White Midrib (WMR) vs Brown Midrib (BMR) sorghum: perspective of nutrient value for ruminant forage

Abstract

Abstract Sorghum (Sorghum bicolor) cultivars can be classified as white midrib (WMR) and brown midrib (BMR). The BMR cultivar is the most potentially to be used as ruminant forage. However, the WMR, as conventional sorghum, has fairly good nutrient characteristics as roughage. The objective of our study was to evaluate the nutrient composition, fiber characteristics and nutrient value predictions of stem, leaf and panicle of Numbu variety (WMR type) and G5 mutant lines (BMR type). Five replication of two cultivars made up a randomized block design during 115 days cultivation in South Jakarta. Nutrient composition, fiber compounds and nutrient value predictions of stem, leaf and panicle were measured. There was no difference on crude protein (CP) content on stem, leaf and panicle between Numbu and G5. Numbu, as WMR type, has higher stem and leaf acid detergent fiber (ADF) and cellulose content (p<0.05) than G5. This study also proved that, G5, as BMR sorghum, had lower stem acid detergent ligin (ADL) level (p<0.05) than WMR. In panicle part, G5 had higher non fiber carbohydrate (NFC) (p<0.01) than Numbu. The stem relative feed value (RFV) represented by G5 is 136.37 and include in premium class. Conversely, Numbu included in good class, with a value of 109.83. Nutrient value characteristics of each part of sorghum is expected to be used as reference in preparing the ingredients for rations based on sorghum forage.