Martin Ladislao Correa Luna

Doctor of Philosophy, (Animal Science)
Study Completed: 2020
College of Sciences


Thesis Title
Dietary crude protein and nitrogen utilisation in two contrasting dairy systems

Grazing dairy systems are well perceived socially because they are associated with better animal welfare when compared to housed systems. However, New Zealand grazed pastures are high in crude protein, which results in low nitrogen use efficiency of cows and in high levels of nitrogen mainly excreted in urine. This elevates the nitrate levels in soil solution and groundwater. The intensification process of dairy systems has led to increasing pressure on natural resources and jeopardises sustainability. Mr Correa-Luna researched aspects of nitrogen use efficiency, milk production, and the profitability of dairy systems varying in intensification level. He found that de-intensifying by means of milking once daily and feeding more pasture with fewer supplements was inconvenient in terms of nitrogen use efficiency, although these systems can be economically and socially viable.

Professor Nicolas Lopez-Villalobos
Professor Peter Kemp
Professor Danny Donaghy