Rest period, forage nutritive value and steer performance on Panicum maximum cv. Mombaca pasture under intermittent stocking

It was assessed the nutritive value of hand plucked forage samples collected along the grazing period and the animal performance on Mombacagrass pasture under intermittent stocking with three rest periods (RP). The RPs were defined by the time required for the expansion of 2.5, 3.5, and 4.5 new leaves per tiller, after six days grazing period. The experimental area was divided into five paddocks for the 2.5 new leaves RP and six paddocks for the 3.5 and 4.5 new leaves RPs. Five crossbreed (Holstein x Zebu) steers were randomly assigned to each treatment (RP) as tester animals; put and taken steers were used to assure residual leaf area index of about 2.0, by the end of each grazing period. A NPK fertilization of 100: 25 and 100 kg/ha of N, P2O5 and K2O, respectively, divided into two applications, was broadcasted on each paddock at the beginning and middle of the experimental period. The following evaluations were performed: chemical composition and in vitro dry matter digestibility of hand plucked forage samples, forage intake and live weight gain of tester animals. The rest period had less effect on forage nutritive value than the grazing period; still, the rest period affected steer live weight gains. The longest RP resulted in low animal performance (433 g/steer x day) and yield (363 kg BW/ha); on the other hand. the shortest RP favored high animal performance (704 g/steer x day) and yield (546 kg BW/ha). It is concluded that rest period of Punicum maximum cv. Mombaca should not exceed the time for the expansion of 2.5 new leaves per tiller, which varied from 24 to 41 days over the experimental period.