High-shear Dry Extruded Products for Highly Digestible Rumen Microbial Protein in Dairy Part II: High Shear Dry Extruded Corn

In a previous blog, I discussed how feeding ExPress® soymeal to dairy provides a highly digestible source of protein and energy while improving milk production and lowering diet costs. Similarly, incorporating other high-quality feed ingredients, such as high-shear dry extruded corn, the ration can be adjusted to match the current milk prices. In other words, when fluid milk prices are down, incorporate more extruded corn and slightly reduce ExPress® soymeal slightly. This will further reduce the diet cost to allow for a better margin on fluid milk.

Typically, animals are fed with the cheapest and most abundant ingredients, however, nutritional quality can suffer. However, when high-quality ingredients are selected, the ration can be simplified – expensive ingredients pulled out – without sacrificing production. In particular, Insta-Pro® extruded corn can be used in place of other cereal grains to promote efficiency by boosting rumen microbial protein. Rumen microbes and their products are a major source of protein in the cow’s diet. As summarized above, highly-gelatinized starch readily feeds the rumen microbes, some of which escape the rumen and are digested by the cow. One of the main sources of microbial protein that feed the cow are the microbes themselves. When they enter the small intestine, they are broken into amino acids and can be used to support milk production. Additionally, rumen microbes produce volatile fatty acids from fermentation of starchy grains which act as a fuel source for the cow and support body condition, growth, and activity levels.

When corn is processed, the bonds which hold the starch molecules together break down or gelatinize – a measure of how well the starch is cooked. Based on which thermal process is used, the degree of starch gelatinization can vary. As summarized below, extruded corn – a fully gelatinized starch ingredient – is degraded efficiently in the rumen. As a result, extruded corn had a 19% increase in digestibility compared to steam flaked corn (partially gelatinized) and a 22% increase in digestibility over ground corn (unprocessed). It is important to note, steam flaked corn only has a slight 3% digestibility advantage over ground corn in the rumen despite a higher degree of starch gelatinization. Furthermore, a greater degree of starch gelatinization – like that from extruded corn – resulted in rumen microbial protein increasing by almost 4X that of steam flaked corn and 8X that of ground corn.

Taken together, extruded corn is a highly digestible source of rumen degradable protein for dairy cows which supports milk production. Inclusion of high quality feed ingredients, such as extruded corn and ExPress® soymeal, in the dairy ration work in synergy to reduce feed costs.

Contact Insta-Pro® International’s sales team today to learn about corn extrusion.