Hoskin S O, Gee E K
Institute of Veterinary Animal and Biomedical Sciences, Massey University, Private Bag 11222, Palmerston North, New Zealand.
N Z Vet J. 2004 Dec;52(6):332-41. doi: 10.1080/00480169.2004.36449.
The feeding value of fresh pasture grazed in situ is determined by animal performance or productivity and could be relatively easily established for growing and lactating horses. Despite this, there is a lack of published information on the relative feeding value of different pastures and forages grazed by horses in New Zealand and the world. In addition, for adult breeding or non-breeding and young or adult sport or performance horses, the definition of feeding value and its determination remain problematic. Limited information suggests that the feeding value of perennial ryegrass-based pasture in New Zealand for young growing horses is high, and growth rates for Thoroughbred horses fed solely on pasture in New Zealand are similar to those reported from the Northern Hemisphere where grain-based supplements are fed in addition to pasture or other forages. Attempts to assess the ability of fresh pastures to meet the nutrient requirements of horses are hampered by problems associated with determination of feed intake by grazing horses and lack of knowledge of the digestibility and utilisation of digested nutrients, including the relative bioavailability of macro- and micro-minerals in pasture. A further challenge for future research is to determine the effect of herbage allowance and grazing behaviour, including pasture species preferences, on voluntary feed intake by grazing horses. Grazing pasture has benefits for equine health and well-being including reduced risk of some nutrition-related disorders and reduced prevalence of stereotypic behaviour. Pastured horses have greater freedom for expression of natural behaviours including social interaction and exercise. However, grazing pasture is also associated with animal health problems, particularly parasitism and diseases related to pasture-associated toxins.
在原地放牧的新鲜牧草的饲用价值由动物的生产性能或生产力决定，对于生长中的马和泌乳母马来说，相对容易确定。尽管如此，关于新西兰及全球马匹所食用的不同牧草和草料的相对饲用价值，仍缺乏公开信息。此外，对于成年种马或非繁殖马以及年轻或成年的运动马或表演马，饲用价值的定义及其测定仍然存在问题。有限的信息表明，新西兰以多年生黑麦草为基础的牧场对幼龄生长马的饲用价值较高，在新西兰仅以牧场草料为食的纯种马的生长速度与北半球的报道相似，在北半球，除了牧场草料或其他草料外，还会补充谷物类饲料。评估新鲜牧场满足马匹营养需求能力的尝试受到以下问题的阻碍：放牧马匹采食量的测定存在问题，以及对消化养分的消化率和利用率缺乏了解，包括牧场中常量和微量矿物质的相对生物利用率。未来研究的另一个挑战是确定牧草供应量和放牧行为（包括对不同牧草品种的偏好）对放牧马匹自愿采食量的影响。放牧对马匹的健康和福祉有益，包括降低某些营养相关疾病的风险以及减少刻板行为的发生率。放牧的马匹有更大的自由来表现自然行为，包括社交互动和运动。然而，放牧也与动物健康问题有关，特别是寄生虫感染和与牧场相关毒素有关的疾病。
