The Effects of Diarrhoea, Tail Length and Sex on the Incidence of Breech Strike in Modified Mulesed Merino Sheep

Abstract

Merino sheep were treated with purgative to induce scouring and the effects of tail length and sex on the incidence and origin of breech strike were examined. In sheep treated with the modified Mules operation, those with tails docked very short were strongly predisposed to tail strike, and to a lesser extent, crutch strike. Tails docked level with, or just below, the tip of the vulva in ewes, and at the equivalent length in wethers, were struck far less frequently. Within each tail length group, wethers tended to be more susceptible than ewes. L. cuprina was the principal species of fly involved in strikes, although the presence of L. sericata and C. augur was conspicuous.

Research into alternatives to mulesing

“…In Western Australia over one season 1.9% of radically mulesed sheep were struck on the breech compared to 6.7% of un‐mulesed sheep 7 . Good technique also involves docking tails to the level of the base of the vulva and retaining some wool bearing skin on the tail to minimise cancer 1,8, 9…”

Breech‐strike on mulesed, clipped and unmulesed Merino ewes and hoggets in south‐eastern Australia

“…18 Despite dag becoming an increasingly important risk factor for breech-strike, and urine stain less so, high stain score was occasionally identified as a risk factor in the clipped and unmulesed ewes in the current study. 18 Despite dag becoming an increasingly important risk factor for breech-strike, and urine stain less so, high stain score was occasionally identified as a risk factor in the clipped and unmulesed ewes in the current study.…”

Tail docking in horses: a review of the issues

“…However, scientific studies are not unanimous: whereas French et al (1994a) showed that intact lambs underwent more fly attacks than docked lambs, in relation with improved rear cleanliness, two other studies (French et al, 1994b;Snoep et al, 2002) showed that docking was associated neither to a lower myiasis prevalence nor to less insect attacks. In addition, docking lambs too short can increase the incidence of fly strike (Watts and Marchant, 1977;Watts and Luff, 1978; see also Watts and Perry, 1975;. Furthermore, in spite of their results, French et al (1994a) concluded that more adequate control of diarrhoea and development of reliable alternative methods of blowfly strike management should be considered, because of the dichotomy between the proportion of docked lambs (about 100%) and the relatively low proportion of lambs likely to be struck (125 attacks for 3172 studied lambs).…”