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Comparative Value of Alfalfa Pasture, Alfalfa Greenchop, or Alfalfa Hay for Lactating Dairy Cows1, 2
Comparative Value of Alfalfa Pasture, Alfalfa Greenchop, or Alfalfa Hay for Lactating Dairy Cows ''~ D. A. STILES, E. E. BARTLEY, G. L. KILGORE, F. W. BOREN, and H. B. PERRY Southeast Kansas Branch Station, Mound Valley, and Department of Dairy and Poultry Science, Kansas State University Manhattan 66502 Abstract
Thirty Holstein cows, distributed among three groups of 10 each, were assigned randomly to treatments of alfalfa hay, alfalfa pasture, or alfalfa greenchop. A grain ration was offered at 1 kg p e r 3.5 kg milk. To prevent bloat, cows pastured on alfalfa or fed alfalfa greenehop received 20 g poloxalene daily. The first nine weeks, cows grazing on alfalfa pasture produced significantly more milk (2.5 kg p e r cow p e r day) than those fed hay but not significantly more (1.4 kg) than those fed greenchop. Cows fed greenehop did not produce significantly more milk (1.1 kg) than those fed hay. The three groups showed no significant differences in fat and solids-not-fat content of the milk or in body weight. Cows fed poloxalene did not bloat. Introduction
Previously we (14) demonstrated that cows produce significantly more milk when they are pastured on alfalfa than when fed alfalfa hay or pastured on bromegrass. Also, Holstein steers and heifers on alfalfa pasture gained significantly more in height and weight than those fed alfalfa hay or greenchop (12). This study presents additional information on the value of alfalfa pasture for lactating cows, especially the relative value of alfalfa pasture and alfalfa greenchop. Previously it has been difficult to assess the full potential of legume pastures for lactating cows because of the tendency of the cows to bloat. Several workers have compared pasture containing mixtures of grasses and legumes with stored feed. Generally milk production has been greater on pasture mixtures than on stored feed (5, 7, 11). Received for publication April 8, 1970. 1 Contribution 20, Southeast Kansas Branch Station, Mound Valley, and no. 787, Kansas Agricultural Experiment Station, Manhattan. 2Supported in part by a grant from Smith Kline and French Laboratories, Philadelphia, Pennsylvania.
Porter and Skaggs (12), in a system of controlled grazing to control bloat, found no significant differences in milk yield among a l f a l f a pasture, greenchop, or silage. Pasturing o f alfalfa was the most economical method. Poloxo alene, established (2, 3, 7, 13) as an effective bloat-preventive agent, was used to p r e v e n t bloat among cows on alfalfa pasture or a l f a l f a greenchop. Experimental Procedure
Thirty Holstein cows were distributed among three groups, each as similar as possible in milk production, stage of lactation, milk composition, age, and body weight. During 14 days preliminary all cows were held in drylot and fed, ad libitum, alfalfa hay and a grain ration containing 12% crude protein (as fed). The ration consisted of 42.75% ground corn, 42.75% ground sorghum grain, 7.5% soybean meal, 5% molasses, 1% salt, and 1% dicaleium phosphate. The alfalfa hay (third cutting) was of excellent quality. Following the preliminary period, groups were assigned randomly to one of these treatments: a) alfalfa (Medicago sativa) pasture, b) alfalfa greenchop, and c) alfalfa hay. During preliminary and experimental periods grain was fed twice daily before each milking at 1 kg for 3.5 kg milk. Each cow on alfalfa pasture or greenchop was fed 38 g Bloat Guard 3 containing 20 g poloxalene daily in her grain ration. H a l f the Bloat Guard was fed before each milking. All cows received dicalcium phosphate and salt free choice. A l f a l f a hay a n d fresh-cut alfalfa greenehop (cut twice daily) were fed ad libitum. The hay and greenchop were from the same field, but the hay was harvested in the year previous to the year of this experiment. Pasture consisted of a series of four plots averaging 2.025 ha each. Cows were moved from one plot to the next as each pasture was grazed down, in this rotation scheme: 1, 2, 4, 3, 1, 2, 4, 3. A f t e r cows were moved from a plot, 3 Trade name of Smith Kline and French Laboratories' product containing 53~'o poloxalene. 65
66
STILES
it was mowed and the hay harvested. Pastures were fertilized February 1968; soil additives were similar in kind and quantity to those reported previously (14). Average distance traveled to and from pastures each d a y ' w a s 2,865 m. No shade was available for any group. Fresh water always was available in drylot and within 91 m for those on pasture. Forage drymatter intake of cows on pasture was measured by the cage method described by Hodgson et al. (9). Five wire cages (1.0 by 1.0 m and 0.6 m high) were placed randomly on each hectare. The pasture under the cages was clipped to a height representative of what remained in the
ET AL.
pasture after grazing. The cows were pastured May 2 to July 3, 1968. H a y and grain fed and refused were recorded. Proximate composition of pasture, greenehop, (representative samples taken from the pasture harvested under the cages) hay, and grain fed was determined by AOAC methods (1). Individual milk weights were recorded at each milking. Individual 24-hour composite milk samples were collected at intervals shown in Table 1. Samples were analyzed for fat by methods outlined i n AOAC (1) and for solids-not-fat ( S N F ) by the Golding bead method (8). All cows were weighed at 7, 21, 35, 49, 56, and
TABLE 1. Mean daily milk yield and milk composition of 30 cows (10 per group) pastured on alfalfa or fed alfalfa greenchop or hay. Group
Pasture
Greenchop
Hay
Weeks
Milk
Milk fat
Solids-not-fat
(kg)
(%)
(kg)
Basal 1 2 3 4 5 6 7 8 9 Mean
24.7 24.5 25.3 26.2 25.8 23.8 22.6 23.9 24.4 24.4 24.5a
3.4 3.3
0.84 0.80 0.81 0.84 0.80 0.74 0.53 0.56 0.65 0.74 0.72a
Basal 1 2 3 4 5 6 7 8 9 Mean
24.6 23.7 23.9 24.9 23.4 22.3 23.3 23.3 22.7 21.8 23.3ab
Basal 1 2 3 4 5 6 7 8 9 Mean
24.6 23.5 23.0 22.5 22.5 21.5 20.9 21.7 22.3 21.3 22.1b
3.2 3.1 2.4 2.8 3.1 2.9a 3.5 3.2 3.0 3.0 3.3 3.0 3.5 3.2a 3.4 3.1 3.5 3.3 2.9 3.2 3.5 3.3a
0.86 0.75 0.70 0.73 0.68 0.65 0.75 0.76 0.66 0.74 0.71a 0.84 0.72 0.81 0.79 0.74 0.71 0.60 0.62 0.71 0.74 0.72a
(%) 8.4 8.4 8.1 8.1 8.0 8.4 8.3 8.2a 8.4 8.3 8.2 8.1 8.7 8.2 8.3 8.3a 8.4 8.4 8.1 8.1 8.0 8.4 8.3 8.2a
(kg) 2.07 2.04 2.05 2.13 2.07 1.91 1.82 1.93 2.04 2.01 2.00a 2.05 1.95 1.96 2.05 1.91 1.82 2.03 2.04 1.86 1.81 1.94a 2.07 1.93 1.85 1.83 1.84 1.76 1.77 1.84 1.86 1.79 1.83a
a,b Values in a column sharing a common letter are not significantly different (P ~ .05). ~OURNAL OF DAIRY SCIENCE VOL. 54, NO. 1
ALFALFA-PASTURE, GREENCHOP OR HAY
67
TABLE 2. Mean daily grain and forage dry matter consumption p e r ~ w and mean body weight. Forage dry matter
Treatment
Grain
Pasture Greenchop Hay
.... (kg)-5.9a 13.6a 5.4a 13.6a 6.3a 14.7a
7
21
Body weight Days 35 49
550b 576e 560a
549b 567a 572a
548b 559ab 565a
56
63
556a 565a 555a
551a 561a 571a
(kg) 561a 567a 564a
a,b,c Values in a column sharing a common letter are not significantly different (P ( . 0 5 ) . 63 days (Table 2). Weather data were obtained from the official U.S. Weather Station at the Southeast Kansas Branch Experiment Station. Results and Discussion
Weekly milk production and composition were adjusted to a common prestudy production average by covariance (Table 1). The first nine weeks cows on alfalfa pasture produced more ( P <: .05) milk than did those fed alfalfa hay but not significantly more than cattle fed alfalfa greenchop. Cows fed greenchop did not produce significantly more milk than did those fed hay. The mean fat content of the milk from the three groups was not significantly different. During six of the first nine weeks, cows receiving hay produced milk of higher (P ( . 0 5 ) fat content than did those on pasture. During Weeks 2 and 3 cows fed hay produced a higher (P <: .05) fat-content milk than did those fed greenchop. The mean milk fat production for the three groups was not significantly different. That was expected in that milk fat content was slightly lower but milk production higher for the cows on pasture. Solids-not-fat content of milk from the three groups was not significantly different indicating that solids production was related to milk production. The pasture group which produced the most milk also produced the most S N F ; the greenchop group produced the next most, and the hay group produced the least quantity of SNF. Difference in mean S N F production was not significant. There were no significant differences in grain consumption among the three groups (Table 2). Although grain was fed according to milk production, grain intake was not related to milk production because cows fed pasture or greenchop refused portions of their grain during periods of high-forage intake; cows fed hay ate all the grain offered. Forage dry matter intake was the same for the pasture- and
greenehop-fed cows (Table 2). H a y - f e d cows consumed more forage dry matter than did either of the other groups, but the difference was not statistically significant. Hay-fed cows gained slightly in weight during the trial (Table 2) ; pasture-fed cows maintained their weight; those fed greenchop lost slightly. Weight differences were significant only during the early weeks of the trial. I n 1967 at this station (14) cows pastured on alfalfa produced significantly more milk, fat, and solids-not-fat than did those fed alfalfa hay. I n this study (1968) pastured cows also produced significantly more milk than did those fed hay. The increase in milk production (2.5 kg per cow p e r day) for pastured cows over hay-fed cows in 1968 was similar to the increase (2.4 kg) in the 1967 study. I n the :i967 study alfalfa pasture was better and alfalfa hay poorer than in 1968. The proximate composition of the feeds in 1968 is in Table 3; composition of those in 1967 appears in the p a p e r by Stiles et al. (14). I n 1967 the average crude protein content of both pasture and hay was 22%; crude fiber of pasture was 28% and of hay, 25%. I n 1968 the average crude protein content of pasture and hay was 18 and 23%; crude fiber was 24% for pasture and 21% for hay. Weather accounted for the difference in quality between the two years. I n 1968 rainfall was lower and average temperature higher (Table 4) than in 1967. Undoubtedly the poorer quality of pasture in 1968 accounted for the lower forage dry-matter intake in 1968 compared with 1967. Even so, the milk stimulus from the pasture was similar for the two years causing us to speculate on what portion of the stimulus resulted from improved nutrition and what from such factors as estrogenic substances in alfalfa pasture (5). Cows fed alfalfa greenchop did not produce as well as pasture-fed cows but better than those fed hay. Slightly lower in protein and considerably higher in fiber content than the hay, greenchop appeared to have a better proxi~OUI~I~AL OF DAIRY SCIENCE VOL. 54, NO. 1
68
S T I L E S E T AL.
TABLE 3. Proximate composition of feeds. Dry basis Feed
Crude protein
Weeks
Ash
Ether extract
Crude fiber
N-free extract
(%) A l f a l f a pasture 1 2 3 4 5 6 7 8 9
16.2 16.2 15.8 23.2 20.7 21.1 16.6 18.4 15.8
7.1 7.1 7.0 9.5 8.6 10.1 7.4 8.0 7.1
2.2 2.2 2.0 2.3 2.3 2.3 2.2 2.2 2.4
34.9 34.9 37.2 28.5 32.2 29.2 37.4 34.5 35.8
39.6 39.6 38.1 36.6 36.3 37.3 36.4 37.0 38.9
Mean
i8.2
7.9
2.2
33.8
37.8
1 2 3 4 5 6 7 8 9
23.4 20.7 20.0 20.] 22.1 20.7 18.2 20.9 23.2
10.0 9.8 9.9 9.7 9.2 8.8 7.7 8.0 8.5
4.0 1.7 2.4 2.0 1.2 1.4 1.2 3.9 2.9
24.3 36.5 36.2 37.5 32.0 27.4 29.9 24.8
38.4 31.3 31.5 29.8 35.7 41.7 43.0 41.2 40.7
Mean
21.0
9.1
2.4
30.5
37.0
Alfalfa hay
22.7
10.0
1.8
20.9
44.6
Grain ration
14.3
4.0
2.9
3.0
75.8
A l f a l f a greenchop
mate composition than did pasture. Cows on alfalfa pasture selectively grazed the top oneTA~.~ 4. (1968).
Weekly temperature and rainfall Temperature
Weeks
Maximum
1 2 3 4 5 6 7 8 9
26 24 22 22 28 32 31 33 29
(c)
Minimum
Weekly rainfall
(c)
(em)
12 14 10 11 18 20 18 20 18
1.07 3.48 ...... 10.16 0.38 ...... 2.01 2.49 3.89 Total
JOURNAL O~ ~AIRY SCIEI~CE ~OL. 54, ~O. 1
26.0
half to two-thirds of the alfalfa plant and may have received better forage than indicated by the analysis (Table 3) of the p l a n t harvested from the cages. Greenchop-fed cows may have received more of the fibrous stem than did pastured cows. That could partially explain production difference between those two groups. H a y in this trial was harvested the previous year. However, hay harvested on similar land to that used for pasture and greenchop provided two cuttings during experiment. The first cutting yielded 3.36 metric tons p e r hectare and the second 1.12 metric tons or a total yield of 4.48 metric tons hay dry matter. Total hay fed during the experiment was 10.64 metric tons (9.25 tons consumed, 1.39 tons refused). To provide 10.64 tons would require 2.37 ha (10.64 tons -- 4.48 tons p e r hectare). Cows in the pasture group had access to 8.09 ha of pasture. During the experiment 23.6 metric tons of hay dry matter were har-
A L F A L F A - P A S T U R E , G R E E N C H O P O1~ H A Y
69
TAB~ 5. Average income over grain-concentrate ration costs for total trial (63 days). Cost
Treatment
]~¢Iilk Valuea produced/ of cow milk
Grainb consumed/ cow
Grain b
Hay Pasture Greenehop
(kg) 1,395 1,549 1,461
(kg) 393 373 341
($) 21.66 20.56 18.80
($) 169.13 187.78 177.16
Bloat Guard ($) 6.30 6.30
Ineome¢/ COW
($) 147.47 160.92 152.06
a Milk price, $5.50 per cwt. b Grain price, $2.50 per cwt. e Income over grain or grain plus Bloat Guard costs. vested from the 8.09 ha in addition to the quantity grazed. The cows consumed a total of 8.5 metric tons of pasture dry matter (determined by cage measurement). Total yield of the 8.09 ha of pasture was 32.1 metric tons (23.6 -~ 8.5). Total yield per hectare was 3.97 metric tons (32.1 -- 8.09). Therefore, to supply the 8.5 tons consumed by the cows, 2.14 ha (8.5 -- 3.97) of pasture would have been required. The hay produced from these 8.09 ha would probably have been of poorer quality than hay produced on unpastured land. Consequently, the 2.14 ha figure ascribed to pasture is probably low. A total of 2.19 ha of land was used for the production of greenchop. I t would appear that the land requirement for hay, pasture, and greenchop in this study is similar. Pasturing cows eliminates harvesting and feeding costs, utilizes surplus forage in early spring or late fall, frees dairymen from winter routines, and relieves cattle from drylot fatigue. But by ignoring those advantages (to which it is difficult to assign a monetary value) and by considering the cost of pasture, greenchop, or hay equal, it was possible to calculate milk income over cost of grain plus Bloat Guard for each form of roughage as in Table 5. Calculated o~ that basis, milk income was highest for the pasture-fed cows, second highest for greenchop-fed cows, and lowest for hay-fed COWS.
I n two successive years, 1967 and 1968, cows pastured on alfalfa produced significantly more milk than did those fed excellent-quality alfalfa hay. Cows fed alfalfa greenehop did not produce significantly more than those fed alfalfa hay. The value of greenehop requires further investigation. Incidence of bloat in cows on pasture or fed greenchop was nil.
Acknowledgment The authors gratefully acknowledge the assistance of Dr. S. F. Scheidy, veterinary medical
director, and Dr. S. M. ~'ree, director of bio~tatics, Smith Kline and French Laboratories, Philadelphia, for their assistance. References
(1) Association of 0ffieial Agricultural Chemists. 1960. Official Methods of Analysis. 9th ed. Washington, ]D.C. (2) Bartley, E. E. 1965. Bloat in cattle. VI. Prevention of legume bleat with a nonionie surfactant. J. ])airy Sci., 48: I02. (3) Bartley, E. E., H. Lippke, H. B. Pfost, R. J. Nijweide, IN-.L. Jacobsen, and R. M. Meyer. 1965. Bloat in cattle. X. E~caey of poloxalene in controlling alfalfa bloat in dairy steers and in lactating cows in commercial dairy herds. J. Dairy Sei., 48: 1657. (4) Baxter, H. D., J. R. Owen, M. J. Montgomery, D. R. Waldo, and J. T. Miles. 1969. Pasturing vs. harvesting of a grass-legume mixture. Tennessee Agr. Exp. Sta., Bull., 454. (5) Biekoff, E. M. Oestrogenie constituents of forage plants. 1968. Review Series No. 1/ 1968. Commonwealth Agricultural Bureaux, Farnham Royal, Bucks, England. (6) Bryant, H. T., R. E. Blaser, J. T. Huber, and R. C. Hammes, Jr. 1965. The value of combinations of hay and pasture with different levels of concentrate for dairy cows. Virginia Polytechnic Inst. Agr. Exp. Sta., Bull., 564. (7) Foote, L. E., R. E. Girouard, Jr., J. :E. Johnston, J. Rainey, P. B. Brown, and W. H. Willis. 3968. Poloxalene for the prevention of legume bloat. J. Dairy Sci., 51 : 584. (8) Golding, N. S. 1964. Procedure for the Golding Plastic Bead Test for solids-not-fat in milk. Washington State Univ. l~.xt. Circ. 340. (9) Hodgson, R. E., J. C. Knott, V. L. Miller, and ~. B. Wolberg. 1942. Measuring the yield of nutrients of e.xperimental pastures. Washington Agr. Exp. Sta., Bull., 411. (10) Huffman, C. F. 1959. Summer feeding of dairy cattle. A review. J. Dairy Sci, 42: 1495. (11) Porter, R. M., and S. R. Skaggs. 1958. ForJOUR~A/~ OF DAIRY SCIENCE VOIJ. 54, ~ 0 . 1
70
STILES ET AL.
age and milk yields from alfalfa under three different harvesting methods. Abstr. J. Dairy Sci., 41: 736. (12) Stiles, D. A., E. E. Bartley, A. D. Dayton, H. B. Perry, G. L. Ki]gore, and 1~. W. Boren. 1970. Growth of Holstein calves fed alfalfa pasture, alfalfa greenchop, or alfalfa hay. J. Dairy Sci., 53: 489. (13) Stiles, D. A., E. ]~. Bartley, A. B. E r h a r t ,
JOURlCAL OF DAIRY SCIENOZ YOL. 54, N0. 1
1%. M. Meyer, and F. W. Boren. 1967. Bloat in cattle. X l I I . Efficacy of molassessalt blocks containing poloxalene in control of alfalfa bloat. J. Dairy Sci., 50: 1437. (14) Stiles, D. A., E. E. Bartley, G. L. Kilgore, 1~. W. Boren, R. L. Ott, and J. G. Clark. 1968. Comparative value of a l f a l f a pasture, bromegrass pasture or alfalfa hay for lact a t i n g dairy cows. J. Dairy Sci., 51: 1620.
Thirty Holstein cows, distributed among three groups of 10 each, were assigned randomly to treatments of alfalfa hay, alfalfa pasture, or alfalfa greenchop. A grain ration was offered at 1 kg p e r 3.5 kg milk. To prevent bloat, cows pastured on alfalfa or fed alfalfa greenehop received 20 g poloxalene daily. The first nine weeks, cows grazing on alfalfa pasture produced significantly more milk (2.5 kg p e r cow p e r day) than those fed hay but not significantly more (1.4 kg) than those fed greenchop. Cows fed greenehop did not produce significantly more milk (1.1 kg) than those fed hay. The three groups showed no significant differences in fat and solids-not-fat content of the milk or in body weight. Cows fed poloxalene did not bloat. Introduction
Previously we (14) demonstrated that cows produce significantly more milk when they are pastured on alfalfa than when fed alfalfa hay or pastured on bromegrass. Also, Holstein steers and heifers on alfalfa pasture gained significantly more in height and weight than those fed alfalfa hay or greenchop (12). This study presents additional information on the value of alfalfa pasture for lactating cows, especially the relative value of alfalfa pasture and alfalfa greenchop. Previously it has been difficult to assess the full potential of legume pastures for lactating cows because of the tendency of the cows to bloat. Several workers have compared pasture containing mixtures of grasses and legumes with stored feed. Generally milk production has been greater on pasture mixtures than on stored feed (5, 7, 11). Received for publication April 8, 1970. 1 Contribution 20, Southeast Kansas Branch Station, Mound Valley, and no. 787, Kansas Agricultural Experiment Station, Manhattan. 2Supported in part by a grant from Smith Kline and French Laboratories, Philadelphia, Pennsylvania.
Porter and Skaggs (12), in a system of controlled grazing to control bloat, found no significant differences in milk yield among a l f a l f a pasture, greenchop, or silage. Pasturing o f alfalfa was the most economical method. Poloxo alene, established (2, 3, 7, 13) as an effective bloat-preventive agent, was used to p r e v e n t bloat among cows on alfalfa pasture or a l f a l f a greenchop. Experimental Procedure
Thirty Holstein cows were distributed among three groups, each as similar as possible in milk production, stage of lactation, milk composition, age, and body weight. During 14 days preliminary all cows were held in drylot and fed, ad libitum, alfalfa hay and a grain ration containing 12% crude protein (as fed). The ration consisted of 42.75% ground corn, 42.75% ground sorghum grain, 7.5% soybean meal, 5% molasses, 1% salt, and 1% dicaleium phosphate. The alfalfa hay (third cutting) was of excellent quality. Following the preliminary period, groups were assigned randomly to one of these treatments: a) alfalfa (Medicago sativa) pasture, b) alfalfa greenchop, and c) alfalfa hay. During preliminary and experimental periods grain was fed twice daily before each milking at 1 kg for 3.5 kg milk. Each cow on alfalfa pasture or greenchop was fed 38 g Bloat Guard 3 containing 20 g poloxalene daily in her grain ration. H a l f the Bloat Guard was fed before each milking. All cows received dicalcium phosphate and salt free choice. A l f a l f a hay a n d fresh-cut alfalfa greenehop (cut twice daily) were fed ad libitum. The hay and greenchop were from the same field, but the hay was harvested in the year previous to the year of this experiment. Pasture consisted of a series of four plots averaging 2.025 ha each. Cows were moved from one plot to the next as each pasture was grazed down, in this rotation scheme: 1, 2, 4, 3, 1, 2, 4, 3. A f t e r cows were moved from a plot, 3 Trade name of Smith Kline and French Laboratories' product containing 53~'o poloxalene. 65
66
STILES
it was mowed and the hay harvested. Pastures were fertilized February 1968; soil additives were similar in kind and quantity to those reported previously (14). Average distance traveled to and from pastures each d a y ' w a s 2,865 m. No shade was available for any group. Fresh water always was available in drylot and within 91 m for those on pasture. Forage drymatter intake of cows on pasture was measured by the cage method described by Hodgson et al. (9). Five wire cages (1.0 by 1.0 m and 0.6 m high) were placed randomly on each hectare. The pasture under the cages was clipped to a height representative of what remained in the
ET AL.
pasture after grazing. The cows were pastured May 2 to July 3, 1968. H a y and grain fed and refused were recorded. Proximate composition of pasture, greenehop, (representative samples taken from the pasture harvested under the cages) hay, and grain fed was determined by AOAC methods (1). Individual milk weights were recorded at each milking. Individual 24-hour composite milk samples were collected at intervals shown in Table 1. Samples were analyzed for fat by methods outlined i n AOAC (1) and for solids-not-fat ( S N F ) by the Golding bead method (8). All cows were weighed at 7, 21, 35, 49, 56, and
TABLE 1. Mean daily milk yield and milk composition of 30 cows (10 per group) pastured on alfalfa or fed alfalfa greenchop or hay. Group
Pasture
Greenchop
Hay
Weeks
Milk
Milk fat
Solids-not-fat
(kg)
(%)
(kg)
Basal 1 2 3 4 5 6 7 8 9 Mean
24.7 24.5 25.3 26.2 25.8 23.8 22.6 23.9 24.4 24.4 24.5a
3.4 3.3
0.84 0.80 0.81 0.84 0.80 0.74 0.53 0.56 0.65 0.74 0.72a
Basal 1 2 3 4 5 6 7 8 9 Mean
24.6 23.7 23.9 24.9 23.4 22.3 23.3 23.3 22.7 21.8 23.3ab
Basal 1 2 3 4 5 6 7 8 9 Mean
24.6 23.5 23.0 22.5 22.5 21.5 20.9 21.7 22.3 21.3 22.1b
3.2 3.1 2.4 2.8 3.1 2.9a 3.5 3.2 3.0 3.0 3.3 3.0 3.5 3.2a 3.4 3.1 3.5 3.3 2.9 3.2 3.5 3.3a
0.86 0.75 0.70 0.73 0.68 0.65 0.75 0.76 0.66 0.74 0.71a 0.84 0.72 0.81 0.79 0.74 0.71 0.60 0.62 0.71 0.74 0.72a
(%) 8.4 8.4 8.1 8.1 8.0 8.4 8.3 8.2a 8.4 8.3 8.2 8.1 8.7 8.2 8.3 8.3a 8.4 8.4 8.1 8.1 8.0 8.4 8.3 8.2a
(kg) 2.07 2.04 2.05 2.13 2.07 1.91 1.82 1.93 2.04 2.01 2.00a 2.05 1.95 1.96 2.05 1.91 1.82 2.03 2.04 1.86 1.81 1.94a 2.07 1.93 1.85 1.83 1.84 1.76 1.77 1.84 1.86 1.79 1.83a
a,b Values in a column sharing a common letter are not significantly different (P ~ .05). ~OURNAL OF DAIRY SCIENCE VOL. 54, NO. 1
ALFALFA-PASTURE, GREENCHOP OR HAY
67
TABLE 2. Mean daily grain and forage dry matter consumption p e r ~ w and mean body weight. Forage dry matter
Treatment
Grain
Pasture Greenchop Hay
.... (kg)-5.9a 13.6a 5.4a 13.6a 6.3a 14.7a
7
21
Body weight Days 35 49
550b 576e 560a
549b 567a 572a
548b 559ab 565a
56
63
556a 565a 555a
551a 561a 571a
(kg) 561a 567a 564a
a,b,c Values in a column sharing a common letter are not significantly different (P ( . 0 5 ) . 63 days (Table 2). Weather data were obtained from the official U.S. Weather Station at the Southeast Kansas Branch Experiment Station. Results and Discussion
Weekly milk production and composition were adjusted to a common prestudy production average by covariance (Table 1). The first nine weeks cows on alfalfa pasture produced more ( P <: .05) milk than did those fed alfalfa hay but not significantly more than cattle fed alfalfa greenchop. Cows fed greenchop did not produce significantly more milk than did those fed hay. The mean fat content of the milk from the three groups was not significantly different. During six of the first nine weeks, cows receiving hay produced milk of higher (P ( . 0 5 ) fat content than did those on pasture. During Weeks 2 and 3 cows fed hay produced a higher (P <: .05) fat-content milk than did those fed greenchop. The mean milk fat production for the three groups was not significantly different. That was expected in that milk fat content was slightly lower but milk production higher for the cows on pasture. Solids-not-fat content of milk from the three groups was not significantly different indicating that solids production was related to milk production. The pasture group which produced the most milk also produced the most S N F ; the greenchop group produced the next most, and the hay group produced the least quantity of SNF. Difference in mean S N F production was not significant. There were no significant differences in grain consumption among the three groups (Table 2). Although grain was fed according to milk production, grain intake was not related to milk production because cows fed pasture or greenchop refused portions of their grain during periods of high-forage intake; cows fed hay ate all the grain offered. Forage dry matter intake was the same for the pasture- and
greenehop-fed cows (Table 2). H a y - f e d cows consumed more forage dry matter than did either of the other groups, but the difference was not statistically significant. Hay-fed cows gained slightly in weight during the trial (Table 2) ; pasture-fed cows maintained their weight; those fed greenchop lost slightly. Weight differences were significant only during the early weeks of the trial. I n 1967 at this station (14) cows pastured on alfalfa produced significantly more milk, fat, and solids-not-fat than did those fed alfalfa hay. I n this study (1968) pastured cows also produced significantly more milk than did those fed hay. The increase in milk production (2.5 kg per cow p e r day) for pastured cows over hay-fed cows in 1968 was similar to the increase (2.4 kg) in the 1967 study. I n the :i967 study alfalfa pasture was better and alfalfa hay poorer than in 1968. The proximate composition of the feeds in 1968 is in Table 3; composition of those in 1967 appears in the p a p e r by Stiles et al. (14). I n 1967 the average crude protein content of both pasture and hay was 22%; crude fiber of pasture was 28% and of hay, 25%. I n 1968 the average crude protein content of pasture and hay was 18 and 23%; crude fiber was 24% for pasture and 21% for hay. Weather accounted for the difference in quality between the two years. I n 1968 rainfall was lower and average temperature higher (Table 4) than in 1967. Undoubtedly the poorer quality of pasture in 1968 accounted for the lower forage dry-matter intake in 1968 compared with 1967. Even so, the milk stimulus from the pasture was similar for the two years causing us to speculate on what portion of the stimulus resulted from improved nutrition and what from such factors as estrogenic substances in alfalfa pasture (5). Cows fed alfalfa greenchop did not produce as well as pasture-fed cows but better than those fed hay. Slightly lower in protein and considerably higher in fiber content than the hay, greenchop appeared to have a better proxi~OUI~I~AL OF DAIRY SCIENCE VOL. 54, NO. 1
68
S T I L E S E T AL.
TABLE 3. Proximate composition of feeds. Dry basis Feed
Crude protein
Weeks
Ash
Ether extract
Crude fiber
N-free extract
(%) A l f a l f a pasture 1 2 3 4 5 6 7 8 9
16.2 16.2 15.8 23.2 20.7 21.1 16.6 18.4 15.8
7.1 7.1 7.0 9.5 8.6 10.1 7.4 8.0 7.1
2.2 2.2 2.0 2.3 2.3 2.3 2.2 2.2 2.4
34.9 34.9 37.2 28.5 32.2 29.2 37.4 34.5 35.8
39.6 39.6 38.1 36.6 36.3 37.3 36.4 37.0 38.9
Mean
i8.2
7.9
2.2
33.8
37.8
1 2 3 4 5 6 7 8 9
23.4 20.7 20.0 20.] 22.1 20.7 18.2 20.9 23.2
10.0 9.8 9.9 9.7 9.2 8.8 7.7 8.0 8.5
4.0 1.7 2.4 2.0 1.2 1.4 1.2 3.9 2.9
24.3 36.5 36.2 37.5 32.0 27.4 29.9 24.8
38.4 31.3 31.5 29.8 35.7 41.7 43.0 41.2 40.7
Mean
21.0
9.1
2.4
30.5
37.0
Alfalfa hay
22.7
10.0
1.8
20.9
44.6
Grain ration
14.3
4.0
2.9
3.0
75.8
A l f a l f a greenchop
mate composition than did pasture. Cows on alfalfa pasture selectively grazed the top oneTA~.~ 4. (1968).
Weekly temperature and rainfall Temperature
Weeks
Maximum
1 2 3 4 5 6 7 8 9
26 24 22 22 28 32 31 33 29
(c)
Minimum
Weekly rainfall
(c)
(em)
12 14 10 11 18 20 18 20 18
1.07 3.48 ...... 10.16 0.38 ...... 2.01 2.49 3.89 Total
JOURNAL O~ ~AIRY SCIEI~CE ~OL. 54, ~O. 1
26.0
half to two-thirds of the alfalfa plant and may have received better forage than indicated by the analysis (Table 3) of the p l a n t harvested from the cages. Greenchop-fed cows may have received more of the fibrous stem than did pastured cows. That could partially explain production difference between those two groups. H a y in this trial was harvested the previous year. However, hay harvested on similar land to that used for pasture and greenchop provided two cuttings during experiment. The first cutting yielded 3.36 metric tons p e r hectare and the second 1.12 metric tons or a total yield of 4.48 metric tons hay dry matter. Total hay fed during the experiment was 10.64 metric tons (9.25 tons consumed, 1.39 tons refused). To provide 10.64 tons would require 2.37 ha (10.64 tons -- 4.48 tons p e r hectare). Cows in the pasture group had access to 8.09 ha of pasture. During the experiment 23.6 metric tons of hay dry matter were har-
A L F A L F A - P A S T U R E , G R E E N C H O P O1~ H A Y
69
TAB~ 5. Average income over grain-concentrate ration costs for total trial (63 days). Cost
Treatment
]~¢Iilk Valuea produced/ of cow milk
Grainb consumed/ cow
Grain b
Hay Pasture Greenehop
(kg) 1,395 1,549 1,461
(kg) 393 373 341
($) 21.66 20.56 18.80
($) 169.13 187.78 177.16
Bloat Guard ($) 6.30 6.30
Ineome¢/ COW
($) 147.47 160.92 152.06
a Milk price, $5.50 per cwt. b Grain price, $2.50 per cwt. e Income over grain or grain plus Bloat Guard costs. vested from the 8.09 ha in addition to the quantity grazed. The cows consumed a total of 8.5 metric tons of pasture dry matter (determined by cage measurement). Total yield of the 8.09 ha of pasture was 32.1 metric tons (23.6 -~ 8.5). Total yield per hectare was 3.97 metric tons (32.1 -- 8.09). Therefore, to supply the 8.5 tons consumed by the cows, 2.14 ha (8.5 -- 3.97) of pasture would have been required. The hay produced from these 8.09 ha would probably have been of poorer quality than hay produced on unpastured land. Consequently, the 2.14 ha figure ascribed to pasture is probably low. A total of 2.19 ha of land was used for the production of greenchop. I t would appear that the land requirement for hay, pasture, and greenchop in this study is similar. Pasturing cows eliminates harvesting and feeding costs, utilizes surplus forage in early spring or late fall, frees dairymen from winter routines, and relieves cattle from drylot fatigue. But by ignoring those advantages (to which it is difficult to assign a monetary value) and by considering the cost of pasture, greenchop, or hay equal, it was possible to calculate milk income over cost of grain plus Bloat Guard for each form of roughage as in Table 5. Calculated o~ that basis, milk income was highest for the pasture-fed cows, second highest for greenchop-fed cows, and lowest for hay-fed COWS.
I n two successive years, 1967 and 1968, cows pastured on alfalfa produced significantly more milk than did those fed excellent-quality alfalfa hay. Cows fed alfalfa greenehop did not produce significantly more than those fed alfalfa hay. The value of greenehop requires further investigation. Incidence of bloat in cows on pasture or fed greenchop was nil.
Acknowledgment The authors gratefully acknowledge the assistance of Dr. S. F. Scheidy, veterinary medical
director, and Dr. S. M. ~'ree, director of bio~tatics, Smith Kline and French Laboratories, Philadelphia, for their assistance. References
(1) Association of 0ffieial Agricultural Chemists. 1960. Official Methods of Analysis. 9th ed. Washington, ]D.C. (2) Bartley, E. E. 1965. Bloat in cattle. VI. Prevention of legume bleat with a nonionie surfactant. J. ])airy Sci., 48: I02. (3) Bartley, E. E., H. Lippke, H. B. Pfost, R. J. Nijweide, IN-.L. Jacobsen, and R. M. Meyer. 1965. Bloat in cattle. X. E~caey of poloxalene in controlling alfalfa bloat in dairy steers and in lactating cows in commercial dairy herds. J. Dairy Sei., 48: 1657. (4) Baxter, H. D., J. R. Owen, M. J. Montgomery, D. R. Waldo, and J. T. Miles. 1969. Pasturing vs. harvesting of a grass-legume mixture. Tennessee Agr. Exp. Sta., Bull., 454. (5) Biekoff, E. M. Oestrogenie constituents of forage plants. 1968. Review Series No. 1/ 1968. Commonwealth Agricultural Bureaux, Farnham Royal, Bucks, England. (6) Bryant, H. T., R. E. Blaser, J. T. Huber, and R. C. Hammes, Jr. 1965. The value of combinations of hay and pasture with different levels of concentrate for dairy cows. Virginia Polytechnic Inst. Agr. Exp. Sta., Bull., 564. (7) Foote, L. E., R. E. Girouard, Jr., J. :E. Johnston, J. Rainey, P. B. Brown, and W. H. Willis. 3968. Poloxalene for the prevention of legume bloat. J. Dairy Sci., 51 : 584. (8) Golding, N. S. 1964. Procedure for the Golding Plastic Bead Test for solids-not-fat in milk. Washington State Univ. l~.xt. Circ. 340. (9) Hodgson, R. E., J. C. Knott, V. L. Miller, and ~. B. Wolberg. 1942. Measuring the yield of nutrients of e.xperimental pastures. Washington Agr. Exp. Sta., Bull., 411. (10) Huffman, C. F. 1959. Summer feeding of dairy cattle. A review. J. Dairy Sci, 42: 1495. (11) Porter, R. M., and S. R. Skaggs. 1958. ForJOUR~A/~ OF DAIRY SCIENCE VOIJ. 54, ~ 0 . 1
70
STILES ET AL.
age and milk yields from alfalfa under three different harvesting methods. Abstr. J. Dairy Sci., 41: 736. (12) Stiles, D. A., E. E. Bartley, A. D. Dayton, H. B. Perry, G. L. Ki]gore, and 1~. W. Boren. 1970. Growth of Holstein calves fed alfalfa pasture, alfalfa greenchop, or alfalfa hay. J. Dairy Sci., 53: 489. (13) Stiles, D. A., E. ]~. Bartley, A. B. E r h a r t ,
JOURlCAL OF DAIRY SCIENOZ YOL. 54, N0. 1
1%. M. Meyer, and F. W. Boren. 1967. Bloat in cattle. X l I I . Efficacy of molassessalt blocks containing poloxalene in control of alfalfa bloat. J. Dairy Sci., 50: 1437. (14) Stiles, D. A., E. E. Bartley, G. L. Kilgore, 1~. W. Boren, R. L. Ott, and J. G. Clark. 1968. Comparative value of a l f a l f a pasture, bromegrass pasture or alfalfa hay for lact a t i n g dairy cows. J. Dairy Sci., 51: 1620.