Risk to livestock emerging due to 'green drought'
18 Dec 2023
A ‘green drought’ is currently being experienced in parts of the Hunter, bringing new risks to livestock. Hunter Local Land Services is warning producers to consider how to manage pastures and feed for dry times, even with the recent rain.
Teresa Hogan, Livestock Officer with Hunter Local Land Services, said “The welcome rain received in some, but not all parts of the region has been enough to put a green tinge about, but it is a long way from drought breaking with a run of hot summer weather now being experienced.
“After rain, it may be tempting to stop feeding livestock or cancel the hay on order, however, by ceasing feeding too soon, or grazing too soon, this will result in pastures taking longer to grow and for less feed to be accumulating.”
Allowing livestock to graze on green pick before it translates into a useful quantity of feed, may seem like a good short-term solution, but will cause you more problems down the track as pastures will likely ‘bounce’ slower on the back of further rain events.
Providing enough quality hay or silage to livestock to meet livestock nutritional needs will reduce their need to chase the green pick but closing the gate is just as important.
While ‘green pick’ is a great sign of pasture growth and a reduced reliance on supplementary feed, new green growth also has a water content of up to 90%, making it impossible for animals to eat enough to satisfy their nutritional needs if they do not also have access to roughage.
It can take between 3 – 8 weeks before pastures offer a useful quantity of feed, with growth depending on the species of pasture and the height and density of these pastures before the rain event. Grazing pastures with a high water content (70-90% water) and short height (30-90mm) means livestock will expend more energy grazing for many hours but can also set pasture recovery back significantly.
“Producers should continue to provide supplementary feed for livestock until pastures mature and the water content drops,” Teresa said.
A good rule of thumb before grazing is that pastures should be at a starting point of 10cm height or over, providing at least 1200kg Green DM/Ha (Green Dry matter per Hectare). Livestock are best fed in smaller paddocks where they can’t chase green pick while those paddocks recover. Another strategy can be to slow down the paddock rotations, giving recovering pastures longer to grow while producers supplementary feed.
The Drought and Supplementary Feed Calculator can be a useful tool to assist in decision making around feeding livestock.
The Hunter Local Land Services District Veterinarian team have also provided advice on the impact of a sudden change of feed which can also result in pulpy kidney.
Pulpy kidney is a livestock disease caused by the overgrowth of clostridial organisms or bacteria in the gut due to the consumption of high carbohydrate feed.
Animals being supplemented with heavy grain feeding or moving onto fresh green pasture are at high risk of the disease, which often manifests in young, fast-growing livestock that are unweaned or recently weaned and are without a full vaccination history. Pulpy kidney is fast acting and there are often no prior signs of sickness in livestock.
A vaccination program of two doses of 5-in-1, dosed 4-6 weeks apart initially followed by a quarterly booster achieve lasting protection against pulpy kidney is recommended.
For more information about livestock health, contact your Local Land Services District Veterinarian or Livestock Officer on 1300 795 299.