05/10/2021
Research is underway to examine ammonia emissions from cattle and the effect of modifying the protein in their diets.
It’s the latest in a series of trials by the University of New England (UNE), as part of its project partnership with the Livestock Export Program (LEP) to understand the interaction between stocking density, ammonia gas generation, and bedding on a livestock export ship, and the effects on sheep and cattle welfare.
High protein feeds support weight gain and growth and are commonly provided to livestock on farms and in feedlots. They are also common during export, even though animals on a ship are fed at maintenance levels rather than for weight gain.
However, previous research has demonstrated that high protein feeds can lead to increased ammonia production in cattle and sheep. In a closed environment such as ship, this has the potential to irritate the eyes and throats, posing a safety issue for both livestock and the humans caring for them.
Adjusting the protein composition of the cattle’s diet may offer scope to reduce ammonia emissions while also supporting optimal animal performance, and potentially reducing the cost of feed.
The trial involves 18 cattle being held in individual metabolism crates – allowing gaseous ammonia to be captured, as well as manure and urine collected for analysis. The animals are being fed one of three diets, each with differing ratios of energy to protein. This will determine which diet produces the least ammonia output while ensuring rumen health can be maintained.
Working in a lab-based environment allows the UNE team to isolate different factors and understand their effects on livestock welfare and performance. This builds a picture of the interactions between stocking density, ammonia gas generation, and bedding which will then be validated on a livestock export ship.
A working group is supporting the four-year partnership, providing valuable industry insights to inform the experimental methodology of each trial, including the breed and type of livestock of animals and where to source them.
Members include experienced exporters, an Australian Accredited Veterinarian, a representative from the department, an independent technical/scientific advisor, and representatives of LiveCorp and MLA. They meet at least quarterly, and more often if required.
Future trials will test additives that can be applied to manure or included in feed to reduce ammonia emissions during a simulated voyage with cattle and sheep.