Case Studies

Step mum study aims for better heifer health

Laura Field TIA calf study

Could having a step mum lead to a less-stressed life for dairy calves?

This is the theory being tested in a world-first trial at the Tasmanian Institute of Agriculture (TIA).

Heifer calves will be reared with non-related older cows that no longer produce milk to test whether it improves their social skills and overall health.

The researchers believe this approach could increase the performance of heifers and help address consumer concerns about calf-cow separation.

Cows are typically separated from their calves to prevent possible transmission of the wasting disease Bovine Johnes Disease.

The TIA project is led by University of Melbourne PhD student Ms Laura Field and supervised by TIA Research Fellow Dr Megan Verdon.

“We think that having a mother figure could really help to improve the underperformance of heifers that often occurs when they join the milking herd,” Ms Field said.

“The stress of entering the milking herd often means that they struggle to perform. We want to see if we can help them adjust more quickly, be more resilient to change and put more energy into growing.”

Ms Field is comparing four groups of 10 calves over the first two years of their life.

The two control groups are being reared with no contact with older cows, as per standard commercial practice, and the two foster groups are with the step mums.

The calves’ behaviour and physical health is being monitored by sampling stress metabolites in faeces, weekly weighing and other social and cognitive tests until they join the milking herd at about two years of age.

While this is a first for dairy cows, Dr Verdon said there is a large body of research across horses, rats and pigs that suggests early development prior to weaning is an important factor for the future health of the animal.

“There is the famous quote – “Give me a child until he is seven and I will give you the man” and there is definitely truth to that when it comes to animals,” Dr Verdon said.

“Those early experiences are essential to shaping who they end up being.”

The research has shown that the early years set up the animal’s development trajectory, so much so, that specific genes can be switched on and off depending on how they are raised.

“It can especially impact how animals cope and react to stress,” Ms Field explained.

“If they have no maternal contact, they tend to be more fearful and less resilient.”

Anecdotally, the team have already noticed that the calves with step mums are less flighty, and more comfortable being handled for their weekly weigh-ins.

And how are the step mums coping?

“They have been loving it. They get to lie around and eat grass and they have really taken to the calves,” Ms Field said.

The trial is taking place at the TIA Dairy Research Facility at Elliott and will run until late 2021.

This project is funded by Dairy Tas. Laura is a student at the Animal Welfare Science Centre at The University of Melbourne and this project is being conducted at the TIA Dairy Research Facility.

Featured Image: Laura Field