Weaning of beef calves is usually completed by separating calves from their dams into distinct paddocks. Yard weaning is increasing in popularity and is where calves are contained in yards for 1-2 weeks instead of a paddock.
A study out of Australia showed that yard-weaned calves grew faster than paddock weaned calves. Other than a few industry reported numbers, there are very little scientific publications comparing yard and paddock-weaned beef calves.
This experiment we have summarised examined the effects of yard weaning vs paddock weaning of beef calves.
In addition, the authors compared calves that were weaned with and without daily human contact.
Key Points
In the first 7 days after weaning, paddock-weaned calves lost more weight than yard-weaned calves but, were similar in weight by 42 days after weaning
Yard-weaned calves tended to have a lower temperament score (were less reactive) 7 days after weaning compared with paddock-weaned calves
Daily vs minimal human contact had little effect on live weight or temperament score regardless of whether calves were yard- or paddock-weaned, however, there was a difference in heart rate.
Keywords: #weaning #beefcalves #calfgrowth #calfbehaviour
Calves were weaned on average at 198 days (~6.5 months) of age and split into 8 groups of 8 calves in each group.
Each group was allocated one of these 2 weaning methods:
Yard-weaning: 4 of the groups were yarded and fed pasture baleage for 7 days
Paddock-weaning: 4 groups were grazed in paddocks and offered ad lib intakes of ryegrass/white-clover
After the 7 days, calves were separated into a mob of heifers and a mob of steers and were grazed in these 2 mobs until 42 days (6 weeks) after weaning.
Are there weight or growth benefits to yard weaning vs paddock weaning?
In the first 7 days after weaning, paddock weaned calves lost more live weight than calves that were weaned in the yards. As seen in Figure 1 below, yard weaned calves (blue) went from 273.6 kg to 268.3 kg (lost on average 0.6 kg/day), whereas, paddock weaned calves (purple) went from 279.6 to 269.8 kg (lost on average 1.19 kg/day).
Once the yard and paddock weaned calves were grazed together (day 7 to 42) their growth rates were similar and by 42 days after weaning calves from both weaning groups were similar in live weight.
Are there behavioural benefits to yard weaning vs paddock weaning?
Beef + Lamb NZ in their factsheet wrote that yard weaning calves and regular contact with people can help make calves easier to manage throughout their lives.
This study used a variety of behavioural measurements; heart rate, temperament score, step count in the weigh crate, and exit time and faecal corticosterone. We have summarised temperament score, and heart rate, the full results are reported in the paper (linked at the bottom of this post).
Were yard-weaned calves quieter than paddock-weaned calves?
In this study, on the day of weaning (day 0), day 7 and day 42, all calves were given a temperament score from 1 to 5 while they were in a weigh crate.
Temperament scores were based on an international scale where the calf was:
1 = calm with no movement in the weigh crate and their head was mostly still;
2 = slightly restless, looking around frequently and moving their feet;
3 = moving feet often but not moving back and forth with excessive head movement;
4 = agitated and moving back and forth in the weigh crate;
5 = agitated with continuous vigorous movement and snorting.
There were no differences in temperament score on weaning day (day 0) and day 42 between the yard-weaned and paddock-weaned calves (Figure 2 below).
Yard-weaned calves on day 7 tended (p-value=0.07) to have lower temperament scores than paddock-weaned calves. What this means is that there is there is some evidence that the yard-weaned calves were more relaxed than the paddock-weaned calves.
A p-value of 0.07 shows there is a 7% chance that these results occurred completely randomly. Usually in animal/agricultural studies such as this one, a p-value of 0.05 or less is used as the threshold of stating that a result is statistically meaningful or not. In other words we are looking for a 5% or less chance that the result occurred randomly.
Sometimes in studies a result with a p-value between 0.05 and 0.10 is referred to as "tended to towards" statistical significance as in the case of this study. Based on the lack of difference between the 2 methods of weaning by day 42, the very slight difference on day 7 is unlikely to be practically useful in raising quieter beef calves.
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Heart rate of calves weaned in the paddock or yards
Similar to weight and temperament, calves from both weaning methods had similar heart rates on day 0 (weaning) and 42 days after weaning (Figure 3).
7 days after weaning, the calves that were paddock-weaned had on average a higher heart rate than the calves that were yard-weaned.
As can be seen in the graph below, the yard-weaned calves heart rate decreased from weaning until day 7, whereas, the heart rate of the paddock-weaned calves increased over the same period (Figure 3).
Heart rate can be used to indicate a response to stress or to increased activity. It is important to note that the paddock-weaned calves need to travel to the yards to be weighed, measured and scored but the yard-weaned calves were already at the yards.
The difference in heart rate may be due to the increased activity of the paddock-weaned calved. It may also be due to the paddock-weaned calves being more stressed being in the yards than the yard-weaned calves.
Are calves quieter if they have daily human contact?
As mentioned before, industry data suggested that yard weaning calves and regular contact with people can help make calves easier to manage throughout their lives. It was unclear whether the yard-weaned calves would be quieter because of being in the yards, or because of regular human contact in the yards due to being fed.
A second aim of this study was to see if daily contact in the yards or daily contact in the paddock would make calves quieter to handle compared with minimal contact either in the yards or paddock.
Daily contact consisted of one person spending 18 minutes with each group of calves and moving as close to each calf in the group as it would allow.
There was no interaction for any of the measurements between the weaning method and human contact treatment (daily vs minimal). What this means is that the effect (or lack of effect) of human contact on calves was the same for yard-weaned calves as it was for paddock-weaned calves.
There was no effect of human contact on weight, weight gain or temperament score over the duration of the experiment. The calves with daily human contact were similar to the calves with minimal human contact in their weight and temperament.
Interestingly, on day 42, the calves that had minimal human contact in the first week after weaning had higher heart rates than the calves that had daily human contact in the first week after weaning (Figure 4).
This difference in heart rate between the 2 human contact groups was not present on day 7.
The authors mentioned that the measurement of heart rate involved human contact and perhaps the calves that had daily human contact were more used to being close with humans and hence why they had lower heart rates on day 42.
Overall this study showed that there may be some short-term benefits of yard weaning calves instead of paddock weaning. Paddock-weaned calves lost more weight and had higher heart rates during the first 7 days after weaning than yard-weaned calves.
It would be beneficial if this study were to be repeated, perhaps with more calves or with calves that had not been previously yarded or exposed to humans before weaning.
The evidence presented in this study somewhat suggested that the previously reported benefits of yard-weaning were due to the yarding process and not the increased human contact.
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