Ep 5: Antonia Olszewski - Turning food waste into farming solutions
In this episode, we chat with PhD student Antonia Olszewski, who’s researching how food-processing by-products like apple pomace, brewers’ grains and potato waste could be turned into animal feed.
What if we could feed our animals and improve our farms – using food waste?
PhD student Antonia Olszewski is exploring that simple idea at Lincoln University, and the potential is huge.
She’s researching how common food-processing by-products like apple pomace, brewers’ grains and potato waste could be repurposed as animal feed instead of ending up in landfill.
Millions of tonnes of food waste are generated each year, but they often end up decomposing in landfill," she said. "We could kill two birds with one stone by using them as supplemental feed for ruminants when pasture cover is too low.
Some New Zealand farmers are already doing this, and in the US, distiller’s grains are a popular supplement, but Antonia is going further than most research has.
She’s tracking the full impact: from bringing biowastes onto the farm, to how they affect animals, and what that means for soil health and pasture growth.
Antonia’s research could help build more resilient, sustainable farming systems in Aotearoa and beyond.
She’s part of the Food Transitions 2050 programme, which connects postgraduate researchers with Crown Research Institutes to tackle some of our biggest food and land-use challenges.
If you'd like to find out more about Antonia's research you can get in touch with her via LinkedIn.
Antonia Olszewski – LinkedIn profile
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Listen to Antonia's episode to hear how her work is turning food waste into farming solutions.
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[Host – Hiraina] Kia ora and welcome to From the Ground Up. I'm your host Hiraina Tangiora and I'm a lecturer and a PhD student here at Lincoln University. This podcast is all about the fantastic research being undertaken by our post-graduate students here at Lincoln and the real world impact this has. In each episode, we’ll sit down with brilliant minds to uncover fresh ideas, share inspiring research stories, and explore their student journey. Today I'm joined by Antonia Olszewski, a PhD student in animal science. Antonia grew up on a small vegetable farm in the North Island and before starting her PhD, she actually completed her studies in environmental science. Her current research is looking into redirecting food bio-waste such as apples and brewers grains away from landfill by feeding them to our farm animals. When she's not deep into her research, Antonia is a fan of playing cards, board, and video games, and curling up with a good murder mystery novel. Welcome to the podcast, Antonia. It’s great to have you here.
[Guest – Antonia] Thank you very much.
[Host – Hiraina] No worries. So, let's start off by hearing a bit about yourself and what you're studying here at Lincoln.
[Guest – Antonia] Yes, absolutely. So, I came from Wairarapa. Then I did my honours in environmental science where I was looking at whether different management practices on the Lincoln University research dairy farm could impact soil carbon stocks. Now I'm in the last year of my PhD and hopefully I'll finish in September, but we'll see how that goes.
[Host – Hiraina] Awesome. And what first inspired you to pursue this area of research?
[Guest – Antonia] During my bachelor's degree, I realised that environmental science is really, really interesting. I would really really love the opportunity to reduce nitrate leeching or greenhouse gas emissions. Farming in New Zealand is really a big part of our identity. So any kind of project where we're looking at our farm animals and potentially any kind of reduction in in environmental issues. I am in my third year of my PhD where I'm basically looking at how we can redirect industrial food wastes away from landfall by feeding them to cows and sheep.
[Host – Hiraina] What inspired you to pursue that area of research in particular?
[Guest – Antonia] I initially did my honours at the University of Canterbury in environmental science with Brett Robinson and that was on looking at soil carbon stocks on the living lab at the Lincoln University research dairy farm. So I knew Rachel Bryant um from that as well. After I finished my honours dissertation, Brett called me up and was like, "Hey, do you think you want to do a PhD?" And I'm like, "Maybe”.
[Host – Hiraina] Nice.
[Guest – Antonia] He set up a meeting with himself, Rachel, and David Whitehead, who is this legendary soil carbon researcher who works at Manaaki Whenua Landcare Research. And they already had kind of an idea for what the PhD would be. They explained that I would be looking at bio-wastes and whether we could feed them to cows. Initially it was going to be dairy but we changed that as we went.
[Host – Hiraina] And when you say soil carbon stocks
[Guest – Antonia] Yeah.
[Host – Hiraina] What do you mean by that?
[Guest – Antonia] The organic matter that is in the soil and that can come from dead plants, living plants, animal dung. Having lots of carbon in the soil is good. It indicates that it's really healthy and you want good soil because then it can grow grow you things.
[Host – Hiraina] Great. No, I mean I'm in the business school so I've got no idea what that means. So I really appreciate you taking the time to explain that.
[Guest – Antonia] Okay.
[Host – Hiraina] Now you've spoken a bit I guess about uh your honors at Canterbury but then the connections that you had to Lincoln University apart from I guess the postgraduate team sort of being your your supervisory team being formed for you. Are there any other reasons that you chose Lincoln for your PhD studies?
[Guest – Antonia] When they proposed it they said that it would be at Lincoln University. I didn't have any problem with that. I thought it would be interesting like trying a different university from the University of Canterbury. Now that I've been here, I can see lots of differences between the University of Canterbury and Lincoln University, and I'm really glad that I came here. I think it's really cool that it's smaller, so it's kind of more of a tight-knit community kind of thing.
[Host – Hiraina] Great. Well, we're lucky to have you, Antonia.
[Guest – Antonia] Thank you.
[Host – Hiraina] So, we're obviously we're in Lincoln, Selwyn.
[Guest – Antonia] Yeah.
[Host – Hiraina] Canterbury, New Zealand. What does, I guess, studying in a place like this mean to our research?
[Guest – Antonia] There's a lot of farmland around here. I think it's really good. Lincoln University has all of these different farms like the Ashley Dean farm, the Lincoln University research dairy farm, uh the Johnson Memorial Laboratory. They normally have sheep and deer. I think it's really good doing my research here because I'm surrounded by farms and that lets me think about how my research could help the real world, you know.
[Host – Hiraina] Yeah.
[Guest – Antonia] Does that make sense?
[Host – Hiraina] Definitely. you I guess you have a close connection between research being conducted and potential output or outcomes of your research.
[Guest – Antonia] Yeah. Yeah.
[Host – Hiraina] Nice. That sounds awesome. And I guess would you say then that your findings and your surroundings here do help you keep you grounded as well?
[Guest – Antonia] Yes, absolutely. Yes. I I think it's really good. Yep. I used to go on farm walks with um Rachel and the farm techs at the research dairy farm. That was really cool. I would learn lots of stuff about um dairy farming and really cool being around the the animals. I really like animals.
[Host – Hiraina] Awesome. Awesome. And I guess Antonia then to get to the crux of your research. What is the core question or what are the core questions you're trying to answer with your PhD?
[Guest – Antonia] The current title of my thesis is beneficial reuse of food processing bio-wastes in ruminant grazing systems. So basically there are two problems. One is that there are a lot of food waste. There's a global hunger problem. So if we can reduce food waste that can help combat hunger. There's also the fact that in New Zealand we have our animals graze pasture. But in the winter or autumn and winter it kind of is hard for the grass to grow enough to keep the cows fed. And so normally farmers need to buy in some kind of extra food, some extra supplement so that they can keep them fed. So what I'm looking into is seeing if we can reduce food waste by supplementing it to our grazing animals. It will give another option for farmers.
[Host – Hiraina] Great. And I guess just another pathway for what would otherwise go to waste.
[Guest – Antonia] Yeah. Exactly.
[Host – Hiraina] And end up biological emissions.
[Guest – Antonia] Yes. Yes. Yes. Yes. Yes. cuz we if they just go to landfall, they're just going to rot and give off greenhouse gases anyway. So, may as well use the nutrients that haven't been tapped.
[Host – Hiraina] Yes. And someone has already gone to this effort to make this food, right?
[Guest – Antonia] Yeah. Yeah. Exactly.
[Host – Hiraina] Love it. This is really important work, Antonia. And who are you hoping will benefit the most from it?
[Guest – Antonia] I think farmers would be an important party that I would like to benefit from this because they work really hard and I want to give them more options.
[Host – Hiraina] So far as a core group, anyone else?
[Guest – Antonia] It would be nice to help the companies who make the food waste, reduce that negative impact. There's actually an organization venture Timaru. They're looking at reducing the company's impact on making food wastes.
[Host – Hiraina] Great.
[Guest – Antonia] So helping those companies find another way to reuse the waste or reduce it. I think that would be really cool.
[Host – Hiraina] And if there sort of a bit of a value ad stream, then all the better, right?
[Guest – Antonia] Yeah. Exactly. Yeah.
[Host – Hiraina] And so you're doing a PhD here and it's sounding relatively canterbury-centric at the moment. Um but you will finish your PhD in September because we all support you to do so. What findings do you think your um sorry, what impact do you think your findings could have on the whole of New Zealand's agriculture primary industries.
[Guest – Antonia] if we took all of the food processing food scraps from New Zealand that are suitable to feed to cows? So there are lots of milk solid waste which I wouldn't want to um feed back to them and meat waste as well. Um, but if we took all of the food processing bio-wastes that are suitable to feed to ruminants and used them as feed, then we could reduce our reliance on palm kernel expeller by about a third, I think, if my calculations is correct.
[Host – Hiraina] And is that by the food waste that already exists in New Zealand anyway?
[Guest – Antonia] Yeah.
[Host – Hiraina] Wow.
[Guest – Antonia] And so instead of instead of importing other people's bio-waste, we can use our own.
[Host – Hiraina] That’s very very cool. We've talking lots about food waste cuz that's really central to your why I suppose why you do this research. Antonia, what are some of the statistics that we're dealing within terms of food waste being in Aotearoa New Zealand?
[Guest – Antonia] Annually there are 2.2 million tons of food processing bio-waste generated in New Zealand each year.
[Host – Hiraina] And so with the 2.2 Two billion tons.
[Guest – Antonia] Million tons.
[Host – Hiraina] Two million tons. That can all be redistributed potentially.
[Guest – Antonia] Yes.
[Host – Hiraina] To our farmers.
[Guest – Antonia] Yes. Yes. There are some logistical problems that we need to work out though. For example, it's normally full of water, so they can go off really quickly. Either you need to be on a farm that's really close to these factories, or you need to find a way to preserve them. Potentially you could freeze them or dry them or in style them, but to doit at the scale that that's going to need some work from some other people that can help us with that.
[Host – Hiraina] Fair enough. You're going to do this part of the puzzle.
[Guest – Antonia] Yeah. Yeah.
[Host – Hiraina] And someone else is going to pick up
[Guest – Antonia] kind of. Yeah. It's just like a proof of concept kind of thing.
[Host – Hiraina] And like you say, we're importing biowaste from other countries which that's got supply chain implications and money in that as well. If we could actually design a New Zealand based system.
[Guest – Antonia] Yeah.
[Host – Hiraina] That's probably a lot better for everyone.
[Guest – Antonia] Absolutely.
[Host – Hiraina] Awesome. And how do you see this relevance um potentially to the international farming sector?
[Guest – Antonia] So there are already farmers who are feeding food scraps, bio-waste to their cows and sheep. There's lots and lots of articles, scientific articles where they feed distillers grains for example, which is the stuff that's left over from making beer alcohol. But the thing about my PhD is that I'm looking at the whole process. So from importing the food scraps onto the farm, letting the animal eat them up, taking the dung from the animal after it's been eaten, and applying it to soil to see if that can change the soil health or the pasture production so that it can grow more grass to feed the cows again.
[Host – Hiraina] Circular system.
[Guest – Antonia] Yeah. Circular system. Yeah.
[Host – Hiraina] Awesome. And how do we get your research into these, I guess, wider global conversations given we're not the only country battling with some of these challenges. Are you at conferences?
[Guest – Antonia] Uh,
[Host – Hiraina] publishing?
[Guest – Antonia] So, I'm really excited to I'm doing thesis by manuscript. So, I'm hoping to get all my chapters published. I'm just writing one up now, two up now actually, for the NZ SAP conference, which is the New Zealand Society of Animal Production.
[Host – Hiraina] That sounds great. Thank you, Antonia. Now I guess looking a bit inward now, what has been the most surprising or rewarding part of your PhD journey so far?
[Guest – Antonia] I really like getting the results and then being able to interpret them and write them up. That has got to be my favourite thing about the PhD. So when I've spent two weeks of hard hard labour feeding some sheep collecting their dung.
[Host – Hiraina] Yeah.
[Guest – Antonia] It's really really cool being able to see the results.
[Host – Hiraina] Of course. Yeah.
[Guest – Antonia] Yes.
[Host – Hiraina] That’s quite an important part of the PhD if you enjoy writing up the results as well.
[Guest – Antonia] Absolutely.
[Host – Hiraina] So I'd say you're in really good stead. And what do you hope to do after you complete your PhD?
[Guest – Antonia] With the CRI's merging, the Crown Research Institutes merging, I don’t know really what's going to happen, but I' I reckon I'd be happy with anything that lets me write up the results of experiments and related to cows and sheep. Even if it was like greenhouse gas emissions, that would be really interesting. Or even more nitrate leeching. If we could if I could do research on that, that would be really awesome.
[Host – Hiraina] We might have to come and stay at Lincoln.
[Guest – Antonia] I might. I might. Yeah, that that will be all right. That will be all right.
[Host – Hiraina] Good. Good. Look forward to seeing you around the hallways even after September as well. Now, Antonia, if someone was considering doing their PhD or any post-graduate study here at Lincoln, what advice would you give to them?
[Guest – Antonia] For anyone who's doing a PhD, I highly recommend you go and talk to other students uh so that you can hear about what their supervisors are like. I really think it's important to have good supervisors. Um, have a good relationship with your supervisors. I really I'm really really happy with mine. I I have Brett Robinson from the University of Canterbury, Rachel Bryant, who's just got the McMaken Award from the NZSAP, and David Whitehead who's this legendary soil carbon researcher. Um, so I think it would be really really good to encourage potential students to talk to other students.
[Host – Hiraina] No, you've answered it well and I actually think that's some of the best advice for new postgraduate students that I've heard.
[Guest – Antonia] Yeah.
[Host – Hiraina] Because you know at the end of the day your supervisors are really critical.
[Guest – Antonia] They are very critical. You do have to talk to them a lot. You
[Host – Hiraina] Yes. Yes. Exactly. And you want to gel with them.
[Guest – Antonia] Yeah. Yeah. Absolutely. Absolutely. Yeah.
[Host – Hiraina] Yeah. So, no, you answer that really well. You've talked about having three different I guess workplaces of your supervisors.
[Guest – Antonia] Yes.
[Host – Hiraina] How has that come about?
[Guest – Antonia] That is because I got the food transition scholarship um food transitions 2050 scholarship. They're anew group which are looking to enhance the PhD student experience, increase our connections with our peers and with different work environments. So we get experience working in the university and also at a crown research institute. I’m really lucky that I got Manaaki Whenua. They let me do one of my experiments in in their labs and I was I was growing grass in pots of soil after I'd added some of the sheep dung to it. So um that was really cool. They let me use their growth cabinets. So it like keeps the light on, turns the light off whenever you want. You can set the humidity and and temperature and that was really cool. The food transitions 2050 scholarship program is really really cool. Like I have a group of students who started around the same time as me. So we get to catch up every every last Wednesday of each month. And normally that's when the directors invite speakers in to come talk to us. Like we once had the science adviser in the government come come speak to us and that was really really cool. Like they provide lots of opportunities for networking um which is really really good.
[Host – Hiraina] Sounds awesome. So I'm guessing it’s financial support but also that co-horting.
[Guest – Antonia] Yeah. Exactly.
[Host – Hiraina] Personal development.
[Guest – Antonia] Absolutely.
[Host – Hiraina] As well.
[Guest – Antonia] Yeah. Yeah. Yep. Absolutely.
[Host – Hiraina] Great. And I guess would you recommend if others are interested in learning more about it to check it out?
[Guest – Antonia] Absolutely. It is. I feel very very lucky that I got the scholarship and I think it's very competitive. Um so if you can I would highly recommend applying but yes.
[Host – Hiraina] Cool. It sounds well deserved.
[Guest – Antonia] Thank you.
[Host – Hiraina] Now what is the one key thing Antonia that you want people to understand about your area of research?
[Guest – Antonia] Feeding bio-wastes to cows and sheep is a potential option to help keep them fed. You've got to be really careful about feeding them new foods too quickly though cuz they can that can upset their gut and you don't want that. But using bio-waste with different nutrient compositions like starch high starches or high fibres or high sugars. If you feed cows a low protein food when the grass is full of protein, chalk full that like they're excreting it out through the urine, you could potentially reduce the amount of nitrogen that they're excreting which could have impacts on nitrate leeching which is really really important here in New Zealand. It's in the media lots.
[Host – Hiraina] So absolutely I'm seeing multifaceted benefits to your study.
[Guest – Antonia] Yeah. Yeah.
[Host – Hiraina] Wonderful. And say someone's listening to our podcast interview and they’re really interested in your line of work and area of research. How could they get involved or support you?
[Guest – Antonia] You could reach out and we could catch up and and we could talk about what what is needed. Um it would be really cool to get a job out of this.
[Host – Hiraina] Of course
[Guest – Antonia] that would I would love that. I'm so excited to finish my PhD so I can get a job. so I can get a house.
[Host – Hiraina] If you could sum up your research journey in just one sentence, which I know as researchers this is very hard, what would it be?
[Guest – Antonia] It'll be a little bit slow with a little bit of a break near the beginning and then it will be hard hard work and then just pure excitement to finish writing up their results. So
[Host – Hiraina] wonderful. A real journey.
[Guest – Antonia] Yeah, absolutely.
[Host – Hiraina] Now we've reached our final session.
[Guest – Antonia] Mhm.
[Host – Hiraina] Two more quick questions. Quickfire questions.
[Guest – Antonia] Okay.
[Host – Hiraina] The first one is, if you had $1 million of research funding, how would you spend it?
[Guest – Antonia] Holy moly. $1 million. Oh my goodness. That's crazy amount. That's a crazy amount. Honestly, we only have like a we have like a $10,000 budget here at Lincoln University. So, that's kind of that's really a lot. Oh my goodness. What would I use? Um, maybe I would use it to investigate how we can reduce nitrate leeching or greenhouse gases emissions from cows or sheep. And I think most of the money would go to labour and sample analysis costs. Gosh, I don't even know if I know the scale of$1 million and how much what that means for research. like yeah I don't really normally deal with that much that amount of money so that's kind of I'm really not sure what I do but yeah
[Host – Hiraina] you would do good with it though by sounds
[Guest – Antonia] I hope so yeah
[Host – Hiraina] Nice and final final question what is your favourite food and fibre product and why
[Guest – Antonia] I am anchored by the fact that I've been using apple pomace potato and brewer’s grains and so the fact that I I think apple pomace would be my favourite just because I can't think of anything else but apple pomace is really cool cuz it’s like full of sugars which can provide energy for the microbes in the rumen.
[Host – Hiraina] So great apple pomace it is.
[Guest – Antonia] Yeah, apple pomace.
[Host – Hiraina] Awesome. Well, thank you so much for your time today. I really enjoyed chatting with you. Thank you.
[Guest – Antonia] Thank you. Thank you.
[Host – Hiraina] No, you've been wonderful to have on the show and all the best for your PhD studies. A massive thank you to Antonia for joining me today and sharing your research journey. That was such an insightful korero to have. This has been from the ground up. I'm your host Hiraina Tangiora. Thank you so much for listening. If you enjoyed today's episode and you want to hear more about our post-graduate research and students don't forget to rate, subscribe and share this podcast with your friends. See you next time.
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