Document Actions
Managing Bermudagrass Pasture to Reduce Winter Hay Feeding
Pasture Preparation
Manage pastures to remove existing forage by late August (graze, clip or hay). Apply 50 - 100 lbs. of N during late August. If a rotational grazing system with a significant legume component is in place, the fertilizer application may not be necessary, or could be reduced. Defer grazing through mid-October or early November. Grazing initiation will need to be flexible depending on timing of fall precipitation, fall temperatures and the first killing frost.
Forage Production
Early fall forage accumulation has been quite variable, with an average of around 2750 pounds per acre (Table 1). Forage production this year (1999) was low with an average of just over 1600 pounds. Low forage production was due to cool weather during September and lack of moisture during October. During the fall of 1998, forage production was 1881 lbs. at Stillwater when first substantial rainfall was delayed until late September. Maximum forage production was 4058 pounds at the Eastern Research Station at Haskell where greater rainfall was available in early September.
During the fall of 1998, Jeff Ball recorded 4,261 pounds of forage accumulation at the Noble Foundation’s Red River Farm, south of Burneyville, Ok. In this work, 60 pounds of N was applied in early August. Jeff points out that 100 pounds of N was applied in the spring and that, undoubtedly, some of this carried over to the fall due to low spring and summer forage production.
Nitrogen response is better on sites that have a history of nitrogen applications or good fertility management. Numerous research and demonstration projects have been conducted throughout Northeast Oklahoma. In this work, we have found that 50 to 100 pounds of fall nitrogen produces anywhere from 1500 to 2500 pounds of forage, depending on time of application as well as timing and amount of precipitation. This work was conducted primarily on sites that had not historically been fertilized with nitrogen.
Table 1. Forage production and harvest efficiency
| Location |
Year |
N application rate, lbs/acre |
Fall forage accumulation, lbs/acre |
Harvest efficiency, % |
|
Haskell |
1997 |
50 |
3324 |
60.4 |
|
Stillwater |
1997 |
50 |
2722 |
61.2 |
|
Haskell |
1998 |
50 |
4058 |
62.0 |
|
Stillwater |
1998 |
50 |
1881 |
64.8 |
|
Burneyville |
1998 |
60 |
4261 |
- |
|
Haskell |
1999 |
50 |
1745 |
- |
|
Stillwater |
1999 |
50 |
1522 |
- |
Grazing Management
Control access to forage to reduce waste and extend grazing. Give cattle 1 to 14 days forage allowance. Greater grazing intensity, coupled with faster cattle movement, should result in improved harvest efficiency, although this issue has not yet been studied in the context of stockpiled bermudagrass forage. Forage allowance can be controlled with a "rotational" system, using permanent fence, or by utilizing temporary electrical fencing to "strip graze" the pastures. In either case a high stocking density should be used. Allowing access to the entire pasture will result in a lot of wasted forage. Another result is good performance early followed by weight loss by the end of the period. Cattle consume all of the high quality leafy material at the top of the plant first, resulting in low quality stems available at the end of the period.
Recommended harvest efficiency is around 60% ± 5%. For example if we managed grazing to utilize 60% of the 3000 pounds of available forage, the cows would be allowed to harvest 1,800 pounds of forage per acre. Greater harvest efficiency should result in lower animal performance. On average, one acre should provide around 60 head days of grazing.
If cool season pasture is available for winter grazing, utilize stockpiled bermudagrass first, usually by the end of December. If native pasture is available for winter grazing, plan on spending no more than 100 days utilizing the stockpiled bermudagrass unless the winter is exceptionally mild. These rules of thumb should be adjusted based on location in the state (shorter grazing window in SE due to greater forage deterioration).
For several years, R.L. Dalrymple has successfully wintered cows with stockpiled bermudagrass through March at the Noble Foundation’s pasture demonstration farm. In this case, recognize that greater protein and energy supplementation may be required compared to shorter grazing programs.
Forage Quality and Supplementation
If the stockpiled forage is truly grown during the months of September and October, forage quality; especially protein content, is usually adequate for gestating beef cows through November. Table 2 includes chemical composition of forage samples that were collected from grazing animals. This data suggests that fall fertilized bermudagrass may contain adequate protein through February to meet the needs of a gestating cow. It was apparent that during both of these studies, cool season annual grasses began to make up a small percentage of the grazed forage in these samples. Consequently, some of the higher protein concentration represents the growth of those cool season annuals.
Table 2. Chemical composition of grazed forage samples at Stillwater, % of dry mattera
|
Sample Date |
Protein |
ADIN |
NDF |
ADF |
TDN |
|
‘97-98 |
|||||
|
Nov. |
13.1 |
1.4 |
56.4 |
30.3 |
54.0 |
|
Dec. |
12.5 |
1.4 |
66.6 |
33.8 |
53.5 |
|
Jan. |
10.9 |
2.3 |
68.0 |
38.0 |
48.9 |
|
Feb. |
12.7 |
1.5 |
63.3 |
32.9 |
47.9 |
|
’98-99 |
|||||
|
Nov. |
15.2 |
1.8 |
60.6 |
30.5 |
48.4 |
|
Dec. |
14.7 |
1.9 |
57.0 |
32.1 |
47.9 |
|
Jan. |
11.6 |
1.8 |
64.6 |
38.9 |
43.3 |
|
Feb. |
13.2 |
1.4 |
62.0 |
33.4 |
46.3 |
aADIN = acid detergent insoluble nitrogen, NDF = neutral detergent fiber, ADF = acid detergent fiber, TDN = total digestible nutrients.
In the grazing trials conducted at OSU, supplementation during November gave no advantage over non-supplemented animals (Table 3). After November, it appeared that there was little difference in animal performance when cows were supplemented with two pounds per day of 12.5, 25 or 37.5 percent protein feed. Based on this data, we suggest beginning supplementing two pounds of 14 to 25% protein feed in early December and continuing through the program. The 25% protein feed is recommended if the stockpiling period begins earlier in August and/or during winters when forage rapidly deteriorates due to high precipitation. Feed can be delivered on a 3- or 4-days per week basis.
Table 3. Cow weight change (pounds) by year and supplement typea
|
Year and Period |
Supplement Treatment |
|||
|
Control |
12.5% CP |
25% CP |
37.5% CP |
|
|
’97-98 |
||||
|
Day 1-30 |
39 |
46 |
46 |
44 |
|
Day 1-79 |
-45 |
13 |
26 |
25 |
|
’98-99 |
||||
|
Day 1-30 |
55 |
57 |
57 |
54 |
|
Day 1-90 |
61 |
91 |
97 |
84 |
Pooled data from Stillwater and Haskell
Economics
A logical and very important question is, "How does the stockpiling system compare to feeding hay or utilizing some other standing forage resource during the same period?" In order address this question, during both years of the experiment described above, a group of 20 cows grazed stockpiled native tallgrass prairie (SNP) at a stocking rate of 1 cow to 3 acres. The native pastures had not been grazed through the spring or summer. Cows in this group were supplemented 2 pounds per day of 38 percent protein feed, consisting primarily of cottonseed meal. Initial and final weights and condition scores were recorded for each group of cows for a total of 79 days in year 1 and 90 days in year 2. Averaged across both years, there was no difference in cow weight or condition score change during this period.
An economic analysis was conducted to compare costs for 5 different systems for a 100-day period:
- Stockpiled native pasture and 38% protein supplement NP
- Stockpiled native pasture, 38% protein and hay supplement (75/25)
- Stockpiled native pasture, 38% protein supplement and hay feeding (50/50)
- Hay feeding alone
- Stockpiled bermudagrass pasture and 25% protein supplement
In each of these comparisons, it was assumed that cow weight and body condition change would not be significantly different. Additional assumptions and costs were as follows:
Bermuda grass pasture rental rate was $18 annually and rental costs were allocated to 120 days of summer grazing and 100 days of fall/winter grazing (Oct. 24 through Feb. 1). Fall forage accumulation was 2800 pounds per acre, stocking rate was 1.6 acres per cow, and harvest efficiency was 60%. Fall nitrogen fertilizer application was 50 pounds per acre with a cost of $12 per acre. Total cost for the stockpiled bermudagrass pasture was $20.18 per acre for the 100-day period. Medium protein range cubes (25%) were priced at $130 per ton and fed for the last 70 days of the 100-day period.
Native pasture rent was $10 per acre with an annual stocking rate of 10 acres per cow. High protein range cubes were priced at $170 per ton and were fed for the last 75 days of the 100-day period.
Grass hay used in the comparisons contained 9% protein and 54% TDN, and would be adequate to meet a gestating cow’s protein and energy needs when fed alone. Hay feeding waste was calculated as 15% above total pounds of hay fed. Hay was priced at $50 per ton.
When hay replaced native pasture forage intake, the amount of supplement fed was prorated accordingly. For example, when hay was "supplemented" at 25% of total forage intake, total pounds of protein supplement was also reduced by 25%. In the native pasture and hay feeding scenario, hay replaced 50% of native pasture forage intake and 50% of the protein supplement.
Costs were also calculated assuming that some producers might want to consider utilizing all of the stockpiled bermudagrass pasture in a shorter time period using a heavier stocking rate. For this scenario, a 60-day grazing period was used with a stocking rate of .83 acres per cow and 2 pounds of 25% protein feed during the last 30 days. Total cost comparisons are given in Table 4.
Table 4. Estimated cost of different feeding systems
|
System |
Cost per day |
Total cost |
|
100 daysa |
||
|
Native pasture and 38% protein supplement |
$.40 |
$40.15 |
|
Native pasture, 38% protein and hay supplement (75/25) |
$.46 |
$45.80 |
|
Native pasture, 38% protein supplement and hay feeding (50/50) |
$.56 |
$56.02 |
|
Hay feeding alone |
$.72 |
$71.88 |
|
Stockpiled bermudagrass and 25% protein supplement |
$.41 |
$41.39 |
|
60 days |
||
|
Short term grazing of stockpiled bermudagrass (60 days) |
$.34 |
$20.65 |
aOctober 24 through February 1.
Obviously, cost of each of these systems will be sensitive to forage production, pasture cost, feed prices, hay price and quality as well as various other factors. It is interesting to note that the native pasture with supplement and no hay fed is still the lowest cost wintering system for the 100-day period. However, it does appear that there is considerable opportunity to manage bermudagrass to reduce winter feeding costs.
Utilizing Stockpiled Bermudagrass to
Reduce Hay Feeding Costs
(PowerPoint Presentation)
David Lalman, Extension Beef Cattle Specialist, Department of Animal Science
Oklahoma State University
Bob Woods, Area Agronomist,
Oklahoma Cooperative Extension Service
Oklahoma State University
John Wheeler, Livestock Specialist,
Noble Foundation
Celina Johnson, Graduate Assistant,
Oklahoma State University
