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2020 Cooper Award: Improving health and fertility of dairy cows

Dr Mallory Crookenden, AgResearch, has received the Cooper Award—the Royal Society Te Apārangi Early Career Research Excellence Award for Technology, Applied Science and Engineering—for key advancements in the use of pragmatic solutions that support immune function around calving to improve animal health on New Zealand dairy farms.

Mallory’s work is focussed on using applied methods to influence inflammation and immunological health, with the aim of reducing the risk of disease and improving fertility in New Zealand dairy cattle.

She uses her expertise in disciplines such as biochemistry, immunology and molecular biology to understand critical issues that affect livestock on New Zealand dairy farms and then provide practical solutions which can be readily applied on-farm. 

Mallory’s PhD research was the first to describe seasonal changes in immune function in low to moderate yielding grazing animals, which had previously only been reported in high-yielding animals in confinement systems. This research created the opportunity to use applied technology to improve the ‘dampening’ of harmful inflammatory immune reactions around calving, thereby improving animal health in New Zealand dairy systems. 

It is estimated that $1.5 billion of revenue is lost annually in New Zealand as a result of health problems and mortality during the calving period. Mallory’s research has investigated immune function and modulation during this time to better understand the mechanisms behind this increased risk of disease. For context, roughly 90% of metabolic disease and 75% of infectious disease occurs during the calving period, with a 3 to 6-fold greater risk of death. This is, therefore, a critical period for potential intervention to improve cow health and welfare. 

Mallory’s research post-PhD has continued to focus on methods to improve the health and welfare of New Zealand dairy cows by improving immune function around calving. One such study involves the investigation of a feed additive, sodium aluminosilicate, more commonly known as Zeolite, to treat low blood calcium concentration (hypocalcaemia) in cows during the early post-partum period.

Hypocalcaemia is the most prevalent metabolic disorder at calving, due to the sudden increase in calcium requirements as lactation begins. An estimated 40-65% of dairy cows undergo a state of subclinical hypocalcaemia at calving, while an additional 3-10% will experience clinical hypocalcaemia.   Feeding Zeolite results in a negative calcium balance that activates homeostatic regulatory mechanisms. The result is an increased efficiency of intestinal absorption of calcium and an acceleration of homeostatic mechanisms to mobilise stored calcium from bone, at which point zeolite is removed from the diet. From a health perspective, this short-term management intervention reduces the risk of clinical and subclinical hypocalcaemia, with blood calcium concentrations remaining normal in cows that receive Zeolite. Mallory’s research confirmed the effect of Zeolite on plasma calcium concentrations and focussed on downstream immune-modulating effects, showing a reduction in harmful inflammation.  This work has led to a subsequent, large-scale trial in over 1,000 animals (in progress). 

Based at AgResearch’s Hopkirk Institute in Palmerston North, Mallory graduated from her PhD (Massey University) in 2018. Her thesis was placed on Massey University’s Dean’s List of Exceptional Doctoral Theses Award. A prolific author, from her first publication in 2015, she is now an author on 24 peer-reviewed articles, with 8 as first-author. 

On receiving the award, Mallory said:

“It is an absolute pleasure to receive this award and I am thankful to Royal Society Te Apārangi for it. I’m also thankful to DairyNZ for allowing me, a molecular biologist, to be a part of the incredible applied research it undertakes. I appreciate AgResearch nominating me for this award and supporting me to continue my research. It is a privilege getting to use molecular biology to work towards improvements in agriculture that help make a positive difference for New Zealand. 

“This work would not have been possible without my family, friends, and colleagues. I am so appreciative of the support and time they have given me. They have allowed me to turn an inquisitive nature into a thoroughly enjoyable career.” 

Royal Society Te Apārangi Early Career Research Excellence Award for Technology, Applied Science and Engineering (the Cooper Award):
For encouraging research excellence in technology, applied science and engineering by early career researchers in New Zealand.

To Mallory Ann Crookenden for her advancements in understanding dampened immune function around calving to improve animal health on New Zealand dairy farms.