Author
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Aiken, Glen |
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Submitted to: Cow Country News
Publication Type: Popular Publication Publication Acceptance Date: 4/23/2016 Publication Date: 5/1/2016 Citation: Aiken, G.E. 2016. From the Lab Bench: The crazy notion of supplemental feeding of cattle grazing lush green forage. Cow Country News. Pgs. 36-37. Interpretive Summary: It seems odd to supplemental feed cattle during the growing season, but forages can often have nutrient deficiencies during some of the growing season. Your pasture forage can be less in crude protein to meet the protein requirement of your cattle, and the forage will naturally decline over the season even if it is fertilized in the spring. Light stocking densities can also cause an accumulation of forage that will mature and decline in nutritive value. Therefore, it is important to understand how the nutritive value of your pasture forages can change over the growing season. Consult your Extension Agent and Specialists, or collect forage samples from your pastures over the growing season, and have them tested. A good fertilization program can give you confidence in the crude protein available in your pastures; otherwise, some protein supplementation may be needed. However, if your pastures are grazed with light stocking rates that allow the forage to excessively accumulate and mature during periods, you may have forage with low total digestible nutrients (TDN)and some energy supplementation may do your cattle some good in a cost-effective way. The more you know about your pasture forage, the more informed decisions that can be made to cost effectively increase cattle production, such as strategically supplementing nutrients that can overcome deficiencies that can occur during the growing season. Technical Abstract: A column was written to discuss the reasons you may want to supplemental feed cattle grazing green and lush pastures. We know there are those times of the year when forage is actively growing, but can this forage be counted on to meet your goals in cattle production? We assume the green forage can supply the nutrients needed to maintain a productive herd of cattle if soil fertility is maintained and minerals are offered. Pastures can be rotationally stocked, limed and fertilized, and the weeds controlled to maximize cattle production potential. As cattle production goals intensify, these recommendations become more relevant; however, there is one factor out of our control that adds a greater challenge to meeting high expectations with forage-based cattle production. If there is adequate forage production (stocking rates are not excessive), it is the quality of the forage that can limit cattle performance. Crude protein of grasses can decline over the growing season to percentages that fall below animal requirements. We have found that split applications of nitrogen can help maintain higher protein in the later growing season, but this may not be feasible or practical for many operations. Grasses will also decline in energy (total digestible nutrients, TDN) as they accumulate and mature. The most promising option is to overseed pastures with high-quality clovers, but another option is to feed a concentrate or co-product feed that targets protein and/or energy deficits. Nutrient supplementation is most cost effective if the supplementation targets a true deficiency, which means cattle producers must understand the quality of their pasture forage and it can trend over the grazing season. |
