Effect of animal sex and size on effort when pelting lambs

Pelting load data were collected and analysed for 304 lambs (comprising 46% ewes, 26% cryptorchids and 28% rams), all of which came from one farm. Although typically about 24% more impulse (Ns) had to be applied for pelting ram lambs than for ewe or cryptorchid lambs, only one-third of this increase was attributable to the distinct sexual category of rams; the rest was due to rams being heavier. Carcass size had a much greater effect on pelting load than animal sex: a change in dressed carcass weight of slightly less than 1 kg has the same effect on impulse requirement as the net sex effect. These findings suggest that the differences in pelting effort associated with animal sex are of relatively minor significance compared with the large differences occurring over the range of lamb size normally processed.