DPH Selection Criteria
Yield: A Hubner DPH hybrid must demonstrate an above-average yield for its maturity.
dNDF: This is the most important criteria in Hubner’s DPH selection process. dNDF is the percent of a corn silage hybrid’s NDF (neutral detergent fiber) that digests inside the rumen within the first 30 hours after consumption. For every one unit increase in dNDF, a cow can consume an additional 0.5 lb in DMI (dry matter intake) and may produce up to 0.53 lb more milk.
Lignin: This is the undigestible portion of fiber inside a corn silage hybrid’s total NDF. Knowing this figure, your Hubner advisor can determine if a given hybrid fits better in a high corn silage or a high haylage feeding ration. Conventional wisdom says lower lignin means better feed quality. However, researchers are finding that low lignin hybrids do not actually feed better than higher lignin hybrids with high overall NDF.
Lig/NDF: Using a formula—lignin divided by NDF multiplied by 100—Hubner can calculate how “lignified” the corn silage hybrid’s total NDF is. A figure of 6.0 or lower is considered excellent and translates into high DMI (dry matter intake) potential.
Starch: Knowing a hybrid’s starch level—or amount of raw food energy—is another key to solving the puzzle of rationing. High starch hybrids serve best when incorporated into a high haylage diet. However, they also serve well in high corn silage diets, with the understanding that it may require pulling dry grain or HMC out of the total feed ration.
Kernel Texture: The softer the kernel, the more available the starch is to the cow. Knowing which hybrids have a soft, medium or hard kernel texture indicates the need for kernel processing and calls out those hybrids that can offer maximum grain harvest if necessary.
IVTD: This is another corn silage hybrid energy measurement. It is calculated based on both the starch content and digestible fiber (dNDF) of a hybrid, yet does not distinguish which of the two factors contribute the most. Two IVTD figures can be the same, with one based on a high starch and the other on high dNDF. Either way, a high IVTD rating represents a cow’s highest potential for milk production. |