Avaliação de espécies forrageiras de inverno submetidas ao pastejo com bovinos

Abstract

In the state of Santa Catarina, winter is characterized by low temperatures and the occurrence of frosts, reducing the forage supply of perennial species to beef cattle. However, crop-livestock integration makes it possible to produce grain in the summer and pasture in the winter. Annual winter pastures are alternatives that play a fundamental role in the production of food in quantity and quality for the beef cattle sector, reducing the seasonality of the critical period of perennial forage supply. The present work aimed to evaluate the forage production and quality of winter species, wheat (Triticum aestivum) double-purpose, wheat for grazing, white oat (Avena sativa), black oat (Avena strigosa) and ryegrass (Lolium multiflorum), under grazing conditions with cattle. The experiment consisted of 6 treatments, namely: Biotrigo Lenox, only for grazing; BRS Tarumã, dual-purpose; Embrapa Black Oat 139; White Oat Border; Ryegrass Nibbio; and Ryegrass Ceronte; with 4 repetitions. The experiment was carried out in strip cultivation, with a complete block design, with 24 plots measuring 220 m each, totaling 5280 m². Up to 4 cuts were performed, evaluating the forage production, and the samples were collected before the cattle grazing, when they reached a height of approximately 30 centimeters, and the animals were removed from the paddocks when the pastures reached about 10 centimeters (residual height) . In each evaluation, a sample was collected per plot, with a sample area of 0.25 m² for quantification of forage production. To evaluate the tillering, two samples were collected per plot, with an area of 0.05 m², and the number of tillers was counted. MS and CP data were submitted to analysis of variance and compared with each other using the Tukey test at 5% probability and evaluated using the Sisvar statistical program. The Aveia Preta Embrapa 139 and Aveia Branca Fronteira pastures showed greater precocity in the production cycle. The ryegrass cultivars Ceronte and white oat Fronteira reached four cuts, maintaining the distribution of forage production throughout their production cycles, in addition to presenting high CP levels, contributing to the best forage quality. Although only three samples were collected, the BRS Tarumã and Lenox wheat cultivars were grazed four times, also presenting four cuts. The dual-purpose wheat cultivar BRS Tarumã showed better DM yield (kg/ha), maintaining the best average among the analyzed cuts.