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Comparison of Feeding Value of Alfalfa Hay, Silage, and Low-Moisture Silage
COMPARISON OF FEEDING VALUE OF ALFALFA HAY, SILAGE, AND LOW-MOISTURE SILAGE J. It. BYERS Department of Dairy Science, University of Illinois, Urbana ABSTRACT
I n a 56-day milk production trial the feeding values of alfalfa hay, silage, and low-moisture silage, with the silages stored in tower silos, were compared. All forages cut at the bud stage, using a conditioner, were of excellent quality. Dry matter consumption amongst the three forages was not significantly different, although there was a trend for the higher dry matter forages to be consumed to a greater extent. Four per cent FCM production and body weight changes were not significantly different. Digestibility of the three rations did not differ significantly. Low-moisture silage can be nmde in tower silos andSt is equal but not superior to the feeding value of hay or high-moisture silage.
Ensiling forages for feeding has received great attention i n recent years because of the development of low-moisture silage. The early work on low-moisture silage entailed using a sealed storage unit which soon led livestock feeders to question if low-moisture silage could be stored in conventional tower silos and, if so, hot" the feeding value of such low-moisture silage would compare with hay and silage made from similar material. Studies by Bartle and Voelker (2) and Gordon et al. (3) suggest that there is little difference in the nutritive value of hay, and lowmoisture silage, but unwilted silage is of lower feeding value than either low-moisture silage or hay. The low-moisture silages were made in air-tight silos. More recent studies by Gordon et a[. (4) show low-moisture silage nmde in a conventional tower silo equal to heat-dried hay ill feeding value and that only small amounts of spoilage were observed. Larsen and Johannes (5) shot" a higher average daily dr)" matter consumption and average daily fatcorrected milk (FCM) production by cows fed low-moisture silage than cows fed hay. This study was to determine the feeding value of an alfalfa-orchard grass mixture harvested in three different forms. The alfalfa was made into hay, silage, and low-moisture silages which were stored in tower silos. EXPERIMENTAL
PROCEDURE
A 30-acre field of DuPuits alfalfa and orchard grass seeded in the spring of 1960 with oats as a cover crop was used to provide the forage for the study. The forage was about Received for publication July 7, 1964.
95% alfalfa and 5% orchard grass. Five acres of the field were cut for low-moisture silage and the forage stored in a conventional tower silo 10 ft in diameter and 20 ft high. The material was left in the swath under excellent drying conditions 24 hr before chopping. Fifteen acres of the field were cut for silage and stored ill a silo 16 ft ill diameter and 40 ft high. Because of rain the material took 24 hr to wilt to a suitable dry matter content. Ten acres were cut for hay with excellent drying conditions. The forage was baled and in the barn within 48 hr after cutting. The alfalfa was cut at prebud to bud stage of development and a hay conditioner was used on all forages. Milk-producing ability of the three types of forages was tested in a milk production trial of 56 days after a seven-day preliminalw period, using three equal groups of five highproducing cows of the Holstein and Brown Swiss breeds. The cows were fed the respective forages ~td libitum and a grain mixture approximating 14% crude protein at the rate of 1 lb of grain to about 3.0 lb of FCM. Digestibility of the rations was determined, using the chromic oxide technique with three cows per ration. The animals were pilled once per day with 10 g of chromic oxide in gelatin capsules for ten days before and during the collection period. Grab samples of feces were taken for the seven days of the collection period at 6 AM and 4 PM, composited with thymol as a preservative and kept under refrigeration until the end of the collection period, at which time the feces were dried at 120 F and ground in a Wiley mill. Samples of hay for analyses were taken from every bale fed with the Penn State Forage
206
FEEDING ALFALFA AND SILAGE
Sampler. Daily samples of the silage and lowmoisture silage were taken and composited by weeks. A.O.A.C. (1) methods were used f o r all chemical analyses, except drying temperatures were at 65 C. Milk was weighed daily with b u t t e r f a t and solids-not-fat test run weekly on a one-day composite of the A~ and P~ nfilkings. Body weights were determined at the beginning and end of the trial by weighing the cattle on three successive days. RESULTS
In measuring the feeding value of any crop f o r livestock, it is essential, in addition to measuring the nutritive value, that the yield per acre be determined. Table 1 gives the yield TABLE 1 Yield per acre Low-moisture Hay silage Silage As stored (tons) Dry matter (~/c) Dry matter (tons)
1.32 86.40 1.14
3.18 50.48 1.61
4.23 33.75 1.21
of fresh material, per cent dry matter, and dry matter in tons p e r acre of each forage that organoleptically would be rated excellent. The higher dry matter yield of the lowmoisture silage may be explained, because the crop cut for low-moisture silage was six days more mature than that portion of the field cut for hay and silage. Table 2 shows the chemical analyses of the forages as they were stored and as they were fed. The ehenfical analyses are quite similar and what differences exist possibly reflect sampling errors and that the analyses of the material as stored represents the entire crop, whereas the as fed analyses represent only that used during
207
TABLE 3 Results of milk production trial (56 days) LOW-
Hay
Silage
moisture silage
(Zb) Feed consumed
(lb /cow/day)
Forage 29.8 Grain ] 5.6 Total 45.4 Dry matter consumed
64.1 15.5 79.6'
49.3 15.4 64.7
Forage 26,2 Grain 13.8 Total ~40.0' FCM per cow daily 47.2 Ratio graln :FCM 3.01 Body weight Average 1,210 Gain 32.6 Lb forage D.M. per ewt FCM 55.8 FCM per lb D.M. consumed 1.18 a One animal lost weighS.
23.7 13.6 37.3 44.3 2.87
24.6 13.5 38.1' 46.1 3.00
(lb/cow/day)
1,123 43.0
1,275 24.6 a
51.2
56.0
1.19
1.21
the feeding trial. The lower protein content of the low-moisture silage probably reflects the fact that the crop was six days more mature when cut. Results of the milk production trial are presented in Table 3. Whereas there was more dry matter consumed from hay than f r o m the low-moisture silage or the silage, the differences are not significant. Differences in F C M production are small and not significant. A v e r a g e p e r cent solids-not-fat produced on tile three forages were 8.99, 8.86, and 9.15 for tile hay, silage, and low-moisture silage, respectively. Differences are not significant. The gross efficiency of the three forages expressed as pounds of F C M produced per pound of dry nmtter consumed differ little, probably because of the excellent quality of all forages.
TABLE 2 Chemical analyses of forages as stored and as fed (per cent) Dry matter
NFE C.P.
E.E.
C.F.
Ash
(Dry basis) Hay As stored As fed Silage As stored As fed Low-moisture silage As stored As fed
86.40 88.00
19.39 18.34
4.30 3.71
28.29 29.64
38.84 39.06
9.18 9.09
33.75 37.70
20.80 21.26
3.92 5.93
28.70 28.83
35.67 33.10
10.91 10.85
50.48 50.10
18.15 18.78
4.45 4.91
27.49 27.92
41.37 38.46
8.54 9.59
J. H. BYERS
208
TABLE 4 Coefficients of digestibility of the rations (dry basis)
Hay -t- grain Silage ~- grain Low-moisture silage + grain
Organic matter
C.P.
E.E.
C.F.
NFE
72.8 67.9 71.8
70.9 64.3 66.3
56.8 71.3 71.3
61.7 55.4 57.8
80.1 75.6 79.5
Table 4 shows the digestion coefficients of the ration determined by the chromic oxide technique, using three cows from each ration. Average digestibility of the nutrients of the silage ration appear lower than those of the hay or low-moisture silage rations, but are not significantly lower. There was quite a large variation within rations and only three cows per ration were used. DISCUSSION
No attempt to measure losses was made as the cattle were put on feed inmmdiately on completion of the filling of the silos. In the making of the low-moisture silage, an attempt was made to have the forage harvester adjusted so that a fine chop resulted. After each load of the low-moisture material was put in the silo, the nmterial was leveled off, which resulted in some trampling of the forage. Spoilage in the low-moisture material was minimum, with some mold around the doors of the silo. In this study the quality of all forages was very high, suggesting that it makes little difference in what form a forage is harvested providing it is of high quality, since there was no significant difference in yield per acre, chemical analyses, d~.w matter consumption, solids-not-fat production, FCM production, gross efficiency of the rations, and digestibility of the rations. I t is likely that had the bay been rained upon, its feeding value would have been lowered because of decreased consumption and lower nutritive value. Had the silage been made from direct-cut material, there is little doubt that consumption of the silage would have been reduced [Gordon et al. (3)]. In addition, had
the crop been harvested at a late stage of development, then dry matter consumption and digestibility of the forage would likely be lower. Under such afore-mentioned conditions, it is possible that the low-moisture silage may have proven superior to the hay. This study has produced evidence that lowmoisture silage made under the conditions of this experiment is of high quality, relished by lactating dairy cows, and equal in feeding value to silage and hay made from the same crop at the same time. The study also shows that lowmoisture silage can be made in a conventional tower silo, providing some added care is taken in chopping the material and filling the silo. REFERENCES
(1) A.O.A.C. 1955. Official Methods of Analysis. Association of Official Agricultural Chemists, Washington, D. C. (2) BARTLE, EMERY, AND VOELKER, H. I-L 1960.
Dairy Research Field Day. Sou~h Dakota State College. Mimeo. (3) GORDON, C. H., DERBYSHIRE, J. C., MELIN, C. G., I~ANE, E. A., SYKES, J. F., AND
BLACK, D. T. ]960. The Effect of Wilting on the Feeding Value of Silages. USDA-ARS 44-76. (4) GORDON, C. H., DERBYSI~IRE, J. C., MCCALMONT, J. R., AND MOORE, L. A. 1961. Making Low-Moisture Silage in Regular Tower
Silos. USDA--ARS 44-101. (5) LARSEN, H. J., AND JOHANNES, R. F.
1961.
Effect on Milk Production, Body Weight, and Dry Matter Consumption when Feeding Haylage, Hay, and Silage with Simple Concentrate Supplements. J. Dairy Sci., 44: 1175.
I n a 56-day milk production trial the feeding values of alfalfa hay, silage, and low-moisture silage, with the silages stored in tower silos, were compared. All forages cut at the bud stage, using a conditioner, were of excellent quality. Dry matter consumption amongst the three forages was not significantly different, although there was a trend for the higher dry matter forages to be consumed to a greater extent. Four per cent FCM production and body weight changes were not significantly different. Digestibility of the three rations did not differ significantly. Low-moisture silage can be nmde in tower silos andSt is equal but not superior to the feeding value of hay or high-moisture silage.
Ensiling forages for feeding has received great attention i n recent years because of the development of low-moisture silage. The early work on low-moisture silage entailed using a sealed storage unit which soon led livestock feeders to question if low-moisture silage could be stored in conventional tower silos and, if so, hot" the feeding value of such low-moisture silage would compare with hay and silage made from similar material. Studies by Bartle and Voelker (2) and Gordon et al. (3) suggest that there is little difference in the nutritive value of hay, and lowmoisture silage, but unwilted silage is of lower feeding value than either low-moisture silage or hay. The low-moisture silages were made in air-tight silos. More recent studies by Gordon et a[. (4) show low-moisture silage nmde in a conventional tower silo equal to heat-dried hay ill feeding value and that only small amounts of spoilage were observed. Larsen and Johannes (5) shot" a higher average daily dr)" matter consumption and average daily fatcorrected milk (FCM) production by cows fed low-moisture silage than cows fed hay. This study was to determine the feeding value of an alfalfa-orchard grass mixture harvested in three different forms. The alfalfa was made into hay, silage, and low-moisture silages which were stored in tower silos. EXPERIMENTAL
PROCEDURE
A 30-acre field of DuPuits alfalfa and orchard grass seeded in the spring of 1960 with oats as a cover crop was used to provide the forage for the study. The forage was about Received for publication July 7, 1964.
95% alfalfa and 5% orchard grass. Five acres of the field were cut for low-moisture silage and the forage stored in a conventional tower silo 10 ft in diameter and 20 ft high. The material was left in the swath under excellent drying conditions 24 hr before chopping. Fifteen acres of the field were cut for silage and stored ill a silo 16 ft ill diameter and 40 ft high. Because of rain the material took 24 hr to wilt to a suitable dry matter content. Ten acres were cut for hay with excellent drying conditions. The forage was baled and in the barn within 48 hr after cutting. The alfalfa was cut at prebud to bud stage of development and a hay conditioner was used on all forages. Milk-producing ability of the three types of forages was tested in a milk production trial of 56 days after a seven-day preliminalw period, using three equal groups of five highproducing cows of the Holstein and Brown Swiss breeds. The cows were fed the respective forages ~td libitum and a grain mixture approximating 14% crude protein at the rate of 1 lb of grain to about 3.0 lb of FCM. Digestibility of the rations was determined, using the chromic oxide technique with three cows per ration. The animals were pilled once per day with 10 g of chromic oxide in gelatin capsules for ten days before and during the collection period. Grab samples of feces were taken for the seven days of the collection period at 6 AM and 4 PM, composited with thymol as a preservative and kept under refrigeration until the end of the collection period, at which time the feces were dried at 120 F and ground in a Wiley mill. Samples of hay for analyses were taken from every bale fed with the Penn State Forage
206
FEEDING ALFALFA AND SILAGE
Sampler. Daily samples of the silage and lowmoisture silage were taken and composited by weeks. A.O.A.C. (1) methods were used f o r all chemical analyses, except drying temperatures were at 65 C. Milk was weighed daily with b u t t e r f a t and solids-not-fat test run weekly on a one-day composite of the A~ and P~ nfilkings. Body weights were determined at the beginning and end of the trial by weighing the cattle on three successive days. RESULTS
In measuring the feeding value of any crop f o r livestock, it is essential, in addition to measuring the nutritive value, that the yield per acre be determined. Table 1 gives the yield TABLE 1 Yield per acre Low-moisture Hay silage Silage As stored (tons) Dry matter (~/c) Dry matter (tons)
1.32 86.40 1.14
3.18 50.48 1.61
4.23 33.75 1.21
of fresh material, per cent dry matter, and dry matter in tons p e r acre of each forage that organoleptically would be rated excellent. The higher dry matter yield of the lowmoisture silage may be explained, because the crop cut for low-moisture silage was six days more mature than that portion of the field cut for hay and silage. Table 2 shows the chemical analyses of the forages as they were stored and as they were fed. The ehenfical analyses are quite similar and what differences exist possibly reflect sampling errors and that the analyses of the material as stored represents the entire crop, whereas the as fed analyses represent only that used during
207
TABLE 3 Results of milk production trial (56 days) LOW-
Hay
Silage
moisture silage
(Zb) Feed consumed
(lb /cow/day)
Forage 29.8 Grain ] 5.6 Total 45.4 Dry matter consumed
64.1 15.5 79.6'
49.3 15.4 64.7
Forage 26,2 Grain 13.8 Total ~40.0' FCM per cow daily 47.2 Ratio graln :FCM 3.01 Body weight Average 1,210 Gain 32.6 Lb forage D.M. per ewt FCM 55.8 FCM per lb D.M. consumed 1.18 a One animal lost weighS.
23.7 13.6 37.3 44.3 2.87
24.6 13.5 38.1' 46.1 3.00
(lb/cow/day)
1,123 43.0
1,275 24.6 a
51.2
56.0
1.19
1.21
the feeding trial. The lower protein content of the low-moisture silage probably reflects the fact that the crop was six days more mature when cut. Results of the milk production trial are presented in Table 3. Whereas there was more dry matter consumed from hay than f r o m the low-moisture silage or the silage, the differences are not significant. Differences in F C M production are small and not significant. A v e r a g e p e r cent solids-not-fat produced on tile three forages were 8.99, 8.86, and 9.15 for tile hay, silage, and low-moisture silage, respectively. Differences are not significant. The gross efficiency of the three forages expressed as pounds of F C M produced per pound of dry nmtter consumed differ little, probably because of the excellent quality of all forages.
TABLE 2 Chemical analyses of forages as stored and as fed (per cent) Dry matter
NFE C.P.
E.E.
C.F.
Ash
(Dry basis) Hay As stored As fed Silage As stored As fed Low-moisture silage As stored As fed
86.40 88.00
19.39 18.34
4.30 3.71
28.29 29.64
38.84 39.06
9.18 9.09
33.75 37.70
20.80 21.26
3.92 5.93
28.70 28.83
35.67 33.10
10.91 10.85
50.48 50.10
18.15 18.78
4.45 4.91
27.49 27.92
41.37 38.46
8.54 9.59
J. H. BYERS
208
TABLE 4 Coefficients of digestibility of the rations (dry basis)
Hay -t- grain Silage ~- grain Low-moisture silage + grain
Organic matter
C.P.
E.E.
C.F.
NFE
72.8 67.9 71.8
70.9 64.3 66.3
56.8 71.3 71.3
61.7 55.4 57.8
80.1 75.6 79.5
Table 4 shows the digestion coefficients of the ration determined by the chromic oxide technique, using three cows from each ration. Average digestibility of the nutrients of the silage ration appear lower than those of the hay or low-moisture silage rations, but are not significantly lower. There was quite a large variation within rations and only three cows per ration were used. DISCUSSION
No attempt to measure losses was made as the cattle were put on feed inmmdiately on completion of the filling of the silos. In the making of the low-moisture silage, an attempt was made to have the forage harvester adjusted so that a fine chop resulted. After each load of the low-moisture material was put in the silo, the nmterial was leveled off, which resulted in some trampling of the forage. Spoilage in the low-moisture material was minimum, with some mold around the doors of the silo. In this study the quality of all forages was very high, suggesting that it makes little difference in what form a forage is harvested providing it is of high quality, since there was no significant difference in yield per acre, chemical analyses, d~.w matter consumption, solids-not-fat production, FCM production, gross efficiency of the rations, and digestibility of the rations. I t is likely that had the bay been rained upon, its feeding value would have been lowered because of decreased consumption and lower nutritive value. Had the silage been made from direct-cut material, there is little doubt that consumption of the silage would have been reduced [Gordon et al. (3)]. In addition, had
the crop been harvested at a late stage of development, then dry matter consumption and digestibility of the forage would likely be lower. Under such afore-mentioned conditions, it is possible that the low-moisture silage may have proven superior to the hay. This study has produced evidence that lowmoisture silage made under the conditions of this experiment is of high quality, relished by lactating dairy cows, and equal in feeding value to silage and hay made from the same crop at the same time. The study also shows that lowmoisture silage can be made in a conventional tower silo, providing some added care is taken in chopping the material and filling the silo. REFERENCES
(1) A.O.A.C. 1955. Official Methods of Analysis. Association of Official Agricultural Chemists, Washington, D. C. (2) BARTLE, EMERY, AND VOELKER, H. I-L 1960.
Dairy Research Field Day. Sou~h Dakota State College. Mimeo. (3) GORDON, C. H., DERBYSHIRE, J. C., MELIN, C. G., I~ANE, E. A., SYKES, J. F., AND
BLACK, D. T. ]960. The Effect of Wilting on the Feeding Value of Silages. USDA-ARS 44-76. (4) GORDON, C. H., DERBYSI~IRE, J. C., MCCALMONT, J. R., AND MOORE, L. A. 1961. Making Low-Moisture Silage in Regular Tower
Silos. USDA--ARS 44-101. (5) LARSEN, H. J., AND JOHANNES, R. F.
1961.
Effect on Milk Production, Body Weight, and Dry Matter Consumption when Feeding Haylage, Hay, and Silage with Simple Concentrate Supplements. J. Dairy Sci., 44: 1175.