In-paddock weighing - A breakthrough in cattle management

Weighing in, from just the front feet.

Several designs were tested, starting with full-length platforms using lick blocks to entice cattle. It was soon determined that the cattle would place two feet on a platform to access the attractant but were hesitant to put all four feet on.

The team began developing a prototype that would read the beast's NLIS tag and record its weight from just the front feet. They also created an algorithm to accurately calculate the whole-body weight based on the recorded weight of the front feet. After rigorous testing and independently-run trials, the Optiweigh system was launched in early 2019.

Live weights of individual animals are recorded when the animal places its two front feet onto the unit as it eats the attractant. The Optiweigh system then uses its specialised algorithm to generate whole live body weights.

Weighing up data on the fly.

It has been established that front feet weighing is highly accurate following research in Australia and the US over the past decade. The Optiweigh team has further developed their own conversion algorithms after extensive research and trials on various animal types and in different environments across Australia. These algorithms have also been independently verified in trials conducted by The University of Sydney.

Accuracy checks and comparisons have found the mob average of a mob weighed through the yards and one weighed using the Optiweigh system will be within 10 kilograms of each other.

In most mobs, it is rare for each individual animal to be weighed by the Optiweigh system because naturally, some animals will be more eager to step onto it to get to the attractant than others. The number of animals weighed also depends on the size of the mob, the size of the paddock and the length of the weighing session.

Generally, for mobs of less than 100 animals, 40-80 animals will be weighed. The number weighed by the Optiweigh system does not increase proportionately as mob size increases unless the system is used in a high traffic setting such as cell grazing or in a feedlot.

Under extensive grazing conditions, sessions of 1-2 weeks are usually required to obtain adequate weight records.

The higher the weight range of a mob, the more animals that need to be weighed to get an accurate average using the Optiweigh system. The required time to get enough weight records for 10kg accuracy depends on the paddock size.

Once a mob is familiar with the Optiweigh unit (usually within a week), taking it away and then bringing it back to them is an excellent way to get a lot of records quickly. Under extensive grazing conditions, sessions of 1-2 weeks are usually required to obtain adequate weight records. Longer sessions will eventually increase the number of animals weighed, but only gradually.

To begin a weighing session, producers log into the Optiweigh website to give the session, mob and paddock a name and tell the system when the session starts. The unit will then send NLIS and associated weight data to the website hourly. The producer can then view and download various reports at any time. These reports include charts showing the number of animals weighed daily and their weights, the weight distribution of the mob (in 25 kilogram weight bands), and the average weekly weights for animals during the current and all previous sessions. A daily email is also available that summarises the activity on the Optiweigh unit over the past 24 hours, including the number of weight records, average mob weight and maximum and minimum weights recorded.