Effect of Holstein–Friesian strain and feeding system on greenhouse gas emissions from pastoral dairy production systems

Reductions in agricultural greenhouse gas (GHG) emissions are likely to be maximised if a systems approach is taken as opposed to introducing single focus mitigation strategies in isolation. With this in mind the Pastoral Milk Emissions Model (PMEModel) was developed at the University College Dublin to determine the effect of management change on GHG emissions. Such an approach is particularly pertinent to pastoral systems where the ability to introduce novel mitigation strategies is curtailed by agricultural practice. This paper reports the findings of a GHG simulation study based on a long term trial comparing the effects of Holstein–Friesian strain and feeding system on milk production and reproductive performance. These emissions are compared against a standard system as recommended for profitable milk production. The dairy cow strains examined were the High Production (HP) North American strain, a High Durability (HD) North American strain and a New Zealand (NZ) Friesian strain. The two feeding systems were a control feeding system (the standard Moorepark system) and a high concentrate feeding system. Under the pastoral production systems practiced within Ireland GHG emissions were lowest for the NZ type cow and highest for the HP cow whilst increased concentrate use also reduced GHG's.