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Sheep CRC Graduate Program - Best Baa None

Posted by Bestprac on Oct 01 2012

By Liz Guerin
Training the next generation of agricultural scientists to service the shortfall in sheep industry needs and accelerate the delivery of innovation has been the objective of the CRC postgraduate program. With 70 students already moving through the program and completing Masters and PhD qualifications, the future of the sheep industry is looking bright.

Below: James Whale and Will Hooke with one of the trial mobs on Will’s property at Serpentine, Vic.

James Whale and Will Hooke with one of the trial mobs on Will’s property at Serpentine, Vic.
CRC for Sheep Industry Innovation (Sheep CRC) Project Leader for Post-graduate Training, Dr Graham Gardner, said the success of the program has been due to a number of factors.

“Students are carefully selected on the basis of academic merit, industry experience and career direction”, Dr Gardner said. “Knowing that up to 50 per cent of our industry professionals are approaching retirement age, it is important that we train people who will be retained in the industry.”

The other feature of the program that Dr Gardner considers one of the keys to its success is the tight alignment of students’ projects to the CRC’s research priorities.

“By doing this the students are ensured projects of high industry interest, which then means greater scrutiny by the industry”, Dr Gardner said.

“Annually we hold a postgraduate conference and bring together a panel of senior CRC scientists and program leaders from across the CRCs. Students prepare and deliver a small publication from their work and receive valuable input and direction from the panel.”

On average, 70% of postgraduates from the program have remained in the sheep and cattle industries, often in senior scientist positions, which Dr Gardner says will stand the industry in good stead for years to come.

“The graduating students will be colleagues for many years so these networks are extremely valuable”, he said. “The students become a cohesive group of industry focussed scientists that will work and collaborate well together.”

For CRC postgraduate program candidate, James Whale, an agricultural consultant with Mike Stephens and Associates in Victoria, the program has been a great opportunity and challenge.

In between full time employment, he has spent the past three years investigating, as part of his Masters thesis, whether it is physically possible and economically feasible for Merino ewes to lamb at 1 year of age.

As part of a series of on-farm trials, James initially tested the Merino’s potential to lamb at that age and showed not only that it could be done, but done well, achieving weaning rates of over 70% with ewes that were joined at 8-9 months of age.

“Once we knew it was possible, and knowing that we had to feed these sheep to get them to higher weights at younger ages, we used the GrassGro modelling program to investigate the extra cost of running a 1-year-old lambing system, as opposed to conventional lambing at 2 years of age”, James said.

By then examining the costs and benefits in different production locations and given different variables, such as supplementary feed prices, weaning rates and lamb values, the probability of a 1-year-old lambing system being a good investment in any given year was evaluated.

“Whilst there was variation between locations, the benefits were greater on low stocking rate lucerne pastures”, James said. “Provided lamb values weren’t too low and supplementary feed prices weren’t too high, all locations had the potential to increase profits with a 1-year-old lambing in a high proportion of years.”

Producers do need to consider their variables and whether the system will work in their environment, but James says that word is catching on and lambing Merinos as 1 year olds is a growing trend.

“When I started there might have been 6 producers in South Eastern Australia who were intentionally lambing Merinos at 1 year of age. In the last couple of years this number has grown to well over 100 producers across SA and Victoria and NSW”, James said. “After a few of good seasons where ewe lambs have been bigger than usual, a lot of people have just had a go and been amazed with the results.”

Kate Plush of South Australia is in the final stages of writing up her PhD thesis, after 5 years of research, on peri-natal lamb vigour and thermoregulation. Kate investigated the hypothesis that lamb survival rates could be increased if maternal nutrition was altered around conception and, therefore, lambs were more ‘mature’ at birth.

“Previous work identified that lambs that rely primarily on amino acids and glucose were less mature than lambs that had shifted to fat and glucose (milk diet)”, Kate said. “We altered nutrition around the time of conception in an attempt to change the maturity of the lamb. We fed high and low maintenance diets 17 days prior to insemination and 6 days post, and then looked at lamb vigour and thermoregulation after birth. However altering nutrition around conception did not appear to make any impact on lamb vigour or survival.”

Kate said that whilst birth weight is a huge determinant of lamb survival, there would seem to be little or no relationship between birth weight and some of these vigour traits.

“Nutrition alone, or energy composition of the diet, might not be enough to simply alter post natal vigour in the lamb”, she said. “From here we need to look at targeting specific pathways to alter maturity where the lamb can better utilise a fat and carbohydrate diet than was used inutero. The goal is to look at lamb behaviour, lamb vigour and lamb survival by using targeted nutritional treatments, at specific times in gestation, to look at ways of increasing survival.”

Sarah John of Western Australia is mid way through her PhD program looking at the biology of resilience to nutritional restriction in adult ewes.

“The theory is that animals that fluctuate less in their weight need less feeding to get them up to condition for the following breeding season or they are better able to maintain weight during pregnancy. So for that reason they can be more valuable animals – more robust or tougher”, Sarah said.

Starting by looking at the information nucleus flock, a database of information on 1000s of animals including pedigree history, Sarah determined how much variation there was within the flock to see if she could select animals that are less likely to lose weight.

“We started off by looking at weight change, which in adult Merinos is a heritable trait. We found that there was a real range in how ewes respond to nutrition and restricted paddock feed, with some of the flock at the same time of year either losing or gaining 5-10% of their bodyweight”, Sarah said. “We also found that ewes from some sires gained 5 kg during summer/autumn whereas ewes from other sires lost 5 kg over the same period.”

With the increased knowledge and awareness of farmers regarding weighing and condition scoring to manage their ewes, Sarah says farmers are becoming more adept at knowing which ewes need more ‘attention’ because they are skinny or because they are twin bearers. However, the sheep that really interested her are the ones that we don’t worry about– the good ‘do-ers’, and their characteristics.

“What we really want to do is to optimise stocking rate, so if we can get 1000 ewes that are doing that little bit better, and run a few more of those, rather than having to work on those that are struggling”, she said. “Particularly considering the costs involved in supplementary feeding and the extra labour and time to enable it.”

Some of the early indicators of Sarah’s research suggest that if selection is being driven only on wool values, you are likely to be selecting against tougher ewes. Conversely, if you are selecting for fat and muscle – this is likely to be helping.

“An experiment with 64 ewes in a shed, who were put under nutritional pressure, showed that ewes with higher clean fleece weight values were losing more weight than ewes with low values for fleece weight, and ewes that have better values for yearling fat held their weight better than those with lower values for fat”, Sarah said. “However, there is huge variation in all of these traits, so even if you are concentrating on improving wool cut, there is still scope to select animals with high fat values and animals that are tougher as well.”

The students all spoke of the invaluable support and input the CRC had into their projects – not only through their scholarships, but through feedback on trial data and through events such as the postgraduate conference.

And with the next crop of agricultural scientists hitting the ground, passionate and motivated about the sheep industry, it is an exciting time.

“The postgraduate program has been an exciting and amazing opportunity for me – one that I am really enjoying”, said Sarah. “I love being able to work in research on a topic that is so useful to producers. The ability to work towards delivering outcomes of practical benefit is really inspirational.”

More information about the postgraduate program and their research can be found by following this link.

Last changed: Oct 02 2012



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