Written by Jeffery Goss, OFN ContributorWhether as grain, forage, ensilage, or all of these, corn plays a part in feeding most Missouri and Arkansas cattle herds. Yet in terms of nutritional value, all corn is not equal.
Field corn varieties can be categorized into two main types: Open-pollinated and hybrid. Most U.S. corn is now hybrid, partly because hybrid varieties tend to have somewhat higher yield potential (under optimal conditions) than equivalent open-pollinated, or non-hybrid, strains. Hybrid corn, however, tends to be less nutritionally complete than open-pollinated corn.
According to a Crop Science report form Nebraska, recommended as a source by Missouri University cattle nutrition specialist Justin Sexten, standard open-pollinated varieties of corn yielded less digestible forage than hybrid "forage corn" did. Forage corn, grown from special hybrid seed available at supply stores, is a maize variety which is mostly sterile and cannot be grown for grain; its sole use is to quickly grow a large amount of green matter for grazing or ensiling. Due to its high-nitrogen-feeding characteristics, it holds a large volume of moisture and limited amounts of cellulose content.
However, the grain itself is higher in protein in open-pollinated strains than in most hybrids, according to the University of Illinois and the Green Haven Open-Pollinated Seed Group, a cooperative of OP corn farmers. Hybrid varieties generally carry a high density of starch in their kernels, whereas OP (non-hybrid) varieties have more free sugars and more minerals, in addition to more protein. For this reason it is often regarded as nutritionally superior. It also appears to be more palatable to animals, according to many farmers who have seen them choose it over hybrid corn when given a choice.
Although OP corn varieties are commercially available, the prevalence of hybrids can make it hard to find OP whole corn at feed stores. For farmers who grow their own corn crop, however, open-pollinated seed is available from a number of sources (see list). The most adapted variety for the Ozarks regions is 'Hickory King', which most of these sources carry.
Hybrid varieties and OP varieties of corn are generally grown the same way, except that OP strains need slightly less nitrogen than hybrids. The OP seed is usually somewhat less expensive than a similar amount of hybrid seed corn; moreover, the grower can select the best ears and save them for next year's stock. These three cost-savings can make up for the slightly lower yield. Moreover, open-pollinated varieties can have a higher yield potential when conditions are sub-optimal.
In terms of feed quality superiority, the higher protein and mineral content of OP corn varieties has led many farm advisors, particularly organic and integrative farm advisors, to recommend feeding open-pollinated whenever possible. They point out that starch without sufficient protein leads to hindered development in colts and calves, and excessive body fat in adult animals.
Sexten agrees on the facts, but is hesitant to agree on the principle. "Corn is not a protein supplement," he said, "from a livestock perspective, we are (most concerned) with the energy content of corn" (i.e., its caloric value). He also warned that OP-versus-hybrid comparisons based on the concentration of protein, or any other nutrient, must be viewed in the context of total yield. Furthermore, he noted that the nutritional advantages said to be present in OP varieties do not extend to forage or silage. Referring to the aforementioned study published in Crop Science, he stated that hybridized varieties, due to their higher digestibility, yielded a more nutritive forage crop. This, according to the study, caused dairy herds to give "more milk per acre" than they did when consuming OP corn silage.
Oklahoma stockman Jim Esbenshade, who has grown both corn types, has a different perspective.
"Cattle do better on it," he said in reference to the open-pollinated 'Wapsie Valley' dent corn he feeds to them. "Its protein is 2 to 4 points higher (than hybrid), and the cattle do better. Now the corn doesn't yield as high, but I'm raising better-quality beef. I think the (hybridizers) know this, but they're pushing so hard for yield, they forget about the quality. They had to pay a price." He also said that in terms of silage, though not in terms of grain, his open-pollinated 'Lancaster Sure Crop' equaled the tonnage, acre for acre, of a currently popular hybrid.
Esbenshade attributes this in part to the OP corn's superior drought resistance. "It's old, reliable, and… it works in the dry weather better."
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