Lambert M G, Clark D A, Litherland A J
AgResearch Grasslands, Private Bag 11008, Palmerston North, New Zealand.
N Z Vet J. 2004 Dec;52(6):311-9. doi: 10.1080/00480169.2004.36447.
A wide range of management techniques is available to enhance quantity and quality of forage supply to grazing animals throughout the annual production cycle. Within broad limits, dry matter (DM) production is relatively insensitive to management of defoliation frequency, severity and duration. However defoliation management has effects on feed quality which can be enhanced, in particular, by control of pasture growth in the spring through maintenance of relatively low average pasture masses. Treading damage can have significant immediate and ongoing effects on pasture production and farmers can use a range of management techniques to minimise these. Fertiliser application practices have a potent influence on pasture production and seasonality of that production. Available soil nitrogen is the primary nutrient deficiency limiting production in New Zealand's characteristically grass-dominant pastures. Nitrogen fertiliser usage has increased markedly in recent years, particularly to grow substantially greater amounts of forage during the cool season, and this trend looks set to continue. However, the use of nitrogen fertiliser has important environmental implications. Pasture renewal and forage crop use has also increased in recent years. Care needs to be taken in conducting cost-benefit analyses, selecting the options that best meet the needs, and in establishment and subsequent management practices. Ryegrass (perennial and hybrids) and white clover remain the primary choice for permanent pasture renewal, the availability of safe endophytes having largely alleviated effects of endophyte toxicosis. Special-purpose mixtures are used, especially in dry environments. Italian ryegrasses, brassicas and chicory are common choices for forage crops. A range of management techniques can be used to alleviate deleterious effects of some forages, including ryegrass endophyte toxicosis, facial eczema, and toxins associated with Fusarium fungi. Generally these techniques are not totally effective. More research is required to increase our understanding of these disorders, and in order to develop more effective and reliable management practices.
在整个年度生产周期中，有多种管理技术可用于提高放牧动物的牧草供应量和质量。在很大程度上，干物质（DM）产量对落叶频率、强度和持续时间的管理相对不敏感。然而，落叶管理会对饲料质量产生影响，特别是通过在春季维持相对较低的平均牧草量来控制牧场生长，可以提高饲料质量。践踏损害会对牧场生产产生重大的即时和持续影响，农民可以采用一系列管理技术来尽量减少这些影响。施肥方式对牧场生产及其季节性有很大影响。有效土壤氮是限制新西兰以草为主的典型牧场生产的主要养分缺乏因素。近年来氮肥用量显著增加，特别是为了在凉爽季节种植大量更多的牧草，而且这种趋势似乎还会持续。然而，氮肥的使用具有重要的环境影响。近年来牧场更新和饲料作物的使用也有所增加。在进行成本效益分析、选择最符合需求的方案以及在建立和后续管理实践中都需要谨慎。黑麦草（多年生和杂交种）和白三叶仍然是永久性牧场更新的主要选择，安全内生菌的可用性在很大程度上减轻了内生菌中毒的影响。会使用特殊用途的混合物，特别是在干旱环境中。意大利黑麦草、芸苔属植物和菊苣是饲料作物的常见选择。可以使用一系列管理技术来减轻某些牧草的有害影响，包括黑麦草内生菌中毒、面部湿疹以及与镰刀菌相关的毒素。一般来说，这些技术并不完全有效。需要更多研究来增进我们对这些疾病的了解，并开发更有效和可靠的管理实践。
