Qualitative and anatomical characteristics of tree-shrub legumes in the Forest Zone in Pernambuco state, Brazil

Abstract

The objective of this study was to characterize the nutritional value of forage legumes Mimosa caesalpiniifolia (Benth.), Bauhinia cheilantha (Bong.) and Leucaena leucocephala (Lan.) and evaluate the anatomy of plants incubated and not incubated in the rumen. The experiment was conducted from September 2007 to November 2008. The experimental plot consisted of three useful plants, totaling three plots per block, and four repetitions. Plants were cut at 1 m height at intervals of 70 days; samples of leaf plus stem with a diameter smaller than 4 mm were collected for determination of dry matter, crude protein, neutral detergent fiber, acid detergent fiber, insoluble protein bound to acid detergent fiber and in vitro dry matter digestibility. The anatomical characterization occurred through the analysis of the proportion of plant tissue nonincubated and incubated in the rumen for a period of 48 hours. The legumes had high crude protein, with an average of 26.1% to Leucena, 22.4% to Sabiá and 18.5% to Mororó, and low levels of in vitro digestibility of dry matter, with an average of 47.3% to Leucena, 42.8% to Mororó and 37.2% to Sabiá. In the leaf blade of Sabiá plants, much lignified tissues that differed from plants of Leucena and Mororó were observed. The degradation process was more visible in the leaves of the Leucena, Sabiá and Mororó plants. The degradation was more pronounced in the spongy parenchyma, leaving the incubated material intact. The average proportion of the epidermis in the incubated and not incubated leaves was 15.8 and 16.4% in Leucena, 16.8 and 19.2% in Mororó and 27.2 and 25.5% in Sabiá, respectively. There are differences in the digestion and nutritional value of leaf tissues of the evaluated legumes.

Keywords

• anatomy
• chemical composition
• degradability
• native forage