Effect of docking and shearing on growth and carcass traits of fat-tailed Ossimi sheep

Abstract

SummaryThirty Ossimi lambs were used in an experiment to compare those whose tail was docked shortly after birth with controls. After weaning at 4 months of age the groups were further subdivided and two of the four groups closely shorn according to a 2 × 2 factorial design.Male lambs at 20 kg were subjected to intensive finishing until the age of 50 weeks and nine were then slaughtered to determine carcass characteristics.There was a trend for increased live-weight gain in the docked lambs in the preweaning stage (up to 16 weeks).This trend was also present, although not statistically significant, in the final phase of intensive feeding from 20 kg weight to 50 weeks. Shearing significantly improved daily gain in this final period (P < 0·05). These increases in gain were also apparently associated with improvements in efficiency, as judged on a group basis.Docking and shearing also tended to cause increases in body measurements: height, chest girth and abdomen girth in the case of docking (P < 0·05) and chest girth, chest depth and abdomen girth in the case of shearing (P < 0–05).Carcass characteristics, measured on a relatively small sample, indicated several effects of docking and shearing on carcass traits although most of these were consistent with the expected differences stemming from the higher carcass weights acheived at 50 weeks of age by docked and sheared lambs.

A review of morphological characteristics relating to the production and reproduction of fat-tailed sheep breeds

“…In general, all carcass measurements of docked animals tended to be higher than those of the intact lambs, with the exception of the MLD area, though the means of the groups did not differ (P>0.05). In contrast, it has been reported in studies on other fat-tailed sheep breeds that the MLD area was positively affected by docking (Marai et al 1987). Gϋndoğan (2007) Wool sample site on the body of fat-tailed sheep affected variously the fiber traits of fat-tailed sheep.…”

“…Samples from hip showed the shortest staple length and the thickest fiber diameter (P <0.05), whereas those taken from mid-side region could be representative of Barbary sheep. Shearing increased chest girth, chest depth, and abdomen girth (P<0.05) in Ossimi docked lambs (Marai et al 1987). Also, a considerable increase of MLD area (16.82 ± 1.84 cm 2 for shorn vs 12.22 ± 0.63 cm 2 for unshorn sheep) and an increase of fat thickness (3.40± 0.36 mm for shorn vs 2.25±0.48 mm for unshorn sheep) were recorded.…”

“…The impact of docking (at birth) and of shearing (at weaning) has been studied in Ossimi breed (Marai et al 1987) and indications for potential importance arose. The docking followed by shearing should be further studied in other fat-tailed breeds in order to elucidate the synergy of the two procedures.…”

“…Joubert et al (1962) observed no significant deviations in respect of the conventional measurements of subcutaneous fat of docked mature Karakul ewes. According to Marai et al (1987), the height, the size of the fore and hind limbs, the chest girth, and the abdominal girth in Ossimi sheep increased significantly (P<0.05) following docking.…”

“…Also, a considerable increase of MLD area (16.82 ± 1.84 cm 2 for shorn vs 12.22 ± 0.63 cm 2 for unshorn sheep) and an increase of fat thickness (3.40± 0.36 mm for shorn vs 2.25±0.48 mm for unshorn sheep) were recorded. Marai et al (1987) Moharrery (2007) The numbers in parentheses represent the number of animals Anim Health Prod (2011) 43:1267-1287 Reproduction…”