Estratégias de manejo alimentar para recria e terminação de bovinos de corte

Abstract

The objective was to evaluate two experiments: a) the first experiment (rearing) evaluated three types of mineral supplements in two grazing systems, one common mineral with 6.0% phosphorus and two types of minerals one with Narasina and another with Flavomycin and two grazing systems, one Intensive and the other Semi-Intensive. The experimental model was used in a completely randomized design with a 3x2 factorial arrangement, with three replications per treatment, 54 Nellore cattle, whole males aged 14 to 16 months, were used. b) in the second experiment (termination), four food management strategies were evaluated, being a traditional feedlot, a 100% diet in the trough, adopting a relationship: concentrated: bulky (75:25) and the other three pasture strategies , low consumption (2.5 kg of day- 1 concentrate), semi-confinement (5 kg of day-1 concentrate) and pasture confinement with (7.5 kg day-1 concentrate) in natural matter, in two evaluative periods period 1 with 53 days duration and period 2 with 84 days, a completely randomized design was adopted as a statistical model, with a 4x2 factorial arrangement, 48 nellore cattle, uncastrated males with initial live weight close to 474, 1 kg (± 26.8 kg). The rearing did not present significant results in most of the evaluated variables (P> 0.05) when comparing the three types of mineral supplement regardless of the management system, such result may have been obtained because both systems have provided pastures in good condition. Nutritional status which resulted and high gains, thus it is not possible for additives to promote an increase in gains per animal. However, when comparing the grazing systems were quite significant and had better results in the Intensive system. However, when evaluating the production of forage mass of the two systems, little difference was observed in the production of total dry matter of the pasture, in which, the Intensive system had greater production of leaf leaf dry mass, consequently providing greater accumulation of total forage. The in period and lower production of dry mass of dead material when compared with the Semi-Intensive system. The Semi-Intensive system had a higher canopy height and this increase of 6.5 cm, may have promoted a change in the structure of the pasture, such an increase may have made it difficult to apprehend the forage which also promoted a greater production of dry mass of dead material. It is and assumed that consequently resulted in a lower average daily gain-1 of the animals in this system when compared to the fine adjustment (0.870 vs 1.022 respectively), a difference of 0.152 kg per animal -1. The Intensive system obtained the highest production in @ per ha-1 together with the highest stocking rate, however, the two systems provided very significant gains in @ per ha-1 36.8 and 15.2 @ per ha-1 for the systems Intensive and Semi-Intensive, respectively, products with additives did not promote increased gain in pastures with good nutritional indices and the intensification of forage production reflects an increase in productivity indices in both animals and plants. In the second experiment, the animals showed no difference (P> 0.05) for most of the production characteristics evaluated, such as final live weight and carcass yield between feeding management strategies, however, when evaluating the Periods, the period 2 performed better, due to the longer time the animals stayed in the system, so the best average daily gains-1 were observed for traditional confinement, not differing from confinement and semi-confinement, but it differed from the low consumption system. However, the best economic results based on average daily gains-1 and daily carcass gains-1 were observed in Period 1, for the semi-confinement system, which consisted of the shortest period of termination, thus, supplementation strategies in termination also provided changes in the stocking rate and the area used, in which when the amount of concentrate used was increased, the area used was reduced and the stocking rate was increased. Finally, the rearing well done based on the management of intensive grazing, provides an increase in the average daily gain-1 and the stocking rate, resulting in an excellent production of @ per hectares, so that it is reared with high zootechnical indexes of animal production it provides a reduction in the termination period and a reduction in the area used, just as termination in a semi-confinement system provides high gains with excellent profitability.