Preference of fodder marandu-grass (Urochloa brizantha cv. Marandu) managed under intermittent stocking and submitted to nitrogen levels in the legal Amazon

Abstract

The objective of this study was to evaluate the preference of forage intake on pastures subjected to doses of N. The experimental design was a randomized blocks, with split plots in 5 x 3, five N rates (0, 25, 50, 75 and 100 kg ha-1 cycle-1) and three instant of grazing (mass initial estimates) and 5 x 2, five N rates and two instants of grazing (estimates related to the disappearance of forage), with four replications, totaling 20 experimental units. The preference for consumption was measured morphogenesis, based on the flow of bodies missing in function of grazing time of grazing. The forage intake showed a linear response to N supply, with a significant reduction in herbage mass values over 6 occupation period to 12 hours of the plots, demonstrating selective grazing on increase doses of N. Marandu-gass are not fertilized only grazed when forage mass in the larger N application rate falls due to the grazing time. The herbage disappearancee in the lower stratum also responded linearly to N in the first 6 hours of grazing, while the forage disappearance of the upper stratum responded quadratically to N supply. The probability of defoliation was different (P<0.05) for the grazing time and N levels. Confirming that cattle prefer to consume forages with high levels of N application on the less, in the early hours of grazing.