The Business of Dairy
The Business of Dairy podcast will look at aspects of management of dairy businesses from both within the farm gate and outside the farm gate, speaking to farmers and service providers with skills, information and knowledge of value to you and your business. We will bring to you monthly discussions on topics that will grow your knowledge and understanding of management areas that will drive strong farm business performance into the future. This series is brought to you by the NSW DPI Dairy Business Advisory Unit with funding and support from the Hunter Local Land Services.
The Business of Dairy
Producing milk with less lactose - why?
Producing milk with less lactose – why might this be important? Our guest this month is Juan Garguilo, one of my NSW DPIRD colleagues. Juan has been involved in a number of research projects as part of the NSW Dairy Up R& D initiative and if you are a long-term listener of this podcast, you will have heard his Argentinian accent before!
Juan, in conjunction with other well known dairy researchers, Professor Yani Garcia (University of Sydney) and Russ Hovey (University of California – Davis) has analysed the lactose content in milk – lactose being a milk solid that you don’t normally hear too much about. Understanding and manipulating lactose content of milk may have farm level and industry level benefits as described by Juan in discussion with Zita Ritchie in this podcast.
Project Update – Producing Milk with less lactose
Journal of Dairy Science paper
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The Business of Dairy
Episode #49 Transcript - Producing milk with less lactose – why?
Sheena Carter: Welcome to the Business of Dairy podcast. I'm your host, Sheena Carter. Producing milk with less lactose, why might this be important? Our guest this month is Juan Garguilo, one of my New South Wales Department of Primary Industries and Regional Development colleagues. Juan has been involved in a number of research projects as part of the New South Wales Dairy Up R&D initiative. And if you are a long-term listener of this podcast, you will have heard his Argentinian accent before. Juan, in conjunction with other well-known dairy researchers, Professor Yani Garcia from the University of Sydney and Russ Hovey from the University of California, Davis, has analysed the lactose content in milk, lactose being a milk solid that you don't normally hear too much about. Understanding and manipulating lactose content of milk may have farm-level and industry-level benefits, as described in discussion with Zita Ritchie in this podcast. Thank you.
Zita Ritchie: Welcome to the Business of Dairy podcast, Juan. Good to have you here today and chat about some of the work that you've been doing in lactose. I think, maybe before we get into the detail, Juan, are you able to just explain to me and the others listening about lactose in milk? You know, firstly, what is it? I think we broadly know what it is, but explain, you know, what is it and why is it actually important and what does it do? Before we get into some of the research, that'd be great. Thanks, Juan.
Juan Garguilo: Hi, Zita. Thanks for having me on the podcast. So, lactose is a really important component of milk, essentially, it's the main sugar in milk, it's around 5% of the milk, and the importance of lactose is that it draws water into the udder, so essentially it's responsible for the milk volume, that's the main characteristic.
Usually, lactose has been considered of low value, and in general, it's not recorded, for example, in herd testing, and also, it's not included in milk payment systems. In general, processors don't pay for lactose. Maybe there are just a few exceptions, but in general, they pay for fat and protein. But it has several uses in the industry, in the food industry, for example, as sweetener or in infant formulas it's also used, and also for example, in the pharmaceutical industry as an excipient for tablets for example. Also, there's a perception that in general lactose is very stable, relatively stable, so it doesn't vary too much – the concentration of lactose – and also that it's in general produced alongside other milk solids like fat and protein so it's, really associated with fat and protein production.
Zita Ritchie: Yeah, well, that's a really good overview. I think why it's important and how it, kind of, relates to the other components as well. So, you've been doing some research in this area and looking at investigating how milk might be produced with less lactose, and this has been funded through the Dairy Up program, which I think Sheena mentioned in the intro, so I won't go into the Dairy Up right now. But how have you done this, and where has that data come from? I think I'm just understanding what's the research looking at and what are you trying to understand with lactose?
Juan Garguilo: Yeah, so as I mentioned, the perception is that lactose in general has low variability, so it's pretty stable. But we know that there is a lot of variability between species. For example, some seals produce really low lactose, but high fat and protein, for example.
Zita Ritchie: Seals? Interesting.
Juan Garguilo: Yeah, yeah. And for example, we know that also there are some differences between breeds, cow breeds. So, essentially, this initiated by research from Professor Russ Hovey at UC Davis in the U.S., where he administered some drugs to cows. It's a glucocorticoid called dexamethasone. And essentially, he found that he could reduce lactose production and therefore milk volume by 45% without affecting the output of fat and protein. So essentially, they concentrated milk and produced the same fat and protein. They found also that this was regulated by genes. So, what we did here is we tried to see if we could find some differences or explain the factors affecting lactose here in Australia. We dug into a really unique data set that we accessed from 30,000 cows across 80 farms and more than 10 years.
Zita Ritchie: And this is just New South Wales data?
Juan Garguilo: Yeah, just New South Wales data. It is only data with lactose production, and it's only 5% of all the data that we had available initially. So, the idea here was to understand first the factors affecting lactose, the production of lactose, and also potentially try to identify some cows producing low lactose and therefore low milk volume but maintaining similar fat and protein output. So that was the aim of this study.
Zita Ritchie: So then, just to recap, so what are the main factors that affect lactose and what were you looking at in the data set?
Juan Garguilo: Yeah, so we tried to explain this data set. So, we analysed lactose and also milk production and composition and milk quality. For example, by stage of lactation, by lactation number, we also assessed the differences between breeds. We also analysed the differences in genetics. We accessed the dairy bulls breeding values data set as well. And also, we collected weather data. So, we analysed the impact of weather on lactose. So, it was trying to understand management, genetics, and environmental factors affecting lactose.
Zita Ritchie: Yeah, wow. So, it's a big data set. So, what was revealed through all of that? So, you had 30,000 cows, 80 farms, over 10 years of data, looking at all those factors. What were some of the main relationships that you discovered there?
Juan Garguilo: So really interesting, lactose percentage or the concentration of lactose is quite stable, as we knew. It varied from 4.8 to 5.2%, on average 5%. We found, on the contrary, that lactose yield, which is the amount of lactose produced per day by a cow, in general measured in kilograms, varies a lot because it's also aligned with the milk yield. Interestingly, what we found is that lactose yield and lactose percentage, or the concentration of lactose, follow the traditional milk curve pattern, so peaked in early lactation and then declined as lactation progressed. And this is unlike fat and protein, for example, that we know that is diluted by the milk volume. So, in general, fat and protein show lower concentration in early lactation.
Zita Ritchie: But not lactose?
Juan Garguilo: Yeah, and then increases, but lactose is the opposite. It increases in peak lactation because, as I mentioned earlier, it is the main responsible of the milk volume and draws water. So, the concentration is relatively stable.
We found that, in general, heifers had higher lactose percentage in comparison to cows in other lactations, but lower lactose yield. And of course, explained also by the milk yield differences that we know that there are between heifers and cows. Another interesting finding is that in general, cows with high somatic cell count had lower lactose percentage. Also, as you know, this also links to the fact that the heifers have higher lactose percentage because you know that heifers in general are less affected by mastitis and somatic cell count, so there's a link also there. Also, the analysis between breeds reveals that in general holsteins produce higher lactose yield, so amount of lactose, but in general lower lactose percentage, so a lower concentration. And on the other hand, jerseys, for example, produce the lowest lactose yield, but higher lactose percentage. So, we found also some differences between breeds.
Also, another interesting finding is that we analysed the weather, as I mentioned, and for example, hot, humid weather, the THI that we usually use to measure this, reduced, of course, lactose yield and the other components and, of course, milk production, but lactose percentage was not affected.
Also, one of the key things that we found here is we were able to identify a group of cows, 80 cows in particular, that produce less lactose but maintain the similar fat and protein output. So these cows produce, on average, 18% less lactose and less milk volume but maintaining the same fat and protein output as the rest of the cows. So essentially these cows produce concentrated milk, maintaining the total production of fat and protein. And interestingly, these cows descended from a few bunch of sires, 13 bull sires. So there is also a genetic link there with this. Those were the main findings from the study.
Zita Ritchie: Yeah, that's interesting. So there was a proportion of cows in there that although that they had lower milk volume yield, they were still able to maintain that high solids, and that was related to lactose. Is that right, if I'm interpreting that correctly?
Juan Garguilo: Yeah, yeah. So these cows were able to produce more fat and protein per unit of lactose.
Zita Ritchie: Okay. Yeah, that's really interesting. So from a practical perspective, what does this mean for our dairy farmers and what are the benefits to them of knowing this, and how do they manage their lactose content in their milk? How do you bring it back down to a practical level?
Juan Garguilo: Yeah, so as I mentioned, we identify some cows that produce concentrated milk. This could have, for example, a series of benefits for the farmers. For example, if we manage to produce less volume with the same solids, this could translate into potentially less milkings for the farmer, so potentially less labour. We could milk a cow less often and therefore less labour. From the point of view of the cow, as I mentioned at the beginning of the podcast, lactose is the main sugar of the milk. So it's a really big effort from the cow from an energy point of view. So producing less lactose could mean less energy demand for the cow and more energy available for producing the other solids or reproduction, for example. This could mean potentially less metabolic diseases. This is all something that needs to be further investigated. It was not the scope of this study, but potentially this could be the benefit for the farmers. And having more information on this could, for example, help farmers for selective breeding, for example, or use of management practices that can optimise this lactose production and potentially concentrating milk.
Zita Ritchie: Yeah, that's really interesting, kind of bringing it down to that practical level. And so are there any other benefits, I mean, aside from understanding this about lactose and the implications it could have on farm? Like, do you see any other benefits for the rest of the supply chain there as a result of lower lactose content in milk, for example, like, either processors or for consumers?
Juan Garguilo: Yeah, this has some major impact across the whole supply chain and the whole industry, I would say. As I mentioned, if we manage to produce the same fat and protein, but with less water volume, essentially that could translate into, for example, higher yields, cheese yields, for example, for processors. Or, for example, a processor would need to transport less water, so that would have an impact on logistics, for example. Also if we found we could naturally produce milk with reduced lactose concentration that could be a new opportunity as a new market for example and also from the point of view of the environment, of course, less water means less waste, less water use, less energy and emissions, so it's a benefit for the whole industry, I would say.
Zita Ritchie: Yeah, that's really interesting. And so, your main collaborators on this research has been who, I know you mentioned some of the data or findings or understanding about lactose from UC Davis. Who else have you been working with on this project through the Dairy Up program?
Juan Garguilo: This has been a collaboration between New South Wales DPIRD, UC Davis, Professor Russ Hovey, and Professor Yani Garcia from the University of Sydney.
Zita Ritchie: So to wrap it all up then, Juan, well, maybe before we do that, it's not just lactose that you've been looking into as well, you've been doing some work with Macquarie University on waste and yeast and different things, is it worth just mentioning briefly, like, what's the focus of this part of the broader program? This is just one aspect of it, isn't it?
Juan Garguilo: Yeah, so this is one sub-project of the P9 Designer Milk Project. In this project, we are essentially trying to look for opportunities to add value to milk and also potentially open new markets for New South Wales dairy products. So, the lactose project is one. The other one is about, as you mentioned, Zita, is the work we are doing with Macquarie University where we are trying to add value to milk waste through fermentation, through precision fermentation. And also there's another project, sub-project, where we are trying to use or understand the use of protein as a biomarker for heat stress.
Zita Ritchie: Oh, wow.
Juan Garguilo: Yeah, it's a really fascinating area of work.
Zita Ritchie: Yeah, there's some really interesting research questions that you're looking into there across that project and program of work. Maybe we can talk more about that another time. It's been great to get some more insights onto lactose for today. Just in summary, as we wrap up, Juan, like what are your key messages or I guess points for farmers, the industry, around lactose? And if we want to find out more information about this work, where can we go to to find that?
Juan Garguilo: Yeah, so I think the main points here is that we found here that lactose has variability. It's not as it was always perceived, that it's super stable – it has variability. We found that there are differences between breeds, for example, and also differences across lactations and days in milk, and also the weather, how that affects, and also we found a genetic link, so there is variability. This provides a better understanding of the lactose production and the association with the other components, and of course can bring opportunities for finding those animals or selecting those animals that could be more efficient and produce a benefit for the whole industry. Yeah, I think this research could have potential applications in the future. Now the next steps here is we are trying to model, with the data that we have, we are trying to model lactation curves and trying to see if we can identify those efficient cows early by analysing the first lactations, if we can identify that those cows maintain that same concentration of milk across the other lactations, we are working with that now. That's in a nutshell, the project and the findings. But if you want to read more about this, you can access the Dairy Up website. There is an article summarising this research and also a recent research publication, we can put that in the show notes.
Zita Ritchie: Yeah, absolutely, I'll provide the link in the episode notes. That's great. Thanks so much, Juan. It's been really good to understand more about lactose, having not known much about it really before now. And really interesting to see what research is coming out of that with this project. And like we said, there's more information if people want that in the episode notes or feel free to get in touch with Juan as well at any time. But thanks a lot, Juan, for joining us today to talk about it.
Juan Garguilo: Thank you, Zita.
Zita Ritchie: Chat soon.
Sheena Carter: That's all for today's episode of The Business of Dairy. We hope you enjoyed diving into the fascinating world of dairy farming and industry insights. As we continue to expand and evolve, we greatly appreciate your support. Our show is thriving, attracting new listeners each week, but we believe there's always room to grow and we need your help to make it happen. If you've found value in our discussions, we kindly ask you to take a moment to rate and leave a comment about the podcast. on your preferred platform. Your feedback not only lets us know what you enjoy, but also helps boost our visibility to others who might benefit from our content. I sincerely thank you for being part of our community and we look forward to bringing you more engaging episodes in the future with the continued funding and support of the Hunter Local Land Services. Until next time, stay curious and keep milking those opportunities.