Composição bromatológica do feijão-dos-arrozais (Macroptilium Lathyroides (L.) Urb.)

Abstract

The objective of the study was to determine its chemical composition throughout the productive cycle. The experiment was carried out in the municipality of the Capão do Leão -RS (31º 52’ S e 52º 29’ W), physiography region of the south coast of Rio Grande do Sul. At 45 days after the emergence of the plants was the first cutting of the forage evaluation and, with intervals of 15 days, another nine cuts were carried out, all 5 cm from the soil. This constitutes an experiment with ten treatments and three repetitions in entirely randomized. The variables studied were Neutral detergent fiber (NDF), Acid detergent fiber (ADF), Acid detergent lignin (ADL), Crude protein (CP), Total lipids (TL), Phosphorus (P), Potassium (K), Calcium (Ca) and Magnesium (Mg). The results were submitted to analysis of variance and polynomial regression. All variables showed significance (P≤0.05) for cubic regressions, with average values of: NDF= 58.15; ADF= 38.94; ADL= 9.15; CP= 11.59; TL= 1.18%; P= 2.29; K= 10.19; Ca= 26.48 and Mg= 4.53 g/kg of MS; similar to other hot-climate forage legumes. The chemical quality of feijão-dos-arrozais varied throughout the productive cycle, being directly influenced by the habit of undetermined growth of the species. From the point of view of chemical quality, the forage for the first growth of Feijão-dos-arrozais should be harvested up to 75 days after the emergency, during which smaller levels of fiber and lignin are combined with higher levels of crude protein, lipids, magnesium and calcium.