New research estimates five to six per cent of calf losses in northern Australia are a result of bottle teat syndrome in cows, but it may not be obvious to producers.
The findings were from a recent CalfWatch project trial in 2019 to 2022, which was undertaken at Manbulloo Station, near Katherine, by principal livestock research officer for the Northern Territory government, Tim Schatz.
He found a number of the commercial cows had bottle teats at calving, but then appeared normal a few weeks later meaning they may be missed at culling time.
Mr Schatz said, by using a system of birthing sensors and GPS collars, they studied 200 cow that were over two years of age.
"The cows were run in a typical north Australian breeder paddock, 2215 ha in size, uncleared with mostly native pastures," he said.
In both 2019 and 2020, calf loses rates were at 17pc and included early abortion, dystocia, infection of the umbilical cord and pneumonia, but these were only one or two cases each.
Mr Schatz and his team worked alongside researchers from the University of Florida to increase the range and usability of the birth sensors in locations with limited mobile phone coverage.
The intra-vaginal birthing sensors and GPS tracking collars were applied in August, before calving in October to January.
He said once the sensor registers a rapid temperature change, the sensor emits a UHF signal.
"The alert is transmitted in real time to a supporting website, which then sends an email to our team," he said.
"Upon receiving the notification, our team locates the cow using its GPS collar and from a distance, we recorded the calf's health, date of birth and maternal observations."
Mr Schatz said that having the ability to find the calf within an hour or so after birth had been a considerable development.
"Historically, determining the cause of calf loss in extensive beef operations has been challenging," he said.
"Large paddocks, trees, tussocky native pastures and predators, such as wild dogs and pigs, have all made locating calf carcases in time for a post mortem, quite difficult.
"Many of the cows that had bottle teats at calving, had normal appearing udders only a few weeks later."
Mr Schatz said birth sensors could be used in the industry to identify calving in high value animals, enable collection of birth date data and traits for Breedplan, and also identify the cause of calf loss.
Some of the 'unknown losses' in the study were likely to have been due to poor mothering, but he said, this was unable to be quantified.
"Using the CalfWatch system, if we found the calf dead, we were able to conduct a post mortem," he said.
"If this is typical of northern herds, it is likely these cows are going through the yards later in the year without being culled.
"If not they will only continue to lose calves so producers could consider culling all cows that don't raise a calf to weaning."
Studies have also found found that bottle teats is moderately heritable. Therefore, it is a good idea to cull cows with bottle teats to avoid them losing more calves in future. This may also help in them producing daughters which may develop bottle teats.