Estrutura do pasto e comportamento ingestivo de bovinos mantidos em pastagem de capim-piatã, manejado sob lotação contínua

Abstract

Animal production in Brazil was bases his development on philosophy that intensive farming is have pastures of Panicum, Pannisetumor Brachiaria, use high doses of fertilizer, especially nitrogen under rotational grazing. That model of intensive farming is responsible for inconsistent results in stacking rate and individual animal performance, which results in frustrations about productivity and profitability of animal production based on the use of pastures, just because that model simplify dynamic and complex processes involving plant and grazing animals in the grassland ecosystem. Within this context, this study aimed to evaluate and understanding the variations in the structure of palisade grass BRS. Piatã , ingestive and animal behavior of beef cattle heifers under continuous stocking management with contrasting high of sward and forage growth rate, using 20 or 40 cm height and 50 or 300 kg N per hectare. The experiment was conducted at the experimental farm Capim Branco , Universidade Federal de Uberlândia, Uberlândia/MG during the period of January to July of 2014. The experimental design for the sward structure was randomized complete block in 2 x 2 factorial with tree replications, totaling 12 experimental units. The experimental design for the ingestive and animal behavior was completely randomized factorial 2 x 2 with 4 replications, totaling 16 animals. Data were analyzed with a significance level of 5% and means compared by Tukey test. It was found that the height management of 20 cm and the dose of nitrogen fertilization of 300 kg N / ha caused an increase in the number of tillers, improved vertical morphological composition of the canopy. Also managing with 20 cm height with dose of nitrogen fertilization of 300 kg N / ha caused greater ease of apprehension forage verified by performing higher bite rate, longer time per feeding station checked by a lower daily time spent with grazing activity .It is conclude that swards grazed lower when fertilized with high nitrogen fertilization promote the production of a plant material with better canopy structure which favors the activities of search and seizure forage grazing.