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Steer Performance on Hardie and Midland Bermudagrass1
Steer Performance on Midland Bermudagrass
Hardie and
1
In 1974, Hardie bermudagrass was released by the Oklahoma Agricultural Experiement Station after small field plot and laboratory evaluations showed it to be well adapted to Oklahoma and to be about 6 % higher than MidlaodJn J:~.oth _dIY _maJrer _yie.ld and in vitro _.dry_ matter disappearance (Taliaferro and Richardson, 1980). This study was conducted to compare the performance of steers grazed on Midland and Hardie bermudagrass during 5 giOwing seasons.
W.E. McMurphy, G.W. Horn, and C.M. Taliaferro 2 ,3 Summary Hardie bermudagrass [Cynodon dactylon (L.) Pers.] was selected and released on the basis of laboratory tests which indicated that Hardie was superior in forage quality to Midland bermudagrass, and that Hardie produced somewhat greater forage yieids from ciipping studies. These two bermudagrasses have now been evaluated in a 5-year grazing trial with yearling steers. Stocking rates were adjusted to utilize available forage with season long tester steers for animal growth measurement and put and take steers for the adjustment. Length of the grazing season averaged 1 55 days for three years and 11 2 days for the two drier years. Average daily gain (AOG) was 0.85 kg for Hardie and 0.71 kg for Midland. Total gain/ha was 714 kg for Hardie and 549 kg for Midland. Carrying capacity averaged 836 and 776 steer days/ha for Hardie and Midland, respectively. These results confirm that Hardie bermudagrass, which was selected on the basis of higher in vitro dry matter disappearance (IVDMD) than Midland, can produce higher ADG and greater beef gain/ha.
Materials and Methods The grazing trials were conducted at the Agronomy Research Station, Perkins, Oklahoma, on Dougherty, Konowa, and Teller fine sandy loam soils (Arenic Haplustalfs, Ultic Haplustalfs, and Udic Argiustolls). Two hybrid bermudagrass cultivars, Midland and Hardie, were tested each year in a replicated randomized complete block design. The pastures were sprigged in 1975, and grazing trials began in 1977. Each of the pastures was about 1 .4 ha and each was subdivided with electric fences into three paddocks to facilitate rotational grazing during the grazing trials. The rotational grazing objective was 1-week grazing of a paddock followed by a 2-week deferment. Thus, throughout most of the bermudagrass growing season, the forage was 2, and never more than 3 weeks of age. However, whenever drought restricted regrowth, the rotation was discontinued with steers allowed access to all three paddocks until rainfall was adequate to promote new growth. No rotation grazing occurred in the last 3 weeks of each season because regrowth had slowed. Stocking rates on the pastures were adjusted to the amount of available forage throughout the grazing trials by use of put-and-take steers described by Jacobson (1962). The utilization objective was to graze to a 6 cm height before rotating. When the first paddock was utilized to this 6 em height (exc!uding urine and fecal spots), then all steers were rotated. Stocking rate adjustments were normally made at weigh dates, but occasionally at the 2-week mid point between weighing. In early June of each year, after the steers were rotated, each paddock was mowed to remove cool season annuals. The pastures were fertilized with 1 68 kg/ha of N using ammonium nitrate in three equal applications (56 kg N/ha) in early April, late June and early August each year. Soil tests revealed that the soil pH was 5.7 to 6.5, and the phosphorus and potassium were at the 100% sufficiency level (Johnson and Tucker, 1982). Hereford and Hereford X Angus steers were usually purchased at a livestock auction in March and grazed on
Introduction Midland bermudagrass [Cynodon dactylon (L.) Pers.] is used extensively in the northern part of the bermudagrass belt where Coastal is unadapted. Like Coastal, Midland has high forage production potential and can significantly increase the animal carrying capacity of pasture units relative to many other available native and introduced forage species. The principle criticism of bermuda as a pasture grass has been its relatively low forage quality compared to other species, particularly during the summer months. Burton et al. (1967) first demonstrated that the nutritional quality of bermudagrass could be increased through breeding and selection. Their early work culminated in the release of Coastcross-1 bermudagrass which averaged 12% higher in in vitro dry matter digestibility than Coastal (Burton, 1972). Subsequent animal grazing trials showed that steers grazing Coastcross-1 had 30% greater average daily gains (ADG) than steers grazing Coastal (Chapman et ai., 1972).
1Journal article 4581 of the Oklahoma Agric . Exp. Stn. , Stillwater, OK 74078. Received September 22,1987 . 2Professors, Dept. of Agronomy, Animal Science Dept., and Dept. of Alljonomy, respectively, Oklahoma State Univ., Stillwater, OK 74078 . Reviewed by: C.J. Brown and Warren Gill.
22
HARDIE AND MIDLAND BERMUDA FOR STEERS Table 1. Average daily gain (ADG) of steers, stocking rate, and total beef gain/ha for Hardie and Midland bermudagrass. Number
ADG
Year of Days Hardie
1977 19 78 19 79 1980 1981
153 114 147 111 165
5-Yr Mean
138
--kg-0.80 0.67 0 .85 0 .78 0.96 0 .78 0.77 0.65 0 .85 0.65
0 .85*
Stocking Rate
Midland Hardie
0 .71
steer days/ha 773 694 640* 598 1003 94 1 655 605 1107 1042
836*
776
Table 2. Rainfall by month from January through the bermudagrass grazing season. Rainfall per month
Total Gain/ha
Midland Hardie
Midland
--kg-618* 466 545 469 964* 737 508 393 937 682
714*
549
23
Year
Jan.
Feb.
Mar.
Apr.
May
June
July
Aug. Sept.
1977 1978 1979 1980 1981
6 23 54 54 1
29 67 6 22 26
64 37 97 61 42
57 47 87 103 27
mm 215 185 173 192 176
48 117 76 223 115
80 23 129 1 124
73 13 41 40 129
45 12 49 73 49
30-Yr. Mean
39
37
56
80
129
116
88
81
97
*Indicates a significant difference (P = 0.05) between Hardie and Midland bermudagrass.
small grain pastures with limited forage until the trial began. ADG during this pretrial period was about 0.4 kg. Bermudagrass grazing began about 5 May each year. The steers were assigned to treatment groups on the basis of breed and weight. These were the tester steers which remained on the pasture all season. Daily gains were calculated from weight gains of tester steers that remained in the pastures throughout each grazing trial (Jacobson, 1962). For calculation of total steer gain/ha, put-and-take steers were assigned daily gains of tester steers during each period. Steer weights were measured after about a 1 6-hour overnight shrink without feed or water. Average initial weight (mean ± standard error of mean) of all tester steers in 1977 was 235 ± 3.8 kg; in 1978, 236 ± 2.9 kg; in 1979, 221 ± 4.9 kg; in 1980, 206 ± 4.1 kg; and in 1981, 227 ± 4.6 kg. Steers were implanted with an anabolic estrogen at the beginning of each trial. Tramisol (Ievamisole phosphate) was given for internal parasite control in April. Excellent fly control was achieved during each season by spraying the steers on each weigh date, except 1 July when a pour-on insecticide for grub control was applied, and by providing dust bags in the pastures. Steers in all pastures had access to trees or constructed shades. A commercial mineral supplement that contained 1 2 % calcium and 12% phosphorus was fed free-choice during the trials.
September indicate that reasonable steer gains can be achieved if forage is available. Severe late summer droughts in 1978 and 1980 caused regrowth of bermudagrass to stop in August, and by the end of the month the inadequate available forage supply dictated that grazing be terminated. Hardie had a significantly higher carrying capacity in May each year. Stocking rate for May averaged 259 steer days/ha for Hardie and 133 for Midland . Since the best steer gains often occurred in May, this combination of higher carrying capacity during the time of greatest steer gains gave Hardie a decided advantage for total gain/ha (Table 1). Since stocking rate does influence ADG (Conrad et aI., 1981), the treatment differences are meaningful only when an inferior treatment has both a lower rate of stocking and a lower animal performance than the superior treatment (Woolfolk, 1962). In this study the Midland bermudagrass was stocked at a lower rate and had a lower animal performance than did the Hardie bermudagrass which produced 1 65 kg gain/ha more than Midland. This study supports the concept of breeding new forage varieties based on laboratory analyses for forage quality and clipping tests for production. Stocking rates were adjusted to use the available forage as it grew. However, a minimum stocking rate of 4.9 steers/ha was maintained. Thus, a realistic approach by producers would be a stocking rate of 4.9 steers/ha. Excess forage that accumulates during flush growth periods should then be removed as hay.
Results and Discussion
The 5-year mean revealed that Hardie bermudagrass produced a significantly higher ADG, steer days/ha, and total beef gain/ha than Midland bermudagrass (Table 1). The dry July and August of 1978 and 1980 probably contributed to a residual soil N effect in the following seasons because very little precipitation occurred after the last application of N fertilizer. Thus, the high carrying capacity and total gains of 1979 and 1981 are a reflection of the greater precipitation (Table 2) and residual soil N. Monthly steer ADG was highest in May for 4 of the 5 years and lowest in July or August (Table 3) . Data for
Table 3. Monthly average daily gain (ADG) of steers grazing Hardie and Midland bermudagrass. Average daily gain Year
May
June
July
Aug.
Sept.
1977 1978 1979 1980 1981
0.68a* 1.33a 1.68a 1.23a 1.30a
0.73a 0.88ab 0.75bc 0.75b 0.82b
kg 0.61a 0.69b 0.99b 0.81b 0.39c
0.64a 0.57b 0.39c 0.12c 0.57bc
0.93a 0.67bc 0.79b
*Within a year, monthly averages followed by the same letter are not significantly different (P = 0 .05) .
24
MCMURPHY, HORN AND TALIAFERRO
Literature Cited
1. Burton, G.w., RH . Hart and R.S. Lowrey . 1967. Improving forage quality in bermudagrass by breeding. Crop Sci. 7:329-332. 2. Burton, G.'v·v. 1972. Registiation of Coastcioss .. 1 bermudagrass. Crop Sci. 12:125. 3. Chapman, H.D., W.H. Marchant, P.R Utley, RE. Hellwig and W.G. Monson. 1972. Performance of steers on Pensacola bahiagrass, Coastal bermudagrass, and Coastcross-1 bermudagrass pastures and pellets. J. Animal Sci. 34:373-378. 4. Conrad, B.E., E.C. Ho!t and W.C. Ellis. 1981. Steer performance on Coastal, Callie and other hybrid bermudagrasses. J. Anim. Sci. 53:1188. 5. jacobson, N.L. i 962. Aiiotment of animais to ex-
perimental treatment. In Joint Committee (ed.) Pasture and range research techniques. In Joint Committee (ed.) Pasture and range research techniques. Comstock Publishing Asso., A division of Cornell University Press, Ithaca, New York. 6. Johnson, G., and B. Tucker. 1982. OSU soil test calibrations. Oklahoma State Univ. Extension Facts 2225. 7. Taliaferro, C.M., and W.L. Richardson. 1980. Registration of Hardie bermudagrass. Crop Sci. 20:413. 8 : Woolf()lk,P.G~ 1962. Measuring yield by animal performance. In Joint Committee (ed.; Pasture and range research techniques. Comstock Publishing Asso., A division of Cornell Universitv Press. Ithaca. New York. . .
Hardie and
1
In 1974, Hardie bermudagrass was released by the Oklahoma Agricultural Experiement Station after small field plot and laboratory evaluations showed it to be well adapted to Oklahoma and to be about 6 % higher than MidlaodJn J:~.oth _dIY _maJrer _yie.ld and in vitro _.dry_ matter disappearance (Taliaferro and Richardson, 1980). This study was conducted to compare the performance of steers grazed on Midland and Hardie bermudagrass during 5 giOwing seasons.
W.E. McMurphy, G.W. Horn, and C.M. Taliaferro 2 ,3 Summary Hardie bermudagrass [Cynodon dactylon (L.) Pers.] was selected and released on the basis of laboratory tests which indicated that Hardie was superior in forage quality to Midland bermudagrass, and that Hardie produced somewhat greater forage yieids from ciipping studies. These two bermudagrasses have now been evaluated in a 5-year grazing trial with yearling steers. Stocking rates were adjusted to utilize available forage with season long tester steers for animal growth measurement and put and take steers for the adjustment. Length of the grazing season averaged 1 55 days for three years and 11 2 days for the two drier years. Average daily gain (AOG) was 0.85 kg for Hardie and 0.71 kg for Midland. Total gain/ha was 714 kg for Hardie and 549 kg for Midland. Carrying capacity averaged 836 and 776 steer days/ha for Hardie and Midland, respectively. These results confirm that Hardie bermudagrass, which was selected on the basis of higher in vitro dry matter disappearance (IVDMD) than Midland, can produce higher ADG and greater beef gain/ha.
Materials and Methods The grazing trials were conducted at the Agronomy Research Station, Perkins, Oklahoma, on Dougherty, Konowa, and Teller fine sandy loam soils (Arenic Haplustalfs, Ultic Haplustalfs, and Udic Argiustolls). Two hybrid bermudagrass cultivars, Midland and Hardie, were tested each year in a replicated randomized complete block design. The pastures were sprigged in 1975, and grazing trials began in 1977. Each of the pastures was about 1 .4 ha and each was subdivided with electric fences into three paddocks to facilitate rotational grazing during the grazing trials. The rotational grazing objective was 1-week grazing of a paddock followed by a 2-week deferment. Thus, throughout most of the bermudagrass growing season, the forage was 2, and never more than 3 weeks of age. However, whenever drought restricted regrowth, the rotation was discontinued with steers allowed access to all three paddocks until rainfall was adequate to promote new growth. No rotation grazing occurred in the last 3 weeks of each season because regrowth had slowed. Stocking rates on the pastures were adjusted to the amount of available forage throughout the grazing trials by use of put-and-take steers described by Jacobson (1962). The utilization objective was to graze to a 6 cm height before rotating. When the first paddock was utilized to this 6 em height (exc!uding urine and fecal spots), then all steers were rotated. Stocking rate adjustments were normally made at weigh dates, but occasionally at the 2-week mid point between weighing. In early June of each year, after the steers were rotated, each paddock was mowed to remove cool season annuals. The pastures were fertilized with 1 68 kg/ha of N using ammonium nitrate in three equal applications (56 kg N/ha) in early April, late June and early August each year. Soil tests revealed that the soil pH was 5.7 to 6.5, and the phosphorus and potassium were at the 100% sufficiency level (Johnson and Tucker, 1982). Hereford and Hereford X Angus steers were usually purchased at a livestock auction in March and grazed on
Introduction Midland bermudagrass [Cynodon dactylon (L.) Pers.] is used extensively in the northern part of the bermudagrass belt where Coastal is unadapted. Like Coastal, Midland has high forage production potential and can significantly increase the animal carrying capacity of pasture units relative to many other available native and introduced forage species. The principle criticism of bermuda as a pasture grass has been its relatively low forage quality compared to other species, particularly during the summer months. Burton et al. (1967) first demonstrated that the nutritional quality of bermudagrass could be increased through breeding and selection. Their early work culminated in the release of Coastcross-1 bermudagrass which averaged 12% higher in in vitro dry matter digestibility than Coastal (Burton, 1972). Subsequent animal grazing trials showed that steers grazing Coastcross-1 had 30% greater average daily gains (ADG) than steers grazing Coastal (Chapman et ai., 1972).
1Journal article 4581 of the Oklahoma Agric . Exp. Stn. , Stillwater, OK 74078. Received September 22,1987 . 2Professors, Dept. of Agronomy, Animal Science Dept., and Dept. of Alljonomy, respectively, Oklahoma State Univ., Stillwater, OK 74078 . Reviewed by: C.J. Brown and Warren Gill.
22
HARDIE AND MIDLAND BERMUDA FOR STEERS Table 1. Average daily gain (ADG) of steers, stocking rate, and total beef gain/ha for Hardie and Midland bermudagrass. Number
ADG
Year of Days Hardie
1977 19 78 19 79 1980 1981
153 114 147 111 165
5-Yr Mean
138
--kg-0.80 0.67 0 .85 0 .78 0.96 0 .78 0.77 0.65 0 .85 0.65
0 .85*
Stocking Rate
Midland Hardie
0 .71
steer days/ha 773 694 640* 598 1003 94 1 655 605 1107 1042
836*
776
Table 2. Rainfall by month from January through the bermudagrass grazing season. Rainfall per month
Total Gain/ha
Midland Hardie
Midland
--kg-618* 466 545 469 964* 737 508 393 937 682
714*
549
23
Year
Jan.
Feb.
Mar.
Apr.
May
June
July
Aug. Sept.
1977 1978 1979 1980 1981
6 23 54 54 1
29 67 6 22 26
64 37 97 61 42
57 47 87 103 27
mm 215 185 173 192 176
48 117 76 223 115
80 23 129 1 124
73 13 41 40 129
45 12 49 73 49
30-Yr. Mean
39
37
56
80
129
116
88
81
97
*Indicates a significant difference (P = 0.05) between Hardie and Midland bermudagrass.
small grain pastures with limited forage until the trial began. ADG during this pretrial period was about 0.4 kg. Bermudagrass grazing began about 5 May each year. The steers were assigned to treatment groups on the basis of breed and weight. These were the tester steers which remained on the pasture all season. Daily gains were calculated from weight gains of tester steers that remained in the pastures throughout each grazing trial (Jacobson, 1962). For calculation of total steer gain/ha, put-and-take steers were assigned daily gains of tester steers during each period. Steer weights were measured after about a 1 6-hour overnight shrink without feed or water. Average initial weight (mean ± standard error of mean) of all tester steers in 1977 was 235 ± 3.8 kg; in 1978, 236 ± 2.9 kg; in 1979, 221 ± 4.9 kg; in 1980, 206 ± 4.1 kg; and in 1981, 227 ± 4.6 kg. Steers were implanted with an anabolic estrogen at the beginning of each trial. Tramisol (Ievamisole phosphate) was given for internal parasite control in April. Excellent fly control was achieved during each season by spraying the steers on each weigh date, except 1 July when a pour-on insecticide for grub control was applied, and by providing dust bags in the pastures. Steers in all pastures had access to trees or constructed shades. A commercial mineral supplement that contained 1 2 % calcium and 12% phosphorus was fed free-choice during the trials.
September indicate that reasonable steer gains can be achieved if forage is available. Severe late summer droughts in 1978 and 1980 caused regrowth of bermudagrass to stop in August, and by the end of the month the inadequate available forage supply dictated that grazing be terminated. Hardie had a significantly higher carrying capacity in May each year. Stocking rate for May averaged 259 steer days/ha for Hardie and 133 for Midland . Since the best steer gains often occurred in May, this combination of higher carrying capacity during the time of greatest steer gains gave Hardie a decided advantage for total gain/ha (Table 1). Since stocking rate does influence ADG (Conrad et aI., 1981), the treatment differences are meaningful only when an inferior treatment has both a lower rate of stocking and a lower animal performance than the superior treatment (Woolfolk, 1962). In this study the Midland bermudagrass was stocked at a lower rate and had a lower animal performance than did the Hardie bermudagrass which produced 1 65 kg gain/ha more than Midland. This study supports the concept of breeding new forage varieties based on laboratory analyses for forage quality and clipping tests for production. Stocking rates were adjusted to use the available forage as it grew. However, a minimum stocking rate of 4.9 steers/ha was maintained. Thus, a realistic approach by producers would be a stocking rate of 4.9 steers/ha. Excess forage that accumulates during flush growth periods should then be removed as hay.
Results and Discussion
The 5-year mean revealed that Hardie bermudagrass produced a significantly higher ADG, steer days/ha, and total beef gain/ha than Midland bermudagrass (Table 1). The dry July and August of 1978 and 1980 probably contributed to a residual soil N effect in the following seasons because very little precipitation occurred after the last application of N fertilizer. Thus, the high carrying capacity and total gains of 1979 and 1981 are a reflection of the greater precipitation (Table 2) and residual soil N. Monthly steer ADG was highest in May for 4 of the 5 years and lowest in July or August (Table 3) . Data for
Table 3. Monthly average daily gain (ADG) of steers grazing Hardie and Midland bermudagrass. Average daily gain Year
May
June
July
Aug.
Sept.
1977 1978 1979 1980 1981
0.68a* 1.33a 1.68a 1.23a 1.30a
0.73a 0.88ab 0.75bc 0.75b 0.82b
kg 0.61a 0.69b 0.99b 0.81b 0.39c
0.64a 0.57b 0.39c 0.12c 0.57bc
0.93a 0.67bc 0.79b
*Within a year, monthly averages followed by the same letter are not significantly different (P = 0 .05) .
24
MCMURPHY, HORN AND TALIAFERRO
Literature Cited
1. Burton, G.w., RH . Hart and R.S. Lowrey . 1967. Improving forage quality in bermudagrass by breeding. Crop Sci. 7:329-332. 2. Burton, G.'v·v. 1972. Registiation of Coastcioss .. 1 bermudagrass. Crop Sci. 12:125. 3. Chapman, H.D., W.H. Marchant, P.R Utley, RE. Hellwig and W.G. Monson. 1972. Performance of steers on Pensacola bahiagrass, Coastal bermudagrass, and Coastcross-1 bermudagrass pastures and pellets. J. Animal Sci. 34:373-378. 4. Conrad, B.E., E.C. Ho!t and W.C. Ellis. 1981. Steer performance on Coastal, Callie and other hybrid bermudagrasses. J. Anim. Sci. 53:1188. 5. jacobson, N.L. i 962. Aiiotment of animais to ex-
perimental treatment. In Joint Committee (ed.) Pasture and range research techniques. In Joint Committee (ed.) Pasture and range research techniques. Comstock Publishing Asso., A division of Cornell University Press, Ithaca, New York. 6. Johnson, G., and B. Tucker. 1982. OSU soil test calibrations. Oklahoma State Univ. Extension Facts 2225. 7. Taliaferro, C.M., and W.L. Richardson. 1980. Registration of Hardie bermudagrass. Crop Sci. 20:413. 8 : Woolf()lk,P.G~ 1962. Measuring yield by animal performance. In Joint Committee (ed.; Pasture and range research techniques. Comstock Publishing Asso., A division of Cornell Universitv Press. Ithaca. New York. . .