Estrutura e valor nutritivo do pasto diferido de Brachiaria decumbens cv. Basilisk durante o período de pastejo

Abstract

The experiment aimed to understand the effect of grazing period on morphology and nutritive value of deferred Brachiaria decumbens cv. Basilisk pasture and on hand-plucking sample with cattle. Subdivided plots were used according to a randomized block design with two replicates. Four grazing periods (1, 31, 57 and 88 days) and two forage samples (available in pasture (AP) and obtained by hand-plucking (HP)) were studied. The live leaf laminae (LLL), potentially digestible neutral detergent fiber (PDNDF), potentially digestible dry matter (PDDM) and crude protein (CP) levels were higher and dead leaf laminae (DLL), and dead stem (DS), neutral detergent fiber (NDF) and indigestible NDF percentages were lower in sample of HP in relation to forage AP. The grazing period decreased linearly the LLL, PDNDF, PDDM percentages, as well as increased linearly DS and indigestible NDF levels in forages. The potential selectivity indexes (PSI) of LLL and indigestible NDF increased linearly with grazing period. The PSI of live stem was smaller and the PSI of CP was higher in interim periods of grazing. The reduction in deferring period results in B. decumbens with better morphological composition and nutritional value, which favors the animal selectivity.