Planos Nutricionais na Recria de Bovinos em Pastejo Durante as Águas.

Abstract

: In view of the search for sustainability in beef cattle production systems, the objective was to evaluate the effect of three nutritional plans during the rearing of cattle on pasture. The animals' diets consisted of pasture + mineral salt - MS (0.92 g kg of BW) or added supplement - AS (1.07 g kg of BW) or energetic protein - EP (4.78 g kg of BW), with supplementation being provided from 10:00 am to 12:00 pm. During 122 evaluation days, in the periods from 04/12/2022 to 01/30/2023 – Period 1 (P1) and 01/31/2023 to 06/04/2023 – Period 2 (P2), in a randomized block design in a split-plot scheme in the time, with three repetitions. 30 male Nelore animals with an average weight of 223.6 kg body weight and age ± 10 months were used, 27 tests and 3 regulators. The animals were weighed and checked for endo and ectoparasites, and then allocated to Urochloa pasture, weighing periodically to evaluate ADG and stocking rate (AU ha-1 ), subsequently productivity. Forage assessments were carried out according to the entry and exit of animals in the paddocks, to verify quantity (square method) and quality (simulated grazing). The data were analyzed by PROC MIXED from SAS, using the Tukey test with a probability of 5%. The forage characteristics were not modified depending on the supplementation, but they were changed depending on the periods. Forage mass (TFM) increased from input to output in P1, from 3.05 to 3.24 t ha-1 , and leaf blade dry mass (LBDM) decreased, with RFC of 1.70 at input and 0. 69 at the exit at P1. In P2, the MST at the entrance was 5.18 t ha-1 and 3.94 at the exit and MSLF 2.07 and 0.56, respectively, while the SLR was 1.05 at the entrance and 0.36 at the exit. Crude Protein was higher at the entrance of P1, with 19.92% of DM against 11.24% in P2, at the exit the average for the two periods was 11.21. Supplement consumption was around 0.92; 1.06 and 4.78 g kg of BW-1 , for MS, AS and EP. The ADG, as well as the Partial ADG Rate from P1 to P2. On average, EP promoted 44% more ADG than MS and 19% more than AS, with an average of 0.935; 0.755 and 0.649 kg cab day-1 , respectively. The ADG rate was higher in P1 and with less variation between supplements, just as the ADG. The stocking rate was higher in P2, but only in AU ha-1 (2.27), on a general average of 3.56 heads ha-1 . P1 has higher animal productivity, with 15.05 @ ha-1 compared to 9.34 in P2, with the same behavior in kg ha day-1. Productivity, both in kg day-1 and @ ha-1 , increased in the following order, MS, AS and EP, with the respective values, 2.34; 2.51 and 3.57 and 10.34; 11.35 and 15.29.