Effect of plastic occlusive clips used as an alternative to mulesing on breech conformation, body weight and survival of Merino lambs

Objective To determine the effect of applying plastic clips to the breech and tail of lambs on the perineal and tail bare areas, breech wrinkle, dag (faecal) accumulation, urine stain, body weight and survival of lambs, compared with unclipped, unmulesed lambs and mulesed lambs. Method The study was conducted on five commercial wool‐growing farms in southern Australia. On each study site lambs (2–12‐weeks‐old) were divided into three groups: (1) unclipped, unmulesed control (tail dock only); (2) treated with clips; and (3) treated with the mules operation. Evaluations of effects, including visual scoring, bare area measurements and body weight, were performed before treatment and on or approximately days 30, 60, 90 and 180 after treatment. On each occasion, lambs were recorded as either present or absent to allow estimates of survival. Results The clip treatment increased the size of the perineal and tail bare areas compared with the unclipped, unmulesed control lambs (P < 0.05), although the increases were less than in mulesed lambs (P < 0.05). The clips reduced breech wrinkle, dag and urine stain to levels partway between those recorded in the unclipped, unmulesed controls and the mulesed lambs (P < 0.05). Clipped lambs weighed more than mulesed lambs after treatment (days 30–90 P < 0.001; day 180 P < 0.01) and had higher cumulative percentage survival to 90 days after treatment (P = 0.03). Conclusions The clips successfully modified the breech region of lambs, although the changes were less than with mulesing. The clips did not reduce the body weight of lambs, compared with the unclipped, unmulesed control lambs, and improved 90‐day cumulative percentage survival compared with mulesed lambs.     

Wound healing after mulesing and other options for controlling breech flystrike in Merino lambs: quantitative and semiquantitative analysis of wound healing and wound bed contraction

Background A two‐part study examined wound healing and contraction occurring after mulesing and two alternative methods of preventing breech flystrike in sheep. Objective To quantify wound healing using a scoring system and to assess the contractility of the wound bed of the breech after mulesing, cetrimide‐intradermal treatment and application of clips. Method The study group of 30 mulesed, 30 cetrimide‐intradermal treated, 30 control and 10 clip‐treated sheep were humanely killed at six time points from 3 to 47 days after each treatment. Wound healing post treatment was assessed using a scoring system, and contractility was assessed by the quantification of myofibroblast expression. Statistical analyses allowed comparisons of temporal wound healing and contraction between treatment groups. Results Mulesing wounds healed faster in the first 11 days, but by 19 days wound healing was similar between the mulesing and cetrimide‐intradermal groups. By 32 days, all three treatment groups had similar wound healing scores. There was greater myofibroblast expression in the mulesing group in the first 11 days after treatment, but by 19 days expression was similar in both the mulesing and cetrimide‐intradermal groups. The clip group had significantly less myofibroblast expression from 32 days after treatment. Conclusion Wound healing is initially most rapid after mulesing, but there are similar wound healing scores in the mulesing and cetrimide‐intradermal treatment groups by 19 days. Both mulesing and the cetrimide‐intradermal treatment induce a similar amount of wound bed contraction, with less contraction observed after application of clips.