The Influence of Severe Drought on Selected Nutritional Characteristics of Commercial Corn Hybrids

Abstract

In 1988, after a severe drought during the growing season, samples from 12 commercial com varieties were collected from the same test area. The average yield was 85 bu/acre (1 bu = 35.24 L; 1 hectare = 2.47 acres), which was 50% lower than yields of the previous year from the same area. Average CP was 9.50% compared with 8.80% recommended by the National Research Council (NRC) in 1984, but there were minimal differences between NRC recommended and analyzed concentrations of methionine and lysine. Analyzed total sulfur amino acid concentrations were approximately 10% higher than NRC levels. Regression equations based on CP concentrations resulted in significantly higher predicted values for lysine, methionine, and methionine plus cystine. The results suggest that when protein values in corn are elevated due to an environmental stress, conservative amino acid values should be used for dietary formulation. (Key words: corn, drought, protein, true metabolizable energy, amino acids) 1991 Poultry Science 70:2329-2334