Sheep lose balance, slip and fall less when loosely packed in transit where they stand close to but not touching their neighbours

There are two opposing views about the space required for sheep in transit. One is that they should be transported at low space (high stocking density) and avoid slipping or falling by bracing themselves against each other. The other is that they should be transported at high space (low stocking density) and avoid slipping or falling by adopting an independent and wide stance to brace against the motion of the vehicle. We here examine the validity of each view by measuring (i) incidences of loss of balance, slipping and falling at different space allowances during transport and (ii) the extent to which sheep show evidence of choosing to brace themselves against each other or to stand independently.Four categories of sheep, shorn and fleeced ewes and lambs, were transported at five space allowances on standard journeys of 6 h. Minimum space allowance, low, was taken from legislation (Anon, 1997), whilst medium-low, medium-high and high allowances were calculated from the allometric equation A = kW0.67 (W: average liveweight/pen and k: empirical constant). k-values of 0.021, 0.026, and 0.037 were used for increasing allowances and fleeced animals were given an additional 25% space. A control group providing more than 1 m2/animal was also included.Results showed that sheep transported at control and high spacing suffered fewer losses of balance and slips than sheep transported at low and medium-low spacing, especially on roads with rough ride characteristics (B roads). Rates of falling were highest for shorn sheep in the low and medium-low spacing, where sheep were also forced to the floor by their pen-mates and unable to stand immediately. Sheep transported at control and high spacing were seen to stand close to, but not touching (independent) their pen-mates, bracing themselves against the motion of the vehicle by spreading their feet, not by leaning on their pen-mates. They were also seen to lie in transit at higher space allowances.Our results suggest that the space provided by minimum legislation and calculations with a k-value of 0.021 are unacceptable, as they do not allow the sheep to adopt their preferred spacing strategy and lead to more losses of balance, slips and falls. Space provided by a k-value of 0.026 and above for shorn sheep and 0.033 for fleeced sheep, was better suited to this independent strategy and led to fewer losses of balance, slips and falls, which is considered better for the welfare of the sheep.