Dr. Fred Owens and Tim Harbaugh
Optimum Quality Grains, L.L.C.
Dairy Update
Introduction
Levels of milk production by U.S. dairy cattle continues to rise. With increased production comes an increase in nutrient requirements. It becomes difficult to pack enough energy, protein, fiber, and other nutrients into the feed that a cow can consume. This problem of inadequate nutrient supply has increased interest in nutrient dense products such as OPTIMUM® High Oil Corn by the dairy industry.
Substituting OPTIMUM High Oil Corn for typical corn generally incr4ases production, and may improve body condition and reproductive health, as well. It also may reduce feed cost and improve income over feed cost when used to replace expensive supplemental fat sources such as tallow, whole soybeans, or whole cottonseed.
What is OPTIMUM High Oil Corn?
OPTIMUM High Oil Corn is an energy-enriched feed ingredient developed by combining years of conventional corn breeding with Optimum Quality Grains’ TOPCROSS® grain production system.
OPTIMUM High Oil Corn has nearly twice the energy-dense oil of typical corn. This is a result of selecting for enlarged size of the germ, where the oil is located, and displacing some of the endosperm, which is largely starch. Since oil has 2.25 times the energy value of starch, OPTIMUM High Oil Corn grain contains 4 to 6% more energy than typical corn. Because the composition of the grain is changed but the stover is not altered, high oil corn silage will contain 2 to 4% more energy than typical corn silage.
The nutrient composition of OPTIMUM High Oil Corn grain produced by the TOPCROSS grain production system is shown in Table 1. OPTIMUM High Oil Corn grain has more oil (fat) and protein but less starch than typical corn. Typically, starch content declines by 1.3% for every 1% increase in crude fat. The increased crude protein of OPTIMUM High Oil Corn is composed largely of germ protein, a protein source richer in essential amino acids (lysine, methionine) than protein from the endosperm portion of the corn kernel.
| Table 1: Nutritional Composition of OPTIMUM High Oil Corn grain, compared to typical corn grain1. | |||
| Nutrient |
Typical |
OPTIMUM |
% |
| Crude fat, % |
4.03 |
7.36 |
82.6 |
| Crude Protein, % |
9.23 |
9.83 |
6.5 |
| Starch, % |
71.40 |
67.90 |
(4.9) |
| Crude fiber, % |
2.27 |
2.40 |
5.7 |
| TDN, %* |
80.3 |
84.6 |
5.4 |
| NEL, Mcal/lb.* |
.84 |
.89 |
6.0 |
| Ash, % |
1.32 |
1.45 |
9.8 |
| Ca, % |
.01 |
.01 |
– |
| P, % |
.28 |
.30 |
7.1 |
| Vitamin E, mg/lb |
12 |
15 |
27.3 |
| 1 Values are expressed on a 100% dry matter basis * Values are based on Weiss (1997) equations. |
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Nutritional Considerations
Since OPTIMUM High Oil Corn has a higher nutrient density than typical corn, it is most beneficial and valuable in situations where a high nutrient density is needed. This makes OPTIMUM High Oil Corn more useful in diets for lactating cows than for growing heifers or dry cows. Within the lactating herd, OPTIMUM High Oil Corn will produce the greatest benefit for high producing cows, enhancing production and persistency by reducing the drain on tissue energy reserves. Through replacing other sources of energy and protein in the diet, the value of OPTIMUM High Oil Corn is dynamic: its value changes with the price of commodities that it replaces.
OPTIMUM High Oil Corn can be used as a feed ingredient in two ways:
- To increase the energy content of the diet, or,
- To replace specific ingredients added to the diet to provide energy or fat.
Several additional benefits may be observed when OPTIMUM High Oil Corn replaces typical corn in the diet. First, because it contains more protein, the amount of supplemental protein that needs to be added to the diet will be reduced. Second, because oil displaces starch, the incidence of digestive upsets/disorders may be reduced, especially with the high starch diets typically fed in the upper Midwest. Replacing starch with oil is particularly useful for transition or fresh-cow rations. Finally, the higher oil level will help alleviate effects of heat stress on cows because oil-enriched corn has a lower heat increment than typical corn.
The oil contained in OPTIMUM High Oil Corn is well digested and has an energy value similar to that of choice white tallow. Also, since the oil is within the germ, it is less readily available in the rumen than added fat. Thereby, OPTIMUM High Oil Corn does not depress dry matter intake or fiber digestion as often occurs when liquid plant fats are added to the diet. In fact, dry matter intakes for cows fed OPTIMUM High Oil Corn generally have been greater than for cows fed typical corn.
Because OPTIMUM High Oil Corn is a “specialty” product as compared to bin-run commercial corn grain, its quality and consistency generally is far superior to typical corn grain. This is because it is “Identity Preserved” and not blended and diluted with grain of substandard quality. Compared to typical corn, OPTIMUM High Oil Corn generally requires less energy to grind and generates less dust when processed. Compared to supplemental sources of liquid fat, OPTIMUM High Oil Corn is easily stored, handled and transported.
OPTIMUM High Oil Corn can be fed as dry corn, high moisture corn, or corn silage. Since the oil is located in the germ or embryo, it is deposited early during kernel development. Because OPTIMUM High Oil Corn differs from typical corn only in chemical composition of the kernel, feeding OPTIMUM High Oil Corn either as earlage or corn silage will have less impact on production than feeding the grain because with earlage or corn silage, the grain is diluted with cob and stover. Table 2 shows the nutritional composition of OPTIMUM High Oil Corn silage in comparison to typical corn silage.
| Table 2: Nutritional Composition of OPTIMUM High Oil Corn silage, compared to typical corn silage1. | |||
| Nutrient |
Typical |
OPTIMUM |
% |
| Protein, % |
7.74 |
8.35 |
7.88 |
| Oil, % |
2.86 |
4.48 |
56.64 |
| ADF, % |
23.40 |
23.75 |
1.50 |
| NDF, % |
41.70 |
42.14 |
1.06 |
| TDN, % |
70.00 |
72.41 |
3.44 |
| NEL, Mcal/lb. 2 |
0.725 |
0.751 |
3.59 |
| NEg, % |
0.467 |
0.496 |
6.21 |
| NEm, % |
0.742 |
0.776 |
4.58 |
| 1 Values are expressed on a 100% dry matter basis 2 Calculated from chemical composition (Weiss et al., 1997). |
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OPTIMUM High Oil Corn Silage
OPTIMUM High Oil Corn produces excellent quality, high-energy silage. As with all silage, the net energy value (NEL) of the silage depends on 1) the grain to stover ratio and 2) the digestibility of the stover and the grain portions of the plant. In addition, added oil from the OPTIMUM High Oil Corn grain increases the energy value of the grain in the silage. In some laboratories that predict NEL values from fiber content alone, the value from the added oil will be overlooked and its nutritive value will not be detected.
When selecting a seed product for producing silage, producers should consider agronomic traits, whole plant yield, grain to stover ratio, and stover digestibility as well as oil level. OPTIMUM High Oil Corn silage should be harvested and managed similar to conventional corn silage for optimum yield and nutritional value.
Research Studies to Determine Feeding Value
Several research trials have been conducted to appraise the nutritive value of OPTIMUM High Oil Corn harvested as grain or as silage. Some of the earlier silage trials evaluated varieties that were marketed before today’s high grain-yielding hybrids were developed. The lactation trials below that have been conducted more recently have assessed the impact of increasing the energy density of the diet by substituting OPTIMUM High Oil Corn for typical corn as both grain and silage.
Three experiments were conducted at the University of Illinois to evaluate the feeding value of OPTIMUM High Oil Corn. Crops were harvested and fed either as dry rolled grain or as corn silage or in combination. Data were pooled across trials since the same experimental design was used in all three studies. No fat was added to the diets containing typical grain.
Averaged across the silage types, substituting OPTIMUM High Oil Corn grain for typical corn grain increased dry matter intake by 3.8 pounds per day and increased milk yield by 2.3 pounds per day. When OPTIMUM High Oil Corn silage replaced typical corn silage in the diet, dry matter intake increased by 1.6 pounds per day and milk production increased by 1.7 pounds per day. No differences in nutrient digestibility were detected between OPTIMUM High Oil Corn and typical corn when fed as either grain or silage; this indicates that the oil provided by the corn grain was not depressing fiber digestibility. In all three trials, the highest dry matter intakes and milk production was achieved when OPTIMUM High Oil Corn grain was fed in combination with OPTIMUM High Oil Corn silage. These trials indicate that diets containing OPTIMUM High Oil Corn can be effectively utilized by lactating dairy cows and that OPTIMUM High Oil Corn (OHOC) can increase milk production when substituted for typical corn in diets without added fat.
| Table 3: Overall Trial Performance Summary | ||||
|
Typical Silage |
OHOC Silage |
Typical Silage |
OHOC Silage |
|
| DM Intake, lb./day |
45.3 |
46.7 |
49.0 |
51.0 |
| Milk, lb./day |
75.1 |
75.7 |
76.0 |
79.9 |
| 4.0% FCM, lb./day |
65.3 |
66.1 |
67.6 |
68.5 |
| % Fat |
3.16 |
3.20 |
3.30 |
3.08 |
| % Protein |
3.11 |
3.07 |
3.11 |
3.08 |
| Graph 1: Effect of OPTIMUM High Oil Corn (OHOC) on 4% FCM Production |
 |
In these studies OPTIMUM High Oil Corn effectively replaced 100% of the typical corn in lactating cow diets that contained no added fat. The increased energy intake from feeding OPTIMUM High Oil Corn may increase milk production, help maintain or increase body condition, and/or improve reproductive health during early lactation. Since the fatty acids in OPTIMUM High Oil Corn are unsaturated, OPTIMUM High Oil Corn should be managed like other oilseeds. However, feeding OPTIMUM High Oil Corn as either grain or silage did not negatively affect fiber or starch digestion in these studies.
The response to feeding OPTIMUM High Oil Corn silage will depend on diet formulation and the seed product used to produce the silage. The seed products used in some of the first research trials are not representative of the improved TC BLEND® seed products sold by most seed companies today. Reputable seed companies will show producers results from comparative grain and silage production trials conducted nearby and assist producers in selecting a variety suited to specific farm and agronomic conditions.
OPTIMUM High Oil Corn Dairy Value Calculator
A calculation system has been developed to easily compare the economic value of OPTIMUM High Oil Corn with other feed ingredients that supply energy and protein in typical midwestern dairy cow diets. In Table 4, OPTIMUM High Oil corn grain and corn silage effectively replaced all the fat being added to the typical corn ration. Diet composition was similar, but by displacing supplemental fat in the diet, the OPTIMUM High Oil Corn grain was worth 41 cents per bushel more than typical corn.
| Table 4: Example Optimum Dairy Value Calculator | ||||||
| Typical corn plus Added Fat vs. OPTIMUM High Oil Corn (OHOC) | ||||||
|
Typical |
OPTIMUM |
|||||
| Ingredient |
lb. as-fed |
lb. DM |
lb. as-fed |
lb. DM |
||
| Alfalfa Hay |
12.00 |
10.20 |
12.00 |
10.20 |
||
| Corn Silage |
60.00 |
21.00 |
– |
– |
||
| OHOC Silage* |
– |
– |
60.00 |
21.00 |
||
| Corn Grain |
12.75 |
10.84 |
– |
– |
||
| OHOC Grain* |
– |
– |
14.73 |
12.52 |
||
| Fat |
0.96 |
0.91 |
– |
– |
||
| SBM |
10.63 |
9.57 |
9.77 |
8.79 |
||
| Vit./Minerals/Buffers |
1.50 |
1.49 |
1.50 |
1.49 |
||
| Total |
97.84 |
54.00 |
98.00 |
54.00 |
||
| *Nutrient profiles based on OPTIMUM High Oil Corn (OHOC) and typical corn samples takenover the past 3 years (OPTIMUM 80) | ||||||
|
Ration analysis, DM Basis |
||||||
|
Typical |
OPTIMUM |
|||||
| Dry Matter Intake, lb./d |
54.00 |
54.00 |
||||
| Ration DM % |
55.19% |
55.10% |
||||
| % Forage* |
42.22% |
42.22% |
||||
| % NDF |
29.64% |
29.62% |
||||
| % CP |
17.01% |
17.00% |
||||
| % Oil |
4.32% |
4.32% |
||||
| % Starch |
26.00% |
25.86% |
||||
| NEL Mcal/lb. DM |
0.77 |
0.76 |
||||
| Cost per day, $ |
$2.89 |
$2.71 |
||||
| Difference, $/day |
$0.18 |
|||||
| OHOC fed/day, bu |
.44 |
|||||
| Net Value of OHOC, $/bu |
$0.41 |
|||||
| * The ration forage level assumes that the corn silage is 60% forage | ||||||
The value of OPTIMUM High Oil Corn depends on several variables. These include:
- Fat and protein level in the OPTIMUM High Oil Corn
- Replacement cost of added fat and protein
- Animal performance and nutrient requirements
- Intrinsic values (less processing costs, dust, etc.)
- Milk price
- Premium paid to grow or purchase OPTIMUM High Oil Corn
- Identity preservation costs
Dairy producers that grow their own crops or contract with other growers are in an ideal position to capture the value of OPTIMUM High Oil Corn. Relative yields of silage and grain as well as cost of seed for OPTIMUM High Oil Corn must be compared with other hybrids available locally. Again, the calculation system described above will simplify these economic comparisons.
Conclusions:
- Feeding OPTIMUM High Oil Corn increases the energy density of the ration compared to diets not supplemented with fat; this should increase milk production and improve body condition and reproductive health.
- OPTIMUM High Oil Corn is more consistent in quality than typical corn because it is identity-preserved.
- Feeding OPTIMUM High Oil Corn will reduce supplement cost and may eliminate the need for on-farm fat tanks.
- OPTIMUM High Oil Corn reduces caking on mixing and delivery equipment; this helps to minimize the risk of drug residues.
- The fatty acid composition of OPTIMUM High Oil Corn is very consistent compared to that of commodity fat sources.
- Ration formulation considerations made with OPTIMUM High Oil Corn should be consistent with those for formulating rations containing supplemental fat.
References
Atwell, D.G., E.H. Jaster, K.J. Moore, and R.L. Fernando. 1988. Evaluation of OPTIMUM High Oil Corn and corn silage for lactating dairy cows. J. Dairy Sci. 71:2689-2698
LaCount, D.W., J.K. Drackley, T.M. Cicela, and J.H. Clark. 1995. OPTIMUM High Oil Corn as silage or grain for dairy cows during an entire lactation. J. Dairy Sci. 78:1745-1754
Drackley, J.K. 1997. Update on OPTIMUM® High Oil Corn for Dairy Cattle. Proceedings from the 4-State Applied Nutrition and Management Conference. Aug. 5-6, 1997. La Crosse, WI
Weiss, W. P. 1997. Improved methods of estimating digestibility and energy values in forages. Silage: Field to Feedbunk. North American Conference, NRAES-99, pp. 278-288.
Bower, J. T. OPTIMUM® High Oil Corn Silage Development Program from 1995 through 1997.
Optimum Quality Grains, L.L.C.
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