SUMMARYThere is little empirical evidence to indicate that dairy cow live weight affects the extent of soil damage at the hoof-soil interface during grazing on poorly drained permanent grassland. In the present study the impact of Holstein-Friesian (HF) dairy cows with a mean (±standard deviation) live weight of 570 (±61) kg were compared with Jersey × Holstein-Friesian (JX) with a mean live weight of 499 (±52) kg each at two stocking densities: mean 2·42 ± (0·062) and 2·66 (±0·079) cows/ha. Soil physical properties (bulk density, macroporosity, gravimetric water content, air-filled porosity, penetration resistance and shear strength), poaching damage (post-grazing soil surface deformation and hoof-print depth), herbage yield and milk production were measured throughout 2011 and 2012. Soil physical properties, post-grazing soil surface deformation and herbage production were not affected by dairy cow breed or by interactions between breed and stocking density. Hoof-print depth was higher in the HF treatments (39 v. 37 mm, s.e. 0·5 mm). Loading pressure imposed at the soil surface was the same for both breeds due to a direct correlation between live weight and hoof size. Poaching damage was greater at higher stocking density. Using the lighter JX cow offered little advantage in terms of lowering the negative impact of treading on soil physical properties or reducing poaching damage and no advantage in terms of herbage or milk production compared with the heavier HF cow.

中文翻译：

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两种不同活重的奶牛在排水不良的黏壤土上踩踏对土壤物理性质、偷猎损害和牧草产量的影响

摘要几乎没有经验证据表明奶牛活重会影响在排水不良的永久性草地上放牧期间蹄土界面处的土壤破坏程度。在本研究中，将平均活重为 570 (±61) kg 的荷斯坦-弗里西亚 (HF) 奶牛与平均活重 499 公斤的泽西 × 荷斯坦-弗里西亚 (JX) 奶牛的影响进行了比较(±52) kg 两种放养密度：平均 2·42 ± (0·062) 和 2·66 (±0·079) 头奶牛/公顷。2011 年全年测量了土壤物理特性（堆积密度、大孔隙度、重量含水量、充气孔隙度、抗穿透性和剪切强度）、偷猎破坏（放牧后土壤表面变形和蹄印深度）、牧草产量和产奶量和 2012. 土壤物理性质，放牧后土壤表面变形和牧草产量不受奶牛品种或品种与放养密度相互作用的影响。HF 处理的蹄印深度更高（39五。37 毫米，瑟. 0·5 毫米）。由于活重和蹄大小之间存在直接相关性，两个品种在土壤表面施加的负载压力相同。在较高的放养密度下偷猎损害更大。与较重的 HF 奶牛相比，使用较轻的 JX 奶牛在降低踩踏对土壤物理特性的负面影响或减少偷猎损害方面几乎没有优势，而且在牧草或产奶方面没有优势。