Don’t forget animal health after the drought breaks!

Don’t forget animal health after the drought breaks!

In recent weeks we have seen welcome rain throughout much of the drought affected regions of eastern and northern Australia. With the prospect of more rain on the horizon, time will tell if this is the beginning of the breaking of the drought, which for many has been the worst in living memory. Now is the time to consider what animal health procedures need to be undertaken to ensure livestock remain healthy after the drought breaks.

According to Craig Stevenson, Technical Services from Elanco Australasia, “the first 6 weeks after the drought breaks is a critical time from an animal health perspective. Producers may have already spent hundreds of thousands of dollars on feed and water costs to maintain animals through the drought. The last thing they want is for poor decision making now to have long lasting implications that continue to have an economic impact for years to come.

1. Releasing stock from stock containment areas

On many properties it is likely that core breeding stock have been contained in drought lots to conserve the energy of the animals being supplemented and also to preserve ground cover on other areas of the property to prevent valuable topsoil from being blown away. Once drought breaking rains are received, it is recommended to hold sheep and cattle in drought lots for the first 6 weeks to allow grasses, clovers and medics to germinate and establish on the rest of the property prior to grazing. When livestock are moved from dry conditions to lush green conditions then they are particularly susceptible to diseases such as pulpy kidney (caused by Clostridium perfringens Type D). It is commonly recommended that all livestock receive a booster clostridial vaccination (e.g. 5 in 1 vaccine) at least 2 weeks prior to being released from the drought lot. If stock have not previously been vaccinated then two doses 4 weeks apart will be required to ensure stock are adequately protected.

Due to the prolonged hot, dry conditions there are likely to be very few (if any) surviving worm larvae on the paddocks outside the drought lot. Therefore, the source of worm eggs to the paddocks will come from any worms that are in the sheep or cattle at the time of being released from the drought lot. It is recommended that a Worm Egg Count (WEC) be conducted on all classes of livestock held in the drought lot at least two weeks prior to being released. A decision can then be made if livestock require drenching prior to exiting the drought lot. Even a low count may be significant in these circumstances. It is important to note that if livestock are drenched prior to exiting and some worms survive treatment that these worms are most likely resistant to the chemical group(s) used and will lead to resistant worms being spread across the property. For this reason, consider using a highly effective drench such as Zolvix™ Plus (combination of monepantel and abamectin) as the drought lot exit drench. Producers should discuss this further with their animal health advisor as in some cases a full quarantine drench may be warranted. If so, Craig recommends to “drench with four broad spectrum drench actives such as Zolvix Plus in combination with a Benzimidazole/Levamisole drench.”

If sheep have been boxed together for putting in the drought lot and one or more mobs had lice at the time of entry, then it has to be assumed that all classes of sheep are now lousy. If sheep have been under nutritional stress then lice numbers may be greater than they otherwise would have been. Monitor the flock for fleece derangement and in some cases a long wool lice treatment such as Extinosad™ Pour-On may be required prior to the next shearing to reduce lice numbers and minimise any further fleece derangement. If lice are present at the next shearing, aim to shear and treat all sheep either off-shears or with a short wool dip (2-6 weeks post shearing).

2. Bringing livestock home from agistment

Whilst many producers were forced to sell breeding stock, others were able to send core breeding ewes and cows away on agistment. When bringing these animals home after the drought breaks it is important that they receive a quarantine drench on arrival to prevent importing resistant worms picked up whilst on the property where they were agisted. For sheep, Craig recommends “that they be treated with at least four broad spectrum drench groups (e.g. Zolvix™ Plus in conjunction with a benzimidazole/levamisole combination). For cattle the recommendation is that they be treated with at least three broad spectrum drench groups including a benzimidazole, levamisole and macrocyclic lactone. Release stock into a holding paddock or a paddock that is going to be cropped (if applicable) in the next season. A follow up Drench Check WEC should be conducted 10-14 days later. If clear of worms, then stock can be moved to other areas of the property.”

If stock have been agisted in regions where liver fluke are known to be present then consider drenching all stock with a triclabendazole based flukicide (e.g. Fasinex™ 240) on arrival.

Be aware that returning sheep may have become infested with lice whilst away on agistment. Returning sheep should be kept separate from other mobs on the property until you are certain they are lice free (3-4 months after arrival) or until after the following shearing. Lice are very difficult to detect and may still be present even if no visible signs of fleece derangement are present. Regardless as to whether lice are detected or not, producers that have sheep returning from agistment should aim to shear all sheep on the property at the same time and treat for lice either off-shears or with a short wool dip (2-6 weeks post shearing) to ensure the flock is lice free moving forward.

Consideration needs to be given to prevent the introduction of other diseases such as virulent footrot. Inspect the returning sheep for any sign of lameness on arrival. Footrot is unlikely to spread during hot, dry conditions. Even if no signs of lameness are present, sheep may still be carrying the bacteria (Dichelobacter nodosus) that causes footrot. This bacteria can survive in soil for a maximum of seven days away from sheep. Yards and laneways where stock are unloaded should be quarantined from use from other stock on the property for at least seven days.

“It is recommended that producers talk to their animal health advisor about the animal husbandry requirements when managing stock after the drought breaks,” Craig says.

Always read and follow the label directions for any animal health products used.

Zolvix Plus contains 25 g/L monepantel and 2 g/L abamectin. Extinosad Pour On contains 20 g/L spinosad. Fasinex 240 contains 240 g/L triclabendazole.  Elanco, Zolvix™, Extinosad™, and Fasinex™ are licenced trademarks of Elanco or its affiliates. @2020 Elanco or its affiliates. PM-AU-20-0038