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Optimising nutrient budgets for livestock systems based on alternative forage crops - LS3642

The Policy Commission report on the Future of Farming and Food, published January 2002, highlighted the need for livestock farming in the UK to address the large gap in farm profitability between the bottom and top third of producers. The report also addresses the need to optimise efficiency of livestock production and to deliver traceable, environmentally-friendly products that meet consumer demands. The Commission encourages a Regulatory framework that includes whole farm plans/audits maintained by the producer in order to improve the balance between sustainable production and environmental impact. Our research project LS0301 (July 1997- June 2002) on the use of alternative forage crops for livestock production has addressed both nutritional and economic benefits of producing home grown protein and energy crops. In order to meet the new challenges facing the agricultural industry, there is a need for scientific studies to assess the impact of nutrient flows from these alternative forage crops in terms of soil/plant/animal interactions.

Nutrient budgeting is now a widely used tool for managing nutrients on farms and as an indicator of the sustainability of farming practices. Balancing the input and output of nutrients within the farm system is critical to ensuring both short-term productivity and long-term sustainability. Maximising the efficiency of use of nutrients within a system is also key to reducing bought-in inputs, which are potentially costly in both economic and environmental terms. There is currently no information available on the effects of incorporating home-grown, high-protein forages into production systems on the flow of nutrients within that system. The overall aim of this research proposal is to provide a scientific basis for the development of decision-support systems that facilitate the best practice for the integration of alternative forages within livestock production systems in the UK.


The proposed programme will investigate the benefits and limitations of integrating a range of alternative forages, including high-protein leguminous crops and catch crops, into livestock production systems. It will incorporate and extend previous nutritional research with alternative forages conducted under LS0301, and will focus on whole-farm nutrient budgeting.

There are six specific objectives:

1) To investigate the effect of feeding ensiled alternative forages on liveweight gain and excreta losses from growing lambs;
2) To quantify the effectiveness of manures from livestock fed on alternative forages as organic fertilisers, and the response of alternative forages to manure applications;
3) To determine seasonal requirements of red clover and lucerne for P and K fertiliser;
4) To investigate the effect of growing alternative forages within rotations on the yield, chemical composition and weed infestation of subsequent crops and nutrient leaching from soil.
5) To investigate the effect of harvesting regime on the quantity and composition of effluent from silages prepared from alternative forages, and its potential as a biofertiliser;
6) To determine the potential of alternative forages to supply minerals and trace elements to ruminant livestock, and associated efficiencies of use.
Project Documents
• Final Report : Optimising nutrient budgets for livestock systems based on alternative forage crops   (1218k)
Time-Scale and Cost
From: 2002

To: 2007

Cost: £599,667
Contractor / Funded Organisations
Institute of Grassland and Environment Research (IGER)
Animal Production              
Livestock Farming              
Natural Resource Use              
Sustainable Production              
Fields of Study