03/04/2023
Stocking density and trough space can potentially influence the welfare of sheep during live export voyages.
This has been the focus of a recent study conducted as part of a Project Partnership between the Livestock Export RD&E Program and the University of New England.
The study assessed the implications for sheep housed at five different stocking densities for 18 days, with either unrestricted or restricted trough space allowance. It also examined behavioural changes, which are often the first response to stressors and provide a good indicator of an animal’s ability to cope with environmental changes.
The results of this study have now been published in the Frontiers in Veterinary Science journal.
The welfare of sheep was not impaired by either reduced pen or trough space during the trial. However, more space can help to reduce the time animals take to adapt to their environment.
The amount of trough space had no important effects on sheep behaviour at the group level at the five stocking densities tested.
There was little difference in the number of sheep lying down during in-active periods of the day. However, sometimes sheep with reduced space spent less time lying down.
When provided with more floor space, more sheep lay down with their legs outstretched and chose to lie away from others rather than resting their heads on other sheep.
Sheep with more space were more likely to engage in positive social interactions and performed fewer negative behaviours. While it is normal to expect some initial aggressive behaviours as animals adapt to a new social hierarchy after mixing, this finding suggests that this happens faster with increased space.
There were no changes to levels of stress hormones in the blood samples taken throughout the trial. This suggests that, despite some behavioural changes, sheep did not experience ongoing or significant stress.
This trial was deliberately designed to replicate ideal conditions to isolate the potential impact of stocking density and trough space on the welfare of sheep. As a result, the study has provided key foundational knowledge and further research is being carried out on other factors likely on livestock export voyages and to determine their cumulative effects.