R.AR.Y OF THL UNIVERSITY Of ILLINOIS G30.7 tto.499-513 cop- 2 ABRICULTURf The person charging this material is responsible for its return to the library from which it was withdrawn on or before the Latest Date stamped below. Theft, mutilation, and underlining of books are reasons for discipli- nary action and may result in dismissal from the University To renew call Telephone Center, 333-8400 URBANA-CHAMPAIGN L16I O-I096 BETTER PASTURES By W. B. Nevens ettVi 505 IVERSITY OF ILLINOIS : AGRICULTURAL EXPERIMENT STATION CONTENTS PAGE PLAN OF EXPERIMENTS 228 ROTATIONAL GRAZING HAS ADVANTAGES 233 More Days on Pasture 233 More Weight Gained per Head and per Acre 233 More Weight Maintained per Acre 236 Bluegrass Suffered Most From Dry Weather 237 CROPS HAVE DIFFERENT MERITS 238 Winter Rye Is Earliest 238 Bluegrass Recovers Best From Close Grazing 240 Alfalfa Makes Excellent Late Pasture 244 Sudan-Soybeans Good Supplementary Pasture 245 Sweet Clover Is Good Midsummer Pasture 251 Bromegrass Can Be Depended On All Season 252 Forage Yields Varied With Year 254 COW URINE IS A GOOD FERTILIZER 254 CHANGES IN PALATABILITY AND FEEDING VALUE 258 WEEDS ARE MAJOR PROBLEM 265 SUMMARY AND CONCLUSIONS.. .269 The gist of the findings from the experiments reported in this bulletin have been published in Circular 553, Supplementing and Improving Dairy Pastures, 8p., 1943. ACKNOWLEDGMENT Grateful acknowledgment is made to other members of the staff for assistance in the planning and execution of this investigation, which was conducted as a joint project in cooperation with the Departments of Agronomy and Animal Husbandry. The late John J. Pieper, Chief in Crop Production, proposed the rotational, or alternate, grazing plan and the crops to be used in it. Many of the details were later carried out almost exactly as he outlined them in the plan drawn up prior to the begin- ning of the field work. Valuable assistance was also rendered by several other members of the Department of Dairy Husbandry, including K. E. Harshbarger, K. A. Kendall, A. F. Kuhlman, E. E. Ormiston, and W. W. Yapp. Urbana, Illinois October, 1944 Publications in the Bulletin series report the results of investigations made or sponsored by the Experiment Station BETTER PASTURES FOR DAIRY CATTLE By W. B. NEVENS, Chief in Dairy Cattle Feeding PASTURE FORAGE, altho it does not by itself supply enough nutrients for high-producing dairy cows, is the most nearly ideal feed for them. During May and June, the peak of the pasture season, milk yields for the country are more than 50 percent higher than at any other time of the year. Fresh, green pasture crops also keep cattle in good health and promote the growth of heifers and young bulls. Pasturing is much cheaper than barn- feeding. For example: In a survey made by the U. S. Department of Agriculture in seven dis- tricts, cows were found to be getting nearly one-third their nutrients from pasture at a cost of only one-seventh the total feed cost. 1 And in a study of specialized New York dairy farms made in 1936, the cost of pasture was found to be only 4 percent of the total milk-pro- duction cost in spite of the fact that cows were pastured for 149 days of the year. 2 Pasturing is also less work than barn- feeding. Not only do the animals do their own harvesting, but it also takes less labor to produce pasture crops than other crops. For example: on the same New York dairy farms mentioned above 154 man-hours a year were required to take care of each cow: 45 man-hours during the pasture season and 109 man-hours during the winter season. On the average farm in the United States it takes about 140 man-hours a year to take care of a cow. 3 Illinois grasses such as bluegrass, redtop, and timothy, however, do not yield enough forage in midsummer to enable dairy cows to maintain good milk yields. Their protein content also declines when they begin to ripen. Cows on such pastures must receive a supple- mentary feed or their milk production falls off and cannot be restored until the next lactation period. 'Cited by Semple, A. T., et al. A pasture handbook. U. S. Dept. Agr. Misc. Pub. 194. 1934. J MiSNER, E. G. Economic studies of dairy farming in New York. N. Y. (Cornell) Agr. Exp. Sta. Bui. 696. 1938. "ELWOOD, R. B., et al. Changes in technology and labor requirements in livestock production: dairying. U. S. Dept. Agr. Bur. Agr. Econ. W.P.A. Re- port No. A-14. 1941. 227 228 BULLETIN No. 505 [October, PLAN OF EXPERIMENTS 1 The object of the experiments reported herein, which were con- ducted at the University of Illinois from 1935 thru 1942, was threefold: 1. To develop a pasture system that would supply ample forage during midsummer. 2. To evaluate alfalfa (Medicago sativa}, Kentucky bluegrass (Poa pratensis), bromegrass (Bromus inermis), winter rye (Secale cereale}, sweet clover (Melilotus alba}, and a mixture of Sudan grass and soy- beans (Andropogon sorghum sudanesis and Sofa max} as pasture crops for dairy cattle. 3. To increase the yield and protein content of Kentucky bluegrass. Highly productive soils used for pastures. In 1935 two tracts of the Dairy Husbandry farm were fenced off into pastures. Both tracts were slightly rolling, with a gentle slope and drainage to the southwest. The tract west of the barns was divided into three fields of 4i/2 acres each and four fields of 2i/4 acres each, and the tract north of the barns was divided into four fields of 41/2 acres each (page 230). The soil, all tillable, was identified as follows: 2 Tract west of the barns. A considerable portion of this field is under- lain by outwash sands. Two soils occur in this outwash area, Brenton silt loam and Drummer clay loam. The highest portions of the field are occupied by Catlin silt loam and the lower portion of the slopes bordering the out- wash by Flanagan silt loam. Tract north of barns. The soil pattern on these fields is rather com- plex. The same soils occur as on the field west of the barn but in a more complex pattern. All are prairie soils. Catlin is subject to erosion, while the major prob- lem on Drummer is drainage. Drummer underdrains well, but its topo- graphic position makes surface drainage slow. The agricultural-value ratings 3 of these soils are: Catlin, 3; Flanagan, 2; Brenton, 2; Drummer, 1. Three fields (Nos. 5, 6a, and 6b) were planted to bluegrass and grazed as a pasture unit each season. All of the remaining fields (except a few not grazed at all some seasons) were planted to a number of different crops, including bluegrass on Field 7a, and grazed 'For reviews of pasture research literature, see references on page 271. 'May 3, 1943, by R. S. SMITH, Chief in Soil Physics and Soil Survey. 3 The number indicates the ability of the soil type to produce the major crops grown in the region, without soil treatment but with the soil in a cleared and drained condition. The scale is 1 to 10, the most productive soil in the state being rated as 1 and the least productive as 10. Experimental pastures. This gently rolling, highly productive land yielded large amounts of forage. It was all tillable and could have grown equally good yields of intertilled crops. in rotation as a comparable unit thru 1941 and as two comparable units in 1942. Lime and manure were principal fertilizers. Both tracts had been limed before the experiments were started. When alfalfa was planted in the spring of 1935, the north tract received another light application of limestone (about 1,000 pounds to the acre). This was applied by using a seed drill with a fertilizer compartment. The last four seasons (1939-1942) four small bluegrass plots (each 2 rods by 2 rods) were treated with cow urine. The only other fertilizer applied during the experiments was barn- Large amounts of barnyard manure were applied to the experimental plots. Adequate fertilization is one of the most effective ways of improving pas- tures. It was responsible in large part for the high yields on these plots. 230 BULLETIN No. 505 [October, yard manure. On the two-crop fields (rye and a combination of Sudan grass and soybeans) it was plowed under with the ripened rye just before the Sudan-soybean mixture was planted. The one-crop fields (alfalfa, bluegrass, bromegrass, and sweet clover) were top- dressed during the barn- feeding season. The usual rate of application was 10 to 12 tons an acre. Forage yields measured by samples. Two sampling sites were located in typical parts of each field, and a small amount of forage was harvested from each location just before each crop was grazed and at monthly intervals thru the season. This not only made possible the cal- BARNS FIELD ARRANGEMENT URINE -FERTILIZED PLOTS 1-4 - 6a 6b 7a 7b Arrangement of experimental pastures culation of acre-yields but also gave much information about the dry- matter and weed contents. In some cases chemical determinations of protein and other substances were made also. Method of harvesting. The forage was harvested by means of grass shears and a metal frame 44 inches square and l^i inches high. A flat bar slid across the frame and guided the shears so that they cut all forage at the same height. The forage was collected in cloth sacks and taken to the laboratory to be sorted by hand into weed and grass portions. Each portion was then resacked in a tared cloth sack, weighed, and dried in a constant- temperature oven at 92 to 100 C. The A method of measuring monthly growth. On the first sam- pling date each season, just before cattle were turned onto pasture, one 44-by-44-inch area was harvested at each sampling location. A 1944] BETTER PASTURES FOR DAIRY CATTLE 231 re-enforced woven-wire cage 48 inches square and 26 inches high was then placed over the area to prevent the cattle from grazing it. (When necessary, two such cages, one above the other, were placed over tall crops like winter rye and Sudan grass.) The forage taken from the two caged areas on each field a month later represented one month's growth and was called the A sample. The frequent cutting, however, sometimes discouraged growth and made A samples not always accurate. So, as a check, the monthly growth was also measured by the B or B-minus-C method. B or B-minus-C method of measuring monthly growth. On the first sampling date of the season a wire cage was placed over a 44-by- 44-inch area of open pasture at each sampling location. The forage from these two caged areas a month later was called a B sample. It represented one month's growth plus whatever forage had been on the open pasture on the previous sampling date. The amount of forage from two 44-by-44-inch areas on open pas- ture on any given date was called a C sample. One month's growth, therefore, was represented by the current B sample minus the C sample of the previous month. The cage was then replaced over the B area to make next month's A sample. The A method of measuring monthly yield. As the forage for each' sample was harvested from %620 of an acre (two 44-by-44-inch areas), the weight of the A sample was multiplied by 1620 to get the monthly yield per acre. The seasonal yield was obtained simply by adding the monthly yields as determined by the A samples. Taking samples of forage. The men are taking a C sample of rye from open pasture. The near cage will be placed over the harvested area to make next month's A sample. The cage in the background protects next month's B sample. 232 BULLETIN No. 505 [October, The B-minus-C method of measuring monthly yield. -To get the monthly yield per acre by the B-minus-C method also called the dif- ference method the C sample of the previous month was subtracted from the B sample of the current month and the difference multiplied by 1620. Final computing of yearly yields. In the case of bluegrass and bromegrass, yields obtained by the A method tallied with those ob- tained by the B-minus-C method. For such crops as sweet clover and soybeans, however, only the B-minus-C method was satisfactory: the low cutting of sweet clover during its second year killed the plants, and the low cutting of soybeans either killed them or greatly retarded their growth. The monthly and seasonal yields cited in these experiments were computed from whichever of the two methods was better adapted to the purpose or, in some instances, from the average of the two methods. Grazing used as final test of pastures. A pasture cannot be judged just by sampling tests. The only sure way to find out whether the crop is palatable and will provide enough digestible nutrients thru the season is by grazing it. Actual grazing is also the only way to find out whether the new pasture will cause physical upsets such as bloat and diarrhea or impair the flavor and the composition of milk. The experimental pastures were therefore tested by grazing cattle on them as well as by sampling. Two systems of grazing the bluegrass system (bluegrass alone) and a rotational system (various crops in succession, each crop usually being pastured a week or two at a time) were tried out. The two systems were rated according to (1) the number of days they were pastured, (2) pasture days supplied per acre, (3) weight gained by cattle per head, (4) weight gained per acre, and (5) weight maintained per acre. 1935-1936. 1935 and 1936 were devoted mostly to studying methods of grazing research. In 1935 the experimental animals were milk cows ; in 1936 they were milk cows and yearling heifers. Supplementary feed- ing was also practiced. 1937-1942. Two variables in results the change in milk yield and the change in weight plus the variable amount of supplement fed made it hard to evaluate the pasture crops accurately for the two previous years. The 1937-1942 experiments were therefore simplified so there would be just one variable the change in weight. Only heifers six months to two years old were pastured and no supplement was fed except salt. 1944] BETTER PASTURES FOR DAIRY CATTLE 233 From 1937 thru 1941 the heifers were divided into two groups each season. Group I was pastured on a rotational system, being moved from one plot to another as the different crops were ready to be grazed. Group II was pastured exclusively on Kentucky bluegrass. In 1942 two separate systems of rotational grazing were tried out. Two separate groups of heifers (I and IA) were therefore pastured on the rotational crops. Another group (II) was pastured on the Ken- tucky bluegrass. ROTATIONAL GRAZING HAS ADVANTAGES The rotational system proved superior to bluegrass alone because: (1) the rotational season was longer; (2) heifers on the rotational system gained more weight both per head and per acre; and (3) the rotational system maintained more weight per acre (Table 1). ^ More Days on Pasture The rotational system provided an average of 149 days of pasture a season; the bluegrass system, 132. The season was usually longer for the rotational system because (1) heifers could be turned to pasture earlier in the year (Table 1), and (2) the crops withstood dry weather better than bluegrass did. Pasture days per acre were figured by multiplying the number of days on pasture by the number of heifers and dividing by the area of the pasture in acres: Days on pasture X Number of heifers Pasture days per acre = 7 ; Area of pasture in acres The yearly average for bluegrass alone was 185 pasture days an acre; for rotational crops, 166. These figures, however, do not indicate how much forage the heifers on either system ate and are therefore of only nominal value. More Weight Gained per Head and per Acre Heifers on rotational grazing gained a yearly average of 36 pounds a head more than heifers on bluegrass alone. The average yearly gain per acre was also larger (20 pounds more) for the rotational system than for bluegrass. Only once, in 1939, were the gains of heifers on rotational grazing unsatisfactory. Early that season, because of dry weather, the heifers had to be taken off pasture and fed in drylot for nearly four weeks. 234 BULLETIN No. 505 TABLE 1. GRAZING TRIALS, 1937-1942 [October, Pasture system Field Total Heifers Number of Pasture Live weight gained Live weight pasture J^TIi days on days per maintained area p pasture acre Per head Per acre per acre 1937 I Rotation system (May 7-Sept. HI) Alfalfa acres 9 4.50 20 52 231 lb. lb. tons 7A 2 25 20 21 187 7B 2.25 20 8 71 Sudan-soybeans 7B, 8 b 6.75 20 56 166 8 4 50 b 20 l b Totals and averages 13 5 20 138 204 160 237 77.9 12.00 20 138 230 160 267 87.6 II Bluegrass alone . . . 5,6 9.00 10 117 130 128 142 64 . 6 (May 7-Sept. 1) 1938 I Rotation system (Apr. Si-Sept. SI) Alfalfa 1, 9A 6 75 16 48 5 115 7A 2 25 16 37 ,263 Winter rye . .. 7B, 8 6.75 16 17.5 ' 41 Sudan-soybeans . .. 7B, 8, 9B 9.00 d 16 51 91 Totals and averages Acre basis 16 154 137 135 120 70.5 Utility basis 17.25 16 154 143 135 125 73.7 II Bluegrass alonei . . . (Apr. 21-Oct. 5) 5,6 9.00 10 167 186 184 205 71.2 1939 I Rotation system (May 7-Sept. 0) Bluegrass . ... 7A 2 25 10 32 142 Winter rye . . . 7B, 9A 4 50 10 27 60 7B,9A,9B 6 75 10 53 79 Totals and averages Acre basis 9 10 112' 124 80 89 57.6 Utility basis 8 25 10 112 f 136 80 97 62 8 II Bluegrass alone .... 5, 6 9 00 10 t> 134 155 85 100 58.0 (May 7-Sept. 17) 1940 I Rotation system (May S-Sept. 25) Alfalfa 3 4 50 h 18 10 25 41 Bluegrass .. 7A 2 25 18 3 14 114 Winter rye 4, 7B 6 75" d 19 26 73 Sudan-soybeans Sweet clover . .. 4, 7B, 9 11.25 8 4 50' 18 19 76.25 19 5 122 82 Totals and averages Acre basis 22 5 18 3k 146 119 165 134 47.7 Utility basis 17 25i 18 3 k 146 155 165 175 62.2 II Bluegrass alone .... 5, 6 9 00 14 90 140 60 93 43.1 (May 6-Aug. 5) (Table is concluded on page 235) In 1938 the heifers on rotational crops gained 135 pounds a head; heifers on "bluegrass alone," 184 pounds a head. Much of this remark- able "bluegrass" gain, however, which was 56 more pounds per head than during the second-best bluegrass year, 1937, was due not to blue- 1944] BETTER PASTURES FOR DAIRY CATTLE 235 TABLE 1. GRAZING TRIALS, Concluded Pasture system Field Total Heifers Number f Pasture Live weight gained Live weight pasture nas (., lre ,j days on days per maintained area p pasture acre Per head Per acre per acre 1941 I Rotation system (May 1-Oct. 16) Alfalfa Bluegrass Bromegrass Winter rye Sudan-soybeans Totals and averages Acre basis Utility basis II Bluegrass alone . . (May 7-Oct. S3) 7A 1.2 7B, 9A, 9B 7B, 9A, 9B 5,6 acres 4.50 1 - 2.25 9.00 6.75 6.75" 22.5" 21.00 h 9.00 20 20 20 20 20 20 20 22 16.5 J80.5 12 37 168 168 170 98 147 179 35 110 149 160 264 120 1 120 115 H>. 107 114 178 62.7 67.4 68.8 1942 I Rotation system (Apr. n-Od. X) Bromegrass-alfalfa . . . 3 4.50 13 7 56 171 Bromegrass 1,2 8.50 13.5 91 145 Winter rye 4 4.50" f4.0 17 53 52 Totals and averages Acre basis 17.5 13.6 164 127 119 92 64.4 Utility basis 14.50 13.6 164 154 119 111 68.2 IA Rotation system (Apr. tt-Oct. t) Bromegrass 8 45 10 100 220 Winter rye .. 7B, 9A 4.5 10 28 62 74 Sudan-soybeans .. 7B, 9A 4.5 10 36 80 Totals and_ averages Acre basis 9.0 10 164 181 123 136 71.0 II Bluegrass alone 5, 6 90 14 SP 150 238 75 119 75.8 (May 6-Oct. I) Average per year, 1937-1942 Rotation systems (acre basis) 149 149 129 131 64 6 Rotation systems (utility basis) 149 166 129 146 70.4 Bluegrass alone 138 185 108 140 63.6 Bluegrass alone, omitting 1938i 132 185 93 126 62.1 The Sudan-soybean mixture was planted on the same field as rye. b The sweet-clover crop was a failure. After one day's pasturing, the field was planted to Sudan grass and soybeans. "Because of the failure of the sweet clover, it was estimated that Field 8 was utilized at only two-thirds of its capacity. ''Field 9B was not used for rye pasture this season. Pasture days per acre for rye averaged 56; for Sudan grass and soybeans, 108. A field planted only to Sudan- soybeans was estimated to be utilized at only two-thirds of its capacity. 'Because of low rainfall, the heifers on rotational grazing were fed silage and hay in drylot from June 29 thru July 23. *At the beginning of the season, Group II consisted of 14 heifers. Four were removed on June 7 because the grass was insufficient, and one was removed August 1 because of illness. h lt was estimated that the first cutting of alfalfa for hay or silage removed one-third of the pasturage for the season. 'As sweet clover was not pastured after July 13, it was estimated that Field 8 was utilized at only half its capacity. 'See notes d, f, and g above. k One heifer was removed June 19. 'Heifers gained an average of 144 pounds per head from May thru September 19 but lost 24 pounds per head during the period of unusually heavy rainfall from September 19 to October 16. "Gain to September 19 was 128 pounds an acre. "This field was not used after the rye season ended and was therefore rated at only one-third of its pasture-producing capacity. "One heifer was removed August 4. pAt the beginning of the season 20 heifers were pastured on bluegrass alone. Six were removed on July 1 and eight more on August 26. iThe remarkable gains that the heifers on bluegrass alone made this season were due, in great part, to the volunteer sweet clover which sprang up in the bluegrass pastures. grass alone but to volunteer sweet clover. Also seasonal rainfall, till September, was above normal and unusually well distributed (Table 2). In order to make a fair comparison of the two pasture systems, there- fore, the 1938 figures for bluegrass alone must be discounted. This has been done thruout this report. 236 BULLETIN No. 505 [October, TABLE 2. WEEKLY RAINFALL AT URBANA DURING THE GRAZING SEASONS 1935-1942 (Inches) I 1 ;35 1< J36 1< J37 1938 1939 1940 1941 1942 April 1-8 1 .10 1 .56 2 .34 2.92 .70 .82 1.37 2.11 April 9-15 Sit Of) 61 2.90 1.04 .66 .80 April 16-23 .23 .25 1 .49 .14 1.72 1.27 2.18 .20 April 24-30 74 ? 30 Q6 .36 .07 .83 .21 May 1-8 . 3 .60 1 .42 1 .36 .40 .26 1.50 2.08 .85 May 9-15 1 .58 .46 ,01 .64 .06 .55 .89 2.48 May 16-23 1 .01 1 00 1 .22 3.08 .56 1.31 .89 .24 May 24-31 74 1 06 .85 .31 1.17 .08 June 1-8 .31 .26 3 .13 .64 .47 1.43 .58 1.46 June 9-15 .13 .09 .82 1.60 3.61 1.40 3.69 1.46 June 16-23 June 24-30 2 39 .81 01 .11 60 ,88 3.43 1.19 .90 .63 1.58 .36 1.56 .42 .58 July 1-8 1 n 10 1.36 .99 1.79 2.81 July 9-15 84 43 1 59 .10 .80 .02 1.05 July 16-23 64 10 2.46 .74 .02 1.00 .30 July 24-31 92 8? 74 2.53 .13 .46 .78 August 1-8 1 .30 .56 .19 1.77 1.43 .29 .05 .16 August 9-15 .80 1 58 ,44 .11 1.06 .33 1.12 .67 August 16-23 ,20 .48 17 1.55 3.89 .52 .89 .18 August 24-31 06 92 .85 1.66 1.58 1.57 September 1-8 1 11 ,77 -OS .04 2.19 .83 September 9-15 1 11 1 38 3 12 .24 .48 1.21 .02 September 16-23 01 07 .59 .11 2.06 September 24-30 1 71 3 61 ? '>? .17 1.51 .95 October 1-8 04 48 8? .93 .99 3.61 .10 October 9-15 .44 .86 .33 .71 1.16 .42 1.11 .23 October 16-23 37 QQ ? 77 1.79 2.44 .16 October 24-31 80 1 16 .45 .52 1.85 1.87 Total for 7 months .. 25 .51 21 .62 25 .89 28.17 23.72 19.69 35.17 24.55 Total for year 37 .21 35 .09 37 ,65 42.77 38.05 30.60 42.87 42.38 More Weight Maintained per Acre Yearling heifers are usually expected to gain from % to 1 pound daily until they approach nearly full size. Some heifers in these trials, however, already weighed 800 to 1,000 pounds at the beginning of the pasture season. The gain of groups with several such heifers was, of course, rather small and not a complete measure of the value of the pasture system. Not only the weight gained but also the weight main- tained must therefore be taken into account. On the whole, rotational crops maintained more weight on the heifers per acre of grazing than bluegrass alone. The rotational system carried more weight in four seasons (1937-1940) and the bluegrass system carried more weight in two seasons (1941 and 1942). The weight maintained per acre was computed by multiplying the average weight (average of three consecutive daily weights taken at monthly intervals) by the number of days on pasture and dividing by the number of acres in the pasture system: Live weight maintained = Average A Hve weight X DayS " pasture Acres in pasture system 1944] BETTER PASTURES FOR DAIRY CATTLE 237 Bluegrass Suffered Most From Dry Weather The heifers always gained more weight when rainfall was abun- dant and well distributed. Dry spells during the season reduced the total yields of both the bluegrass and the rotational systems. All the other crops, however, proved more resistant to dry weather than did bluegrass. The best example of the relative staying power of the two pasture systems during dry weather is found in the 1940 test. That year, altho the rotational season lasted 146 days, bluegrass could be pastured only 90 days. Heifers on the rotational system gained 165 pounds a head; those on the bluegrass gained only 60 pounds a head. The gain per acre for rotational crops was 175 pounds; for bluegrass, only 93 pounds. Bluegrass pastures need supplementing in midsummer. This pasture was almost bare on August 8, 1936, a season of low rainfall. Compare with the alfalfa pasture shown on page 244, photographed the same day. Occasionally well-distributed showers keep bluegrass pastures producing well in mid- summer, but usually barn feeding or supplementary pastures are needed. Bluegrass was at its best when rainfall was heavy and frequent. In 1941, for example, the very heavy rainfall in September and October made it practicable to pasture bluegrass until October 23. The gain per acre that year was 178 pounds for bluegrass, 114 pounds for rota- tional crops. These late heavy rains not only muddied the bromegrass fields but evidently caused less forage to be eaten, for the heifers on the rotational system lost 24 pounds a head during the last month of grazing. 238 BULLETIN No. 505 [October, CROPS HAVE DIFFERENT MERITS It is to the advantage of a dairy farmer to plan a pasture system that will provide an ample supply of nutritious and palatable forage as long as possible. Individual crops should be rated according to (1) their feeding value, (2) palatability, (3) economy of produc- tion, (4) amount and timeliness of yield, (5) length of pasture season, (6) resistance to drouth, weeds, and tramping, (7) likelihood of causing bloat or other upsets, and (8) adaptability to soil and climate. Winter Rye Is Earliest Winter rye is a highly palatable early pasture crop. It has a large yield (Tables 3 and 4) and is practically free from weeds. It can be planted in the fall after corn for silage is harvested or Sudan grass pastured, and plowed under in the spring in time to plant corn or Sudan grass again. Rye, however, develops so rapidly when the weather becomes warm that not all the forage can be used and much is lost by tramping. As ripening nears, palatability declines greatly. Since the sod is loose, it cannot be pastured immediately after a heavy rain. Sometimes, too, rye impairs the flavor of milk, altho this difficulty can be overcome by feeding hay in addition and by pasturing cows on the rye only after they have been milked and only for a few hours a day. Winter rye (1.5 bushels to the acre) was planted with a grain drill late in September or early in October after the pasturing of Sudan grass. As it was unable to get a good start in the fall, it was less Winter rye was first crop ready for grazing. Seeded the previous autumn, it made good early pasture. Cattle were turned onto it about May 1 in most years, as early as April 15 one year. Picture was taken on May 10. 1944] BETTER PASTURES FOR DAIRY CATTLE 239 Winter rye makes extremely rapid growth. Under favorable conditions growth is so rapid that it is hard to utilize it. In its early stages winter rye combines two qualities of good dairy feed: high palatability and high pro- tein content. vigorous in the spring than rye planted in late August or early Sep- tember would have been. When the crop residue on the field was small, a satisfactory seed- bed was prepared by disking instead of plowing. Rye was the first crop to be pastured under the rotational system and was usually ready a week or two before bluegrass (Table 1). It was grazed either until forage gave out or until it began to mature and Too far advanced for good pasture. By May 9 hot weather had caused this rye to develop so rapidly that the cattle could not eat it fast enough to prevent its heading out. As ripe rye is unpalatable, much forage went to waste. This crop was followed by Sudan and soybeans. 240 BULLETIN No. 505 [October, TABLE 3. DRY-MATTER YIELDS OF FIVE PASTURE CROPS ON FIRST SAMPLING DATES, 1937-1942 (Pounds per acre) Crop May 6, 1937 April 26, 1938 May 5, 1939 May 2, 1940 April 29, 1941 April 23, April 30, 1942 1942 Alfalfa 1 240 580 920 540 Bluegrass 690 690 460 300 590 600 1 690 1 030 Sweet clover 500 .... 2 040 2 530 1 710 990 1 120 2 660 the heifers would not eat it anymore. The longest season was 28 days, April 22 thru May 19, in 1942. The average season was 19 days. In these experiments barnyard manure was spread on the fields as soon as rye pasturing was discontinued, and the land was then plowed and planted to a mixture of Sudan grass and soybeans. Bluegrass Recovers Best From Close Grazing Bluegrass usually makes excellent pasture in late spring. When green it supplies very palatable forage, and it recovers from too close and too early grazing better than other pasture crops. It is also a good emergency pasture after heavy rainfall, when grazing would injure crops that do not form a firm sod, and is a good reserve pasture when cattle are being accustomed to a legume. Bluegrass pastures given rea- sonable care can be maintained over an indefinite period of years with but little expense for labor and seed. As bluegrass approaches maturity, however, it declines markedly in yield and protein content and palatability. Usually the amount and quality of forage supplied during July and August are too small and TABLE 4. ANNUAL DRY-MATTER YIELDS OF FIVE PASTURE CROPS (Pounds per acre) Crop 1937 1938 1939 1940 1941 1942 Alfalfa 5 900 5 950 6 600 6 700 Bluegrass . . 2 750 2 750 2 950 3 600 4 450 Bromegrass 7 150 5 550 Winter rye 2 050 3 650 4 150 4 100 2 700 3 100 Sudan-soybeans . . 4 600 4 850 5 100 5 900 8 800 6 500 Total for rye and Sudan-soybeans* 6 650 8 500 9 250 10 000 11 500 9 600 The Sudan grass and soybean mixture followed winter rye on the same field in the same pasture season. b lncludes volunteer sweet clover. 1944] BETTER PASTURES FOR DAIRY CATTLE 241 too poor to support milk yields of high-producing cows. Production drops and cannot be restored, a situation that causes great loss. A short- age of feed for growing heifers for a time is much less serious, as normal gains in weight can be restored after a period of no gains. Another disadvantage of bluegrass is that the season for it begins later, the forage contains more weeds, and the yearly yield is lower than that of most other pasture crops grown in central Illinois. Each year except in 1942 a small bluegrass field (7a) was pastured immediately after rye in the rotational system. The field was also used intermittently thru the grazing season for an emergency and reserve pasture. If winter rye or the mixture of Sudan grass and soybean had been pastured right after a heavy rain, the ground would have been severely tramped and the crop injured. After heavy rains, therefore, heifers that were on rye or Sudan-soybeans were transferred to the bluegrass field for a day, sometimes for two or three days. The bluegrass field also served as a paddock and reserve while heifers were being accustomed to alfalfa and sweet clover. For the first few days heifers were pastured on the legumes for periods ranging from only half an hour to an hour and spent the rest of the day on the bluegrass field. The days on pasture and the pasture days per acre credited to the 2i/2-acre bluegrass field in Table 1 have small significance, however, because the field sometimes furnished little or no forage. Bluegrass makes good reserve pasture. From the end of the rye season till the beginning of the Sudan-soybeans season, bluegrass served as a good reserve pasture. It was also good emergency pasture whenever heavy rains made the sod of winter rye or Sudan-soybeans too soft to pasture for a day or two. Picture was taken on June 15. 242 BULLETIN No. 505 [October, Effect of good management. The experimental bluegrass pas- tures were well managed. Barnyard manure was applied regularly. Cattle were turned to pasture only after the grass had made a good start and were removed in the fall in time to permit late fall growth of the grass. Large weeds, such as dock and thistles, were dug out by Bluegrass responds to good management. This well-managed pasture was supplying an abundance of forage on July 4, when most bluegrass pastures are bare. Cattle were turned on bluegrass only after it had made a good start and were taken off in time to permit late fall growth. hand. In seasons of low rainfall cattle droppings were broken up and spread by a tractor-drawn harrow. Attempts were also made to adjust the number of cattle to the amount of forage. As a result of these management procedures, the experimental blue- grass pastures not only supplied twice as much forage as comparable pastures poorly managed, but the forage was also much higher in feeding value. Alternate versus continuous grazing of bluegrass alone. Field 5 was grazed continuously every season. During 1937, 1938, and 1939 Fields 6a and 6b were grazed alternately at two-week intervals. But no difference in yield or other supposed benefits of alternate grazing were observed; so after 1939 the alternate grazing was discontinued. One reason that alternate grazing did not benefit these experimental bluegrass pastures may have been that they were not stocked heavily, 1944] BETTER PASTURES FOR DAIRY CATTLE 243 Not a good early-season pasture. A great disadvantage of bluegrass as the sole pasture crop is its failure to produce enough forage early in the season. Compare this pasture with the rye shown below. Pictures were taken on the same day, April 26. for rotational grazing did greatly benefit Sudan grass and other crops injured by close grazing. During the rest periods growth was hastened, and rains, which washed some of the cattle excrement into the soil, freshened the forage. Abundant winter rye on April 26. Winter rye furnished nearly as much for- age (dry-matter basis) during the 2- to 4-week period it was pastured as a comparable field of bluegrass did during the entire season. 244 BULLETIN No. 505 [October, Alfalfa Makes Excellent Late Pasture Alfalfa is high in yield (Table 4) and palatability and resists dry weather well. If pastured in the spring, however, it is likely to cause bloat; and in areas where it is subject to plant diseases, the stand be- comes thin and weedy within two or three years. In 1937 and 1938 alfalfa was pastured over a period of about 3 1/2 months from about the first of June to the middle of September. Such early pasturing was inadvisable, as some animals, despite careful watching, developed mild cases of bloat. In 1940 and 1941, therefore, the first crop was removed for hay, and pasturing was begun in late June or early July. Alfalfa is resistant to dry weather. Altho lack of rainfall reduces yields to some extent, the experimental alfalfa pastures continued to produce well during dry weather. Compare with bluegrass (page 237) on the same date, August 8, 1936. The alfalfa-bromegrass mixture seeded in the fall of 1939 pro- duced a crop that consisted largely of alfalfa in 1940 and 1941. By 1942, however, the crop was composed of nearly equal parts of alfalfa and bromegrass. Alfalfa furnished palatable green forage in the late summer of 1937 and thru most of the summer of 1940, when bluegrass furnished no feed at all. Alfalfa proved satisfactory for two seasons after the first seeding. The third season bacterial wilt weakened the stand so much that the weeds almost overran the alfalfa and the field had to be reseeded. (In order to control disease other crops should usually be grown for a few years before alfalfa is replanted in the same soil.) 1944] BETTER PASTURES FOR DAIRY CATTLE 245 Reseeding was a serious disadvantage in these experiments where pasture space was limited because ( 1 ) the seed cost per acre was high, (2) pasture was lost during the year of reseeding, as spring planting required the use of a nurse crop and late-summer planting required summer fallowing to control weeds. Reseeding is not, however, a serious disadvantage on farms where crops are grown in rotation, for the alfalfa can be planted either in Alfalfa seeding simplified. The seed passes from the seed box thru the tubes and between the corrugated rollers. The machine also helps to prepare the seedbed and turns a light covering over the seed, all in one operation. the spring with a grain like oats or in late summer after an early pasture crop like rye, an early hay crop like soybeans, or an early canning crop such as peas. Sudan-Soybeans Good Supplementary Pasture A mixture of Sudan grass and soybeans has several advantages from a pasture standpoint. The main advantages are (1) high yields (Table 4) ; (2) abundance of forage in midsummer; (3) high palata- bility, even of coarse stems, and (4) readiness for pasturing within a short time after seeding (usually 5 to 6 weeks). The mixture is ex- cellent for supplementary use with perennial grass or legume pastures. It is unwise, however, to use this crop as a staple pasture because of (1) its short season; (2) its loose sod, which cannot be pastured for a day or two after a heavy rainfall; (3) rapid growth, making it diffi- cult to use all forage and causing much to be lost thru the tramping of stock; (4) danger of prussic-acid poisoning; (5) slow recovery after close grazing; and (6) annual expense of seeding. 246 BULLETIN No. 505 [October, Sudan grass and soybeans were planted as soon as possible after rye pasturing, at the rate of 25 pounds of Sudan grass and 1.5 bushels of soybeans to the acre. 1 The seeds were mixed on a clean floor and then planted in one operation with a grain drill. If the land had not been planted to soybeans for several years, the soybean seed was in- oculated. To avoid prussic-acid poisoning, the crop was not grazed until it was at least 18 inches high. Seeding Sudan-soybean mixture in late May. The grain drill was used to plant the mixed seed in one operation. As soon as the winter rye was ex- hausted or too advanced to be eaten readily, the field was plowed and planted to this quick-growing forage. Grazing began between June 28 and July 7, except in 1939, and ended between September 16 and 25. In 1939, because of the long rye season (27 days) and the heavy rains during the second week of June, planting was postponed until June 21, and grazing did not begin until July 24. The average Sudan-soybean season was 75 to 80 days. The longest season was 90 days, June 28 thru September 25, in 1940. A plant disease attacked the Sudan grass and spotted the leaves in several seasons. This spotting, or rusting, was worst in 1942. The grass, however, did not lose all its palatability, for the heifers con- tinued to eat it. Effect of good management. Mowing or close grazing retards the further growth of a Sudan-soybean mixture, especially when the crop has headed out and the stalks have become coarse. If, however, the crop is rested as soon as cattle have eaten the leaves and upper stalks, it 'Sudan grass was planted without soybeans in 1939. Sudan and soybeans produce a crop in a short time. This growth had devel- oped by June 29, the crop having been planted the latter part of May. Pas- turing was usually begun during the first or second week of July. recuperates, puts out a new set of leaves, and is ready in three or four weeks for a second grazing. Highest yield. A field planted first to rye and then to a mixture of Sudan grass and soybeans yields much more forage than a com- parable field planted to a single pasture crop (Table 4, page 240). But even if there were no other disadvantages, the combination still could not be used as a pasture unit because of the disuse of the 2-crop field (for at least a month) between the end of the rye season and the beginning of the Sudan-soybean season (Table 5, page 249). Sudan-soybean mixture on August 20. The forage provided by this mixture is most abundant during the last half of the pasture season, when bluegrass and similar grasses are at their worst. 248 BULLETIN No. 505 [October, This field of Sudan and soybeans is due for a rest! The cattle have eaten most of the leaves and the upper parts of the stalks. The field in the back- ground has been rested and is now ready for a second grazing. Picture was taken August 20. Abundance of Sudan grass and soybeans on September 8. At this date the bluegrass pasture was dry and bare. Altho the fungus disease that attacks Sudan grass reduced forage yields some years, they were still satisfactory There are few insect enemies of this grass. 1944] BETTER PASTURES FOR DAIRY CATTLE 249 TABLE 5. SEASONAL DISTRIBUTION OF DRY-MATTER YIELDS OF FOUR PASTURE CROPS (Percent of annual dry-matter yield harvested during each sampling period) Crop April 23 May 25 June 17 July 16 Aug. 19 Sept. 11 to to to to to to May 9 June 9 July 6 Aug. 12 Sept. 1 Sept. 30 Alfalfa _ 1937 21 23 16 24 9 7 Bluegrass 1937 25 35 21 13 2 4 1938. 16 15 15 19 25 9 1939 17 31 28 6 18 1940 10 55 19 4 12 1941 16 24 14 18 10 18 1942 13 22 26 18 12 9 Average 1937-1942 16 30 21 13 12 ' 12 Bromegrass Average 1941-1942 26 29 11 20 5 9 Sudan-soybeans Average 1937-1942 14 42 25 19 Sudan-soybean pasture resists drouth. Despite the low rainfall in 1940 this field made good pasture until September 25. The bluegrass fields dried up and could not be pastured at all after August 5. 250 BULLETIN No. 505 [October, On fertile soils Sudan grows tall. It is not unusual for this grass to reach a height of 7 to 9 feet. This picture was taken on August 17, three days before the one on the pre- ceding page. Volunteer sweet clover in bluegrass. Altho volunteer sweet clover sprang up in this pasture, the yield of bluegrass remained about the same as usual. The total yield of forage was almost doubled. Sweet Clover Is Good Midsummer Pasture Sweet clover has a high yield, resists drouth, and provides much feed during the summer slump in bluegrass. But, like other highly suc- culent legume crops, in its early stages it is apt to cause too laxative a condition in animals. After the end of the rye season in 1940 grazing was alternated be- tween sweet clover and bluegrass until the Sudan-soybean pasture was ready. The sweet clover was not used until about June 1, however, as it was too high in water content to make good pasture earlier. On May 2, when the dry-matter content of the bluegrass was 25 percent, the dry-matter content of the sweet clover was only 11 per- S\veet clover on June 1. Grazing was alternated between bluegrass and sweet clover from about June 1 until the Sudan-soybean pasture was ready, about July 10. Sweet clover had too high water content to be pastured earlier. Luxuriant growth of bromegrass on June 2. Altho the grass is headed out, it is still green and palatable. The leaves stay green even after the seed ripens. cent (Table 12, page 264). Even on June 2, when the dry- matter con- tent of bluegrass was 30 to 36 percent, the dry-rnatter content of sweet clover was only 15 percent. Sweet clover, however, was not used enough in these experiments to justify a full discussion of its merits and demerits as a pasture crop for dairy cattle. Bromegrass Can Be Depended On All Season Bromegrass is a dependable source of feed during the entire season ; it is an especially good crop when pasture space is limited and a fixed Seeding bromegrass. The seed of bromegrass is so large and light that ordi- nary seeding implements are not satisfactory. The two men in the back are operating hand seeders, and the double corrugated roller turns a light cov- ering of soil over the seed. 1944} BETTER PASTURES FOR DAIRY CATTLE 253 Bromegrass provides green forage in August. Unlike bluegrass and redtop and most other perennial pasture grasses, brome stays green and provides good forage thruout the summer. Picture was taken August 8. number of cattle must be fed. Midsummer forage is green despite less- than-normal rainfall. Also, it is less expense as well as less work to seed and establish a perennial like bromegrass than an annual like Sudan grass or a biennial like sweet clover. If, however, it must compete with weeds or fast-growing crops like oats and wheat, bromegrass is slow to establish itself. If it is not grown Bromegrass establishes itself quickly. It spreads thru root growth as well as by seed and soon develops a firm sod that resists tramping. Picture was taken on August 20, just a year after the field was seeded. 254 BULLETIN No. 505 [October, with a legume like alfalfa or sweet clover, the yield usually falls off. Also, bromegrass is slow to recover from close pasturing, and close mowing is apt to kill young plants. Three fields (Nos. 1, 2, and 8) were planted to bromegrass alone, and yields were well maintained by the heavy application of barnyard manure. Bromegrass was also planted with alfalfa on Field 3 (see page 230). At the beginning of the season bromegrass furnished more forage than either bluegrass or alfalfa, as shown by Table 3, page 240. The yield was good in midsummer despite heat and drouth, and the leaves remained green even when a seed crop matured. Bromegrass, it was found, should not be pastured when it is less than 6 inches tall. Likewise clipping, if to control weeds, should not reduce the height of the plants to less than 6 inches. Clipping to re- move headed seed stalks is unnecessary. ( Forage Yields Varied With Year Yearly yields in these tests (Table 4, page 240) varied mainly be- cause of differences in rainfall and temperature. There were other reasons, however, for yearly variations: (1) the planting dates of the annual crops winter rye, Sudan grass, and soybeans were not the same each year; (2) grazing was more intensive some seasons; (3) stands of crops, especially bromegrass and alfalfa were thicker some years than they were other years; and (4) each application of barnyard manure tended to restore or increase the fertility of the soil. COW URINE IS A GOOD FERTILIZER The urine of cows is a valuable source of both nitrogen and potas- sium. From one-third to one-half of the nitrogen and at least three- fourths of the potassium that a dairy cow excretes is in her urine. For every ton of feces she excretes, she urinates 12 to 16 pounds of nitrogen and 10 to 12 pounds of potassium. Cow urine, however, has only a trace of phosphorus. From 1939 thru 1942 cow urine was applied to four plots, each 2 rods square, which were laid out in a well-sodded and nearly level part of a bluegrass field (see pages 230 and 255). The plot* were separated from one another by 1-rod borders. No fencing other than short posts at the four corners of each plot were used, so that cattle had equally free access to all plots and to the rest of the field. 1944] BETTER PASTURES FOR DAIRY CATTLE 255 Bluegrass plots treated with cow urine. The plots that received the heaviest applications (Nos. 3 and 4) have been most closely grazed. The grass on these plots had a higher protein content than the grass on the other plots. The urine used contained about 1 percent of nitrogen and 1 per- cent of potassium (Table 6). It was collected from high-producing dairy cows into clean pails during the act of urination. Within a few hours it was applied to the plot by means of garden sprinkling cans. Whenever the moisture in the surface soil was low, the urine was mixed with an equal volume of water; otherwise it was applied undiluted. The rates of application at each treatment were: Pounds Pounds an acre an acre Plot 1 1,250 Plot 3 3,750 Plot 2 2,500 Plot 4 5,000 About once a month samples were taken from the four treated plots and from an untreated area. The grass portions were then analyzed to determine their dry matter and protein contents. Forage Yields Increased All treated plots produced much more forage than the untreated remainder of the field. Also plots that received heavy applications tended altho there were some exceptions to have higher yields than plots that received light applications (Table 7). As this treatment of the four plots with cow urine was in addition 256 BULLETIN No. 505 [October, TABLE 6. NITROGEN AND POTASSIUM IN SAMPLES OF Cow URINE APPLIED TO BLUEGRASS PLOTS (Percent) Date of application Nitrogen Potassium Date of application Nitrogen Potassium April 8. May 11 June 12 June 8, April 14 1939 1 08 07 11 29 25 1 1 1 1 12 22 91 04 07 May 17, 1941 .85 1 1 1 00 05 86 03 1939 . . 1 June 10, 1941 .. 1.12 1939 1 May 7 1942 .92 1940 . . 1 Average . . 1.09 , 1941 . . 1 to the annual treatment with barnyard manure (pages 229-230), it is evident that a good way to improve bluegrass pasture is by saving as much as possible of the urine excreted during the barn- feeding season and applying it to pastures when grass is making its early growth in the spring. Some progressive farmers have drains which carry the urine from gutters in the stable to storage cisterns or tajiks. Protein Content Increased In most instances cow urine increased the protein content of blue- grass, and the more urine was applied the richer the grass was in protein (Table 8). Exceptions occurred when pastures were nearly dormant in August and September of some seasons. A samples had a higher protein content than B samples. This was probably because the A samples represented only new growth, while the B samples included both new growth and older forage. TABLE 7. YIELDS OF TOTAL FORAGE AND OF GRASS ON BLUEGRASS PLOTS FERTILIZED WITH DIFFERENT AMOUNTS OF Cow URINE (Pounds of dry matter per acre) Year PlotO No treatment Plot 1 Light treatment Plot 2 Medium treatment Plot 3 Heavy treatment Plot 4 Very heavy treatment Forage including weeds 1939... 2 580 3 300 3 500 4 050 4 200 3 760 3 130 3 810 4 530 4 110 3 900 3 740 3 560 3 860 4 520 3 920 4 600 4 260 4 840 4 370 4 520 1940 2 190 1941 2 850 1942 3 010 Average 2 660 Grass portion 1939... 2 320 3 140 3 400 3 600 3 450 3 400 3 090 3 690 4 080 2 980 3 460 3 440 2 980 3 400 2 740 3 140 4 310 3 760 4 280 2 920 3 820 1940 2 040 1941 2 370 1942 2 170 Average , 2 220 1944] BETTER PASTURES FOR DAIRY CATTLE 257 TABLE 8. PERCENT OF DRY MATTER AND OF PROTEIN IN BLUEGRASS TREATED WITH DIFFERENT AMOUNTS OF Cow URINE (Averages of four seasons, 1939-1942) Plot Treatment April 29- May 5 May 25-June 7 July 2-16 August 1-19 September 11-29 Dry matter Protein in dry matter Dry matter Protein in dry matter Dry matter Protein in dry matter Dry matter Protein in dry matter Dry matter Protein in dry matter C samples A samples 1 2 3 4 26.3 26.8 26.3 24.1 24.9 18.0 19.3 23.6 21.8 22.3 29.2 32.7 32.3 30.3 30.8 11.3 13.4 15.9 17.3 18.1 34.3 33.0 30.2 30.1 30.7 13.4 15.8 16.2 17.9 18.2 30.1 33.3 31.0 28.7 33.8 14.3 15.5 15.6 16.0 17.1 38.4 37.3 34.8 33.8 36.2 17.7 18.4 20.9 20.2 21.3 Light Medium Heavy Very heavy. . B samples . . 36 ? 4 43.5 8.6 41.5 10.4 44.9 14.0 1 Light 34. ? 10 6 39.1 10.8 41.2 12.2 41.5 15.4 2 35 q 12 1 38.0 11.5 36.9 13.4 39.8 17.2 3 Heavy 33 3 14 6 35.9 14.1 40.7 13.5 40.2 17.1 4 Very heavy 34, 2 14 8 36.4 14.8 36.5 15.7 35.5 19.4 NOTE. For method of sampling see page 230. The effect of the urine treatment on protein content also carried over a little from year to year. In 1940 and 1942, for example, grass was sampled before urine was applied; and the C samples from plots treated with urine the season before were richer in protein than the C samples from plots not treated with urine the season before. Palatability Increased From 1938 thru 1942 four different groups of heifers grazed the bluegrass field where plots were treated with cow urine. All four TABLE 9. PALATABILITY OF BLUEGRASS FERTILIZED WITH DIFFERENT AMOUNTS OF Cow URINE AS DETERMINED BY FORAGE LEFT ON OPEN PASTURE (Average of four years, 1939-1942) Forage including weeds Grass portion Plot Treatment Annual dry- matter yield in pounds per acre Average left on open pasture on sampling t- dates innu; matt in p pel il dry- er yield lounds acre Average left on open pasture on sampling dates* Pounds per acre Percent of annual dry- mat- ter yield Pounds per acre Percent of annual dry- mat- ter yield 1 2 3 4 . 2 660 760 900 920 520 750 830 640 550 590 28 22 16 14 13 2 3 3 3 3 220 400 460 140 820 660 810 590 480 520 30 24 17 15 14 Light 3 Medium 3 3 4 Each figure is the average of 22 C samples, which were taken thruout the season duringfour years. The pasture had not been grazed when the first C sample was taken each season. 258 BULLETIN No. 505 [October, groups found the treated plots more palatable. Altho Plot 1 looked about like the untreated part of the pasture in some seasons, it was always obvious that Plot 2 was more intensely grazed than the un- treated part of the pasture, also that Plots 3 and 4 were more in- tensely grazed than Plots 1 and 2. Relative palatability of the plots was measured fairly exactly by the C samples taken on the 22 harvest dates over the four years (Table 9). As heifers had equal access to all parts of the bluegrass field, the C sample, which showed the amount of forage left on each plot, was a good gage of how intensely they had grazed it, or how palatable the forage was. More forage was left on the untreated plot (0) than on the treated plots, and on the lightly treated plots (1 and 2) than on the heavily treated plots (3 and 4). Thus palatability, or intensity of grazing, tended to vary in proportion to the amount of cow urine applied. ..' CHANGES IN PALATABILITY AND FEEDING VALUE Why do cattle prefer young, green grass to ripe, brown grass? Why does the young grass promote better growth in cattle ? Why, when two crops such as bluegrass and sweet clover are equally tall before grazing, will cattle do well on one and poorly on the other? Chemical studies answer these and similar questions, at least in part. Palatability Linked With Moisture Content Altho the bluegrass treated with cow urine was richer in protein, this by itself did not explain why four different groups of heifers sought out the same small area in the middle of the 4i/-acre field and grazed it most intensely. As likely factors were the high mineral and vitamin contents of the treated area. Also the treated bluegrass, since it stayed greener and matured more slowly, lignified later. Palatability was probably directly related to moisture content, for the treated bluegrass had a consistently higher moisture content (lower dry-matter content) than the untreated (Table 10). From 1939 thru 1942 the averages of 201 samples from four treated plots were compared with the averages of 268 samples from five un- treated plots. Out of the 53 comparisons so made, 37 showed a lower dry-matter content in the treated bluegrass; 4, no difference; and 12, a higher dry-matter content in the treated bluegrass. The high dry- 1944] BETTER PASTURES FOR DAIRY CATTLE 259 2 -! 3 >S (M U Q, > O 2 "8 ~_o 53 1 v " a 7, *> N M M ^ '5'3,> > o P Ot^OiO -iio' ++ + 2 --Ht~i>O -csfsur*ts O cs'es 00 io ts (N T)< ts T)< + ++ : :od^ BULLETIN No. 505 Palatable new growth of bluegrass on September 16. Showers and cooler weather in late summer and fall usually cause renewed growth, which is much more palatable than the dry grass of midsummer. The fact that fer- tilized bluegrass has a higher moisture content than unfertilized bluegrass is believed to account for its greater palatability. Sudan grass stays moist and palatable. Its high moisture content thruout most of the pasture season is believed to be one reason why dairy cows find this crop so palatable. Even the coarse stems are eaten. Picture was taken on September 5. 1944] BETTER PASTURES FOR DAIRY CATTLE 261 matter content of the treated grass occurred mostly in 1942, when rain- fall was below normal from July 16 to August 23 (Table 2). An analysis of the data (Table 10) by Student's method 1 shows that the odds against the differences in dry-matter content being caused by chance were 46 to 1 for the A samples ; 193 to 1 for the B samples, and 49 to 1 for the C samples. Further evidence that low dry-matter content might be a factor in determining the palatability of pasture crops was sought by additional study of the crops used in these trials. Analysis of samples taken during the months of April to September inclusive, in five of the six years of these tests, showed that the bluegrass contained more than 30 percent of dry matter thruout a large part of the pasture season, whereas the Sudan-soybean pasture rarely reached as high as 30 percent. Samples containing more than 30 percent Number of dry matter of samples Number Percent Alfalfa 71 17 24 Bluegrass 380 359 92 Bromegrass 30 9 30 Sweet clover 16 6 38 Sudan-soybeans 38 1 3 It was observed that the bluegrass, except during the rainy periods of early spring and early fall, when growth was luxuriant, was of much less interest to the cattle than Sudan grass, which was readily grazed thruout most of the summer even tho it has large coarse stems. It is assumed, therefore, that the lower dry-matter content of such crops as Sudan grass is in large measure responsible for their high palatability. Feeding Value Declines as Forage Matures Thruout 1941 samples of bluegrass from the untreated plot (0) and the most heavily treated plot (4) were analyzed to determine their contents of dry matter, protein, lignin, and cellulose at different times during the season (Table 11). In order to have a better basis for making comparisons, similar analyses were made of bromegrass and winter rye in 1942. (Lignin and cellulose are the two compounds that make up most 'STUDENT. The probable error of a mean. Biometrika 6, Part 1, page 19. 1908. 262 BULLETIN No. 505 [October, TABLE 11. FEEDING VALUE OF BLUEGRASS (TREATED AND UNTREATED), BROMEGRASS, AND WINTER RYE AT DIFFERENT STAGES OF DEVELOPMENT j-j Protein and fiber in dry matter matter Date of harvest Cow urine applied matter content Protein Lignin Cellulose Bluegrass (B samples) 1941 perct. perct. perct. perct. April29 None 26.7 19.6 12.2 23.4 Very heavy 24.4 28.8 9.5 22.2 May26 None 36.4 9.9 18.3 33.3 Very heavy 32.9 17.0 22.0 31.0 June 17 None 47.0 8.3 19.0 32.0 Very heavy 36.8 17.1 24.0 31.1 July 16 None 50.8 7.5 18.1 34.5 Very heavy 39.0 14.3 21.8 32.6 August 19 None 52.7 8.5 16.9 31.3 Very heavy 36.2 16.6 19.8 27.7 September 15 None 40.0 13.1 21.9 31.4 Very heavy 25.8 26.8 21.9 24.4 Bromegrass (B samples) 1942 April 23 22.5 21.5 14.3 21.8 May9 22.7 15.8 15.3 28.1 May 25 26.0 8.9 16.6 35.4 July 2 34.8 8.6 16.9 32.8 August3 37.8 10.0 19.6 32.5 August31 48.7 9.4 21.2 35.2 September 29 43.4 10.6 19.7 32.9 Winter rye (C samples) 1942 April23 18.8 17.7 10.5 21.8 April 30 15.1 15.2 13.1 30.9 May9 24.5 10.3 15.4 30.8 of the fibrous part of a farm crop. In ordinary analyses they are classed together as "crude fiber." Cellulose, however, is digestible by livestock, while lignin is indigestible. It is important, therefore, to know how much of the fibrous part of a pasture crop is cellulose and how much is lignin.) At the beginning of the season the dry-matter and lignin and cel- lulose contents of bluegrass were low. A month later they had increased and, except for a slight drop in August, stayed at about the same level the rest of the season. The protein content, however, declined as the grass developed. These seasonal changes in composition were charac- teristic of both treated and untreated grass. Bromegrass and winter rye showed a less abrupt rise in dry matter, lignin, and cellulose. Their protein content also gradually declined until it was only about half as great as it was early in the season. 1944] BETTER PASTURES FOR DAIRY CATTLE 263 Getting an early start with winter rye. Winter rye not only furnishes abun- dance of pasture early in the spring but also makes it possible to delay pasturing bluegrass and bromegrass until they have developed a heavy growth, thus lengthening the pasture season two or three weeks. The dairy cow on young, growing grass in the spring, therefore, may get all the protein she needs. But as the season progresses and the protein content of the pasture becomes less, she is likely to need protein supplements in increasing amounts. Bromegrass is another excellent early pasture crop. Altho later than winter rye, bromegrass furnishes more forage than bluegrass at the start of the season. Picture was taken early in May. 264 BULLETIN No. 505 [October, Early Pasture Cannot Be Judged by Appearance First samples those taken just before heifers were turned on pasture, around May 1 showed that the bromegrass and winter rye consistently yielded more forage than the bluegrass at the beginning of the season (Table 3, page 240). Sweet clover, during the one year when results were available, yielded no more forage than bluegrass at this time (around May 1); nor in some seasons was alfalfa any more advanced than bluegrass. The yield of a crop at the beginning of one season, however, was no indication what the yield would be at the beginning of the next season. On May 2, 1940, for instance, the bluegrass yielded only 300 pounds an acre, while bluegrass on slightly earlier dates in 1940 .and 1942 yielded double this amount. Rye fluctuated even more: the yield on the first sampling date in 1942 was three times as great as the yield on the first sampling date in 1941. i ' TABLE 12. DRY-MATTER CONTENT OF GRASS PORTION OF FIVE PASTURE CROPS ON FIRST SAMPLING DATES, C SAMPLES (Percent) f Crop May 6, 1937 April 26, 1938 May 5, 1939 May 2, 1940 April 29, 1941 April 23, 1942 Alfalfa 14 4 20.2 20.6 23 9 Bluegrass 24.2 26.5 30.7 28.7 27.3 31. O b Bromegrass 15.3 23.9 Sweet clover 11 3 Winter rye 31.8 17.0 16 9 15.4 17.4 19.0 "Mixture of alfalfa and bromegrass. b Thte sample was taken on April 30 instead of April 23. The percentage of dry matter in the different crops varied a great deal also at this time of year (Table 12). On May 2, 1940, for example, sweet clover contained 11.3 percent of dry matter; winter rye, 15.4 percent; bluegrass, 28.7 percent. Forage, moreover, is often deceiving in appearance, bluegrass that is 6 to 8 inches tall before grazing usually containing much more dry matter than sweet clover that is the same height. The inexperienced dairy farmer who depends upon pasture for the sole ration in early spring must therefore proceed cautiously. 1944] BETTER PASTURES FOR DAIRY CATTLE 265 Most weeds not only make forage unpalatable but are also likely to impair the flavor of milk. Much hay and straw were bought to feed and bed the cattle at the experimental farm. Barnyard manure applied to the pastures un- doubtedly contained many weed seeds. When the fields were fertilized once a year, therefore, weed seeds were spread with the manure. The weed content of some crops, such as rye, however, was consistently small, while the weed content of other crops, such as bluegrass, was consistently large. The weed content of pasture forage is evidently related to the kind of pasture crop (Table 13). Alfalfa becomes weedier each year. Alfalfa was less weedy in April, May, and June than during the rest of the season. A samples were highest in weed content and C samples lowest, altho differences were not large. Weed content was comparatively low during the first pasture season (next year after seeding) but increased until, toward the end of the third year of pasturing, bacterial wilt killed many alfalfa plants. This thinning of the alfalfa stand encouraged the heavy growth of common annual weeds such as foxtail, pigweed, common ragweed, smartweed, and crabgrass. Dandelions predominate in bluegrass. Dandelions made up the bulk of the weed portion of bluegrass. As dandelions become largely TABLE 13. WEED CONTENT OF FIVE PASTURE CROPS (Percent in dry matter) Total num- Crop ber of usable April May June July August Septem- ber Average samples Alfalfa, 1937. 1938, 1941, 1942 28 12 32 27 50 19 28 B sample 30 10 9 15 37 32 26 21 1 2 26 49 31 22 79 1 11 9 23 45 26 26 Bluegrass, 1935-1942 121 17 19 29 21 23 22 B sample 134 20 12 14 13 13 14 155 26 14 7 7 7 9 10 Average 410 26 16 13 16 14 15 15 Bromegrass, 1941 average. . . . 32" 48 26 5 2 5 12 Bromegrass, 1942 average. . . . 55>> ( c ) 1 () Winter rye, 1937-1942 average 31 () ( c ) Sudan-soybeans, 1937-1942 41 3 1 4 2 First year after seeding. b Second year after seeding. c Less than .5 percent. 266 BULLETIN No. 505 [October, dormant after July unless rainfall is above normal, bluegrass was usually weediest early in the season. Also A samples were nearly always weedier than B and C samples: the frequent cutting and protection of the A areas seemed to retard the growth of the grass, and dandelions made up a larger proportion of the forage there. The heifers (which received no supplementary feed) ate the dandelions readily, and after July 1 both grass and weeds were closely grazed. The milk cows that TABLE 14. WEED CONTENT OF BLUEGRASS (C SAMPLES) DURING GRAZING MONTHS OVER EIGHT- YEAR PERIOD, 1935-1942 (Percent of total dry-matter yield which was in weed portion) Year April May June July August Sem ~ 1935... 4 3 1936 6 4 4 () 1937 10 2 6 7 2 1938 19 5 11 9 13 12 1939 24 4 9 2 8 1940 9 8 ' 5 2 47b 1941 ... 19 24 15 9 7 11 1942 40 21 15 15 14 26 "Less than .5 percent. b ln this season of low rainfall the September C samples of two fields showed only 356 pounds of total forage per acre; two other fields were so bare that no C samples could be taken. were fed supplements in the preliminary trials in 1935 and 1936, how- ever, avoided the dandelions. Foxtail, lamb's quarters, common ragweed, and sorrel appeared in the bluegrass in small amounts. Dock and other large weeds were dug out by hand ; and the sod, altho filled with dandelions, was always heavy. Yet the weed content of the bluegrass did not decline from year to year (Table 14). The percentage of weeds in 1941 and 1942 per- haps because of heavier stocking then was even higher than in the earlier years. Bromegrass becomes less weedy each year. The April and May samples of the first bromegrass season (first pastured on May 17, 1941, after seeding in August, 1940) were 25 to 50 percent weeds (Table 13). Foxtail, pigweed, lamb's quarters, crabgrass, and other annuals pre- dominated. As the season progressed, the stand of bromegrass became more dense and the percentage of weeds decreased. By the end of the second year of pasturing, the forage was practically free from weeds. Rye and Sudan-soybeans have low weed contents. The twice- yearly plowing or thoro cultivation of the two-crop pastures kept the weed content of rye at a minimum. Weeds, when present at all in rye, usually made up less than .5 percent of the dry matter (Table 13). 1944] BETTER PASTURES FOR DAIRY CATTLE 267 Bromegrass prevents weed growth. After the bromegrass pastures became well established during their second year, they were remarkably free from annual weeds such as ragweed, foxtail, and smartweed, and also from dande- lions. This picture was taken September 16, a time when weeds are espe- cially troublesome in most pastures. The growth of tall-growing perennial weeds such as curled dock and Canada thistle was not prevented, altho their spread may have been retarded. Sudan-soybean pasture almost free of weeds. The twice-yearly plowing of this field (once for rye and once for the Sudan-soybean mixture) kept the weeds, except a few velvet weeds that appeared late in the season, at a mini- mum. Winter rye pastures were practically free of weeds. 268 BULLETIN No. 505 [October, The Sudan-soybean mixture also benefited from the twice-yearly seedbed preparation. Velvet weed, however, was rather troublesome here. It was controlled by being pulled by hand, removed from the field, and burned. Common pigweed and crabgrass appeared in small amounts during the latter part of some seasons. Curled dock affects several crops. Curled dock appeared in alfalfa, bluegrass, and bromegrass and was dug out by hand nearly every year. Its incidence seemed to have little or no relation to the kind of pasture crop except that plowing twice yearly in preparation for the growing of winter rye and the Sudan-soybean mixture formed an effective control. Weed-resistant crops have low dry-matter content. A study (Table 15) was made of the dry-matter levels of the grass and weed portions in the samples of three crops alfalfa, bluegrass, and brome- grass. Many samples of each crop could not be used for this purpose, however, because they contained no weeds or at least not enough to make a reliable determination of the dry-matter content of the weed portion. Out of the 513 bluegrass samples taken over the four years, for example, only 133 were usable in the study. The grass portion of the bluegrass forage the crop lowest in yield always had a higher percentage of dry matter than the corresponding weed portion. The mean values for all 133 samples were 37 percent dry matter in the grass portion and 20 percent dry matter in the weed portion. The difference in dry-matter content between the grass and weed portions of alfalfa and bromegrass both crops with high yields was small. Out of 53 alfalfa samples only 11 had a higher percentage of dry matter in the weed portion than in the grass portion. Out of 21 bromegrass samples 13 had a higher percentage of dry matter in the weed portion than in the grass portion. One reason bluegrass was such a poor competitor of weeds may well TABLE 15. AVERAGE DRY-MATTER CONTENT OF GRASS AND WEED PORTIONS OF THREE PASTURE CROPS Crop Total number of usable samples Dry matter in grass portion Dry matter in weed portion perct. perct. Alfalfa, 1937, 1938, 1941, 1942 53 28 24 Bluegrass, 1939-1942 133 37 20 Bromegrass, 1941-1942... 21 23 25 1944] BETTER PASTURES FOR DAIRY CATTLE 269 be that during much of the season it was in an inactive or partially in- active stage of vegetation (as evidenced by its high dry-matter con- tent), whereas the weeds during most of the season were in an active vegetative stage (as evidenced by their low dry-matter content). SUMMARY AND CONCLUSIONS Rotational grazing increases the yield and feeding value of pastures. Bluegrass is usually not satisfactory to use as the only pasture crop for dairy cattle in central Illinois because of its low yields and low feeding value during midsummer. These two faults can be somewhat overcome by good management practices such as fertilizing heavily, beginning grazing only after good growth of the grass, re- moving cattle early in the autumn, and digging out large perennial weeds. A more effective way to get more and better forage from the same amount of pastureland, however, is to use several pasture crops such as winter rye, bluegrass, alfalfa, a Sudan-soybean mixture, bromegrass, and sweet clover in rotation. The mixture of Sudan grass and soy- beans, for instance, makes a high-yielding and drouth-resistant mid- summer pasture. Rotational grazing lengthens the pasture season. Winter rye is ready for grazing one to two weeks earlier than bluegrass, and brome- grass is ready several days earlier than bluegrass. In seasons of low rainfall the rotational system furnishes pasture for a longer time than bluegrass. Yield is not the only measure of pasture value. For example, a pasture planted first to winter rye and then to a mixture of Sudan grass and soybeans usually has a much higher yield than a pasture planted just to one crop, but the supply of forage is not continuous. Likewise, while both alfalfa and bromegrass have higher yields than bluegrass, alfalfa needs reseeding more often, and bromegrass does not recover from close grazing so quickly. Pasture crops for dairy cattle should be rated not only on total yield but also on (1) feeding value, (2) palatability, (3) economy of pro- duction, (4) timeliness of yield, (5) length of pasture season, (6) re- sistance to drouth, weeds, and tramping, (7) likelihood of causing bloat or other upsets, and (8) adaptability to soil and climate. Fertilizing with cow urine improves pastures markedly. Fertiliz- ing with cow urine in addition to manure increases the yield, protein 270 BULLETIN No. 505 [October, content, and palatability of bluegrass. The lower dry-matter content (higher moisture content) of fertilized grass probably explains its greater palatability: urine-treated grass has a consistently lower dry- matter content than untreated. Feeding value of most crops changes as season advances. As bluegrass, bromegrass, and winter rye develop, the dry-matter, lignin, and cellulose contents rise. At the same time the protein content gradu- ally falls, until the forage contains only about half as much protein as it does at the beginning of the season. There appears to be a close rela- tion between low dry-matter content (high moisture content) and palatability. Weeds are a major problem. Some crops tend naturally to be weedy; the weed content of bluegrass pastures in these experiments did not decline despite good management for eight years. Bromegrass, winter rye, and the Sudan-soybean mixture made good dairy pastures because of their low weed content and their high yields. PREVIOUSLY PUBLISHED PROGRESS REPORTS OF THIS INVESTIGATION Improved dairy pastures possible thru new studies. 111. Sta. Ann. Rpt. 49, p. 141. 1937. Improvement in dairy pastures possible. 111. Sta. Ann. Rpt. 50, p. 156. 1939. Cows' urine as a fertilizer for bluegrass pastures. Jour. Dairy Sci. 24, 761. 1941. Higher yields from dairy pastures obtained in tests. 111. Sta. Ann. Rpt. 51, p. 147. 1942. Improving dairy-cattle pastures. Jour. Dairy Sci. 25, 677. 1942. Pastures for corn-belt dairy farms. Amer. Dairyman 2, 22-23, 29. 1942. Results of experiments in improvement of pastures for dairy cattle. 111. State Acad. Sci. Trans. 35, 35. 1942. Relation of kind of pasture crop to weed content of forage. Jour. Dairy Sci. 26, 877. 1943. 1944] BETTER PASTURES FOR DAIRY CATTLE 271 REVIEWS OF PASTURE RESEARCH Readers who are interested in reviews of other research on pasture problems are referred to the following works: DAHL, A. S. Abstracts of pasture literature. U. S. Dept. Agr. Soil Conser- vation Service. 1937. PIETERS, A. J. A digest of pasture research literature in the continental United States and Canada, 1885 to February 1937. U. S. Dept. Agr. Bur. Plant Indus. 1937. A digest of some world pasture research literature (exclusive of continental United States and Canada). U. S. Dept. Agr. Bur. Plant Indus. 1937. CURRENT PUBLICATIONS ON PASTURE CROPS The following bulletins and circulars of the Illinois Agricultural Experiment Station and Extension Service give information about the culture and use of various pasture crops in Illinois: Pasture Improvement and Management. Circular 465. 52p. Bromegrass and Bromegrass Mixtures. Bulletin 496. 20p. Supplementing and Improving Dairy Pastures. Circular 553. 8p. Sweet Clover for Illinois. Circular 559. 24p. How to Get Good Yields of Alfalfa. Circular 560. 16p. Lespedeza, Its Place in Illinois Agriculture. Circular 561. 20p. Anyone desiring these publications can obtain them free of charge by writing the COLLEGE of AGRICULTURE, URBANA, ILLINOIS. ABUNDANT GREEN FORAGE from early spring to late fall is the dream of every dairy farmer. Midsummer pastures are, however, a problem in Illinois, for the hot dry weather that comes then often stunts or destroys the forage and causes serious loss in milk yields. Rotational grazing with a variety of pasture crops winter rye, bluegrass, alfalfa, a Sudan- soybean mixture, bromegrass, and sweet clover along with good management, seems to be the solution to this problem, as demonstrated by the tests reported in this bulletin. Each of these crops has certain merits and certain shortcomings. By combining them in a rotation system, Illinois dairy farmers, particu- larly those in the central and northern parts of the state, can work out plans that will give them good forage thruout the pasture season. 1205010-4428323