Productivity of dual-purpose wheat genotypes under grazing with lactating cows

ABSTRACT The objective of this research was to evaluate the productivity of two dual-purpose wheat genotypes BRS Tarumã and BRS Umbu under grazing with lactating cows. The experimental design was completely randomized, with two treatments, three replications (paddocks) and repeated measures (grazing cycles). Studied variables were early growth, the structural composition of wheat, forage production, leaf blade biomass, the stocking rate, the herbage and leaf blade allowance, the grazing efficiency, the herbage intake and grain yield. The earliest genotype for forage production was the BRS Umbu. Differences in herbage yield between BRS Umbu and BRS Tarumã genotypes (3196 vs. 4143kg DM/ha) and leaf blade production (2281 vs. 3205kg DM/ha), respectively, were detected. Similar values between cultivars were found in stocking rate (2,26AU/ha); grazing efficiency (52,26%), herbage intake (2,91 %) and grain yield (1716kg/ha). The BRS Tarumã genotype is the most suitable for dual-purpose under grazing with dairy cows.

摘要：本研究旨在评估两个兼用型小麦基因型BRS Tarumã与BRS Umbu在泌乳奶牛放牧条件下的生产性能。试验采用完全随机设计，设置2个处理、3个重复（放牧小区）及重复测量（放牧周期）。测定指标涵盖早期生长势、小麦群体结构组成、牧草产量、叶片生物量、载畜率、饲草与叶片可利用量、放牧采食率、饲草采食量及籽粒产量。在牧草生产方面，BRS Umbu为早熟基因型。本研究检测到BRS Umbu与BRS Tarumã的饲草产量分别为3196与4143kg干物质（DM）/公顷，叶片产量分别为2281与3205kg干物质（DM）/公顷，二者存在显著差异。两个品种在载畜率（2.26 动物单位（AU）/公顷）、放牧采食率（52.26%）、饲草采食量（2.91%）及籽粒产量（1716kg/公顷）上的数值相近。综上，BRS Tarumã基因型是泌乳奶牛放牧条件下兼用型小麦种植的最优选择。