To date, Pillars has successfully trained 5 interns, 2 Masters students, 8 PhDs and 4 Post-Doctorates. Many of these emerging scientists have continued within the Pillars programme, enabling further career progression and capability growth for dairy science in NZ.
We are currently training 5 students (1 Masters, 4 PhDs) and 4 Post-Doctorate researchers. Find out more about their research below.
Stacey’s PhD studies at Massey University investigated the use of lying and activity behaviours as measures of animal health during the ‘transition’ period. “These 3-4 weeks before and after calving are when cows are most at-risk of ill-health,” says Stacey.
Read more about Stacey's research
“I used a DairyNZ dataset to determine if behaviours differed between cows that remained healthy and those that developed a subclinical metabolic disorder around calving.”
Stacey’s work determined that changes in lying and activity behaviours, measured using a leg-mounted device, could be used to help farmers identify sick cows before they start showing symptoms and predict when a cow is about to calve.
She found that cows that developed subclinical ketosis post-calving spent less time lying and were more active up to three weeks before calving.
Her studies also indicated that wearable devices could detect cows with low blood calcium because they are less active and spend more time lying the day before and of calving. “Further R&D will lead to behaviour-based alert systems for farmers to identify cows at risk of going down with clinical milk fever and succumbing to other diseases,” says Stacey. “Earlier detection and, therefore, earlier intervention generally result in a better health outcome.”
Stacey is now a Post-Doctoral Scientist at Massey University, collaborating with DairyNZ to investigate subclinical ketosis in grazing cows.
Olivia’s PhD investigates how a dairy cow’s inflammatory state during the transition period affects their reproductive performance. “Some inflammation around calving is normal and it performs important functions, but it’s damaging if it is excessive or goes on too long.” says Olivia.
Read more about Olivia's research
Olivia is conducting her PhD through the University of Auckland in collaboration with DairyNZ and AgResearch. To date, she has determined some blood markers of cows that still have uterine inflammation (endometritis) at five weeks postcalving. These cows have elevated blood levels of specific inflammation markers, especially in the week before and the two weeks after calving. “In future, this could enable us to identify cows at risk of reproductive issues early on using a blood test. Early detection also allows proactive treatment options to improve animal health and welfare.”
The next phases of this research will determine whether treating cows with anti-inflammatory compounds reduces persistent inflammation and then improves reproductive outcomes. If successful, these treatments will be another tool for farmers to help improve their herd reproduction.
Massey University Masters student Jessica has been a DairyNZ scholar for two years. Last summer, she worked as an intern on a Pillars transition cow health study into supplementing synthetic zeolite, pre-calving.
Read more about Jessica's research
“Cows go through a lot of change around calving, and they’re susceptible to metabolic and infectious diseases,” says Jessica. “Zeolite reduces the risk of milk fever and we wanted to know how it affects cows’ feeding behaviours.”
“We found that zeolite-supplemented cows spent less time feeding precalving, but had a rebound in their feeding time after calving, when supplementation stopped. They also differed in their patterns of feeding during the day, which may contribute to how zeolite works to reduce milk fever.”
Jessica says being involved with this study has been “an awesome opportunity” to connect with scientists in the sector, see what careers are out there and gain experience. She will now investigate the effects of different pre-calving management on lying and activity behaviours in relation to cow health for her Masters.
Charlotte recently completed her PhD at Victoria University of Wellington in collaboration with DairyNZ. She examined how genetic merit for fertility affects the cow’s oocytes (unfertilised eggs). “Up to 30 percent of cows’ pregnancies are lost in the first week, and oocyte quality is a major factor driving this early pregnancy loss, which limits conception rates,” says Charlotte.
Read more about Charlotte's research
“Up to 30 percent of cows’ pregnancies are lost in the first week, and oocyte quality is a major factor driving this early pregnancy loss, which limits conception rates,” says Charlotte.
Charlotte’s work compared oocyte quality between cows with high (+5%) and low (-5%) Fertility Breeding Values (BV). She also examined the composition of the follicular fluid that surrounds the oocyte prior to ovulation. “The early stage of pregnancy relies on nutrients within the oocyte to support development”, says Charlotte.
Charlotte determined that high Fertility BV cows had better quality oocytes and a different follicular fluid composition, which may provide them with a greater chance of establishing a successful pregnancy.
Another PhD student at Victoria is exploring how these differences in follicular fluid composition affect oocyte function. “Ultimately, we want to use this knowledge to improve conception rates either via better genetics or management to ensure a high-quality oocyte when cows are bred”,” says Charlotte.
Charlotte is now a Post-Doctoral Researcher at DairyNZ investigating differences in heat behaviours and oestrous cycle length between high and low Fertility BV cows. Her work will determine if high Fertility BV cows have stronger or longer heats that make detection easier. She will also investigate if they have shorter intervals between heats (i.e. shorter cycles). The aim is to determine if these traits could improve the accuracy of the Fertility BV.