Effect of Fat-Tail Docking on the Reproductive Performance in Ghezel and Mehraban Sheep
الموضوعات :
1 - Department of Animal Science, Shiraz University, Shiraz, Iran
2 - Department of Animal Science, Shiraz University, Shiraz, Iran
الکلمات المفتاحية: Sheep, Reproduction, docking,
ملخص المقالة :
78 Ghezel and 76 Mehraban sheep were used to evaluate the effect of fat-tail docking on reproductive performance. Within two days after birth the tails of 32 Ghezel female lambs and 28 Mehraban female lambs were docked using a tight rubber ring. The lambs were allowed to reproduce for three lambing opportunities and their reproductive performances were evaluated. The effect of docking on the fertility (ewe lambing per ewe exposed), litter size (lambs born per ewe lambing) were evaluated employing a multivariate logistic regression procedure, through the inclusion of tail docking in a 2-way interaction with breed, the fixed effect of parity and the random effect of the ewe. The results showed that the interaction of docking and breed significantly impacted fertility rate (P<0.05). In Ghezel ewes, docking reduced fertility [odds ratio (OR) (95%confidence interval (CI))= 0.29 (0.11-0.79) for docked vs. undocked Ghezel ewes]. Docking had no effect on fertility in Mehraban ewes [odds ratio (OR) (95% confidence interval (CI))= 1.19 (0.38-3.71) for docked vs. undocked Mehraban ewes]. The interaction effect of docking and breed had no impact on litter size, lamb birth weight and lamb weaning weight.
Abouheif M.A., Kraidees M.S. and Shatat R.A. (1992). Effect of docking and sex of lamb on carcass characteristics of fat-tailed Najdi sheep. J. Appl. Anim. Res. 1, 91-101.
Alkass J.E., Rashid N.H., Ishak M.A. and Talib H. (1985). The combined effects of docking and castration on growth rate and carcass of Awassi lambs. World Rev. Anim. Prod. 21, 49-52.
Gokdal O., Aygun T., Bingol M. and Karaku F. (2004). The effects of docking on performance and carcass characteristics of male Karaka lambs. South African J. Anim. Sci. 33, 185-192.
Jawad N.A.J., Alkass J.E. and Al-Wahab R. (1986). Effect of season of lambing and docking on the puberty and reproduction performance of Awassi ewe lambs. Agric. Res. 3, 1777-1786.
Kent J.E., Molony V. and Robertson I.S. (1995). Comparison of the Burdizzo and rubber ring methods for castrating and tail docking lambs. Vet. Record. 136, 192-196.
Khaldari M., Kashan N.E.J., Afzalzadeh A. and Salehi A. (2007). Growth and carcass characteristics of crossbred progeny from lean tailed and fat tailed sheep breeds. South African J. Anim. Sci. 37, 51-56.
SAS Institute. (2010). SAS®/STAT Software, Release 9.1. SAS Institute, Inc., Cary, NC. USA.
Schoenian S.G. and Burfening P.J. (1990). Ovulation rate, lambing rate, litter size and embryo survival of Rambouillet sheep selected for high and low reproductive rate. J. Anim. Sci. 68, 2263-2270.
Shelton M. (1990). Influence of docking fat-tailed (Karakul) sheep on lamb production. Small Rumin. Res. 3, 73-76.
Yami A. and Markel R.C. (2008). Sheep and Goat Production. Handbook, Ethiopia Sheep and Goat Productivity Improvement Program (ESGPIP), Addis Ababa, Ethiopia.