Watts J E, Luff R L
Aust Vet J. 1978 Jul;54(7):356-7. doi: 10.1111/j.1751-0813.1978.tb02493.x.
While the radical Mules operation reduced the incidence of breech strike from 59% to 13% in scouring sheep, the problem was further alleviated by docking lambs' tails at the correct (medium) length. Docking lambs' tails very short strongly predisposed radically mulesed ewes and wethers to faecal soiling and breech strike (20% struck). Radically mulesed sheep with tails docked midway down the vulval orifice in ewes, and the corresponding length in wethers, were rarely struck (3%) and did not appear to require crutching to prevent breech strike associated with scouring or urine staining.
虽然根治性穆尔斯手术将正在梳毛的绵羊的臀击发生率从59%降至13%，但通过将羔羊尾巴剪至正确（中等）长度，这一问题得到了进一步缓解。将羔羊尾巴剪得非常短，会使接受根治性穆尔斯手术的母羊和阉羊极易出现粪便污染和臀击（20%受到感染）。对于接受根治性穆尔斯手术的母羊，将尾巴剪至阴门孔中部，对于阉羊则剪至相应长度，这样的羊很少受到感染（3%），而且似乎不需要进行阴部修剪来预防与梳毛或尿液污染相关的臀击。
