Duration 3 years commencing May 2006
Team and Leader L.E.R. Dawson, D.L. Easson, B.W. Moss
Organisations involved Agricultural Research Institute of Northern Ireland and Department of Agriculture and Rural Development for Northern Ireland
Background and Summary
The main objective of the Nitrates Directive is to reduce water pollution caused or induced by nitrates from agricultural sources. On of the key action programmes within the Nitrates Directive for Northern Ireland is to ensure that the amounts of chemical fertilizer and organic manures applied do not exceed crop requirements for nitrogen.
While the positive effects of nitrogen fertilizer on grass growth are well documented, increasing costs of inorganic fertilizers and the Nitrates Directive has led many beef producers to reduce inputs of inorganic fertilizers. The Report of the British Survey of Fertilizer Practice (BSFP) indicates that nitrogen use on grassland in 2004 has fallen to the lowest recorded level since records began in 1983. The latter developments necessitate the evaluation of alternative forages for growing and finishing cattle which produce optimum yields, make most efficient use of N applications, make more efficient use of organic N sources and sustain optimum animal performance.
A number of crops and forages have been evaluated in small plots at AFBI, Hillsborough. These have included (i) leguminous plants (lupins, peas and beans) and mixtures of forage lupins and triticale whole crops grown with zero N input (Easson 2005) and (ii) red clover, ‘low input’ grass mixtures and ryegrasses (diploids, tetraploids and hybrids) receiving from zero up to 75 m3 slurry/ha and zero chemical fertilizers (Dale et al 2005). Yields of up to 10 t DM/ha have been achieved with legume/triticale mixtures and 18 t DM/ha with red clover (3 cut system; zero slurry). While beef cattle have exhibited superior or comparable performance when offered red clover silage relative to grass silage (Steen, 1982) limited information is available on the ensilability and nutritive value of the other forages when offered to beef cattle and levels of performance sustained.
As N excretion represents one the major potential environmental pollution sources, information also is required on the efficiency of conversion of N into animal product. For example, for red clover the efficiency of conversion of N into milk has been shown to be well below the theoretical potential.
The objectives of proposed study:
(i) To evaluate the potential of low input, alternative forages and grass mixtures as rations for beef cattle.
(ii) To produce an economic evaluation of the role of alternative forages and grass mixtures in beef production systems
(i) Spring 2006 and 2007 – sow lupins/triticale mixture, red clover and low input grass mixtures
(ii) Harvest and ensile crop in September 2006/2007;
(iii) Winter 2006/07 and 2007/08 – evaluate effect of ensiled forage and level of inclusion with grass silage-based diets on the performance of finishing beef cattle;
(iv) 2008/09 statistically analyse data and produce scientific reports/papers.
Provide information on methods by which low input forages can be produced which sustain optimum levels of animal performance to improve overall economic viability of beef production systems. Expected benefits – improved output value of cattle, reduced variable costs.
Outputs with timescales:
Scientific: Papers for scientific conferences in 2008 & 2009.
One full scientific paper by May 2009.
Industry: Preliminary results to industry by October 2007; full results by May 2009 – Farmers meetings, Press releases, Open Day at AFBI, Hillsborough
AgriSearch (NI): Progress reports to AgriSearch on 1 December 2006, 1 December 2007, 1 December 2008, with the final report on 1 July 2009.