Charlotte Nugent Podcast

Charlotte Nugent, an extension officer for MLA, discusses her research project on increasing on-farm productivity in sheep. The project aimed to test the hypothesis that heavier and older ewe lambs at breeding would wean more offspring. The research was conducted across properties in Western Victoria and South East South Australia, with data collected for over 11,500 ewes over an eight-year period. The results showed that increasing the live weight of ewes at breeding by one kilogram had the same effect on weaning rate as an additional seven days of age. The age of ewe lambs at breeding had a greater impact on offspring survival. Producers can improve breeding performance and profitability by considering the trade-off between live weight and age at breeding. Hi, and welcome to another episode of Sheep Connect Now. I'm Tony Jones, your host for today and today I have in studio with me Charlotte Nugent who's going to speak to us about her recent findings from a research project that looks at making more bang for your buck when you're joining Maiden Youth. Welcome Charlotte. Hi Tony, thanks for having me. So before I start today, I just want to give a little bit of an explanation about how I am involved in the project. So I am working as an extension officer for MLA, working predominantly in the fields of extension across production outputs for our sheep and our cattle. So this project was an MLA co-funded project and that's sort of how I came to be involved in it. Well, that sounds really interesting. So can you tell us a bit about your project? What did you do? What was involved? What were the aims of your project? Yeah. So as producers, we're constantly looking for ways to increase our on-farm productivity, basically through our best management practices and looking for ways to increase productivity to put more money in our back pocket. So with the main aim of the research for us was to test the hypothesis that we established that ewe lambs that are heavier and older at breeding will wean more offspring, and this being due to increased reproductive rates, offspring survival and lower maternal mortality. Through increasing our weaning percentages, we in turn increase our productivity potential and thus more money in our back pocket. So we conducted the research across properties in Western Victoria and into South East, South Australia. However, the results that we obtained I think are relevant to producers right across Australia. Great. So in terms of the data set, what did that look like? Like how many animals were involved in your research and what was the size of that data set? Yeah. So over the course of the trial, we collected data and analysed data for more than 11,500 maternal composite ewes and we collected it over an eight-year period and each ewe had her own pedigree recording, including her birth type, age, live weight and her breeding, plus the records of her birth weight and survival of her offspring and her dam. So you had a data set for each individual ewe that you entered into the trial, correct? Yeah, that is correct, Toni. So by the end of the trial, we had more than 11,500 individual data sets for each ewe that entered the trial. Obviously, with the data being analysed on the ewe in her maiden breeding season, each ewe was only in the trial for one season. So sort of moving into it, we sort of look at the fact that ewe lambs will begin to reach puberty sort of between that seven to ten months of age and if we can breed ewe lambs at this age, we can maximise our financial performance on farms through increased productivity. And so basically the question from that became how do we counteract the research that shows that joining younger ewes potentially can sort of have poor and highly variable weaning rates and so we tried to counteract this to increase our breeding performance in joining our younger ewes. Yeah, great. So how do producers achieve that optimal breeding performance from their younger ewes and what's the secret to achieving more lambs being weaned? Yeah, okay. So in answering this, I'll just go a little bit into the data and the research. So sort of over the course of the trial period, the average live weight of the flock was about 40 kilos, varying slightly year on year and it's also important to note that the live weight of breeding was also influenced by the birth type of the ewe lamb in the trial so on average, singles were heavier than multiples. So our research showed that the number of offspring weaned per ewe increased by about 3% for each additional kilogram of live weight at breeding for the ewe between their range of sort of 35 to 45 kilos. So each ewe in the trial sort of sat in that range of 35 to 45 kilos and was sort of in that six to nine month age range. So within this range, it's noted that a one kilo increase in live weight at the start of breeding had the equivalent effect on weaning rate as an extra seven days of age at the start of the breeding period so essentially, we established that weight compensates for age. But so yeah, we kind of just looked at the earlier that we can breed our ewe lambs, how successfully, the easier they can be integrated into our adult flock and start to be productive producers on property. The only trade-off that we found was that by reducing the breeding age of the prospective ewe lambs by one month required them to grow 30% faster from birth to avoid compromising the weaning rates for their progeny. So making the principle clear that it's our nutritional management on property that we really need to focus on to counteract this. Yeah, great. So what has more impact then on lamb survival? Is it age or is it live weight at breeding? Yeah, so that's a good question. Research results also concluded that ewe lambs that were older at the start of the breeding period weaned more offspring due to increased reproductive rates and higher offspring survival. And yeah, interestingly, the age of ewe lambs at breeding had a greater impact on offspring survival and we put this down purely to their maturity and their ability to have higher lactation through maturity patterns. Yeah, great. So basically ewe lambs that are heavier and older at the start of the breeding period generally wean more offspring than your lighter and younger ewes. Essentially. So as producers if we're able to quantify the data between the live weight and the age of breeding and understand the trade-off between these, how we can begin to make more informed decisions relating to breeding time and our nutritional management, increasing our productivity and profitability. Excellent. Thanks for sharing all that with us today, Charlotte. So anything that producers can do to put more money back into their pockets is a great outcome all round. So thanks everyone. That's it for today. I hope you've enjoyed today's session and we'll see you again. You'll speak with us next week.