Search

 

Contact Details:

C/- Rural Directions Pty Ltd

Clare SA
Tel (08) 8841 4500
Fax (08) 8842 1766

ARTICLES >> Livestock Articles

Ewe Nutrition in the Pastoral Zone – Realising your Potential

Posted by Bestprac on Dec 04 2012

By Liz Guerin
The principles of ewe nutrition in the pastoral zone are no different to ewe nutrition in any other area. In fact, considering the differences in feed base, growing season length and, in some instances, poorer feed quality, – they become even more important.

Dr Jason TrompfDr Jason Trompf of J.T. Agri-source says that there is a genuine opportunity for producers in the pastoral zone to be more proactive in managing ewe nutrition as, once a ewe has lost condition, it is a challenge regaining it and can be costly in terms of lost production.

Building on the networks and knowledge, created in programs such as ‘Bred Well, Fed Well’ and ‘Lifetime Ewe Management’, can help producers understand what a ewe requires relative to what is available in the paddock, the implications of nutritional deficit and what options they have to intervene.

“Doing a little early is almost always better than doing a lot late. Early decisions to preserve ewe body condition will help to sustain her performance throughout the different phases of her reproductive cycle,” Dr Trompf said.

“Where 3 kg of cereal grain will maintain a kilo of body weight, it takes 7-8 kg to regain a kilo of body weight. So feeding a little early, for maintenance or controlled weight loss, is twice as efficient as letting a ewe crash in condition and trying to get her to rebound.”

Jason says that through simple changes, such as better allocating feed to different classes of stock on the basis of condition score or pregnancy status, intervention can be achieved in an efficient manner, and it is possible to lift performance to a new level across your whole ewe base.

“Many producers attending ewe nutrition workshops have commented that focusing effort on ewe nutrition and simple changes has enabled them to get the bottom 25% of their ewe flock to perform as good as, or better than their average.”

For pastoralists looking to make some simple changes, Jason recommends starting by separating mobs at weaning, based on their condition score. Reasons for variation could include that some ewes will have reared twins, some single lambs and some no lambs – and this information, combined with a reproduction audit, presents an opportunity to start this whole process for next year.

“So often, we thought that ewes that were below average for body condition were the poorer ‘doing’ ewes. We are now beginning to understand that it is these sheep that are working the hardest and we need to give them the opportunity to rebound and build their body condition back up for the next reproduction cycle,” Jason said. “Ewe nutrition that is not meeting critical targets will be indicated in things like conception rates and the percentage of ewes joined that have gone twins versus single.”

Jason says that on a national flock basis, only about 25% of ewes rearing twins, will back up and conceive twins in the next year. This, he says, is a symptom of not managing their nutrition and is a huge lost opportunity for producers.

“Successfully rearing twins, in a pastoral environment, is a real challenge and producers need to ensure that twin bearing ewes don’t run too far down in body condition. This may mean weaning a little earlier than they typically would to give that ewe the recovery time to go again.”

Improvements in ewe nutrition can also increase lamb survival. Not only does it help to increase lamb birth weight (making lambs more robust), but better ewe nutrition in late pregnancy also drives higher colostrums and milk production, positively influencing maternal behaviour.

“We have minimal chance against a predator when the ewe has gone up to 400 metres away, in the paddock, looking for a feed. So pairing proactive ewe nutrition with proactive predator management becomes necessary in the pastoral areas.”
Jason said that knowing your potential is also important, and many producers scanning for multiples have been surprised at the results.

“In pastoral areas, with a great start to 2012, many producers were scanning over 150%. To be able to assist lamb survival and feed those resultant lambs took focussed management and targeted nutrition in late pregnancy but, by knowing their potential, producers were able to put proactive plans in place.”

The extra level of detail, gained from multiple scanning (rather than wets versus dries), will give you information about how well the ewes have joined, whether there has been a conception issue - even whether it is associated with a ram or the ewe, and finally your lambing potential.

“Because you know what you have got, producers are better able to proactively (rather than reactively) manage their ewes which helps to improve both lamb and ewe survival. Producers have fewer surprises, even in tough seasonal periods, and can set plans and allocations based on scanning information and available feed resources,” Jason said. “Even with things like worm management – those ewes in poorer body condition, that might come under greater internal parasite challenge sooner, then become the sheep you more proactively monitor in that phase. These small things help to play the game.”

The other thing Jason suggests producers do is to step back and take a breath before jumping in.

“Sometimes it is useful to ask yourself simple questions like, ‘what happened this year?’, ‘what did we get right?’ and ‘what were some of our missed opportunities?’”

Jason says that pastoralists also need to make the most of genetic opportunities – particularly in merinos.

“In the past, we have leant towards single trait selection for fleece traits and often neglected the constitution, or ‘doing’ ability of the sheep,” he said. “Pastoralists need to be able to keep that in balance, as genetic fat level and muscle are the two key resources that a ewe draws upon in tough times.”

Research by Mark Ferguson, of Murdoch University in W A, has shown that a ewe with a higher level of genetic fat and muscle has a much greater ability to buffer her performance in times of nutritional stress. (Link to Mark's research)

In trials, two groups of ewes were fed to either recommended condition score 3 or to condition score 2.5, throughout late pregnancy. Where the sheep were fed well (to condition score 3), it didn’t matter whether ewes were genetically lean or highly positive for fat (+1 or greater on the yearling fat breeding value in merinos), there was no bearing on the birth weight of the lamb she had. Whereas under nutritional stress (2.5 condition score in late pregnancy), the ewes that were genetically lean could not buffer lower nutrition and lamb birth weights dropped by almost 1kg, significantly compromising the lambs survival.

“The ewes that had genetic fat levels of 1 or greater were able to buffer that lamb’s birth weight, under low nutrition, so they almost delivered the same birth weight under low nutrition that they did under high.” Jason said. “It is the robustness of the merino ewe that I think pastoral zone producers need to think about – and combine nutrition with good genetics.”

More information about ewe nutrition, Bred Well, Fed Well and Lifetime Ewe Management can be gained from your local livestock officer or Jason Trompf 0408 386 896 (j.trompf@latrobe.edu.au)
 

Last changed: Dec 05 2012

Back

Comments

None Found

Add Comment