308  
      
Asian-Aust. J. Anim. Sci.
Vol. 23, No. 3 : 308 - 311 
March 2010 
www.ajas.info 
 
 
Effects of Progestagen and Pmsg on Estrous Synchronization and  
Fertility in Kivircik Ewes during Natural Breeding Season 
 
M. Koyuncu* and S. Ozis Altıcekic 
University of Uludag, Faculty of Agriculture, Department of Animal Science, 16059 Bursa, Turkey 
 
ABSTRACT : An experiment was conducted using indigenous Kivircik ewes to evaluate the effect of intravaginal progestagen 
sponges, containing 30 mg of fluorogestone acetate (FGA), followed by administration of pregnant mare serum gonadotrophin (PMSG) 
on inducing synchronized oestrus in the season and fertility. Three times of PMSG administration relative to sponge withdrawal (24 h 
before (n = 30), at (n = 29) or 24 h after (n= 29)) and two routes of PMSG administration (intramuscular (n = 46) and subcutaneous (n = 
42) were compared for estrous response, number of multiple births and fecundity rates. There were no significant differences in terms of 
estrous response, due to differences in the time and route of PMSG administration. Lambing percentage, proportion of multiple births 
and fecundity were 75.6, 51.6 and 114.6%, respectively. The administration had a significant effect on lambing (p<0.05), multiple birth 
and fecundity rates (p<0.01). The subcutaneous administration of PMSG resulted in a significantly higher lambing rate (p<0.05) and 
fecundity rate (p<0.01), compared to the intramuscular injection of the PMSG. (Key Words : Kivircik Ewe, Synchronization, PMSG,
Progestagen, Fertility) 
 
INTRODUCTION events that lead to the maturation of ovarian preovulatory 
 follicles and their subsequent ovulation are inhibited 
Estrous synchronization is a valuable management tool (Hansel and Convey, 1983). Therefore, when progestagen 
which has been successfully employed to enhance impregnated sponges are withdrawn, follicular growth, 
reproductive efficiency, particularly in ruminants (Kusina et estrus and ovulation occur within 2-8 days (Gordon, 1975; 
al., 2000). In small ruminants, estrous synchronization is Hansel and Convey, 1983).  
achieved either by reducing the length of the luteal phase of Progesterone-impregnated vaginal sponges have been 
the estrous cycle with prostaglandin F2α or by extending the widely used for estrous synchronization of ewes during the 
cycle artificially with exogenous progesterone or more breeding and non-breeding seasons. Breeding season of 
potent progestagens (Evans and Maxwell, 1986; Jainudeen sheep shows regional changes. The breeding estrus term in 
et al., 2000; Kusina et al., 2000). As prostaglandin treatment Turkey is the end of summer and months of fall, when 
is limited to the breeding season, different protocols of daytime begins to shorten and sunlight begins to reduce its 
estrous synchronization using progestins have been effectiveness.  
introduced (Ainsworth and Wolynetz, 1982; Godfrey et al., The Kivircik is the exclusive breed of sheep in the 
1997; Rosado et al., 1998). Thracian part of Turkey; it is also raised in the southern and 
Two pharmacological agents are frequently used to eastern provinces of Marmara Region and in some Aegean 
synchronize estrus in small ruminants during the breeding provinces. Mating of Kivircik ewes takes place in June and 
season: luteolytic drugs (Thimonier, 1981) and progesterone July in the southern Marmara Region and in July and 
or its analog progestagen (Gordon, 1975). Both August in Thrace (Yalcin, 1986). 
progesterone and its synthetics, when administered orally, Oestrus in the ewe is a less obvious event than in other 
by implantation or by means of intravaginal sponges, exert ruminants (Ptaszynska, 2001). Hence, a detailed detection 
negative feedback on LH secretion so that the endocrine of estrous stages becomes crucial in this species, 
particularly in hand-mating or AI. Synchronization of 
* Corresponding Author: M. Koyuncu. Tel: +90-224-2941556, oestrus has been used to increase reproductive efficiency in 
Fax: +90-224-4428152, E-mail: koyuncu@uludag.edu.tr  most animals including ewes. The aim of PMSG use in the 
Received July 13, 2009; Accepted October 10, 2009 
 
Koyuncu and Altıcekic (2010) Asian-Aust. J. Anim. Sci. 23(3):308-311 309
present study was to determine that the majority of ewes The following traits were evaluated in each of the 
lambed over a short period of time (2 weeks). This study treated and control groups: 
aimed at evaluating the effect of route and time of PMSG Estrous response: (percentage of ewes showing 
administration relative to sponge removal on the efficiency estrous/total ewes treated), lambing rate: (percentage of 
of estrous synchronization and overall fertility in Kivircik ewes lambing/total ewes mated), multiple birth rate: 
ewes during the breeding season.  (percentage of multiple lambing/total lambing), fecundity: 
 (percentage of lambs born/total ewes mated). 
MATERIALS AND METHODS Data regarding the onset, end and duration of estrus 
 were analyzed using the General Linear Models (GLM) 
The experiment was conducted at the Application and procedure of SAS (1991). A chi-square test was used to 
Research farm of the College of Agriculture, Uludag analyze the estrous response, fecundity, lambing and 
University, Bursa province (southern Marmara Region). multiple birth rates among the groups at the 5% and 1% 
The site is situated at 28° 50″ E longitude and 40° 13″ N level of significance. 
latitude and at an altitude of 100 m above sea level. The  
yearly absolute minimum and maximum temperatures in the RESULTS 
area average -16.4°C (February) and 43.8°C (July),  
respectively, with a mean annual rainfall of 706.0 mm. From the 123 ewes used in the trial, 118 (96.0%) 
A total of 123 Kivircik ewes, ranging in age from 2 to 4 exhibited overt signs of estrous during the 48-72 h 
years and weighing 38 to 64 kg, were used in the trial. The observation period. No significant difference in percentage 
experimental flock was maintained under standard farm of ewes exhibiting estrous was recorded with time and route 
management practices. The ewes were grazed daily for 8-10 of PMSG administration. 
h on a pasture consisting of a mixture of common vetch The overall lambing, multiple birth and fecundity rates 
(Vicia sativa L), Hungarian vetch (Vicia pannonica L), recorded following estrous synchronization was 75.6, 51.6 
alfalfa (Medicago sativa) and sainfoin (Onobrychis sativa). and 114.6%, respectively. No significant difference in terms 
In addition, the ewes received 200 g concentrate (wheat of multiple birth rates was recorded between routes of 
75%, sunflower oilcake 23%, limestone 1.4%, salt 0.5% PMSG administration. The time of PMSG administration 
and premix 0.1%)/head/day during the entire period of relative to the time of sponge withdrawal had a significant 
study.  effect on lambing (p<0.05), multiple birth and fecundity 
Animals were routinely drenched for fluke and rates (p<0.01). The highest lambing, multiple birth and 
roundworm, and vaccinated for pasteurellosis and clostridia fecundity rates were recorded in ewes receiving PMSG 24 h 
infections. Clean water was available throughout the study prior to sponge withdrawal or at sponge withdrawal, 
period.  compared to ewes given PMSG 24 h after sponge 
The treatments included two routes of 500 IU PMSG withdrawal or the control animals (Table 1). Furthermore, 
administration (intramuscular or subcutaneous); three times the subcutaneous administration of PMSG resulted in a 
of PMSG treatment (24 h prior to sponge withdrawals, at significantly higher lambing rate (p<0.05) and fecundity 
sponge withdrawal or 24 h after sponge withdrawal). The rate (p<0.01), compared to the intramuscular injection of 
intravaginal progestagen sponges (FGA 30 mg) remained in PMSG. 
situ for a period of 14 days in all ewes. All ewes were  
checked twice daily (morning and evening) to ensure that DISCUSSION 
sponges remained in place during the treatment period. At  
the end of the treatment period with intravaginal Increasing Kivircik sheep productivity by increasing 
progestagen sponges, animals were randomly allotted to lambing frequency and fecundity is considered important in 
four groups of 30, 29, 29, and 35 animals, respectively. The the development of Kivircik sheep production in Turkey. 
1st, the 2nd and the 3rd groups were treated with 500 IU On the other hand, increasing rate of fecundity in sheep 
PMSG 24 h prior to sponge withdrawal, at sponge offers the best opportunity to increase the efficiency of lamb 
withdrawal and 24 h after sponge withdrawal, respectively. meat production. In the present study, estrous was induced 
The fourth groups of ewes served as a control (no PMSG in 96.0% of the ewes, 48-72 h after sponge withdrawal. 
treatment). Among ewes administered PMSG, 46 were This technique (FGA+PMSG) has an estrous response 
injected intramuscularly while 42 were injected similar to the 97.0% obtained by Zeleke et al. (2005) in 
subcutaneously. Fertile Kivircik rams were placed with all Dorper ewes, but higher than the 66.0% obtained with 
the ewes 24 h post-sponge withdrawals for estrous detection Romney Marsh ewes (Gatica and Correa, 1993), and lower 
and ewes in estrous were hand-mated.  than the 100% reported in Karakul ewes (Hashemi et al., 
 
310 Koyuncu and Altıcekic (2010) Asian-Aust. J. Anim. Sci. 23(3):308-311 
Table 1. Effect of time and route of PMSG administration on estrous response, lambing, multiple birth and fecundity rates in Kivircik 
ewes 
Treatment n Estrous response (%) Lambing rate (%) Multiple birth rate (%) Fecundity (%) 
Time of PMSG administration  ns * ** ** 
24 h before sponge withdrawal 30 96.7 76.7b 73.9a 132.0a 
At sponge withdrawal 29 95.9 86.2a 61.9a 127.6a 
24 h after sponge withdrawal 29 96.9 72.4b 44.0b 120.7a 
Control 35 94.8 68.6b 29.2b 71.4b 
Route of PMSG administration  ns * ns ** 
Intramuscular 46 95.1 73.9b 55.9 117.4b 
Subcutaneous 42 97.3 83.3a 62.9 147.6a 
Overall 123 96.0 75.6 51.6 114.6 
Means in the same column with different superscripts are significantly different. 
* p<0.05, ** p<0.01. ns = Not significant. 
2006). The slight discrepancy between the results obtained performance. A similar study done by Zeleke et al. (2005) 
in the current study and those of Greyling et al. (1994) may also indicated an increase in fertility when PMSG was 
be due to differences in the breed of sheep used and the administered 24 h prior to sponge removal. However, the 
season in which the studies were executed. results in the present trial were not in agreement with the 
The overall lambing, multiple birth and fecundity rates findings of Eppleston et al. (1991) which indicated that the 
recorded in this study (Table 1) are comparable to results time of PMSG treatment did not yield a constant 
obtained by Zeleke et al. (2005) in Dorper ewes. Lambing improvement in fertility, except for shortening the time to 
rate in the treated ewes was 75.6%. This is similar to 80% ovulation.  
reported by Zarkawi et al. (1999), higher than 64.3% Attainment of significantly higher lambing rates 
(Alkass et al., 1989) and lower than 90% reported by (p<0.05) and fecundity (p<0.01) in ewes given 500 IU 
Crosby and O’Callaghan (1991) in ewes fitted with PMSG subcutaneously, compared to ewes given PMSG 
intravaginal sponges followed by PMSG injection. intramuscularly, demonstrates the advantage of this 
The multiple birth rate in Kivircik sheep is low and administration route. The reason for this difference is vague, 
averages 10-20% (Kaymakcı, 2006). Hormonal treatment and the work of Greyling and van Niekerk (1989) suggested 
increased multiple births overall by 51.6%. Increased the pre-ovulatory LH surge to be significantly shorter in 
lambing rate is very economical and sought-after by sheep subcutaneously-injected does, compared to intramuscularly-
holders in semi-intensive production systems. It has been treated animals. This may be due to the difference in the 
observed that in semi-intensive sheep production systems, rate of absorption and metabolism of PMSG between 
rams are able to mate ewes at almost any time of the year. subcutaneous and intramuscular administration (Zeleke et 
PMSG injection is required to stimulate follicular growth, al., 2005). 
leading to a higher ovulation rate by an estrous animal  
outside the breeding season (Greyling and van Niekerk, CONCLUSION 
1991).   
Many researchers have indicated the importance of The study was designed to determine estrous response 
administering PMSG to obtain a more predictable and in Kivircik ewes synchronized with different protocols of 
compact estrous or ovulation, even though cyclic ewes or progesterone during the natural breeding season. The results 
does are expected to demonstrate oestrus shortly after suggest that it is possible to induce synchronization of 
intravaginal progestagen withdrawal without administration estrous and fertile estrous and successful pregnancy and 
of PMSG (Zhang and Yuan, 1988; Knight et al., 1992; lambing, to improve fecundity. Administration of PMSG 
Artiningsih et al., 1996; Cordova et al., 1999; Cline et al., preferably 24 h prior to or at progestagen sponge 
2001). The lower lambing, multiple birth and fecundity withdrawal is essential to obtain better fertility rates. The 
rates in ewes which did not receive any PMSG, compared to subcutaneous administration of PMSG is preferable to 
those injected with PMSG in the present study indicates the intramuscular administration as it resulted in higher 
importance of administering PMSG to achieve better lambing, multiple birth and fecundity rates. 
fertility. Besides the mere administration of PMSG, the time  
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