printStock Journal Feature - August 2024
Author: Deb Scammell, Talking Livestock
What a tough season! Most areas of South Australia have been supplementary feeding for an extended period of time. One of the hardest seasons we’ve had for many years for livestock.
In most places we have now got some green feed starting to come through, however a run of frosts and cold weather has reduced the pasture growth rates significantly. Unfortunately, some regions are still limited by available moisture, so growth is likely to slow down even more over the next few weeks pending rainfall.
The pasture that is available is relatively high-quality as it is still in phase 1 or phase 2 of pasture growth. Digestibility of the pasture is also very high, legumes such as medics and clovers have had a good germination in most areas which will increase the overall digestibility of the pasture. Pasture digestibility correlates to energy, meaning energy levels are high as well.
The protein levels of pastures are high, which is common in early green feed. Feed tests of perennial and sown annual pastures have shown average protein between 20 – 30% over the last few weeks. This will easily meet protein targets for growing stock.
Fibre levels of most pastures have been quite low due to the late germination and delayed growth. If there isn’t dry matter available in the paddock (retained over summer) additional fibre can assist the rumen to effectively process the highly digestible and low dry matter pastures.
Unfortunately, in most places the limiting factor isn’t quality of the pastures but quantity. A lot of the pastures are still in phase 1 and are only 10 – 20% dry matter (which is the portion of the plant that contains the nutrients). As plants get more mature, dry matter will increase with some getting closer to 30 – 40%. This still means for a young lamb to harvest 1kg of dry matter of feed per day they will need to consume 10kg of paddock feed if 10% dry matter and still 3.3kg of paddock feed if it’s more mature and up to 30% dry matter.
Once pasture growth rates increase with longer days, more sunshine, and pending additional moisture, livestock will have the ability to harvest sufficient quantities to meet nutritional requirements. Unfortunately, until then, to hit growth targets in many areas supplementary feed is still required.