Reproductive Characteristics of Awassi Ewes Under Cornell Alternate Month Accelerated Lambing System

We investigated the reproductive responses of Awassi ewes under Cornell alternate month accelerated lambing (CAMAL) system. Ewes were randomly allocated to two experimental groups. The first group (control group) consisted of 20 ewes exposed to rams in September under conventional management system, while the second group (CAMAL) was divided into four sub-flocks containing each 20 ewes exposed to rams to obtain three lambing in two years with different breeding and lambing months. In CAMAL ewes, oestrus was synchronized using intra-vaginal sponges with progesterone and Pregnant Mare Serum Gonadotropin (PMSG) administration. The results obtained revealed that within CAMAL group, the percentage of animals in heat, onset of oestrus, litter size, birth weight and weaning weight were affected by mating months. September and November were the most appropriate months for oestrus ratio (97.5%) and litter size (1.18 and 0.98, respectively). Lambs of control group were heavier at birth and weaning than those of CAMAL group. On the other hand lamb yield was not affected statistically by the CAMAL administration.

[1]  S. Galal,et al.  Awassi sheep as a genetic resource and efforts for their genetic improvement—A review , 2008 .

[2]  L. Schwalbach,et al.  Effect of progestagen and PMSG on oestrous synchronization and fertility in Dorper ewes during the transition period , 2005 .

[3]  J. P. Mittal,et al.  The effect of thermal stress on superovulatory response and embryo production in Bharat Merino ewes , 2004 .

[4]  M. Bryant,et al.  Seasonality of reproduction in sheep , 2003 .

[5]  R. Baker,et al.  Reproductive performance and productivity of Menz and Horro sheep lambing in the wet and dry seasons in the highlands of Ethiopia , 2002 .

[6]  J. Rege,et al.  Factors affecting reproductive performance and estimates of genetic parameters of litter size in Horro sheep , 2002, The Journal of Agricultural Science.

[7]  Notter.  Effects of ewe age and season of lambing on prolificacy in US Targhee, Suffolk, and Polypay sheep. , 2000, Small ruminant research : the journal of the International Goat Association.

[8]  G. María,et al.  Litter size, lambing interval and lamb mortality of Salz, Rasa Aragonesa, Romanov and F1 ewes on accelerated lambing management , 1999 .

[9]  R. Sormunen-Cristian,et al.  Out-of-season lambing of Finnish Landrace ewes , 1999 .

[10]  I. Gordon.  Controlled reproduction in sheep and goats. , 1997 .

[11]  D. Notter,et al.  Ewe fertility in the STAR accelerated lambing system. , 1996, Journal of animal science.

[12]  W. Jackson,et al.  Ewe productivity and subsequent preweaning lamb performance in St. Croix sheep bred at different times during the year. , 1995, Journal of animal science.

[13]  S. Schoeman,et al.  Performance of Dorper sheep under an accelerated lambing system , 1992 .

[14]  M. Aboul-Ela,et al.  Breeding activity of two subtropical Egyptian sheep breeds under accelerated lambing system , 1991 .

[15]  M. Fahmy.  THE ACCUMULATIVE EFFECT OF FINNSHEEP BREEDING IN CROSSBREEDING SCHEMES: EWE PRODUCTIVITY UNDER AN ACCELERATED LAMBING SYSTEM , 1990 .

[16]  R. Kassem.  The Awassi sheep breeding project in Syria , 1988 .

[17]  E. Thomson,et al.  Increasing Small Ruminant Productivity in Semi-arid Areas , 1988, Current Topics in Veterinary Medicine and Animal Science.

[18]  N. Rawlings,et al.  Response of Purebred and Crossbred Ewes to Intensified Management , 1987 .

[19]  D. E. Hogue,et al.  Frequent lambing systems. , 1987 .

[20]  L. D. Van Vleck,et al.  Lambing performance of Morlam and Dorset ewes under accelerated lambing systems. , 1986, Journal of animal science.

[21]  N. Fogarty,et al.  Lamb production and its components in pure breeds and composite lines. I. Seasonal and other environmental effects. , 1984, Journal of animal science.

[22]  J. Huston.  Production of fine-wool ewes on yearlong rangeland in West Texas. II. Effects of supplemental feed and breeding frequency on reproductive rate. , 1983, Journal of animal science.

[23]  D. Notter,et al.  Performance of Finnish Landrace Crossbred Ewes under Accelerated Lambing. I. Fertility, Prolificacy and Ewe Productivity , 1980 .