JOURNAL TRANSCRIPT
TEXAS A&M U~IIVERSITY liBRAR
B-1553
Texas Agricultural Extension Service
Nutnent Composition of
F~l Ry "
Ronald J. Gill and Dennis B. Herd*
Forages normally supply protein and digestible energy cheaper than any other feedstuff. Pastures, which cows harvest themselves, are basic to a cowcalloperation. Harvested forages in the form of hay or silage are a more expensive source of nutrients, but normally they are cheaper than concentrate feeds such as grain and protein supplements. Where forage quality is poor (forages lacking in protein and energy) it is necessary to feed limited amounts (0 to 8 pounds) of expensive supplements in order to obtain satisfactory animal performance. A mineral supplement should be available to cattle on a free choice, year-round basis. Protein, energy and vitamin A supplements are normally needed during the winter or drought periods when available forage is often limited in amount as well as quality. Requirements for various nutrients may be found in Extension publication B-1554, "Nutrient Requirements of Beef Cattle."
Mineral Content of Forages Forages typically contain adequate to high levels of calcium (0.25 to 0. 7 percent with 0.3 to 0.5 percent typical) and deficient to adequate levels of phosphorus (0.02 to 0.3 percent with 0.1 to 0.2 percent typical). The calcium content tends to vary among forages, but remains more consistent within a specific forage than phosphorus. The phosphorus content of forages varies greatly due to the soil phosphorus content and the stage of maturity of the plant. Like protein, phosphorus is much higher in leafy young growing plants than in mature stemmy plants. Forages are normally deficient in salt (sodium chloride) and phosphorus and sometimes deficient in magnesium, copper and zinc. Potassium is only deficient in droughty, weathered or leached forages. Problems concerning forages and other minerals are not common in Texas. More detailed information on minerals is available in Extension publication L-2213, "Mineral Recommendations for Pastured Beef Cattle in Texas". *Extension livestock specialist and Extension beef cattle specialist, The Texas A&M University System.
APR 20 1987
~ rS A M Vitamin A Content of orages Green, growing forages normally contain adequate carotene which yields vitamin A. During dormancy, mature forages are deficient. Because vitamin A supplements are relatively cheap and analytical procedures to check for carotene or vitamin A are expensive, vitamin A supplementation is suggested if there is any doubt about the adequacy of the vitamin. Other vitamins should not be a problem for grazing cattle.
Protein Content of Forages The protein content of several classes of forage is presented in Figure 1. As a class, the cool season grasses and legumes are highest in protein content followed by the warm season legumes and then the warm season grasses. Within each general class a number of factors influence the exact concentration of protein. Principal of these are the effect of soil type, soil fertility, age and growth rate of the plant. In general, increasing soil fertility (especially nitrogen) and growth rate results in increased protein content. Increasing age with accompanying decreasing growth rate results in reduced protein content. As a forage class, the cool season grasses and legumes contain protein in excess of the requirement of all classes of beef cattle. Only when they become very mature and dormant are they deficient. Similarly, the warm season legumes contain more than adequate concentrations of crude protein for all classes of beef cattle. Warm season grasses are commonly deficient in protein. Protein deficiency occurs during the summer and fall when forage growth rate slows down. This can be minimized by maintaining favorable growing conditions (fertility and water). There are areas, like some very alkaline, high pH, blackland soils, where forages do not respond well to nitrogen or phosphorus fertilization. Most warm season grasses will contain adequate protein to meet the protein requirement of cattle during the periods of rapid forage growth. With the advent of a killing frost, the protein content of warm season grasses drops rapidly below
Texas Agricultural Extension Service • Zerle L. Carpenter, Director • The Texas A&M University System • College Station, Texas
plants make a low quality feed and definitely need supplementation. Feeding value of dormant forage in late winter in the 30-inch plus rainfall areas is quite limited.
the requirement of all classes of cattle. This decrease in protein is accentuated by high rainfall and in lowgrowing forages such as the bermudas.
The composition of several hay crops analyzed by the Extension Forage Testing Service is reported in Table 1. The values are from producer submitted samples and give some idea of the field situation. Complete information concerning the forage testing service is available through county Extension offices. Study of Table 1 should reveal that there is a tremendous range in the protein content of forages. Because of this and the high cost of protein supplementation, testing for protein is a money-making management tool. A forage's energy content varies, but not to the extent that protein varies. Testing for energy is suggested for more advanced, intensive operations or in cases where there are problems and closer observation may be helpful.
Energy Content of Forages The range in digestible energy content observed for various classes of forage is shown in Figure 2. Within each forage class, digestibility and energy value for specific species will lie within a more restricted portion of the range shown. As an example, Coastcross 1 bermudagrass is known to have higher values than Coastal, other things being equal (Table 1). Forages have higher values when they are well fed, young, actively growing, leafy and vegetative. As maturity sets in and growth slows, there is a decline in digestibility. For large yields of protein and energy, plants must receive adequate nutrition from naturally rich soils or from fertilization. Management determines whether forage will be grazed or cut for hay when it is high in quality or later when the feeding value is reduced because of plant maturity.
Variation in the nutrient content occurs primarily because of fertilization and stage of maturity. Management determines when crops will be harvested. Young, growing, well-fertilized plants will have the higher values resulting in superior animal performance while mature, poorly fertilized plants will have the low values.
Forages which maintain higher digestibility at maturity make better standing hay crops. Mature
Figure 1. Protein Content of Forages.
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COOL SEASON = GRASSES & LEGUMES
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DRY PREG. COW 6
6
2
2
J
F
M.
A
M
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MONTH OF YEAR
W.C. Ellis, Beef Cattle Short Course, August 1973.
2
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s
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Table 1. General summary of forage analyses performed through the Extension Forage Testing Servlce8 • Digestible Energy, Mcal./lb.
Crude Protein,% Type Forage Alfalfa Coastal bermudagrass Common bermudagrass Alicia bermudagrass Coastcross 1 bermudagrass Johnsongrass Forage sorghum Sudan & hybrids Bahiagrass Kleingrass Introduced bluestemgrass Native prairiegrass Weeping lovegrass Misc. legumes, clover vetch, peas
Average
Range
Average
18 9 9 9 11 7 6 7 7 7 5 5 7 15
11-26 3-20 4-17 4-15 3-16 3- 15 2- 13 3- 17 4-12 2-15 2-8 4-8 3-14 10-22
1.08 0.92 0.91 0.90 1.08 0.97 0.97 0.96 0.96 0.93 0.92 0.85 0.91
Range 0.95-1 .23 0.80-1 .07 0.79-0.97 0.80 -0.99 1.06-1 .10* 0.91-1 .02 0.89-1 .06 0.81-1 .10 0.93-1.00* 0.86-0.98 0.87-1 .02 0.77-0.91 0.88 -0.96
a Data reported on an as-fed basis of approximately 90 percent dry matter. 10 percent moisture. • Small number of samples analyzed.
Figure 2. Variation In energy content of various forages relative to the requirements of various classes of caHie (values given on a dry maHer basis).
D.E. Mcal./lba DDM%b 1.61
80
1.50
75
1.40
70
1.29
65
1.19
60
Weaned Heiler
---------- ·----- ---- ----- -· ------r-------- -----------· r------ ----- ----- ---- ------ ------· -· r----- 1----- ----- ---- -----· -· ~-- ~-----
~-----
1.08
55
.98
so
.87
45
.77
Cow 1st Call
-·Lactating Cow
~----- ~-- ~------ - Pregnant Heiler
----- -· ----·
___________________ - - - - - - - ________________ Dry Pregr:-ant
Cow
40 Growing Pastures Grass Hay
Warm Season Perennials
Cool Season Perennials
8 Digestible
energy as megacalories per pound. boigestible dry matter.
3
Warm Season Annuals
Cool Season Annuals
legumes
..
Feed Ingredient Ana~sls Tables (Adapted from NR , 1984). Forages (Dry MaHer Basis)
Feed Name
Description*
Alfalfa
SCSCSCSC-
EB MB LB Mature
Vit.A Equiv./lb 1000 IU
ME (Mcal/lb)
TDN
CP
Ca
p
(%)
(%)
(%)
(%)
.98 .95 .85 .82
60 58 52 50
18.0 17.0 14.0 12.9
1.41 1.41 1.43 1.13
.22 .24 .25 .18
25.5 6.0 2.1
Bermudagrass
sc
.80
49
6.0
.43
.20 .
18.9
Clover, Alsike Crimson Ladino Red
sc sc sc sc
.95 .93 .98 .90
58 57 60 55
14.9 18.4 22.0 16.0
1.29 1.40 1.35 1.53
.26 .22 .31 .25
33.9 3.1 15.1 3.6
Fescue
SC- EV SC- EB
1.00 .79
61 48
12.4 9.5
.51 .30
.36 .26
Lespedeza
SC- EB SC- MB SC- FB
.90 .82 .77
55 50 47
15.5 14.5 13.4
1.23
.25
24.9 10.0 2.3
Oat
sc
.90
55
9.3
.24
.22
5.0
Orchardgrass
SC- EB SC- LB
1.06 .88
65 54
15.0 8.4
.27 .26
.34 .30
6.8 3.6
Peanut
sc
.90
55
10.8
1.23
.15
6.3
62 54
.62
.34
52.7
60
10.3 5.5 8.6
.65
.32
21.8
Ryegrass, Italian Perennial
sc
1.02 .88 .98
Sorghum, Johnsongrass Sudangrass
sc sc
.87 .92
53 56
9 ~5
8.0
.84 .55
.28 .30
7.0 10.7
Soybean
SC - MB
.87
53
17.8
1.26
.27
6.0
Timothy
SCSCSCSC-
1.02 .96 .93 .92
62 59 57 56
17.0 15.0 9.1 8.1
.66 .53 .48 .43
.34 .25 .22 .20
22.7 9.5 9.5
Wheat
sc
.95
58
8.5
.15
.20
15.5
SC- LV SC- EB
LV EB MB FB
* SC (sun cured) , EV (early vegatative), EB (early bloom), MB (mid-bloom), LB (late bloom), FB (full bloom), LV (late vegatative)
(
4
Roughages (Dry MaHer Basis)
Feed Name
Description
ME (Mcalllb)
TDN
CP
Ca
p
Vit.A Equiv./lb
(%)
(%)
(%)
(%)
10001U
Alternate Sources, Roughages Almond
Hulls
.90
55
2.1
.23
.11
Barley
Straw
.65
.40
4.3
.30
.07
Citrus
Dehyd. Pulp
1.35'
82
6.7
1.84
.12
Corn
Fodder w I ears Fod. w I mat. ear Stover Cobs, ground
1.06 1.13 .82 .82
65 69 50 50
8.9 8.0 6.6 3.2
.50
.25
.57 .12
.10 .04
Cotton
Hulls Bolls, SC
.69 .72
42 44
4.1 11.0
.15 .90
.09 .12
Oat
Hulls Straw
.57 .74
35 45
3.9 4.4
.15 .24
.15 .06
Peanut
Hulls
.36
22
7.8
.26
.07
Rice
Hulls Straw
.19 .67
12 41
3.3 4.3
.10 .21
.08 .08
Rye
Straw
.50
31
3.0
.24
.09
Sorghum
Fodder Stover
.95 .88
58 54
7.5 5.2
.40 .52
.21 .28
Soybean
Hulls* Straw
1.05 .69
64 42
12.1 5.2
.49 1.59
.21 .06
Wheat
Straw
.67
41
3.6
.1 8
.05
• Feed may be used as protein or energy supplement.
Abbreviations Used in Tables ME TON CP Vit IU
Meal lb Equiv Ca
p Mg K
Na
metabolizeable energy total digestible nutrients crude protein vitamin international unit megacalorie pound equivalent calcium phosphorus magnesium potassium
s
Co Cu F I Fe Mn Se Zn g Kg
5
sodium sulfur cobalt copper fluorine iodine iron manganese selenium zinc gram kilogram
9.4 4.1
Supplements (Dry MaHer Basis) Feed Name
Description
ME (Mcal/lb)
TON
CP
Ca
p
Vit.A Equiv./lb
(%)
(%)
(%)
(%)
10001U
Protein Supplements
Alfalfa
Meal
1.00
61
18.9
1.52
.25
Bone
Meal
1.18
72
53.8
11.25
5.39
Corn
Gluten meal
1.41
86
46.8
.16
.50
Cottonseed
Meal, mech. ext. Meal, solv. ext. Whole
1.28 1.31 1.57
78 80 96
44.3 45.6 23.9
.21 .22 .16
1.16 1.21 .75
Fish
Meal
1.07
59
58.4
4.20
2.40
Peanut
Meal, mech. ext. Meal, solv. ext
1.36 1.26
83 77
52.0 52.3
.20 .29
.61 .68
Rapseed
Meal, mech ext. Meal, solv. ext.
1.25 1.13
76 69
38.7 40.6
.72 .67
1.14 1.04
Soybean
Meal, mech. ext. Meal, solv. ext. Meal, solv. ext., no hull Hulls
1.39 1.38 1.43 1.05
85 84 87 64
47.7 49.9 55.1 12.1
.29 .33 .29 .49
.68 .71 .70 .21
Barley
Grain
1.38
84
13.5
.05
.38
Brewers
Grain, dehy
1.08
66
29.4
.33
.55
Citrus
Pulp, dehy
1.34
82
6.7
1.84
.12
Corn
Dist. grain* Grain, grade
1.44 1.47
88 90
25.0 10.1
.15 .02
.71 .35
Cottonseed
Whole seed
1.57
96
23.9
.16
.75
Fats
Animal
2.90
177
Molasses
Sugarcane, dehy
1.18
72
5.8
1.00
.11
Oats
Grain Groats
1.26 1.54
77 94
13.3 17.7
.07 .08
.38 .48
Sorghum
Grain
1.38
84
10.1
.04
.34
Triticale
Grain
1.38
84
17.6
.06
.33
Wheat
Grain
1.44
88
16.0
.04
.42
Yeast, Brewers
dehy
1.29
79
46.9
.13
1.49
Energy Supplements
* Feed may be used as protein or energy supplement. mech ext - mechanical extracted solv. ext. - solvent extracted
6
23.8
3.2
Composition ot Mtnerat5upptements for Beef CaHie* (Adapted from NRC, 1984). (P) (%)
(K) (%)
(Na) (%)
(S) (%)
30.1 31 .5
.6 .6
14.1 14.2
.2 .2
.4
.2
39.4 16.4
.1 .6
21 .6
.1 .1
.1 .1
1.2
2.1
.3 15.8
.3 .4
.1
22.0
.6
19.3
.1
.1
1.1
1.8
14.4
.3
.1
25.9
2.6
(CA) (%)
BONE charcoal meal, steamed 'CALCIUM carbonate (limestone) phosphate, monobasic (Monocalcium phosphate) phosphate, dibasic (Dicalcium phosphate) sulfate (Gypsum)
(CI) (%)
.2
17.2
.4
9.1
12.8
34.3
.8
14.1
460.0
(Zn) (g / kg)
.3
.5
15.0
19.2
5.5
3.5
254.5
.2
803.4
IRON (FERROUS) sulfate
218.4
12.4
LIMESTONE limestone magnesium
34.0 22.3
MAGNESIUM carbonate oxide MgO
3.1
.1
2.1 10.0
.1 .4
.1
3.5 .8
.2
30.8 56.2
.1
MANGANESE oxide MnO
774.5
OYSTERSHELL ground (flour)
38.0
.3
.1
.1
.2
PHOSPHATE defluorinated
32.0
.4
18.0
.1
4.9
39.1 50.5 21.0
1.0
SODIUM bicarbonate chloride phosphate, monobasic selenite sulfate tripolyphosphate
(Se) (g/kg)
2.0
ETHYLENEDIAMINE dihydroiodide
POTASSIUM bicarbonated chloride iodide
(Mn) (g/kg)
.8
.1
COPPER (CUPRIC) sulfate CURACAO •phosphate
(Co) (Cu) (g / kg) (g/kg)
23.5
COBALT carbonate COLLOIDAL clay
(F) (I) (Fe) (g/kg) (g/kg) (g/kg)
(Mg) (%)
Feed name
.1
47.3
.1
1.8
.2
2.9
.1
6.7
.2
.1
.6 681 .7
27.0 60.7
39.3 22.5 25.0
16.7 26.6 14.3 31 .0
ZINC oxide sulfate
456.0 10.0
17.7
.1
*Mineral compositions of feed grade mineral supplements vary by source, mining site, and manufacturer. Use manufacturer's analysis when available.
7
1.0
.1
780.0 363.6
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