Calculating a Feed Budget

Stock Journal Feature Article – February 2024

When we look at ewe nutrition through the feed gap and how much feed we are likely to need, it’s first important to look at what is available in the paddock. We can then decide if stock need to be supplemented in a containment area or sacrifice paddock. Alternatively, if there is adequate ground cover and roughage available, they could be supplemented in the paddock.

In most areas of South Australia reliant on annual pastures, the feed value left in the paddock is very low. Most stubbles had minimal grain available and the rain on stubbles and dry pastures have deteriorated the feed quality further.

Often during the summer and autumn feed gap a high proportion of stock are pregnant meaning we have to meet gestational energy requirements. Meeting these energy requirements enables us to hit condition score targets throughout this period, which can substantially improve results at lambing.

A feed budget can be a bit more complicated during this time as you will need to calculate the most cost-effective way to meet requirements incrementally as the ewes move through gestation. Often feed rations are calculated every 10 days to determine the shortfall of energy from paddock feed or roughage being provided (if in a containment area). To meet the shortfall, energy dense feed such as grain or pellets often need to be added depending on the gestation stage and whether ewes are carrying single or multiple foetus’s.

When looking at these feed rations you will then need to multiply out the required daily quantity of feed by the number of single and multiple bearing ewes you are going to feed to give you a daily feed quantity required. The hardest part then is determining when the ‘break of the season’ is likely to be – once the break of the season occurs it can be at least four weeks before high-quality feed is available to meet the energy requirements of an ewe getting towards late gestation. Perennial plants can often respond quicker but when relying on sown or self-regenerating annual pastures ewes often need to be supplemented until a sufficient quantity and quality of feed is available. I would recommend determining the average break and feed budgeting for a daily quantity of supplementary feed for at least 2 – 4 weeks post this date depending on your pasture base and how quickly it is likely to respond.

Determining energy requirements of your ewes and calculating rations to meet these requirements allows you to calculate a feed budget. Calculating a feed budget early gives you the advantage of purchasing or holding onto adequate grain and fodder to maintain stock until pasture quantity and quality is sufficient to meet requirements. Purchasing fodder early often works out a lot more economical than trying to top up supplies later in the season after a late break when many people will be chasing last minute feed.