NDSU Dickinson Research Extension Center

North Dakota State University * Dickinson Research Extension Center
1089 State Avenue, Dickinson, ND 58601-4642 Voice: (701) 483-2348 FAX: (701) 483-2005

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 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.

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
Days Grazed			127				133
Stocking Rate			1.77 Acres/AUM				0.95 Acres/AUM
	Weigh Date	No. of Days	Per Head	Gain/Hd	ADG	BCS	Per Head	Gain/Hd	ADG	BCS
	May 25 initial		874.53			7.15	862.53			7.06
	June 15	21	901.57	+27.04	1.29	7.02	887.23	+24.70	1.18	7.02
	July 7	22	951.63	+50.06	2.28	----	925.59	+38.36	1.74	----
	July 28	21	993.47	+41.84	1.99	7.17	978.61	+53.02	2.52	7.20
	Aug. 17	20	993.70	+0.23	0.01	7.07	978.16	-0.45	-0.02	7.27
	Sept. 9	23	1031.67	+37.97	1.65	7.10	1039.46	+61.30	2.66	7.13
	Sept. 29	20	1038.37	+6.70	0.34	7.21	1048.93	+9.47	0.47	7.21
Change in BCS						+0.06				+0.15
TOTAL GAIN			163.84	1.29			186.40	1.47
Gain/Acre			37.52#/A				46.39#/A
Gain/Acre/Day			0.295				0.37
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
Acres	131	131	131
Number of heifers	24	30	27
Days grazed	125	127	126
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
Acres	225	225	225
Number of heifers	52	56	54
Days grazed	125	127	126
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
Acres	131	225
Number head
Cows	17	35
Calves	17	35
Days Grazed	128	128
Gain per head
Cows	112.6	111.4
Calves	322.6	336.6
Average daily gain
Cows	0.88	0.87
Calves	2.52	2.63
Gain per Acre
Cows	14.62	17.32
Calves	41.86	52.37

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

Hay quality
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. Combined hay yields.	1992	1993	1994	Ave.
Acres harvested	34.5	34.5	34.5	34.5
Yield per acre
1st. cutting	2.0	0.80	0.80	1.20
2nd. cutting	0.87	0.63	---	0.75*
Dry matter
1st. cutting	96.40	96.70	97.4	96.80
2nd. cutting	95.96	92.50	----	94.23*
Ash
1st. cutting	5.75	8.6	8.29	7.55
2nd. cutting	10.08	8.9	---	9.49*
Crude protein
1st. cutting	8.40	12.13	11.66	10.73
2nd. cutting	18.70	18.55	----	18.62*
Acid detergent fiber
1st. cutting	52.50	19.20	39.39	37.03
2nd. cutting	36.08	32.80	----	34.44*
Neutral detergent fiber
1st. cutting	74.9	45.00	42.96	54.29
2nd. cutting	53.96	41.00	----	47.48*
* 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.