Comparing Vegetation Characteristics and Production Outcomes of Semi-Natural Permanent Grassland and Sown Ley: A Case Study in a Hemi-Boreal Region

Semi-natural grasslands support biodiversity, but their capacity to combine conservation with beef production remains insufficiently quantified. This case study compared a sown ley and a permanent semi-natural grassland in Lithuania during the 2019–2020 grazing seasons, using eight bulls annually (16 animal observations; four per field per year). Plant diversity, herbage yield and composition, liveweight change, and beef quality were evaluated. Soil phosphorus status differed, with lower extractable phosphorus in the permanent grassland. Species richness was higher in permanent grassland than in sown ley (84 vs. 12 species), whereas herbage dry matter yield was lower (1.45 vs. 2.92 t DM ha −1). Permanent grassland had half the livestock unit density and twice the land area per animal, resulting in similar dry matter yield per animal. Despite the greater land requirement, unadjusted growth differences varied in direction between years, and the adjusted difference in final liveweight was imprecisely estimated (permanent grassland minus ley: −10.1 kg; 95% CI: −39.7 to 19.5 kg). Beef from the studied permanent grassland had less saturated and more unsaturated fatty acids, lower atherogenicity and thrombogenicity indices, and a higher hypocholesterolaemic-to-hypercholesterolaemic fatty acid ratio. Multi-site studies are needed to assess the broader applicability of these differences.