North Dakota State University * Dickinson Research Extension Center
1089 State Avenue, Dickinson, ND 58601-4642 Voice: (701) 483-2348 FAX: (701) 483-2005
GRAZING VALUE AND MANAGEMENT OF CRP LANDS
James L. Nelson
North Dakota State University
Dickinson Research & Extension Center
Grazing bred yearling heifers on CRP acreage in South West North Dakota for a period of 126 days from May to September has yielded gains of 1.55 lbs./day for seasonlong grazing compared to 1.53 on a Twice Over Rotation system. However, gain per acre favored the TOR system at 46.2 lbs. compared to 39.5 lbs. on the SL system.
Cow- calf data from 1993 show the same advantage for the TOR system of grazing with cow gain averaging 17.3 lbs. and calves averaging 52.4 lbs./ acre. This compares to SL gains with cows averaging 14.6 lbs. and calves gaining 41.9 lbs./acre.
Hay production has averaged 1.2 ton for the first cutting and O.75 ton on the second cutting. A second cutting was not taken in 1994. Hay quality has improved after the first year's haying due to the removal of dead material found in the hay the first year.
This trial is due to continue for two more years and the results may change in the future.
The objectives of this study are to determine:
The floristic composition and structure of CRP lands and to note changes in floristic composition and structure due to grazing and haying over 5 years.
The production and utilization of CRP land vegetation under seasonlong and twice-over grazing.
The production and quality of hay from CRP lands.
The success of game and non-game wildlife species on CRP lands.
The erosion from CRP lands that have been variously grazed and hayed and to compare this with similar cropland.
The economic returns from grazing and haying CRP lands.
MATERIALS AND METHODS
The third year of a proposed five year project to study the effects of haying and grazing on Conservation Reserve Program acres was conducted by the Dickinson Research Center in 1994.
Eighty six crossbred yearling heifers were allotted to either a 131 acre pasture grazed for the entire season (SL) or to a set of three 75 acre rotation pastures (TOR). There were 30 heifers on the seasonlong pasture and 56 heifers on the rotation pastures. The heifers grazed from May 25, 1994 to September 29, 1994, a period of 127 days.
The stocking rate was 1.3 acres/AUM on seasonlong and 1.2 acres/AUM on rotation pasture.
All heifers had been synchronized for estrus using a combination of MGA and Lutalyze. Artificial insemination followed synchronization using sires with known EPD's for birth weight and gain. Angus, Red Angus and Hereford clean up bulls, were turned with the heifers on June 10, 1994 and remained until July 14, 1994, a period of 34 days.
All heifers were individually weighed and body condition scored at the start, finish, and at intermediate dates based on rotation times. Heifers started grazing in pasture #3, rotated to #1 and then to pasture #2, back to 3, 1, and finished in pasture #2. (see diagram). Animal performance and body condition score (BCS) are shown in Table 1. Bull weights are not included in this report.
Pasture arrangement on Sec. 26 and 35-130-102
Table 1: Heifer Performance -1994
|Season Long||Twice over Rotation|
|Pasture Size||131 Acres||3 X 75 Acres = 225 Acres Total|
|No. of Head||30||56|
|Stocking Rate||1.77 Acres/AUM||0.95 Acres/AUM|
|Weigh Date||No. of Days||Per Head||Gain/Hd||ADG||BCS||
|May 25 initial||874.53||7.15||862.53||7.06|
|Change in BCS||+0.06||+0.15|
|Value of Gain/Acre*||$22.51||$27.84|
|Table 2 shows two year average performance of yearling heifers grazing CRP acreage. Table 2a. summarizes cow-calf performance for 1993.|
|Table 2. Heifer Performance||1992||1994||Ave.|
|Season Long grazing|
|Number of heifers||24||30||27|
|Gain per head||226||164||195|
|Average daily gain||1.81||1.29||1.55|
|Gain per acre||41.45||37.52||39.48|
|Twice Over Rotation|
|Number of heifers||52||56||54|
|Gain per head||199||186||193|
|Average daily gain||1.59||1.47||1.53|
|Gain per acre||45.93||46.39||46.16|
|Table 2a. Cow-calf data -1993||Seasonlong||Twice over rotation|
|Gain per head|
|Average daily gain|
|Gain per Acre|
Table 3 shows the yield of hay harvested from the CRP in 1994.
|Table 3. Hay production on CRP acres - 1994|
|Total acres harvested||34.5|
|Harvest date||July 3|
|Number of large bales||62|
|Average weight per bale||890 lbs.|
|Total weight (Tons) harvested||27.6 T|
|Tons per acre||0.8 T|
|Gross return per Acre @ $45.00 per ton||$36.00|
|Per cent Dry Matter||97.37|
|Per cent Ash||8.29|
|Per cent Crude Protein||11.66|
|Per cent Acid Detergent fiber||39.39|
|Per cent Neutral Detergent fiber||42.96|
Table 3a shows the combined yield of hay for the years 1992, 1993
|Table 3a. Combined hay yields.||1992||1993||1994||Ave.|
|Yield per acre|
|Acid detergent fiber|
|Neutral detergent fiber|
|* Two year average|
Results to date with both heifers and cow-calf pairs show satisfactory gains for both classes of cattle. The pastures grazed contain a significant amount of alfalfa in the grass mixture which has caused concern for the possibility of bloat. In all three years, proloxalene (Bloat-Guard) has been mixed with the mineral mixture in order to reduce or prevent bloat. However, in 1993, one cow died of suspected bloat, although too much time had elapsed after death for an autopsy to confirm cause of death.
Both grazing programs have provided more than adequate forage at the stocking rates used to date.