Evaluation of Reproductive Performance of Afshari Ewes with a Short Estrus Synchronization Program in Non Breeding Season

Estrus synchronization is a valuable management tool that has been employed in enhancing reproductive efficiency in ewes. This study was conducted to investigate the reproductive performance of ewes with short and long-term estrous synchronization programs accompanied by eCG or GnRH during the non-breeding season. A total of 48 Afshari ewes were randomly selected and divided into two groups. In the first group, ewes received intravaginal sponges for 7 days (n=24) and in the second group ewes received intravaginal sponges for 14 days (n=24). At the time of sponge removal, each group was divided into two subgroups of 12 ewes; intramuscularly received 500 IU eCG and 100 IU GnRH, respectively. Blood samples were collected at the time of sponge removal. Considering plasma progesterone concentrations, there were no significant differences between 7 and 14 days groups (P>0.05). In 14 days group, estrus and lambing rates of eCG subgroup were significantly higher than those in GnRH subgroup (P <0.05). Conception and lambing rates of eCG subgroup in 7 days group were significantly higher than those in GnRH subgroup in 14 days group (P<0.05). In 7 days group, twinning rate of eCG subgroup was significantly higher than that of GnRH subgroup (P<0.05). Therefore, in this study, short-term estrus synchronization programs (7 days) and injection of 500 IU eCG simultaneous with sponge removal exhibited the best reproductive performance in Afshari ewes during non-breeding season.

[1]  Mehri,et al.  Effect of injection of GnRH and hCG on day 5 post mating on maternal P4 concentration and reproductive performance in Afshari ewes , 2017 .

[2]  J. Juengel,et al.  Successful induction of oestrus, ovulation and pregnancy in adult ewes and ewe lambs out of the breeding season using a GnRH+progesterone oestrus synchronisation protocol. , 2015, Animal reproduction science.

[3]  M. Mamouei,et al.  The effects of short and long term medroxy progesterone acetate (MAP) sponge treatments on reproductive performance during the non-breeding season of Arabian ewes. , 2014 .

[4]  B. Farrag.  Effect of progestagen, PGF2α, PMSG AND GnRH on estrus synchronization and some reproductive and productive traits in Barki ewes , 2014 .

[5]  C. Viñoles,et al.  Comparison between the reproductive performance of ewe hoggets and mature ewes following a progesterone-based oestrus synchronization protocol , 2013 .

[6]  S. Aslan,et al.  Effect of subsequent two short-term, short-term, and long-term progestagen treatments on fertility of Awassi ewes out of the breeding season , 2011 .

[7]  N. Metodiev,et al.  EFFECT OF THE SHORT-TERM PROGESTAGEN TREATMENTS PLUS PMSG PRIOR RAM INTRODUCTION ON THE ESTRUS SYNCHRONIZATION AND THE FERTILITY OF ILE DE FRANCE EWES , 2011 .

[8]  R. Kridli,et al.  Estrus synchronization in sheep and goats using combinations of GnRH, progestagen and prostaglandin F2alpha. , 2008, Reproduction in domestic animals = Zuchthygiene.

[9]  H. Amer,et al.  The effect of different progesterone protocols on the reproductive efficiency of ewes during the non-breeding season. , 2009 .

[10]  K. Çoyan,et al.  Synchronization of estrus with short- and long-term progestagen treatments and the use of GnRH prior to short-term progestagen treatment in ewes , 2009 .

[11]  M. Ababneh,et al.  The Effects of Short or Long Term FGA Treatment with or without eCG on Reproductive Performance of Ewes Bred Out-of-season , 2007 .

[12]  H. Moravej,et al.  The relationship between plasma leptin and FSH concentrations with ovulation rate in Iranian native sheep. , 2007, Pakistan journal of biological sciences : PJBS.

[13]  H. Ustuner,et al.  Effects of Long and Short-Term Progestagen Treatments Combined with PMSG on Oestrus Synchronization and Fertility in Awassi Ewes during the Breeding Season , 2007 .

[14]  M. Kafi,et al.  Estrous response to synchronization of estrus using different progesterone treatments outside the natural breeding season in ewes , 2006 .

[15]  A. Saki,et al.  Effect of Controlled Internal Drug Release Device Treatment Duration and eCG Dose on Reproductive Performance of Seasonally Anestrous Fat-tailed Iranian Ewes , 2006 .

[16]  M. Aköz,et al.  Induction of synchronized oestrus in akkara- man cross-bred ewes during breeding and anestrus seasons : the use of short-term and long-term progesterone treatments , 2006 .

[17]  J. Viana,et al.  Induction of estrus in non-lactating dairy goats with different estrous synchrony protocols. , 2005, Animal reproduction science.

[18]  R. Ungerfeld,et al.  Short term primings with different progestogen intravaginal devices (MAP, FGA and CIDR) for eCG-estrous induction in anestrus ewes , 2002 .

[19]  C. Viñoles,et al.  Effect of long-term and short-term progestagen treatment on follicular development and pregnancy rate in cyclic ewes. , 2001, Theriogenology.

[20]  L. Johnston,et al.  CIDR: A new progesterone-releasing intravaginal device for induction of estrus and cycle control in sheep and goats , 1993 .