V A L U E OF CORN A N D S O R G H U M S I L A G E FOR MILK PRODUCTION 1
J. R. OWEN, J. T. MILES, W. C. COWSERT, J. W. LUSK, E. W. CUSTER, AND J. W. CARDWELL
Dairy Depart,merit, Mississippi State College, State College Corn, and varieties of sorghum silage, were prepared from alternate plots in the same field. One double-reversal and two Latin-square feeding trials were conducted with from 22 to 27 cows, to compare them. Cows produced more milk, consumed more silage, and gained more weight on corn than on any variety of sorghum. Tracy sorghum imparted a stronger silage flavor to milk than did any of the other silages. Editor.
Sweet sorghum is one of the most i m p o r t a n t silage crops grown in the South, although its feeding value has been questioned. Good et al. (6) reported that, pound for pound, sorghum silage was only 72.2% as valuable as corn silage in fattening steers ; however, when yields of the two crops were considered, sorghum was 92.2% as economical as corn. LaMaster and Morrow (8) concluded that sorghum was 72.17% as efficient as corn for milk production. C u n n i n g h a m and Reed (4) and Nevens and Kendall (10) reported a slight advantage in milk production for corn silage over sorghum silage. New varieties of sorghum ( S a r t and T r a e y ) have been developed recently
(13, 14) and are being used widely throughout the South. Investigators (1, 2, 3, 11) have reported the yield per acre of these varieties of sorghum; however, little work has been reported concerning their feeding value. R a y and T h u r m a n (11) reported less silage consumption by, and lower daily gains in, steers fed Sart sorghum t h a n when fed either T r a c y or Atlas sorghum. I n these tests, the feeding values of T r a c y and Atlas sorghum were about equal. EXPERIMENTAL PROCEDURE
Three experiments were carried out during the years 1954-55, 1955-56, and 1956-57. Each year, Dixie 18 hybrid corn and one or more varieties of sorghum were grown in alternate strips in the same field. Cultural practices were the same for all crops, with the exception that an additional 33 lb. of nitrogen was used per acre on the corn. Silage was stored in u p r i g h t concrete silos. Production cost per ton of stored silage was obtained on all crops. I n 1954-55, a double-reversal feeding trial involving 22 cows was used to compare silage made front corn and f r o m S a r t sorghum. Three 28-day test periods with 7-day changeover periods were used. I n 1955-56, a Latin-square feeding trial with 27 cows was used to compare silages made from corn, Sart sorghum, and T r a c y sorghum, and in 1956-57 the same design was used with Received for publication June 3, 1957. 1Journal Article No. 663, Mississippi Agricultural Experiment Station, State College. 1554
CORN AND S O R G H U M SI,LAGE F O R ~IILK P R O D U C T I O N
24 COWSto compare corn, Traey sorghum, and Texas seeded-ribbon silages. Both of these trials involved three 21-day test periods and 7-day changeover periods. I n each study, cows of the Jersey, Guernsey, and Ayrshire breeds were used. Cows were fed silage ad libitum twice each day and 0.5 lb. of alfalfa hay per 100 lb. body weight once a day. Silage and hay consumption were recorded daily for all cows. Rate of concentrate feeding was adjusted weekly according to production of 4% milk during the previous week. Daily niilk weights were recorded on all cows, and butterfat tests were determined weekly, on separate samples of milk obtained in the morning and evening milkings. Change in body weight was determined from an average of three consecutive daily weights, at the beginning and ending of each comparison period. D u r i n g the feeding trials in 1955-56 and 1956-57, samples of milk were obtained from each cow two or more times during each comparison period, to be scored for flavor. The samples were cooled inunediately after being obtained, and refrigerated until scored. Flavor scores were determined by two experienced judges, using the official score-cards ( 5 ) . RESULTS
Yield per acre and cost of stored silage per ton for each year are shown (Table 1). I n 1954-55, the yield of Dixie 18 hybrid corn was 6.0 tons per acre, compared to 19.1 tons per acre of Sart sorghum. A severe drought seriously affected the yield of the corn; whereas, the sorghum withstood the drought and made considerable growth following late summer rains. The corn was ensiled on A u g u s t 9 and the sorghum on October 6. The rainfall during the next two summers was more evenly distributed throughout the summer months and the difference in yield between crops was not so large. Cost of stored silage was determined by the nmnber of man- and equipmenthours used in producing the silage, actual cost of fertilizer and seed, and a charge of $10 per acre for rent of the land used. The year-to-year variation in cost was affected by the yield of silage per acre, and the amount of lodging of the crop, which slowed down the silage-cutting operation. The sorghum was lodged to some extent each y e a r ; however, the principal variation caused by lodging was on the corn, in 1956. TABLE 1 Y i e l d o f cor~l and sorgl~wm silage per acre, a~d cost of stored silage"
Dixie 18 corn
1954 1955 1956
6.0 14.5 11.1
19.1 19.3 .......
........ 20.0 20.9
........ 5.62 4.89
1954 1955 1956
8.19 4.73 8.23 In tons.
5.2t) 5.09 ........
J. R. OWEN ET AL
Average daily feed co~sumption, mil~" production, and body weight change on corn and sorghum silages Crop
(~b.) E x p e r i m e n t 1, 1954-55 7.6 52.1 7.0 48.1 2.22
Dixie 18 corn Sart sorghum L.S.D. ( P < 0.01)
Dixie 18 corn Sart sorghum Tracy sorghum L.S.D. ( P < 0.01)
Dixie 18 corn Traey s o r g h u m Texas seeded-ribbon L.S.D. ( P < 0.01)
4.5 4.5 4.7
26.8 24.5 1.29
+ 0.41 -- 0.44 0.70
54.1 55.9 2.8
27.0 27.4 1.24
+0.08 -- 0.59 -- 0.34 0.53
27,3 25.2 23.5 1.20
+ 0.64 -- 0.16 -- 0.79 0.64
E x p e r i m e n t 2, 1955-56
E x p e r i m e n t 3, 1956-57 7.2 54.5 7.0 49.5 6.6 47.4 3.11
Data on feed consmnption, milk production, and change in body weight are shown (Table 2). Differences in hay fed were due to changes in body weight on the different types of silage fed. In the same manner, the amount of grain fed was based on the anmunt of milk produced. When analyzed, the differences in hay and grain consumption were significant; however, statistical data are not shown in Table 2, because the differences were small and were a reflection of change in body weight and level of milk production. In each feeding trial, the differences in silage consumption, production of 4% FCM, and change in body weight were highly significantly (P < 0.01) in favor of corn silage over each variety of sorghum silage (12). In Experiment 2, the differences between Sart and Tracy sorghmns were not significant. In Experiment 3, the difference in milk production in favor of Tracy sorghum over Texas seeded-ribbon was highly significant (P < 0.01), and the difference in change in body weight on the two silages was significant (P < 0.05). The difTABLE 3
Moistm'e and che.micat composition of silages Silage
(%) Dixie 18 corn Sart s o r g h u m
E x p e r i m e n t 1, 1954-55 1.72 0.46 1.05 0.46
Dixie 18 corn Sart sorghum Tracy s o r g h u m
73.27 75,89 73.07
E x p e r i m e n t 2, 1955-56 1.95 0.60 1.17 0.45 1.21 0.49
7.56 8.17 8.12
1.15 1.24 1.05
15.47 13.08 16.06
Dixie 18 corn Tracy s o r g h u m Texas seeded-ribbon
72.35 70.16 75.74
E x p e r i m e n t 3, 1956-57 1.98 0.67 1,55 0.75 1.27 0.54
8.58 9.12 8.49
1.67 1.66 1.39
14.75 16.76 12.57
CORN AND SORGHUM
TABLE 4 Daily feed cost and income per cow on differe~t silages Item
($) Feed cost "~ Value of milk ~ Income above feed cost Adjusted income above feed cost ~
Experiment 1, 1954-55 0.51 0.40 1.34 1.22 0.83 0.82 1.05 0.64
................ ................ ................ ................
Feed cost ~ Value of milk b Income above feed cost Adjusted income above feed cosff
Experiment 2, 1955-56 0.45 0.42 1.50 1.35 1.05 0.93 1.09 0.68
0.43 1.37 0.94 0.79
........ ........ ........ ........
Feed cost "~ Value of milk ~ Income above feed cost Adjusted income above feed cost ~
Experiment 3, 1956-57 0.51 ........ 1.36 ........ 0.85 ........ 1.21 ........
0.40 1.26 0.86 0.79
0.35 1.18 0.83 0.49
Grain cost, $60 per ton; hay cost, $30 per ton; silage cost as shown in Table 1. b Based on $5 cwt. Class I milk. Change in body weight converted to milk equivalent; 3.53 lb. TDN per lb. gain, 2.73 lb. TDN per lb. loss, and 0.32 lb. TDN per lb. FCM produced. ference in silage consumption
between the two varieties of sorghum
ment 3 was not significant. The higher consumption of all silages in Experiment 2 than in Experiments 1 and 3 cannot be explained by the authors, unless it was that palatability of the silages was affected by more favorable climatic conditions during that growing season. Moisture and chemical compositions of the silages are shown (Table 3). Data on feed cost and income per cow are shown
T h e f e e d cost
was higher in each experiment when cows were fed corn silage than when fed any variety of sorghum; however, on a Class I market, the value of the increased m i l k p r o d u c e d w a s e q u a l t o o r e x c e e d e d t h e d i f f e r e n c e i n f e e d cost. I n a d d i t i o n , cows gained weight when fed corn silage and lost weight on each variety of sorghum.
Since a change-over type design was used in each of the feeding trials,
a n d n o p r o v i s i o n s w e r e m a d e t o m e a s u r e c a r r y - o v e r effects b e t w e e n p e r i o d s , t h e adjusted income above feed cost was calculated on a TDN basis (presented in TABLE 5 Arerage flavor scores of differe.~tt silages Silage
No. of samples
Dixie 18 corn Sart sorghum Tracy sorghum
Experiment 2, 1955-56 157 159 170
37.1 37.2 36.1
Dixie 18 corn Tracy sorghum Texas seeded-ribbon
Experiment 3, l°56-57 80 78 78
36.8 35.8 36.9
J . R . OWEN ET AL
Table 4). The T D N allowances used were those recommended by the National Research Council (9)--0.32 lb. T D N per lb. F C M ; and Knott, et al. (7)--3.53 lb. T D N per lb. of gain in body weight, and 2.73 lb. T D N per lb. of loss in body weight. D a t a on the flavor of milk produced are shown (Table 5). T r a c y sorghum produced a stronger silage flavor in the milk than a n y of the other types of silage fed. Some of the samples of milk f r o m cows fed T r a c y sorghum would not have been acceptable on a Class I market. SUMMARY
Corn, and one or more varieties of sorghum, were grown for silage in alternate strips in the same field in three tests. The yield of corn was considerably less than a n y v a r i e t y of sorghum each year, especially during the d r y summer of 1954. One double-reversal and two Latin-square design feeding trials were conducted with from 22 to 27 cows in each test, to compare silage f r o m these crops. Cows produced more milk, co~sumed more silage, and gained more weight each year on the corn silage than on a n y v a r i e t y of sorghum. These differem~es were highly significant (P ~ 0.01). Milk produced by cows receiving T r a c y sorghum had a stronger silage flavor than that produced by any other type of,silage fed. REFERENCES (1) BLO~'NT, C. L. Serge, Millet Crops Compared in Silage Study. Mississippi Farm Researctt, 17(2) : 1. 1954. (2) C~OCKETT, S. P. Corn Compared with Sorghum in Silage Test. Mississippi Farm Research, 1 6 ( 4 ) : 4. 1953. (3) CROCKETT, S. P. Corn and Sorghum Silage Compared in North Mississippi. Mississippi Farm Research, 1 7 ( 3 ) : 5. 1954. (4) C u ~ I t z G ~ _ ~ , W. S., A.~I) t~E~]), J. R. Japanese ]-loneydrip Sorghum Silage versus June Corn Silage for Milk Production. Arizona Agr. Expt. Sta., BM1. 122. 1927. (5) DOWNS, P. A., ANI)ERSON, E. O., BABCOCK, C. J., HERZEI~, F. m., AND TROUT, O. M. Committee on J u d g i n g Dairy Products, A.D.S.A. Evaluation of Collegiate Student Dairy Products J u d g i n g Since World War II. J. Dairy Sci., 37: 1021. 1954. (6) GOOD, E. S., HOF~LACHER, Z. J., AND GRIJ[ES, J. C. A Comparison of Corn Silage and Sorghum Silage for F a t t e n i n g Steers. :Kentucky Agr. Expt. Sta., B~dl. 233. 1921. (7) K~OTT, J. C., ]7~ODGSON, ]~. E., .iN]) ELLINGTON, E. V. Methods of Measuring Pasture Yields with Dairy Cattle. Washington Agr. Expt. Sta., B~dl. 295. 1934. (8) L.~MASTE~, J. P., AND MOaROW, K. S. Corn Silage versus Sweet Sorghum Silage for Milk Production. South Carolina Agr. Expt. Sta., B~dl. 254. 1929. (9) I~OOSLI, J. K., HUFI~]~I:AR T, C. F., PE.TEgSEN, W. E., AND PHILLIPS, P. H. Reco,mme~tdcd Nutrient Allowances for Domestic Animals. I I I . Recomme~tded N~drient Allowances for Dairy Cattle. National Research Council, Washington, D. C. 1950. (10) NEVENS, W. B., AND KE~I)ALL, ~[. A. Sorghums and Soybeans as Silage Crops for Milk Production. Illinois Agr. Expt. Sta., B~dl. 578. 1954. (11) RAY, M. :L., AND THURI~[AN, R. L. Tracy Silage Equals Atlas Serge Silage. Arkansas Agr. Expt. Sta., Far.m Research, 5(2) :8. 1956. (12) S~EDECOR, G. W. Statistical Methods. Iowa State College Press, Ames. ]946. (13) STOKES, I. E., COLEMAN, O. I-I., O']~ELLY, J. ~., CROCKETT, S. P., KUYKENDALL, ]=~., ~REE~IAN, K. C., AND HURT, B. C. T r a c y - - A New Mid-Season Variety of Serge for Sirup Production in Mississippi. Mississippi ]Farm Research, 1 5 ( 6 ) : 1953. (14) STOKES, I. E., COLE]~IAN, O. H., O tKELLY, J. F., HURT, B. C., KUYKENDALL, ~:~., AND Ct~OCKETT, S. P. Sart Developed in Six-Year Test of Hondreds of Seedlings at Four Locations. Miss,issippi Farm Research, 14(3) : 1. 1951.