BY: LYNDA GRAY
Lincoln University is entering a new wave of deer research.
A $200,000 upgrade of the university’s deer research facility, including specially adapted pens to study the diet-related metabolic processes of deer, is the engine room of research led by Pablo Gregorini, Professor of Livestock Production.
Since joining the faculty of Agriculture and Life Sciences three years ago he has developed a research relationship with the deer industry working on projects looking at dietary influences on the feed utilisation, welfare, and environmental effects of deer.
The results of one of the projects suggest that replacing a ryegrass diet with plantain could reduce the environmental footprint of deer.
“We have found that red deer fed plantain excrete more urine with less nitrogen, and drink less water compared to those grazing ryegrass,” Gregorini says.
Another project was looking at the best method for measuring the drymatter intake (DMI), as well as the digestibility and faecal output of deer. Methods had been developed for sheep and cattle, and the research hoped to validate whether these were applicable to deer. Long term the methods and data generated could help identify and select more feed efficient deer with a lower environmental footprint.
Another project was looking at whether deer, which are highly susceptible to stress-related diseases, could potentially self-medicate by grazing a diverse herbbased diet.
“We see that this could possibly add value to venison.”
One of Gregorini’s PhD students Cristian Moreno Garcia is replicating a beef project for deer, looking at their different grazing “personalities”. This involved tracking over time where, what, and how different classes of deer grazed, and the results could lead to the design of forage and herb mixes according to landscape.
The deer projects are part of broader based studies looking at the development and potential of pastoral livestock systems which are profitable, and sustainable and ethical from a consumer perspective.
Some of the research questions the environmental sustainability of traditional ryegrass and white cloverbased ruminant systems. In research papers co-authored by Grigorini he said such systems produced an excess of crude protein (nitrogen) of which only 30% was utilised by the animal for growth. The rest was excreted, mainly in urine.
Also, ryegrass and clover systems were focused on maximising production and profitability at the expense of biodiversity, water and air quality and soil health.
In a research paper submitted for academic review Grigorini and co-author Matthew Beck argue that ‘functional dietary diversity’, as opposed to ‘dietary monotony’ offers livestock better nourishment, health benefits and wellbeing.
Grigorini is lead organiser of an international workshop on ‘Grazing in Future Multiscapes’ to be held in July 2021.