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ARS Home » Plains Area » Lincoln, Nebraska » Wheat, Sorghum and Forage Research » Research » Publications at this Location » Publication #205119

Title: Case Study: Nutrient values for spring and summer annual forages in a single cut harvest

Author
item WEICHENTHAL, B. - UNIVERSITY OF NEBRASKA
item BALTSENBERGER, D. - UNIVERISTY OF NEBRASKA
item Vogel, Kenneth
item Masterson, Steven - Steve
item KRALL, J. - UNIVERISTY OF WYOMING

Submitted to: Professional Animal Scientist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/15/2008
Publication Date: 12/5/2008
Citation: Weichenthal, B.A., Baltsenberger, D.D., Vogel, K.P., Masterson, S.D., Krall, J.M. 2008. Feed values for annual forages in the Central Great Plains. Professional Animal Scientist 24: 668-674.

Interpretive Summary: Annual forages with adequate feed quality can be a primary source of nutrients required by growing beef cattle or by beef cows in various stages of gestation and lactation. Annual forages including spring sown cereal crops (oats, barley, and triticale), three annual legumes (peas, soybeans, and vetch), and five summer annuals (forage sorghum, sorghum x sudangrass hybrids, sudangrass, pearl millet, and foxtail millet ) were grown in the Central High Plains of the USA in both irrigated and dryland trials and the harvested forage was analyzed for forage composition and energy concentration. All the forages evaluated in this trial had adequate Total Digestible Nutrients (TDN) or energy values for beef cows or growing beef cattle. Depending on the forage, some protein and mineral supplementation would be needed for beef cattle. Nitrate nitrogen values exceeded safe levels for millets grown with high N fertilizer rates.

Technical Abstract: Annual forages were grown in the Central High Plains of the USA in both irrigated and dryland trials and the harvested forage was analyzed for forage composition and energy concentration. Three spring cereal crops (oats, barley, and triticale), three legumes (peas, soybeans, and vetch) and five summer annuals (forage sorghum, sorghum x sudangrass hybrids, sudangrass, pearl millet, and foxtail millet) were evaluated. Cultivars of these groups were harvested in a single cut system after cereals and summer annuals had produced seed heads and legumes were in early bloom or pod-fill stages of maturity. For all harvested forages, ruminal undegradable intake protein (UIP) was generally in a range of 5 to 10% of crude protein (CP) for samples cut fresh and frozen. These values were slightly lower than UIP levels suggested by National Research Council (1996) for fresh grass and legume forages. Energy values of these forage crops were all similar. The means for digestibility (IVDMD) were similar within crops and management systems, but tended to be lower for summer annuals in irrigated trials compared to dryland trials. Annual forages with adequate feed quality can be a primary source of nutrients required by growing beef cattle or by beef cows in various stages of gestation and lactation. All the forages evaluated in this trial had adequate Total Digestible Nutrients (TDN) values but depending on the forage, some supplementation would be needed for CP and some minerals. Nitrate nitrogen values exceeded safe levels for millets grown with high N fertilizer rates.