![Page 1: The Right Forages for Dairy Heifers - USDA ARS...• Routinely test forages and have ration balanced (energy, protein) based on appropriate heifer size/weight. Title Microsoft PowerPoint](https://reader033.vdocuments.site/reader033/viewer/2022060922/60ae60b6e9a50b32467f2157/html5/thumbnails/1.jpg)
The Right Forages for Dairy HeifersWayne K. Coblentz, USDA-ARS
U.S. Dairy Forage Research Center, Marshfield, WI
![Page 2: The Right Forages for Dairy Heifers - USDA ARS...• Routinely test forages and have ration balanced (energy, protein) based on appropriate heifer size/weight. Title Microsoft PowerPoint](https://reader033.vdocuments.site/reader033/viewer/2022060922/60ae60b6e9a50b32467f2157/html5/thumbnails/2.jpg)
Some Thoughts About Forage Quality
![Page 3: The Right Forages for Dairy Heifers - USDA ARS...• Routinely test forages and have ration balanced (energy, protein) based on appropriate heifer size/weight. Title Microsoft PowerPoint](https://reader033.vdocuments.site/reader033/viewer/2022060922/60ae60b6e9a50b32467f2157/html5/thumbnails/3.jpg)
Forage quality is highly dependent on climate, forage
type, harvest management, and many other factors.
![Page 4: The Right Forages for Dairy Heifers - USDA ARS...• Routinely test forages and have ration balanced (energy, protein) based on appropriate heifer size/weight. Title Microsoft PowerPoint](https://reader033.vdocuments.site/reader033/viewer/2022060922/60ae60b6e9a50b32467f2157/html5/thumbnails/4.jpg)
83.0
69.9
64.4
24-h Dig
84.077.8.15Veg
70.765.2.16Bud
65.858.9.13Mid Bloom
48-h Dig
12-h Dig
Kd, /h
81.1
74.4
65.2
24-h Dig
84.971.4.102nd
Node
80.363.2.08Boot
72.054.2.07Full Head
48-h Dig
12-h Dig
Kd, /h
Orchardgrass →
← Alfalfa
Sources: Hoffman et al., 1993
0
20
40
60
80
0 20 40 60 80 100Incubation T ime (h)
% D
M R
emai
ning
Alfalfa (late vegetative)Alfalfa (late bud)Alfalfa (midbloom)
0
20
40
60
80
0 20 40 60 80 100Incubation Time (h)
% D
M R
emai
ning
Orchardgrass (2nd node)
Orchardgrass (boot)
Orchardgrass (fully headed)
Maturity
![Page 5: The Right Forages for Dairy Heifers - USDA ARS...• Routinely test forages and have ration balanced (energy, protein) based on appropriate heifer size/weight. Title Microsoft PowerPoint](https://reader033.vdocuments.site/reader033/viewer/2022060922/60ae60b6e9a50b32467f2157/html5/thumbnails/5.jpg)
68.4
81.1
24-h Dig
79.652.9.06VegRegrowth
(AR)
84.971.4.082nd node (WI)
48-h Dig12-h DigKd, /h
Sources: Hoffman et al., 1993; Ogden et al. (2005)
Temperature
0
20
40
60
80
0 20 40 60 80 100Incubation T ime (h)
% D
M R
emai
ning
Orchardgrass (2nd node)
Orchardgrass (Veg, AR)
![Page 6: The Right Forages for Dairy Heifers - USDA ARS...• Routinely test forages and have ration balanced (energy, protein) based on appropriate heifer size/weight. Title Microsoft PowerPoint](https://reader033.vdocuments.site/reader033/viewer/2022060922/60ae60b6e9a50b32467f2157/html5/thumbnails/6.jpg)
0
20
40
60
80
0 20 40 60 80 100Incubation Time (h)
% D
M R
emai
ning
Alfalfa (late bud)Orchardgrass (boot)Bermudagrass (WS)
0
20
40
60
80
0 20 40 60 80 100Incubation Time (h)
% D
M R
emai
ning
Alfalfa (midbloom)Orchardgrass (fully headed)Bermudagrass (42 days)
69.0
74.4
69.9
24-h Dig
80.654.5.05BG
80.363.2.08OG
70.765.2.16Alfalfa
48-h Dig
12-h Dig
Kd, /h
56.0
65.2
64.4
24-h Dig
69.344.2.03BG
72.054.2.07OG
65.858.9.13Alfalfa
48-h Dig
12-h Dig
Kd, /h
Moderate Quality →
← High Quality
Sources: Hoffman et al., 1993; Galdamez-Cabrera et al., 2003; Ogden et al., 2003.
Forage Type
![Page 7: The Right Forages for Dairy Heifers - USDA ARS...• Routinely test forages and have ration balanced (energy, protein) based on appropriate heifer size/weight. Title Microsoft PowerPoint](https://reader033.vdocuments.site/reader033/viewer/2022060922/60ae60b6e9a50b32467f2157/html5/thumbnails/7.jpg)
IVDMD vs. Maturity (Alfalfa)
30
40
50
60
70
80
0 20 40 60Days from May 28
IVD
MD
, % o
f DM
LeafStem
Adapted from Van Soest, 1982
![Page 8: The Right Forages for Dairy Heifers - USDA ARS...• Routinely test forages and have ration balanced (energy, protein) based on appropriate heifer size/weight. Title Microsoft PowerPoint](https://reader033.vdocuments.site/reader033/viewer/2022060922/60ae60b6e9a50b32467f2157/html5/thumbnails/8.jpg)
IVDMD vs. Maturity (Van Soest, 1982)
30
40
50
60
70
80
0 20 40 60Days from May 28
IVD
MD
, % o
f DM
LeafStem
Adapted from Van Soest, 1982
![Page 9: The Right Forages for Dairy Heifers - USDA ARS...• Routinely test forages and have ration balanced (energy, protein) based on appropriate heifer size/weight. Title Microsoft PowerPoint](https://reader033.vdocuments.site/reader033/viewer/2022060922/60ae60b6e9a50b32467f2157/html5/thumbnails/9.jpg)
0
20
40
60
80
100
0 20 40 60 80 100
Incubation Time (h)
% N
DF
Rem
aini
ng
Alfalfa, 10% BloomEastern Gamagrass, Mature
26.3.0378.0Eastern gamagrass
32.3.0840.9Alfalfa
NDFD*, %Kd, /hNDF, %
* Effective degradability of NDF calculated on the basis of a 6%/h passage rate.
![Page 10: The Right Forages for Dairy Heifers - USDA ARS...• Routinely test forages and have ration balanced (energy, protein) based on appropriate heifer size/weight. Title Microsoft PowerPoint](https://reader033.vdocuments.site/reader033/viewer/2022060922/60ae60b6e9a50b32467f2157/html5/thumbnails/10.jpg)
47.7.0925.4Leaf
32.3.0840.9Whole-plant
20.2.0559.4Stem
NDFD*, %
Kd, /h
NDF, %
0
20
40
60
80
100
0 20 40 60 80 100Incubation Time (h)
% N
DF
Rem
aini
ng
Alfalfa (late vegetative)Alfalfa (late bud)Alfalfa (midbloom)
47.9.1131.0Veg
32.0.0942.6Bud
28.6.0747.3Midbloom
NDFD*, %
Kd, /h
NDF, %
Source: Coblentz et al. (1998)
Source: Hoffman et al. (1993)
0
20
40
60
80
100
0 20 40 60 80 100Incubation T ime (h)
% N
DF
Rem
aini
ng
LeafStemWholeplant
Alfalfa - Maturity (NDF)
Alfalfa - Plant Part (NDF)
*Passage rate = 6%/h
![Page 11: The Right Forages for Dairy Heifers - USDA ARS...• Routinely test forages and have ration balanced (energy, protein) based on appropriate heifer size/weight. Title Microsoft PowerPoint](https://reader033.vdocuments.site/reader033/viewer/2022060922/60ae60b6e9a50b32467f2157/html5/thumbnails/11.jpg)
A discussion of appropriate forage quality (the right forage) is highly
dependent on what you intend to feed.
![Page 12: The Right Forages for Dairy Heifers - USDA ARS...• Routinely test forages and have ration balanced (energy, protein) based on appropriate heifer size/weight. Title Microsoft PowerPoint](https://reader033.vdocuments.site/reader033/viewer/2022060922/60ae60b6e9a50b32467f2157/html5/thumbnails/12.jpg)
Assuming this is a 1200-lb (pregnant, nonlactating) beef cow wandering aimlessly in
the Ozarks, the required energy density of her diet
should be about 47.1% TDN.
XX X
![Page 13: The Right Forages for Dairy Heifers - USDA ARS...• Routinely test forages and have ration balanced (energy, protein) based on appropriate heifer size/weight. Title Microsoft PowerPoint](https://reader033.vdocuments.site/reader033/viewer/2022060922/60ae60b6e9a50b32467f2157/html5/thumbnails/13.jpg)
Relationship between TDN and NDF (NRC, 2001)
LegumeY = 0.016x2 - 1.93x + 112.5
R2 = 0.978
Cool-Season GrassY = 0.012x2 - 1.86x + 125.5
R2 = 0.991
50
54
58
62
66
70
30 40 50 60 70
NDF, %
TDN
, %
Corn Silage
300 lbs
600 lbs
900 lbs1200 lbs
![Page 14: The Right Forages for Dairy Heifers - USDA ARS...• Routinely test forages and have ration balanced (energy, protein) based on appropriate heifer size/weight. Title Microsoft PowerPoint](https://reader033.vdocuments.site/reader033/viewer/2022060922/60ae60b6e9a50b32467f2157/html5/thumbnails/14.jpg)
Within this context ……,
maturing forages are not necessarily a problem, and in many cases actually may be desirable.
The “right forage” may not be the one with the best or highest quality.
![Page 15: The Right Forages for Dairy Heifers - USDA ARS...• Routinely test forages and have ration balanced (energy, protein) based on appropriate heifer size/weight. Title Microsoft PowerPoint](https://reader033.vdocuments.site/reader033/viewer/2022060922/60ae60b6e9a50b32467f2157/html5/thumbnails/15.jpg)
35
40
45
50
55
60
65
ND
F or
TD
N, %
of D
M
0 5 10 15 20Days from Stage 2
NDF TDN
● linear increase of NDF (0.4 percentage units/day), plus an associated reduction of TDN (0.25 percentage units/d) following Stage 2
2000
2500
3000
3500
4000
4500
5000D
M Y
ield
, lbs
/acr
e
0 5 10 15 20Days from Stage 2
adapted from Brink (unpublished)
● mean of eight harvests of ‘Affinity’ alfalfa over two years (2004-2005)
● increase of 92 lbs DM/acre/d following Stage 2
● results in improved harvest efficiency and (possibly) fewer harvests.
Effects of Maturity on Alfalfa Yield and NDF
![Page 16: The Right Forages for Dairy Heifers - USDA ARS...• Routinely test forages and have ration balanced (energy, protein) based on appropriate heifer size/weight. Title Microsoft PowerPoint](https://reader033.vdocuments.site/reader033/viewer/2022060922/60ae60b6e9a50b32467f2157/html5/thumbnails/16.jpg)
Relationship between CP and NDF (NRC, 2001)
LegumeY = 0.017x2 - 1.86x + 69.2
R2 = 0.962
Cool-Season GrassY = 0.043x2 - 5.53x + 189.1
R2 = 0.959
0
5
10
15
20
25
30
30 40 50 60 70NDF, %
Cru
de P
rote
in, %
Corn Silage
300 lbs
600, 1200 lbs900 lbs
![Page 17: The Right Forages for Dairy Heifers - USDA ARS...• Routinely test forages and have ration balanced (energy, protein) based on appropriate heifer size/weight. Title Microsoft PowerPoint](https://reader033.vdocuments.site/reader033/viewer/2022060922/60ae60b6e9a50b32467f2157/html5/thumbnails/17.jpg)
Effects of Alfalfa Harvest Timing on Estimates of RDP by SGPMethod (Coblentz et al., 2008)
18
20
22
24C
P, %
of D
M
0 5 10 15 20Days from Stage 2
2004, Quadratic (P < 0.001)
60
65
70
75
RD
P, %
of C
P
0 5 10 15 20Days from Stage 2
2004, Linear (P < 0.001)
Increased maturity also results in lower CP and rumen degradable protein (RDP), both of which are desirable generally for dairy heifers.
![Page 18: The Right Forages for Dairy Heifers - USDA ARS...• Routinely test forages and have ration balanced (energy, protein) based on appropriate heifer size/weight. Title Microsoft PowerPoint](https://reader033.vdocuments.site/reader033/viewer/2022060922/60ae60b6e9a50b32467f2157/html5/thumbnails/18.jpg)
A Practical Application
![Page 19: The Right Forages for Dairy Heifers - USDA ARS...• Routinely test forages and have ration balanced (energy, protein) based on appropriate heifer size/weight. Title Microsoft PowerPoint](https://reader033.vdocuments.site/reader033/viewer/2022060922/60ae60b6e9a50b32467f2157/html5/thumbnails/19.jpg)
Many commercial dairy heifer growers would like to maximize the use of corn silage and by-
products of the ethanol industry in the diets of replacement
heifers.
● This has created the need for ‘cutter’ forages that (ideally) exhibit:
- high DM yield
- high fiber (~ 70% NDF)
- low energy (45 – 50% TDN)
- high protein (~ 15% CP)
- low K (~ 1.5%)
![Page 20: The Right Forages for Dairy Heifers - USDA ARS...• Routinely test forages and have ration balanced (energy, protein) based on appropriate heifer size/weight. Title Microsoft PowerPoint](https://reader033.vdocuments.site/reader033/viewer/2022060922/60ae60b6e9a50b32467f2157/html5/thumbnails/20.jpg)
22393962.31200
15434363.3900
0505066.0600
Grain505068.0300
Cutter Forage
(48% TDN)
Alfalfa Silage
(60% TDN)Corn Silage (72% TDN)
Energy Requirement,
TDNBodyweight,
lbs
------------- % of Dietary DM -------------
Source: P. C. Hoffman, University of Wisconsin
![Page 21: The Right Forages for Dairy Heifers - USDA ARS...• Routinely test forages and have ration balanced (energy, protein) based on appropriate heifer size/weight. Title Microsoft PowerPoint](https://reader033.vdocuments.site/reader033/viewer/2022060922/60ae60b6e9a50b32467f2157/html5/thumbnails/21.jpg)
eastern gamagrasstropical corn
20
25
30
35
40
45
50
55
TDN
, %
B1 B2 B3 O1 O2 O3 O4 O5 O6 O7 O8 O9
Sample Number
Energy Density of Oat and Barley Straws
1) delayed harvest schedules
2) comparisons of straws
3) tropical corn
4) perennial warm-season grasses
Source: P.C. Hoffman, University of Wisconsin
Synchrony of Forage and Livestock Needs
![Page 22: The Right Forages for Dairy Heifers - USDA ARS...• Routinely test forages and have ration balanced (energy, protein) based on appropriate heifer size/weight. Title Microsoft PowerPoint](https://reader033.vdocuments.site/reader033/viewer/2022060922/60ae60b6e9a50b32467f2157/html5/thumbnails/22.jpg)
All of these forages might be the “right forage”, it just depends.
![Page 23: The Right Forages for Dairy Heifers - USDA ARS...• Routinely test forages and have ration balanced (energy, protein) based on appropriate heifer size/weight. Title Microsoft PowerPoint](https://reader033.vdocuments.site/reader033/viewer/2022060922/60ae60b6e9a50b32467f2157/html5/thumbnails/23.jpg)
Final Thoughts• Alfalfa and corn silage tend to
complement each other in heifer diets, and often do not allow for incorporation of other low-cost nutrients, especially those with relatively high energy densities.
• Use of significant proportions of corn silage may necessitate limit feeding or the use of an ‘energy diluting’ forage.
![Page 24: The Right Forages for Dairy Heifers - USDA ARS...• Routinely test forages and have ration balanced (energy, protein) based on appropriate heifer size/weight. Title Microsoft PowerPoint](https://reader033.vdocuments.site/reader033/viewer/2022060922/60ae60b6e9a50b32467f2157/html5/thumbnails/24.jpg)
Final Thoughts
• Producers might consider being proactive in their harvest management of legumes and grasses – “dairy quality” is not necessarily helpful.
• Avoid being “boxed in”, where you have only “dairy quality” or low-energy forages available.
• Routinely test forages and have ration balanced (energy, protein) based on appropriate heifer size/weight.
![Page 25: The Right Forages for Dairy Heifers - USDA ARS...• Routinely test forages and have ration balanced (energy, protein) based on appropriate heifer size/weight. Title Microsoft PowerPoint](https://reader033.vdocuments.site/reader033/viewer/2022060922/60ae60b6e9a50b32467f2157/html5/thumbnails/25.jpg)