Our Sustainable Agriculture Manager Peter Clifton attended a recent Rumen8 workshop presented by Western Beef Association. These were his takeaways…
- Rumen8 is a free software package developed by independent WA consultants Dr Martin Staines and Richard Morris. It has a long track record since 1996 and was initially designed for dairy but was recently updated for beef cattle. It is based on published feed standards and currently has about 4,000 to 5,000 users across 60 countries.
- Before beef producers use the program, they need to have a basic understanding of nutrition for beef animals.
- When allocating feed to livestock, it’s vital to understand its nutritional value or quality of the feed. This will help with allocating the right feed and amount of feed to the right animals and achieve production targets efficiently.
- The most limiting factor in terms of ruminant nutrition is energy content of the feed they consume.
- The energy content of feed determines how quickly the feed is processed. When feed enters the animal’s rumen, it is broken down by microbes. These microbes need energy to perform this function. Low energy diets means microbes are less active and feed takes longer to process, slowing the supply of protein and minerals and potentially causes weight loss. Because lower quality feed takes longer to process, animals get full quicker and stop eating.
- Energy in livestock feed is measured as megajoules of Metaboliseable (available) Energy (ME) per kilogram of feed. While a feed with an ME of 9.5 MJ/kg may not seem much different to one with 10 MJ/kg, a difference of 0.5 megajoule per kilogram has a huge impact on livestock.
- Some animal classes such as lactating cows and young growing animals have different nutritional requirements and therefore need higher quality diets to perform. This is especially the case if you are aiming for high rates of weight gain compared to maintaining weight and condition.
- One of the first steps in allocating feed efficiently is getting the feed tested. The quality of feed varies widely. For example, the energy content in straw is about 6-7 MJ/kg. Hay can vary from about 7-10 MJ/kg, while silage may be 9-12 MJ. Protein also varies widely. Knowing the numbers for different feeds helps to allocate feed to different animal classes efficiently.
- Given animals are eating standing pasture, it is worth testing the quality of that too, perhaps a few times a year for a few years to get an indication of what it is providing. Depending on the pasture’s maturity, it will vary through the year from about 6 MJ/kg for rank summer pasture, to about 11 MJ/kg of lush spring pasture.
- Another critical step in allocating feed is knowing the Dry Matter (DM) content of your feed. The weight in lush pasture is mostly water. Silage weight is about 40% water and Hay is about 15% water.
- To standardise feed calculations, all feed volumes are given in dry matter per kilogram. So, there is a need to convert the weight of feed to Dry Matter. For example, if a 500kg silage bale is 50% water, you have 250 of dry matter and 250kg of water. Calculating how much energy and protein will be provided by the roll can only be done after converting it to dry matter per kilogram.
- Another component of feed quality is fibre content. Feed tests measure fibre several ways, including Neutral Detergent Fibre (NDF – total fibre). Higher NDF means quality will be lower. NDF should ideally be less than 55% of the feed. However, ruminants need some fibre to stimulate rumination and salivate. If animals don’t salivate, the rumen pH can drop and cause acidosis, resulting in poor animal health or death. Too much energy in the diet can kill the rumen microbes. Producers need to be cautious if the starch component of a diet goes above 15%.
- Protein is also a critical component of feed. If you are growing animals, their diet should be at least 12% protein. Again, different classes of animals and different production targets have different requirements.
- Minerals in feed are also essential for metabolism. Calcium, phosphorus and magnesium are particularly important. But prioritise feed allocations based on energy content and then protein, rather than mineral content.
- To develop a diet, it’s important to know the average weight of bales. This can be done by weighing a few bales with scales lifted by a tractor. Then calculate DM.
- It is also important to estimate feed out losses (not eaten). This can be up to 35% and depends on where it is fed out and the quality of the feed. Typically, feed wastage ranges from 5% on feed pads, 15% on pasture and 25% in sacrifice paddocks.
This event was presented by Western Beef Association with funding support from the Australian Government’s Future Drought Fund.
