one-fifth, or below, up to the sixteenth sample and then slightly rises to the thirty-sixth sam- ple. Here the amount of ammonia nitrogen decreases slowly and the amount of amino nitrogen decreases rapidly; consequently, the proportion of ammonia nitrogen to amino nitrogen in the last two samples is raised to over one-fourth. The specific gravity ranges from 1.027 to 1.046 and the acidity from an amoimt requiring 21.4 cubic centimeters to an amount re- quiring 39.5 cubic centimeters normal alkali for 100 grams of juice. The total nitrogen varies from 0.139 per cent to 0.323 per cent, and the albuminoid nitrogen from 0.0112 per cent to 0.0496 per cent. The ammonia nitrogen ranges from 171.7 to 448.7 parts per million and the amino nitrogen from 710 to 2,139 parts per million. It will be seen from the tables that the greater part of the nitrogen present in the juice escaping from the silo is in the form of soluble nonalbuminoid nitrogen compounds. Although the actual food value of such compounds is still somewhat a matter of controversy, yet it may be a matter of interest, from a practical standpoint, to ob- serve the possible loss of food material caused by the escape of juice these two years. If the total nitrogen of the 2,579 pounds of juice collected in 1914-15 is expressed as pure protein, we have a loss of 28.89 pounds, which represents the protein in about 1,500 pounds of average silage. Expressing in the same way the results for the season of 1915-16, we have a loss of 150.75 pounds in the 9,494.5 pounds of juice collected, representing the protein in about 7,500 pounds of average silage. On a technical basis the results of the two seasons' study of silage juice may furnish some explanation for the large variations in the losses of soluble silage constituents which are occasional!}' reported by investigators. It shows how a large amount of juice, carrying with it much soluble food material, may sink to the bottom of the silo or easily be lost through cracks or through an earthen floor. NITROGEN AND OTHER LOSSES IN ENSILING CORN. 15 CONCLUSIONS. The two years' work furnishes evidence of a downwash of the juice in the silo, carrying with it sohible-food materials, so that the silage in the lower part of the silo may gain in food material at the expense of the upper part. There was an average loss for all the bags of nearly 10 per cent of the dry matter, which apparently is due largely to the fermentation of the carbohydrates and to the carrying away of soluble material by the juice. The reducing and nonreducing sugars almost entirely disappeared. There was a considerable loss in crude fiber and in the furfurol-yielding bodies. There was a loss in total nitrogen. It is probable, however, that this loss is due largely, if not entirely, to the nitrogenous compounds which escaped in the juice. The albuminoid nitrogen suffered a loss of over 50 per cent, while the nonalbuminoid forms increased several times their own weight. There was a gain in ether extract, which is probably due to the formation of new ether-soluble bodies. The juice which was collected the second.season amounted to nearly 10,000 pounds. This juice averaged 0.263 per cent total nitrogen, 0.0283 per cent albuminoid nitrogen, and 317.9 parts ammonia nitro- gen and 1,472.9 parts amino nitrogen per million. REFERENCES TO LITERATURE. (1) MosEE, J. Conserviruiigsversuche mit Mais von J. Mosei*, Aus *' Erster BericUt iiber Arboitoi der K. K. Laudwirthscliaftlich-chemischeu Versuchs-Statioueu in Wien, aus den Jahren 1870-1877." (Abstracted in Jahresbericht tJber die Agrikultur-Chemie, Hoffman, 1879, p. 360-361.) (2) Weiske, H., and Schxilze, B. Versuche ilber die beiiii Einsiiueru des Griin- futters entsteheuden Voriiudeningen und Verluste. .Tournal fiir Land- wirtlischaft, v. 32 (1884) Seite 81-100. (3) JoEDAN, W. H. Report on Ensilage. Annual Report, Pennsylvania Agri- cultural Experiment Station (1884), p. 36-48. (4) Abmsby, H. p., and Caldwell, W. H. Comparison of Ensilage and Field- curing for Indian Corn. Annual Report, Pennsylvania Agricultural Experiment Station (1889), p. 117-123. (5) Heney, W. a., and Woll, F. W. A. Comparison of Shocking and Siloing Fodder Corn. Fifth Annual Report, Wisconsin Agricultural Experi- ment Station (1888), p. 67-74. (6) WoLL, F. W. A. Uber die Zersetzung Organisher Ammoniak-Verbindungen in Silofutter-mitteln. Die Landwirthscliaftlichen Versuchs-Statiouen (1889), V. 36, p. 161-179. (7) Shoet, F. G. Ex-periments with Fodder Corn and Ensilage. Sixth Annual Report (1889), Wisconsin Agricultural Experiment Station, p. 127-130. (8) Woll, F. W. Comparison of Siloing and Field-curing of Indian Corn. Seventh Annual Report, Wisconsin Agricultural Experiment Station (1890), p. 215-227. 16 BULLETIN 953, V. S. DEPARTMENT OF AGRICULTURE. (9) WoLL, F. W. Losses in Ensiling and Field-curing Indian Corn. Eighth Annual Report, Wisconsin Agricultural Experiment Station (1891), p. 227-231. (10) King, F. H. The Necessary Loss of Dry Matter in Corn Silage. 12th Annual Report, Wisconsin Agricultural Experiment Station (1895), p. 273-276. (11) CooKE, W. W. Fodder Crops. Third Annual Report, Vermont Agricul- tural Experiment Station (1889), p. 96-98. (12) Cooke, W. W., and Hllls, J. L. Report on Dairying. Fifth Annual Re- port, Vermont Agricultural Experiment Station (1891), p. 75-79. (13) CooKE, W. W., and Hills, J. L. Report on Dairying. Sixth Annual Re- port, Vermont Agricultural Experiment Station (1892), p. 163-197. (14) Hills, J. L. Report on Dairying. Eighth Annual Report, Vermont Agri- cultural Experiment Station (1894), p. 168-192. (15) Director New York Experiment Station. Certain Changes Taking Place in the Silo. Eleventh Annual Report Director New York Agricultural Experiment Station, Geneva (1892), p. 162-173. (16) Clements, H. F. J., and Russell, E. J. On IMaize Ensilage. Journal South-Eastern Agricultural College, Wye, Kent, England, No. 13, June, 19(H, p. 18-36. (17) Russell, E. J. Investigations on Maize and Maize Silage. Journal South-Eastern Agricultural College, Wye, Kent, England, No. 17, (1908), p. 434-^41. (18) Annett, H. E., and Russeill, E. J. The Composition of Green Maize and of the Silage Produced Therefrom. Journal of Agricultural Science, v. 2, part 4, July, 1908, p. 382-391. (19) Feruglio, D., and Mayeb, L. Ricerche Chimiche sull' infossamento del Mais. Estratto dal Ricerche sperimentali ed attivita spiegata nel biennio (1909-10), pp. 65-00. (Abstracted in Jahre^bericht iiber die Agrikultur-Chemie, Hoffman, 1913, p. 261.) LIBRARY OF CONGRESS 022 267 576 5 % ADDITIONAL COPIES OF THIS PUBLICATION MAY BE PROCURED FROM THE SUPERINTENDENT OF DOCUMENTS GOVERNMENT PRINTING OFFICE WASHINGTON, D. C. AT 5 CENTS PER COPY V LIBRARY OF CONGRESS « 022 267 576 5