Alfalfa Silage Preservation Comparison of Phosphoric Acid and Molasses as Preservatives B. CONNOR JOHNSON, W. H. PETERSON, W. A. KING, AND G. BOHSTEDT University of Wisconsin, Madison, Wis. about 23 tons of each type were PREVIOUS publication Alfalfa silages prepared by the phosphoric put up. (10) compared the A. I. V. acid and molasses methods have been comCommercial blackstrap molasses and the molasses methwas used in the preparation of the pared during three years. The comparison molasses silage. 5The undiluted ods, covering three years of exwas based on chemical analysis of the molasses was a plied to the alfalfa perimentalwork on the ensiling of back of the feefroll of the ensila e silages and on the quantity and quality of alfalfa. The conclusion reached cutter, immediately before t f e was that “molasses alfalfa silage milk produced by cows fed these silages. blower. The phosphoric acid was diluted so that 40 pounds of reappears to be equal to A. I. V. Chemical studies show no pronounced sultant solution were added per alfalfa silage, and conditions of differences between the phosphoric acid ton of forage, and was applied farm practice probably make in t h e same manner as t h e silage (20-30 pounds per ton) and the momolasses silage more suitable for molasses. lasses (65 pounds per ton), but show poorer The molasses was added at the general use”. rate of 65 pounds per ton, the A method which has certain preservation and greater carotene losses phosphoric acid at rates varying advantages over the A. I. V. with lower amounts of phosphoric acid. from 8 to 30 pounds of 75 per process is the use of phosphoric cent acid per ton. Either is satisfactory as to palatability acid to replace the mixture of and milk production, and no harmful efhydrochloric and sulfuric acids. Analysis of Silage fect on milk flavor has been noted. Virtanen in 1932 (24) and later At the time of ensiling, the Wilson (26) described the use of The carotene and vitamin A contents of alfalfa was analyzed for dry phosphoric acid to lower the pH milks produced on phosphoric acid (20-30 matter and carotene. Samples of forages for silage making, and pounds per ton of forage) and the molasses of silage were taken every 2 compared it with the use of hysilages are high as compared to averages for to 3 weeks after the silo was drochloric and other acids. Later Wisconsin winter-market milk, while milk opened, and analyzed for pH, a mixture of hydrochloric acid d r y m a t t e r , ammonia, a n d and phosphoric acid obtained produced on silage made with 8-15 pounds carotene. The carotene was from the action of water on phosof phosphoric acid is in the same range as determined by the method of phorus pentachloride (12))the soaverage winter milk. Hegsted, Porter, and Peterson called Penthesta solution, was (9). Table I gives the averages tried in Europe (3, 11, 20-23). of these determinations for each of the silages. h’o extensive articles on the use of phosphoric acid in comGood alfalfa silage should have a pH below 4.5 and an amparison with other silage preservatives have appeared, almonia nitrogen content of less than 10 per cent of the total though short reports on the use of this method have been nitrogen. Thus, 20-30 pounds of phosphoric acid per ton given by several workers (4, 11, 17, 19). produced good silage while 15 pounds or less did not. I n 1939 I n a survey of northeastern United States farms in 1938 the pH was satisfactory but the odor was poor. All of the (2), thirty-two farmers out of a total of three hundred and molasses silages were good and most were excellent. I n 1938 eighty reported using phosphoric acid with satisfactory rethe forage was not tramped a t all during ensiling while in the sults. other years it was, and this seems to have made considerable A number of commercial producers have advocated the difference in the quality of the silage. However, the carotene use of phosphoric acid, and have published pamphlets on the content of the green alfalfa was lower in 1938 than in the other preparation of silage with it. The acid is sold under various years. trade names, “Phosilage”, “Ensilaid”, “Silo-phos”, etc. Carotene losses varied from 3 to 15 per cent for the molasses The phosphoric acid method has the great advantage, as silage, from 3 to 9 per cent for the silage preserved with 20 compared with the A. I. V, method, of using a weaker acid pounds or more of phosphoric acid, and from 24 to 44 per cent which is much less corrosive to the equipment and hence can for the silages made with less than 20 pounds of phosphoric be applied directly to the forage a t the silage cutter. I n this acid per ton. Thus again it is seen that the quality of the respect i t is on a par with molasses. phosphoric acid silage improved markedly as the amount of phosphoric acid was increased from 8 to 30 pounds per ton of Preparation of Silages forage. Alfalfa silages prepared by the phosphoric acid and molasses In the use of phosphoric acid for silage it is important that, methods have been compared during three years of ex erimental the fluorine content be low (about 0.05 per cent). Fluorine work. The silages were prepared from first-cutting alglfa in the analyses were made by a modification of the method of Armearly bloom stage. About 14 tons of phosphoric acid silage were strong (7) on various samples of phosphoric acid alfalfa silage put up in 1937 and 23 tons of molasses silage. In 1938 and 1939
A
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INDUSTRIAL AND ENGINEERING CHEMISTRY
their effect on milk production and maintenance of weight of the animals. Milk samples from each lot were taken after pooling the milk from morning and evening milkings. Carotene and vitamin A determinations were made on the whole milk by the method of Olson, Hegsted, and Peterson (16). Samples were analyzed every 3 or 4 weeks from the beginning of the feeding period late in October until the end of the experiment in March.
TABLEI. COMPOSITION OF SILAGE
Silage
Preservative Lb./Tk
Green alfalfa Phosphoric acid Phosphoric acid Molasses
15 30 65
Green alfalfa Phosphorio acid Phosphoric acid Molasses
15 30 65
..
..
..8
Green alfalfa Phosphoric acid Phosphoric acid Phosphoric acid Molasses
14 20 65
Dry matter,
Am: mania N, % ' of total N pH
% 1937 27.3 25.9 9:s 4:b 25.5 5.0 3.9 26.4 8 . 8 3.9 1938 23 8 2216 li;3 k:9 24.9 10.7 4.3 25.2 12.1 4.5 1939 28.4 b .. , 26.8 b 4.2 26.8 b 4.0 26.9 b 4.0 25.9 b 4.2
Carotene MicrAgrams/G. Dry Matter
Quality"
184 139 190 156
Fair Excellent Excellent
126 64 119 121
Poor Good Good
.. .
...
TABLE 11. AVERAGE DAILYFEEDCONSUMPTION, DAILYMILK PRODUCTION, AND CHANGES IN LIVEWEIGHT PER Cow ?ecl?ne
.II'
...
196 119 110 177 177
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Fair Fair Good Good
Daily Milkb Pro-
Daily Milkb Production, Lb.
Initial Weight, Lb.
Gain in Weight, Lb.
5.8 5.0
1053.2 1049.2
37.2 44.2
5.5 5.8
1051.1 1022.9
83.7 96.7
Grain SiduoMixturea, la e, tion, Lot Lb. L%. Lb. 1938 10.6 42.7 27.4 Phosphoricacid 5.9 10.6 42.4 26.5 5.9 Molasses 1939 8.3 8.4 38.5 20.9 Phosphoricacid 8.4 38.7 21.8 Molasses 8.3 a The grain mixture waB made up as follows: Phosphorio Acid Lot, % 70.1 Ground corn 27.9 Ground oats 1.0 CaCOs Bone meal i:o Iodized salt b 4 per cent fat-corrected milk. Alfalfa Hay, Lb.
a Based on color, odor, and chemical analysis. b Not determined.
in 1938. The university silage averaged 10.6 p. p. m. fluorine, while some farmers' silages, prepared with different grades and amounts of phosphoric acid, contained from 40 to 1050 p. p. m. of fluorine (dry basis).
Analysis of Milk Cows from the university herd were divided into two lots, approximately equal in weight, age, breed, stage of lactation, and milk and butterfat production. Preliminary feeding trials only were made with the phosphoric acid silage in 1937, and no data on the results are given in the table. I n 1938 each group of cows consisted of one Holstein, two Guernsey, one Jersey, and one Brown Swiss, and in 1939, of two Holstein, two Guernsey, one Jersey, and one Brown Swiss. Table I1 gives the rations, milk production, etc., of the animals. At the rate of consumption given, silage made up approximately 38 per cent of the dry matter of the rations. Both silages were equally satisfactory as to palatability and in
21
20
18
-
17-
A . V I T A M I N A VALUE OF MILKS
- ,I
I
. 2
NOV
m e
DEC.
JAN. IS30
FEe.
MAR.
i:9 1.0
Figure 1A gives graphs for the total vitamin A potency for 1938, obtained by adding together the vitamin A figures and half of the carotene values (14) for each sample. The vitamin A value of Wisconsin market milk, as found by Dornbush, Peterson, and Olson (6) in this laboratory, is included for comparison. This figure indicates that in 1938-39 the molasses alfalfa silage milk about maintained its original level in February and March, which was well above the market milk. Silage preserved with 15 pounds of phosphoric acid per ton
FIGURE1. COMPARISON OF THE VITAMIN A VALUES OF WINTER-MARKET MILK AND EXPERIMENTAL SILAGEMILKS
I-
Molasses Lot, % 69.4 27.7
APR.
IS30
I940
INDUSTRIAL AND ENGINEERING CHEMISTRY
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and does not increase proportionally with increasing carotene intake; these facts are also evident in Table 111.
gave poor results, as would be expected from the low carotene content of the silage. However, with 30 pounds of phosphoric acid per ton of silage, the vitamin A value of the milk became much better and essentially equaled that of the milk produced on the molasses silage. Figure 1B gives the same graphs for 1939-40. The vitamin A value of milk produced on molasses alfalfa silage was much above that of average market milk, while that of milk from the phosphoric acid silage dropped a t approximately the same rate as the carotene content of the silage (Table I). TWO-YEAR AV.
WINTER
MILK
.DEC.-APRIL
330
PHOSPHORIC ACID-ALFALFA
I
0
MOLASSES-ALFALFA I I 100
MILK
200
V I T A M I N A VALUE, MICROGRAMS
MILK
430
510
I
PER QUART OF
I
I
300
SO0
400 MILK
VITAMIN A VALUESOF WINTER-MARKET FIGURE 2. AVERAGE MILKAND EXPERIMENTAL SILAGE MILKS
Averaging the carotene and vitamin A contents (micrograms per gram) of the butterfats produced on these silages for the two years gave the following results: phosphoric acid, carotene 7.3, vitamin A 7.5; molasses, carotene 9.8, vitamin A 8.0. If the total potency (carotene and vitamin A) is expressed in micrograms per quart value, and the averages for the months January to March for the two years are compared with the average for Wisconsin market milks over the same period, it is seen from Figure 2 that the feeding of these silages maintained the vitamin A potency of the milks a t a considerably higher level than that of average winter milk in this region.
Blood Analysis On three cows of each group in 1939-40, plasma carotene and vitamin A were determined a t intervals throughout the experiment. The method of Kimble (1.3) was used, and the results are given in Table 111, Here again it is seen that the plasma level of carotene and vitamin A from the cows on the phosphoric acid silage dropped, as did the value of the silage (Table I), as the feeding went from the 20- to the %pound per ton layer. On the other hand, the carotene and vitamin A contents of the plasma from the cows on the molasses alfalfa silage increased throughout the feeding period and approximated the values given by Moore (16) for the same breeds of cows on fresh pasture. Peterson, Bird, and Beeson (18) reported that feeding A. I. V. silage for 7 weeks to ten cows on winter feed increased the plasma carotene from 5.2 to 9.6 micrograms per CC. Davis and Madsen (5) reported that the blood carotene level is dependent on the carotene intake, while vitamin A tends to level off
VOL. 32, NO. 12
Discussion This work seems to indicate that for the production of wellpreserved phosphoric acid alfalfa silage with a carotene content equal to that of molasses alfalfa silage, it is necessary to use 20-30 pounds of phosphoric acid (75 per cent) per ton of forage. Bender et al. (2) state that “the maximum amount of acid necessary to preserve legume crops seems to be 16 pounds per ton of green material. All cases of severe spoilage could be traced to the use of less acid.” Sixteen pounds per ton would seem to be a minimum, and 20 pounds or over would appear to be preferable. The various commercial producers of phosphoric acid recommend 14 to 18 pounds per ton for legumes. In 1938-39 silage put u p with 30 pounds of phosphoric acid proved more palatable than the molasses silage, while in 1939-40 the molasses silage proved more palatable than that made with 14 and 8 pounds of phosphoric acid. These observations check well with the degree of preservation, and thus the palatability of good phosphoric acid alfalfa silage is approximately equal to that of good molasses alfalfa silage. Anderson et al. ( l ) ,Garrett et al. (8), and Whitnah et al. (26) reported the relation between carotene content of the feed of the cow and the production of milk of good flavor. Low carotene was associated with oxidized flavor in the milk. A single test late in the feeding trials showed no particular effect on flavor or development of oxidized flavor in milks from cows fed these two types of silage.
Acltnowledgment The work reported in this paper is a cooperative experiment by the Departments of Biochemistry, Dairy Husbandry, and Agricultural Engineering. Various phases of the work have been done with the advice or supervision of F. W. Duffee, C. A. Elvehjem, E. B. Hart, B. H. Roche, I. W. Rupel, and H. Steenbock. The analytical work for 1937 was done by D. M. Hegsted. Credit is due G. M. Werner and C . E. Zehner for direct supervision of the feeding of the cows and collection of the milk samples. We are indebted to George M. Rommel of the Tennessee Valley Authority, to the Monsanto Chemical Company, and to the Victor Chemical Works for the phosphoric acid used in these studies, and to Robert J. Evans for the fluorine analyses.
AND VITAMIN A CONTENTS OF TABLE111. CAROTENE PLASMA OF Cows FEDSILAGES
THE
BLOOD
(In micrograms per cc. of plasma) Content 10/24/39a 11/14 11/28 12/12 1/16/40 2/14 Cows Fed Phosphoric Acid Alfalfa Silageb Carotene 17.7 11.9 11.6 10.0 6.4 8.6 93 Holstein VitaminA 0.65 0.31 0.28 0.34 0.23 0.34 Carotene 19.0 12.7 10.1 11.6 10.8 12.2 445 Guernsey VitaminA 0.79 0.80 0.12 0.30 0.30 0.38 Carotene 13.0 8.5 7.5 6.8 5.7 5.7 827 Brown Swiss VitaminA 0.29 0.32 0.32 0.30 0.31 0.34 Cows Fed Molasses Alfalfa SilageC 12.5 13.6 10.7 11.5 8.5 9.7 Carotene 92 Holstein 0.37 0.41 0.35 0.28 0.21 Vitamin A 0.31 25.3 29.7 25.2 30.3 25.5 Carotene 19.3 416 Guernsey 0.57 0.37 0.60 0.24 1.05 0.74 Vitamin A 24.1 31.2 19.5 19.1 19.0 22.5 Carotene 472 Guernsey 0.60 0.66 0.17 0.41 0.85 0.36 VitaminA a Silage feeding was begun 11/1/39 b Layer preserved with 20 lb. phosphoric acid per ton, fed from 11/1/39 to 11/21/39. with 14 lb. Der ton fed from 11/21/39 to 1/3/40; and with 8 lb. per ton fed from 1/3/46 until conclusion of experiment. 0 Preserved with 66 Ib. of molasses per ton.
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INDUSTRIAL AND ENGINEERING CHEMISTRY
Literature Cited (1) Anderson, J. A., Hardenbergh, J. G., and Wilson, L. T., J . Dairy SCi., 19,483-4 (1936). (2) Bender, C. B., Morrison, F. B., Olmstead, R. H., Merrill, A. R., and Hamlin, F., N. J. Agr. Expt. Sta., Bull. 643 (1938). (3) Brioux, Ch., J . agr. prat., 99,435-7 (1935). (4) Camburn, 0. M., Ellenberger, H. B., and Crooks, G. C., J. DaiTy Ed.,22,456-7 (1939). (5) Davis, R. E.,and Madsen, L. L., Div. of Biol. Chem., Am. Chem. SOC.,Cincinnati, 1940. (6) Dornbush, A. C., Peterson, W. H., and Olson, F. R., J . A m . Med. Assoo., 114,1748-51 (1940). (7) Evans, R. J., and Phillips, P. H., Proc. SOC.Expt. Biol. Med., 39, 188-91 (1938). (8) Garrett, 0. F., Hartman, G. H., and Arnold, R. B., J. Dairy S C ~ .22, , 717-27 (1939). (9) Hegsted, D. M., Porter, J. W., and Peterson, W. H., IND. ENQ. CEEM.,Anal. Ed., 11, 256-8 (1939). (10) Hegsted, D. M., Quackenbush, F. W., Peterson, W. H., Bohstedt, G., Rupel, I. W., and King, W. A., J . Dairy Sci., 22, 489-500 (1939). (11) Henglein, F. A., Chem.-Ztg., 58,869-71 (1934). (12) I. G.Farbenindustrie A.-G., Brit. Patent 404,805 (1934). (13) Kimble, M.S.,J . Lab. Clin. Med., 24, 1055-65 (1939).
(14) Mead, T.H., Underhill, S. W. F., and Coward, K. H., Biochem. J., 33, 589-600 (1939). (15) Moore, L. A., J . Dairy Sci., 22,513-20 (1939). (16) Olson, F. R., Hegsted, D. M., and Peterson, W. H., Ibid., 22, 63-6 (1939). (17) Perkins, A. E., Hayden, C. C., Monroe, C. F., Krauss, W. E., and Washburn, R. G., Ohio Agr. Expt. Strt., Bimonthly Bull. 190,3-12 (1938). (18) Peterson, W. H., Bird, H. R., and Beeson, W. M., J. Dairy Sei., 20, 611-23 (1937). (19) Peterson, W.H.etal., Wis.Agr. Expt.Sta., Bull. 446,27-9 (1939). (20) Rehm, E., Landw. Jahrb., 82,215-52 (1935). (21) Rodenkirchen, J., PTOC.1 l t h World’s Dairy Congress, Berlin, 1937,2,217-19. (22) Ruschmann, G.,Landw. Jahrb., 78, 169-207 (1933). (23) Ruschmann. G., and Dunker. L.. Ibid., 80,497-520 (1934). . (24j Virtanen, A: I.,’Schweiz. landw. Mh., 10,257-69 (1932). (25) Whitnah, C. H.,Peterson, W. J.. Atkeson, F. W., and Cave, H. W., J . .4gr. Research, 58,343-57 (1939). (26) Wilson, J. K.,J.Dairy Sci., 18,317-25 (1935). PRESENTED in part before the Division of Agricultural and Food Chemistry a t the 99th Meeting of the American Chemical Society, Cincinnati, Ohio. Published with the approval of the Director, Wisconsin Agrioultural Experiment Station, University of Wisconsin.
A PHILATELIC ALCHEMIST. . . . .
U n d e r the U. S. Revenue Act of 1862 all matches, perfumery, playing cards, and proprietary medicines, likewise documents, etc., had to have U. S. Internal Revenue stamps affixed to each package. Many manufacturers took advantage of the provision which permitted them to have their own stamps engraved. Among these was the firm of Johnston, Holloway & Company of Philadelphia, who used 1and ?--cent stamps. In the center of these stamps (used from 1862 until 1883, when the stamp tax was repealed) appears the engraving which we have reproduced as No. 120 in the Berolzheimer series of Alchemical and Historical Reproductions.
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.Artist Unknown
We have been unable to trace this engraving to any earlier paint.ing or drawing, and there is no reproduction in the series, even remotely resembling the present illustration.
50 East 41st Street New York, N. Y.
D. D. BBROLZHBIMER
A list of the first 96 reproductions a pared in ow January, 1939, issue age 124. T h e list of reproductions 97 to 108 a pcirc~! in January. 1940, page 134. An ;!ditionaI reproauction ippeirr each month.
