With the livestock game turning some strong profits in the last few years, there has been a proliferation of new sheep handlers and scales. Some of the new gear comes with potential cost saving devices, here we take a look at the economics of automatic drench guns
Automatic drench guns have been around for a while, and the theory is pretty simple. As sheep are being weighed through a handler or a crate, the indicator tells the electronic gun how much drench to give the animal, based on the animals liveweight.
Traditionally drench doses have been based on the heaviest animal, and this is often a guess. This results in light animals receiving much more than required, and the heaviest animals, in some cases, being underdosed.
The price of everything is going up, and drench is one of them, so it is worth taking a look at what saving might be available.
Figure 1 shows a histogram of weights of 317 crossbred ewes. It’s a nice statistical bell curve, with most sheep weighing between 54 and 84 kilograms. The heaviest ewe is 104 kilograms, so traditionally all would be drenched to this weight.
For this example we’ll use a dose rate of 1ml for every 10 kilograms liveweight, which would mean a dose of 21ml. The total drench used would be 3.29 litres. A ‘cheap’ levamisole or dual drench will cost $20/litre, so the total cost for the mob is $66, or an average of 21¢/head.
If the mob is drench as per individual weights, the total drench used is 2.22 litres, for a cost of $44 for the mob, or 14¢/head.
It might be in using break drenches where the real benefit of the weighing technologies come in. Zolvix costs around $210 per litre, and Startect $110 per litre, but is used at double the dose.
If we run the same analysis, the cost of drenching the 317 head mob comes in at around $660, or $2.08 per head drenching for the top weight. If dosing for actual weights the cost is $444 or $1.4 per head.
What does it mean?
A Tepari ‘Revolution Dosing Gun’ starts at $1,500. If you’ve already got the handling setup and using expensive drench, and drenching sheep with a large weight variation, payback on the gun would be on 2200 sheep.
If you have to buy a handler to go with the gun, at $20,000 plus, it’s obviously going to take a lot more sheep to get a return, if you don’t include all the other benefits of the handler.
Key Points
- New technologies allow for automatic precise dosing of sheep using scales and a drench gun.
- Savings of drench are significant if the mob has a wide weight range.
- If using expensive drench, automatic drench guns make some sense.
Click on figure to expand
Data sources: MLA
