Resumen

SANCHEZ, Alexander; GONZALEZ CANO, Javier  y  FARIA MARMOL, Jesús. Compared evolution of the chemical composition with the cuttimg age in the species Leucaena leucocephala and L. trichode. Zootecnia Trop. [online]. 2007, vol.25, n.3, pp.233-236. ISSN 0798-7269.

ABSTRACT Plant maturity effects on the contents of crude protein (CP), neutral (NDF), acid detergent fiber (ADF), and in vitro organic matter digestibility (IVDOM) were evaluated in the species Leucaena leucocephala and L. trichodes at 40, 60, 80, 100, and 120 days of sprout age. Plants were arranged randomly in a 2x5 experimental design, with three repetitions of eight plants each.  The area is located in a tropical dry forest region, with an average yearly rainfall of 800 mm, and a loamy texture soil with a pH of 5.8. Samples analyzed included leaves and shafts lower than 6 mm of diameter. The statistical analysis included as variation sources specie and cutting age (fixed factors), and its interactions. Estimates of CP, NDF and ADF were higher in the specie L. trichodes (P<0.001) with values of 25.7 vs. 24.3, 33.8 vs. 30.5, and 24.3 vs. 22.1%. Maturity had limited effects on most variables: CP decreased whereas the remainder variables increased. These variations were always smallest in L. trichodes. The IVDOM estimate was higher in L. leucocephala (P<0.001) with mean values of 80.7 vs. 77.7%. The nutrient content and OM digestibility recorded for these species showed its high potential as forage source for ruminant nutrition in tropical areas

Palabras clave : Leucaena leucocephala; Leucaena trichodes; maturity; chemical composition; digestibility.