Maternal bonding of dairy cattle assessed
August 31, 2020
A new study from the University of British Columbia's (UBC) Faculty of Land & Food Systems measures how strong a bond develops between a dairy cow and her calf based on the amount of time spent together and whether suckling takes place.
“Previous studies suggested that a strong cow-calf bond can be established even in the absence of suckling,” said Dan Weary, a Natural Sciences & Engineering Research Council of Canada industrial research chair in animal welfare at UBC. “But our results show another dimension — that the activity of suckling dramatically increases the bond between mother and calf.”
The results published in Scientific Reports, "Effect of Cow-Calf Contact on Cow Motivation to Reunite with their Calf," outlines research in which cow-calf pairs were divided into three groups:
• Those who spent a maximum 2 hours together immediately after birth, but did not see each other regularly;
• Those who spent 1.5 days together after birth and reunited each night, and
• Those who spent 1.5 days together after birth, reunited each night and were allowed to suckle.
Cows that were suckled by their calves built the strongest bond compared to those who spent the same amount of time with their calves but were not suckled and those who did not spend time with their calves, UBC said. The bond was measured by seeing how much weight a cow would push to open a gate that provided access to her calf. Cows that were suckled by their calves showed much higher motivation — pushing a weight twice as heavy as those that were not suckled.
“Oxytocin, known as a bonding hormone, may be the main reason,” said Margret Wenker, a doctoral student at Wageningen University & Research in the Netherlands, and a co-author of the study. “Oxytocin is known to be increased when a mother feeds her young and it has a rewarding effect — suckling is considered one of the most hedonic maternal activities.”
There was no noticeable difference in motivation between the cows that were not suckled and those that did not see their calves regularly. Also, all cows showed similar behavior once reunited — licking their calves and being attentive.
On many dairy farms, the calf is removed from the cow soon after birth, but as Weary explained, “Some dairy farmers are interested in trying to keep calves and cows together; our results suggest that an important feature of the cow-calf system is that the cow is able to suckle her calf.”
The study included 34 Holstein cows at UBC’s Dairy Education & Research Centre in Agassiz, B.C.