A recent study challenges the practice of housing calves individually to limit the spread of disease and improve health.
Housing pre-weaned calves individually has been a tradition among many dairy farmers in Canada, the United States and Europe but the practice has come under scrutiny recently.
A recent study by researchers at the University of British Columbia looked at how motivated very young calves are to seek social contact.
“In North America, individual housing has and continues to be the most common method of housing milk-fed dairy calves,” said Marina von Keyserlingk, an NSERC Industrial Research Chair in dairy cattle welfare at the university’s Faculty of Land and Food Systems.
“This study was set up to allow five- to 10-day-old calves to choose a social partner if they wanted to by pushing (through) a weighted gate. We then increased the weight on the gate, requiring calves to work harder to access another calf. From our results, even at a week old, calves were highly motivated for social contact.”
Von Keyserlingk said in a news release previous behavioural studies have suggested that lack of social interaction can negatively affect calves’ feed intake, social skills, coping abilities and cognitive performance.
“However, previous studies on social motivation among young cattle have not addressed the first six to eight weeks of life when individual housing is the most common,” she said.
The project was run by post-doctoral fellow, Dr. Thomas Ede, at the UBC Dairy Education and Research Centre in Agassiz. Ten bull calves were studied over a 15-day period. They averaged five days of age at the beginning of the study. The calves were individually housed in a central home pen with access to one pen on either side, each connected by a one-way clear plastic push gate.
All the pens were identical in size and resources with the same amounts of feed, hay, and water. One side pen housed another calf while the other side pen was empty. The calves could see through the clear gate as well as through gaps above and below.
The calf had three options. It could stay in its own pen. It could enter the empty pen. Or it could enter the pen containing a companion calf.
“They (the calves) were very motivated when they saw a calf on the other side of the clear plexiglass barrier. The gate was one way, which allowed us to focus the study on the ‘focal’ or ‘subject’ calves.”
Once a calf had pushed open the gate and accessed a side pen, he would stay there until the next milk feeding when he was returned to his central, home pen.
“After each successful pushing event, additional weight was added to the gate,” she said. “Initially it was a small amount, then incrementally higher.”
According to the report, the initial weight was 0.5 kilograms. Additional, incremental weights were in the region of 0.25 kg and, after eight pushing events, the total weight increase would be three kg. The maximum weight pushed and the number of pushes by each calf over the 15-day trial were recorded for both the partner pen and the empty pen.
Of the 10 calves tested, eight pushed more for the social side, one pushed more for the empty side, and one pushed the same weight for both sides. The calves pushed on average one kg more to access the pen with a companion versus the empty pen. All the calves, but one, pushed through a gate for the first time on the study’s first day, often within 10 minutes of the start of the experiment.
Von Keyserlingk said that the design of the pen structure was such that the task of pushing through the gate was effortless at the beginning of the trial. This facilitated spontaneous learning. In addition, the pen that held the companion calf was randomly assigned each day so that the calves would not simply learn which side housed their companion and act accordingly.
The results of the study clearly showed that very young calves are highly motivated for full social contact regardless of the partial contact through visual or auditory means. She wrote in the report that the result suggested pushing a see-through gate is sufficiently intuitive for calves to learn the skill on their own, suggesting that this task could be used to efficiently assess motivation in other situations. All the calves pushed for access to the empty pen to some degree. Since the companion calf was randomly positioned between one adjacent pen or the other, the subject calf was consistently challenged to identify the specific social pen.
Von Keyserlingk said that a common argument for individual housing is to limit the spread of disease and improve health.
“The research done on this topic, however, does not support these claims as studies on the effect of social housing on calf health show no differences in terms of health between individual and small (less than eight to 10 calves) groups.”
She said that when calves are housed in a social environment, they not only learn new things more quickly, eat more starter foods and are quicker at trying new foods but also have more confidence to take more risks when presented with ambiguous situations.
Von Keyserlingk said that although some farms have adopted social housing for milk-fed calves, the current Draft Code of Practice for the Care and Handling of Dairy Cattle, which was recently made available for public comment, states that effective Jan. 1, 2033, healthy calves must be housed in pairs or groups by two to four weeks of age (in indoor or outdoor systems).
Time will tell if this date will be changed in the final version once public comments have been reviewed.
“Our research is another piece of evidence that indicates this timeline should be reconsidered given that calves are highly motivated to engage in social contact even as young as one to two weeks of age,” she said.
The study was presented at a scientific conference at the International Society of Applied Animal Behaviour.
“One point discussed was that the simplicity of the design makes a straightforward argument that calves enjoy social contact and will work to achieve it.”
Source: Western Producer