Amidst the challenges posed by drought conditions, livestock producers seek innovative solutions to bridge feed gaps for their cattle. One such strategy, highlighted by University of Missouri Extension beef nutritionist Eric Bailey, involves utilizing grazing cornstalks or drought-stressed corn as a viable feed option. While this method can alleviate feed shortages, there are nutritional considerations and management tactics that must be adopted for successful implementation. Cattle producers can tap into the benefits of cornstalk grazing, provided they navigate these nuances effectively.
Cattle exhibit selective grazing behavior, naturally opting for higher-protein and easily digestible plant components. Within the corn plant, stalks rank low in the hierarchy, yet they become a valuable resource during feed shortages. Despite their fibrous and indigestible nature, cornstalks can fill the stomachs of cattle when feed alternatives are scarce. However, a key challenge emerges in managing the consumption of these fibrous materials.
Eric Bailey emphasizes that expecting cattle to consume large quantities of cornstalks is unrealistic due to their bulky and poorly digestible composition. A typical beef cow cannot consume more than 1.5% of its body weight in cornstalks daily, as they lack the necessary gut capacity. To counteract this calorie deficit, producers must offer supplementary feed.
During the initial 30 days of grazing, energy is not a limiting factor, as cattle focus on consuming higher-protein portions of the corn plant. However, after this period, protein becomes a limiting nutrient at approximately 0.5 pound of crude protein per cow per day. This factor becomes more significant for lactating cows, fall-calving cows, or stocker calves with greater nutritional demands.
Bailey stresses that cornstalk-based diets are deficient in both energy and protein. These forage resources fall below even the quality of poor fescue hay, with total digestible nutrient (TDN) levels around the mid-40s. Considering that beef cows require diets with 50%-60% TDN, producers need to supplement to meet these energy requirements adequately.
Furthermore, crude protein deficiency is prevalent in straw-based diets. Producers should aim to provide at least half a pound of crude protein from supplements to offset this deficiency arising from straw consumption.
Bailey offers a straightforward formula for estimating grazing days per acre: bushels per acre divided by 3.5. For instance, if a field yields 150 bushels per acre, there would be enough residue for 42 grazing days (150 divided by 3.5). A more refined approach involves factoring in the residue produced per bushel of grain—16 pounds of leaf and husk residue per bushel. This method allows producers to estimate dry feed availability more accurately.
Considering the potential for dry matter loss due to trampling and weathering, Bailey suggests assuming a 50% harvest efficiency. To prevent cattle from consuming lower-quality plant parts like stalks and cobs, he recommends keeping them on the field for less than two months and offering supplementary feed to compensate.
While grazing corn during droughts offers relief, an elevated risk of nitrate poisoning exists, particularly during dry conditions. To mitigate this concern, Bailey emphasizes the importance of nitrate testing before allowing cattle to graze on cornstalks.
Incorporating grazing cornstalks or drought-stressed corn into cattle diets presents a viable solution for feed shortages during drought. Eric Bailey's insights underscore the significance of effective nutritional management, mindful consumption, and supplementary feeding. By implementing these strategies and remaining vigilant about potential risks, cattle producers can leverage cornstalks as a valuable resource, ensuring the well-being of their livestock even in challenging climatic conditions.
Bailey, E. (2021). Grazing Cornstalks and Drought-Stricken Corn as Feed. University of Missouri Extension. https://extension2.missouri.edu/g2095
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