On-line version ISSN 1678-992X
CASTRO, Flávio Geraldo Ferreira et al. AGE AT CUTTING, YIELD, CHEMICAL COMPOSITION AND DRY MATTER DIGESTIBILITY OF FLORICO STARGRASS. Sci. agric. [online]. 1999, vol.56, n.1, pp. 225-234. ISSN 1678-992X. http://dx.doi.org/10.1590/S0103-90161999000100030.
The objective of this study was to evaluate dry matter production, chemical composition, variation in macro and micro mineral content and mineral uptake by `Florico' stargrass, as related to plant age at cutting. The experiment was a randomized complete block design with six treatments replicated four times. Treatments consisted of six cutting periods every 10 days, with the first cut 20 days after staging. Data, analysed at a probability level of P < 0.05, showed that dry matter production incresed quadratically between 20 and 70 days of regrowth, whereas dry matter concentration increased cubically . True "in vitro" dry matter digestibility and crude protein concentration decresead quadratically with increasing age. Conversely, neutral detergent fiber and acid detergent fiber concentrations increased quadratically. Concentrations of the macroelements potassium, calcium, magnesium, and sulfur decresead linearly, whereas nitrogen and phosphorus concentrations decreased quadratically. Copper concentration was not affected by age, but boron concentration declined cubically. Concentrations of iron and zinc decreased quadratically, whereas manganese decreased linearly. Chemical composition and digestibility were considered adequate up to 35 days after cutting, except for zinc and cooper concentrations. With advanced maturity, the nutritive value parameters remained at reasonable high levels, turning make stargrass an option for stockpiled forage.
Keywords : chemical composition; cutting age; Cynodon; pasture.