WISCONSIN
FORAGE COUNCIL
AM/PM FORAGE
HARVEST STUDY
Jerry Clark[1]
Randy Knapp[2]
Situation:
Recent studies done at USDA Agricultural Research Stations in Idaho indicate that pm harvested hay had greater concentrations of mono- and disaccharides (sugars), greater total nonstructural carbohydrates, and tended to have lower concentrations of both neutral detergent fiber and acid detergent fiber. In a production test, lactating dairy cows preferred p.m.-harvested hay more than a.m. harvested hay, had greater intake levels, and produced more milk (Mayland, 2000).
It is not known if these same results would occur in
the Midwest. If the same response
occurs in the Midwest, this could be very important to dairy producers and
profitability. However, differing environments,
especially with regard to drying conditions, may cause this response of
increased sugar content not to occur in the Midwest.
Response:
The Wisconsin Forage Council and UW-Extension Team
Forage studied the effect of a.m. vs. p.m. cutting to see if there is a
difference in sugar/starch content between these two cuttings in
Wisconsin. A protocol was developed for
Wisconsin Forage Council members and UW-Extension agricultural agents to follow
to gather samples. Morning cutting and harvest were targeted between 9:00 am
and 10:00 am. Afternoon cutting and
harvest were targeted between 4:00 pm and 5:00pm. Stored harvested samples were
targeted to be taken anytime after four weeks of harvest.
Wisconsin Forage Council members collected
information with the help of county UW-Extension Agricultural Agents. Five farms from four counties participated
in the study. UW-Extension Team Forage
paid for the research analytical fees for this study. All samples were analyzed for DM, CP, ADF, and NDF.
Results:
Analysis of the data showed a
difference in the starch/sugar content of the a.m. harvested hay and the p.m.
harvested hay. Table 1 displays the
p.m.-a.m. difference in the starch/sugar content of the farms involved with the
study.
Table 1. Starch/Sugar Difference of AM/PM Harvest Study
(% on dm basis)
Waupaca Boerst Windrow am 3.07
Windrow pm 4.79 1.72
Blower am 1.74
Blower pm 2.14 0.40
Storage am 1.01
Storage pm 1.38 0.37
Chippewa Sedlacek Windrow am 4.10
Windrow pm 5.27 1.17
Chopped am 2.54
Chopped pm 2.53 -0.01
Eau Claire Jungenberg Windrow am 4.78
Windrow pm 4.83 0.04
Baling am 1.82
Baling pm 2.59 0.77
Baleage am 0.99
Baleage pm 1.30 0.31
Manitowoc Schuler Windrow am 2.06
Windrow pm 2.11 0.05
Baling am 1.72
Baling pm 1.81 0.09
Manitowoc Kepline Windrow am 1.08
Windrow pm 0.74 -0.34
Before baling am 1.27
Before baling pm 2.04 0.77
Baled am 1.33
Baled pm 2.19 0.87
Eau Claire Jungenberg Windrow am 1.97
Windrow pm 3.30 1.33
Baling am 1.31
Baling pm 1.60 0.28
Baleage am 1.35
Baleage pm 1.91 0.57
Summary:
In 5 of the 6 farms sampled, the afternoon cutting
did show a higher level of starch/sugar during cutting. In these 5 farms the level of difference
between p.m. and a.m. cutting ranged from 1.72 to 0.04 percent starch/sugars on
dry matter basis. The higher
starch/sugar concentrations were retained in the p.m.-harvested forage through
the storage stage.
At cutting, 3 of the 6 p.m. samples were lower in
ADF, 2 samples were lower in NDF and 4 were higher in CP.
Samples taken at harvest indicated that 2 of the 6
p.m. samples were lower in ADF, half were lower in NDF and 2 of the 6 were
higher in CP.
Of the 4 samples that were taken out of storage, 3
were lower in ADF and NDF and 3 were higher in crude protein.
Data from the study at Idaho consistently indicated
a lower ADF and NDF and higher mono-and disaccarides during the p.m. cuttings
over three months of harvest.
Based on the low number of samples submitted for this study, no recommendations or conclusions can be drawn relative to starch/sugar concentrations. However, in order achieve statistical reliability, larger number of cooperating farms and samples will be needed. It is recommended the Wisconsin Forage Council continue this project.
Table
2. Sample
Analysis of AM/PM Forage Harvest Study
|
County |
Date
of harvest |
Description |
am/pm |
Moisture |
ADF |
NDF |
Starch/sugars |
CP |
ADIN |
|
|
|
|
|
|
|
|
|
|
|
|
Waupaca |
20-May-00 |
Windrow |
am |
81.71 |
25.65 |
33.77 |
3.07 |
22.50 |
0.77 |
|
|
24-May-00 |
Windrow |
pm |
81.33 |
24.26 |
31.23 |
4.79 |
23.20 |
0.62 |
|
|
|
|
|
|
|
|
|
|
|
|
|
20-May-00 |
Blower
|
am |
52.75 |
26.22 |
30.95 |
1.74 |
25.50 |
0.49 |
|
|
24-May-00 |
Blower
|
pm |
52.62 |
25.86 |
29.45 |
2.14 |
25.50 |
0.53 |
|
|
|
|
|
|
|
|
|
|
|
|
|
20-May-00 |
Storage |
am |
57.10 |
27.95 |
33.39 |
1.01 |
25.50 |
0.56 |
|
|
24-May-00 |
Storage |
pm |
50.49 |
27.90 |
33.87 |
1.38 |
25.70 |
0.50 |
|
|
|
|
|
|
|
|
|
|
|
|
|
pm-am
difference |
|
|
-0.38 |
-1.39 |
-2.54 |
1.72 |
0.70 |
-0.15 |
|
|
|
|
|
-0.13 |
-0.36 |
-1.50 |
0.40 |
0.00 |
0.04 |
|
|
|
|
|
-6.61 |
-0.05 |
0.48 |
0.37 |
0.20 |
-0.06 |
|
|
|
|
|
|
|
|
|
|
|
|
Chippewa |
6-Jun-00 |
cut |
am |
81.18 |
32.95 |
41.16 |
4.10 |
20.40 |
0.82 |
|
|
6-Jun-00 |
cut |
pm |
84.25 |
27.96 |
34.24 |
5.27 |
22.60 |
0.66 |
|
|
|
|
|
|
|
|
|
|
|
|
|
6-Jun-00 |
chopped |
am |
57.60 |
34.63 |
41.51 |
2.54 |
19.50 |
1.00 |
|
|
6-Jun-00 |
chopped |
pm |
55.69 |
34.99 |
42.86 |
2.53 |
18.10 |
0.89 |
|
|
|
|
|
|
|
|
|
|
|
|
|
pm-am
difference |
|
|
3.07 |
-4.99 |
-6.92 |
1.17 |
2.20 |
-0.16 |
|
|
|
|
|
-1.91 |
0.36 |
1.35 |
-0.01 |
-1.40 |
-0.11 |
Table
2. (Cont.)
|
County |
Date
of harvest |
Description |
am/pm |
Moisture |
ADF |
NDF |
Starch/sugars |
CP |
ADIN |
|
|
|
|
|
|
|
|
|
|
|
|
Eau
Claire |
3-Jun-00 |
Windrow |
am |
80.13 |
30.32 |
45.96 |
4.78 |
18.30 |
0.57 |
|
|
2-Jun-00 |
Windrow |
pm |
80.12 |
31.68 |
48.52 |
4.83 |
18.40 |
0.61 |
|
|
|
|
|
|
|
|
|
|
|
|
|
4-Jun-00 |
Baling |
am |
53.85 |
34.10 |
48.95 |
1.82 |
19.70 |
0.67 |
|
|
4-Jun-00 |
Baling |
pm |
60.83 |
34.15 |
52.32 |
2.59 |
17.70 |
0.56 |
|
|
|
|
|
|
|
|
|
|
|
|
|
3-Jun-00 |
Baleage |
am |
52.54 |
34.55 |
49.34 |
0.99 |
19.60 |
0.76 |
|
|
2-Jun-00 |
Baleage |
pm |
58.75 |
34.75 |
47.62 |
1.30 |
20.00 |
0.89 |
|
|
|
|
|
|
|
|
|
|
|
|
|
pm-am
difference |
|
|
-0.01 |
1.36 |
2.56 |
0.04 |
0.10 |
0.04 |
|
|
|
|
|
6.98 |
0.05 |
3.37 |
0.77 |
-2.00 |
-0.11 |
|
|
|
|
|
6.21 |
0.20 |
-1.72 |
0.31 |
0.40 |
0.13 |
|
|
|
|
|
|
|
|
|
|
|
|
Manitowoc |
|
cut |
am |
81.92 |
42.12 |
51.98 |
2.06 |
20.10 |
2.26 |
|
|
|
cut |
pm |
80.79 |
44.78 |
58.02 |
2.11 |
17.80 |
1.95 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
baling |
am |
21.07 |
36.29 |
45.75 |
1.72 |
19.00 |
0.74 |
|
|
|
Baling |
pm |
19.83 |
36.46 |
45.04 |
1.81 |
19.80 |
0.89 |
|
|
|
|
|
|
|
|
|
|
|
|
|
pm-am
difference |
|
|
-1.13 |
2.66 |
6.04 |
0.06 |
-2.30 |
-0.31 |
|
|
|
|
|
-1.24 |
0.17 |
-0.71 |
0.09 |
0.80 |
0.15 |
|
|
|
|
|
|
|
|
|
|
|
|
Manitowoc |
|
Windrow |
am |
80.31 |
35.19 |
43.43 |
1.08 |
24.70 |
1.44 |
|
|
|
Windrow |
pm |
81.11 |
36.78 |
45.07 |
0.74 |
23.50 |
1.52 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
before
bale |
am |
15.91 |
32.21 |
40.80 |
1.27 |
20.50 |
0.77 |
|
|
|
before
bale |
pm |
23.26 |
31.74 |
39.05 |
2.04 |
20.30 |
0.75 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
baled |
am |
18.98 |
31.78 |
41.43 |
1.33 |
20.80 |
0.81 |
|
|
|
baled |
pm |
19.23 |
28.65 |
37.29 |
2.19 |
21.30 |
0.75 |
|
|
|
|
|
|
|
|
|
|
|
|
|
pm-am
difference |
|
|
0.80 |
1.59 |
1.64 |
-0.34 |
-1.20 |
0.08 |
|
|
|
|
|
7.35 |
-0.47 |
-1.75 |
0.77 |
-0.20 |
-0.02 |
|
|
|
|
|
0.25 |
-3.13 |
-4.14 |
0.87 |
0.50 |
-0.06 |
Table
2. (Cont.)
|
County |
Date
of harvest |
Description |
am/pm |
Moisture |
ADF |
NDF |
Starch/sugars |
CP |
ADIN |
|
|
|
|
|
|
|
|
|
|
|
|
Eau
Claire |
29-Aug-00 |
Windrow |
am |
72.01 |
31.55 |
39.84 |
1.97 |
22.90 |
0.66 |
|
|
30-Aug-00 |
Windrow |
pm |
83.53 |
30.20 |
40.15 |
3.30 |
23.20 |
0.60 |
|
|
|
|
|
|
|
|
|
|
|
|
|
31-Aug-00 |
Baling |
am |
41.59 |
31.15 |
38.51 |
1.31 |
23.60 |
0.58 |
|
|
31-Aug-00 |
Baling |
pm |
57.17 |
32.01 |
38.64 |
1.60 |
22.80 |
0.56 |
|
|
|
|
|
|
|
|
|
|
|
|
|
29-Sep-00 |
Baleage |
am |
46.36 |
32.08 |
38.17 |
1.35 |
23.30 |
0.49 |
|
|
29-Sep-00 |
Baleage |
pm |
55.29 |
31.06 |
38.06 |
1.91 |
22.60 |
0.32 |
|
|
|
|
|
|
|
|
|
|
|
|
|
pm-am
difference |
|
|
11.52 |
-1.35 |
0.31 |
1.33 |
0.30 |
-0.06 |
|
|
|
|
|
15.58 |
0.86 |
0.13 |
0.28 |
-0.80 |
-0.02 |
|
|
|
|
|
8.93 |
-1.02 |
-0.11 |
0.57 |
-0.70 |
-0.17 |
Reference
H.F.
Mayland, USDA-ARS, Wisconsin Forage Council 24th Forage Production
and Use Symposium Proceedings, January 25 and 26, 2000, pp. 30-33.