Silage is playing a much bigger role in the feeding systems of livestock producers in southern NSW and with crop and pasture growth better than previous seasons, it raised the prospect of fodder conservation for many.
Knowing that making good silage is involved, Local Land Service and NSW DPI are collaborating to bring farmers a series of webinars on silage, with John Piltz from NSW DPI making four presentations with the first being 'Forage quality and how it impacts silage quality and livestock production'.
Mr Piltz is a livestock research officer (NSW DPI) and adjunct Research Associate (CSU) and he has worked in forage conservation and ruminant nutrition research since graduating from University of NSW in 1982.
Mr Piltz opened the first webinar by asking - what is feed quality?
And he answered by saying in his opinion for beef and sheep meat producers the key components to think about are dry matter content (DM) and metabolizable energy (ME).
"Dry matter is everything that is in that silage or forage except water and the reason we want to know about dry matter content is that all the energy, protein and minerals we need allow the animals to maintain body weight and grow are contained within that DM," he said.
"Metabolizable energy is the most important aspect of feed quality because ME is the energy which is available to animal for maintenance, heat production and for growth, milk production, wool production and sustaining a pregnancy."
Mr Piltz said ME is the first limiting nutrient in most ruminant diets and because it can't easily be measured, instead the digestibility of the forage or silage is measured.
"For all of your feed analysis results, ME would have calculated from digestibility," he said.
"Digestibility is an expression of how much of the feed DM is absorbed by the animal under set conditions."
To put that in perspective, Mr Plitz said to maintain weight the feed needs a digestibility of about 55 per cent or ME of eight.
"An increase between eight and 11 ME is going to give you an extra 100kgs of beef produced for every ton of silage DM you feed," he said.
"Small changes in digestibility can lead to large changes in liveweight gain.
"Protein content is the other crucial parameter because essentially we need to ensure there is sufficient protein to meet the animals needs for the amount of energy they are consuming and additional protein is of no real value to the animal."
When making silage, Mr Piltz said we are converting forage in a wet form and store it in an airtight environment and preserve it due to a fermentation process.
"If we increase dry matter content we actually favour good bacteria which means the wrong bacteria can't dominate the fermentation and fermentation quality has a big impact on intake," he said.
- Further information on successful silage resources: silage manual, silage notes plus other helpful tools can be found at https://www.dpi.nsw.gov.au/agriculture/pastures-and-rangelands/silage
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