Disappointing spring pasture growth in Western and Northern Victoria means farmers are turning to alternative feed sources to help ewes regain condition after lambing. Regaining the condition that has been lost through lactation is critical to a successful joining.
While there is plenty of cereal straw available in most regions, straw will not provide the nutrition required by most livestock. Cereal straw tends to be low in both energy and protein and is almost always high in fibre.
It can be a valuable fibre source to complement a high-grain diet when no other fibre source is available (like pasture or hay).
Feeds with low potential for liveweight gain (such as straw) are characterised by two factors: animals can’t eat very much of it, and what they can eat doesn’t yield much energy or protein.
The high fibre percentage in straw limits how much animals can consume – it takes so long to be broken down in the rumen that it moves very slowly through the digestive tract.
Cereal straw can take up to 48 hours to pass through the rumen, while a more digestible, higher-quality feed can pass through the rumen in under 12 hours.
To put weight on ewes, energy is the most important ingredient, followed closely by protein. To make sure that adequate weight gains can be achieved on a straw-based diet, it is likely that the straw will need to be matched with a high-energy and protein supplement.
To be able to balance the ration and make sure that it has sufficient energy, it’s important to know the feed quality of the straw and grain you will be feeding, even if they came from your own property. Knowing the quality of the feed you have on hand enables you to create a ration that meets the nutritive needs of your stock.
Many producers have taken a failed crop and added value to it by baling it for hay. While there is a quality-quantity trade-off between having sufficient dry matter to cut and the decline in feed quality as the crop matures and/or dries out, in many cases this becomes a worthwhile feed source.
Once again, it’s important to check the feed quality of the hay by doing a feed test. Then you can work out an effective ration for the lowest cost and add the required amount of energy to reach the target level of animal performance.
Understanding the energy, protein and fibre levels of your feeds is one half of a feed budget. The other half is knowing the energy, protein and fibre requirements of the animals that you are feeding.
Lifetime Wool has shown that the number of lambs born is directly related to condition scores at joining, assuming ewe condition can be maintained during pregnancy. Where breeding ewes are in lighter than ideal condition, a rising plane of nutrition in the lead up to joining increases conception rates.
Keeping stock in good condition gives you options if you decide to sell later. Putting on condition is more costly than maintaining condition, so feeding early is the best strategy.
Dr Hannah Manning is Industry Development Officer for Agriculture Victoria Livestock.