Resources for assessing feed and animal requirements over summer
Jane Court, Agriculture Victoria
It can be quite difficult to assess the value of pastures (and crop stubbles) as they dry off and deteriorate over summer. This is especially true for sheep, because they are very good at selecting the best bits of the pasture to graze to quite low levels. Monitoring stock condition over summer is critical for assessing whether the feed is meeting their needs. Some good resources for making initial assessments of both pastures and crops can be sourced on the Feeding Livestock website. The Livestock feed on offer assessment guide is a comprehensive picture guide to the feed value and quantity of a range of crops. The Australian Wool Innovation Feed On Offer library provides a similar picture guide for some pasture types. Both can be accessed from the ‘Pasture resources’ page.
If you want quick access to the feed values (energy, protein and fibre) of some common supplements or the feed requirements of a range of livestock classes, these can be found as ‘Useful tables’ under the ‘Sheep resources’ and ‘Beef resources’ tabs.
Table 1 is an example of a table showing energy and protein requirements for sheep.
Table 1. Energy (MJ ME) and protein (CP) requirements for different classes of sheep (Source: Drought Feeding and Management of Sheep, table 3.1)
|Class of stock||Live weight (kg) and condition score||DSE rating||Energy requirement MJ ME/day||Approximate protein requirement CP (%)|
|Adult dry sheep (wether or ewe dry or early stages of pregnancy)||40 kg CS 2||0.7||6|
|Adult dry sheep (wether or ewe dry or early stages of pregnancy)||45 kg CS 2||0.8||6.5|
|Adult dry sheep (wether or ewe dry or early stages of pregnancy)||50 kg CS 2||0.9||7|
|Adult dry sheep (wether or ewe dry or early stages of pregnancy)||50 kg CS 3||1||8||6–8|
Compare feeds and develop rations
If you are after some resources to help work out rations for sheep or cattle, several tools are available under the ‘Beef tools and calculators’ and ‘Sheep tools and calculators’ pages (under the ‘Sheep resources’ and ‘Beef resources’ tabs). Ones that include the pasture contribution are the Lifetime ewe tables (sheep only); GrazFeed; the NSW Drought and Supplementary Feed Calculator and the Tactical Feed Budget (beef only). Others available can help you to assess the best-value and most appropriate ration, and/or estimate the costs.
The NSW Drought and Supplementary Feed Calculator is available as an app and as a web version. It is a good, simple tool that can be used to compare feeds and develop a ration for different classes of stock.
Table 2 shows an example of comparison of lupins and faba beans from the NSW Drought and Supplementary Feed Calculator.
Table 2. Compare and choose best feed
|MJ per tonne 'as fed'||11250.0||12150.0|
|Cost cents per MJ||$3.11||$3.29|
|Cost $/kg protein||$1.52||$1.39|
|Cost $/tonne dry matter||$388.89||$444.44|
|On-farm cost ($/t)||$350.00||$400.00|
|Dry matter (%)||90%||90%|
|Energy (MJ/kg DM)||12.5||13.5|
|Crude protein (% DM)||26%||32%|
The example illustrates how feeds can be compared both for the cost per unit of energy and for the cost per unit of protein. So if you know what your prime need is, you can pick the cheapest source. In this example, faba beans and lupins, and their default energy and protein feed values, were selected from the drop-down menu (you can change these if you have the feed values for your feeds). For this example, faba beans were costed at $350/t and lupins at $400/t. Lupins are the dearest but also the highest in both energy and protein. Using these costs and feed values, faba beans are cheaper than lupins if you are after energy – $2.67 per megajoule (MJ) for faba beans and $3.29/MJ for lupins. Note that both are well above all livestock needs for protein. However, if you need a protein source only (see ‘Underperforming animals in a paddock full of feed’ in this newsletter), lupins are a cheaper source at these costs and feed values ($1.39/kg protein for lupins and $1.52/kg protein for faba beans). You can use this data, with or without pastures, to develop a ration for different classes of livestock in the app. If you haven’t used many apps or online tools before, this would be a great one to start with, because it’s user friendly and backed up by robust science. It saves on the hard work and gives you many of the answers you need to meet your animals’ nutritional requirements.
You can access the web version and the Pearson square calculator (to develop a mix of two feeds to get protein and energy requirements) by going to ‘Sheep tools and calculators’ from the ‘Sheep resources’ tab. There is also a link to the Dairy Australia grain and hay reports on both the Sheep and Beef Resource pages that provide current prices for several hays and grains.