The objective of this study was to estimate genetic, phenotypic and residual correlations between ewe reproductive and lamb weight traits in D’man sheep. Data used in this study were 1804 reproductive and weight records collected between 1988 and 2015 from 530 replacement females, born from 82 sires and 298 dams. The ewe reproductive traits included litter size and litter weight at birth (LSB and LWB) and at 90 days (LSW and LWW) per ewe lambing and mating weight (MW), while the lamb weight traits investigated were weights at birth (BW), 90 (WW) and 135 (W135) days. Covariance components between the reproductive traits on the one hand and the weight traits on the other hand were estimated using bivariate analyses by employing the animal model that was deemed to be most appropriate from the univariate analyses for each trait. The genetic correlations between litter traits and body weights were low and in general not significantly different from zero ranging from -0.12 to 0.11, whereas those between ewe MW and lamb weights were positive and moderate varying from 0.16 to 0.51. The corresponding phenotypic correlations were slightly lower and varied from -0.04 between LSW and WW to 0.12 between LWW and BW and between LSW and W135. The residual correlations were in general similar to genetic correlations, except those between MW and body weights that were lower. It was concluded that selection for a genetic improvement in either of reproductive and weight traits would have little effect on genetic response in the other trait.

Data used in this study related to reproductive traits in Shal sheep that were collected during 1998 to 2009 by Agricultural Jahad organization of Qazvin province. Reproductive performances studied in this research were analyzed via main and composite traits. The main traits were conception rate, number of lambs born and number of lambs at weaning. The composite traits were total litter weight at birth, total litter weight at weaning, total litter weight at birth per ewe exposed and total litter weight at weaning per ewe exposed. The data were analysed with restricted maximum likelihood procedure by the use of ASREML software. The effect of environmental factors such as mating year and age of ewe at mating were significant (P<0.05) on all of reproductive traits. Estimates of heritability for animal genetic effects were mainly small and ranged from 0.06 to 0.13. The low level of heritability may be due to the typical high influence of environmental factors on reproductive traits and non-normal distributions of some traits. Estimates of repeatabilities for animal permanent environmental effects were small to medium 0.10 to 0.19. Genetic and phenotypic correlations among conception rate with number of lambs born, number of lambs at weaning, total litter weight at birth, total litter weight at weaning are negative but other genetic and phenotypic correlations among traits are positive estimated. The results suggested that selection based on TLWW could be more effective than the other traits for improvement of reproductive performance in Shal ewes.

Seven healthy and sexually adult ewes were slaughtered. Immediately after slaughter, whole reproductive systems of animals were collected. Different tissues including: corpus luteum, ovary, muscular and mucosal layers of uterine horn, uterine body, cervix, vagina and vestibula were carefully separated and arginase specific activity (ASA) was determined in tissue extract and compared by modified paranitrophenylglyoxal (PNPG) method. The result of this study indicate that although all the tissues contained different amounts of arginase activity, based on the level of ASA, ewe reproductive system may categorized in two groups which have significant difference (P<0.05). The mucosal layer of vagina showed lowest ASA (32.85 IU/mg tissue soluble protein) in the first group and in the second group, mucosal layer of cervix had highest ASA level (85.14 IU/mg tissue protein). Presence of this enzyme at different levels in all parts of ewe reproductive system may be related to different rate of cell proliferation, differentiation or some other unknown physiological and biochemical activities of the enzyme in this system.

The objective of this study was to evaluate the reproductive responses to different flushing treatments in Lori-Bakhtiari ewe-lambs and mature ewes. For this purpose, a total of 55 ewe-lambs and 245 mature ewes in a flock containing 400 ewes, were selected and randomly divided into three groups. The treatments were as: 1; no flushing (control), 2; flushing with barley and 3; flushing with barley and fat. Flushing diets were offered from 2 weeks before to 3 weeks after ram introduction. The conception and parturition rates in ewe-lambs, were significantly affected by treatments (p<0. 05) so that, ewe-lambs in the treatment 3, had the highest conception (95 %) and parturition (95 %) rates. The number of lambs born per ewe exposed, in ewe-lambs at the treatment 3 (122 %) was higher than (p<0. 05) the treatment 2 (94 %) and the control (88 %) but, in mature ewes, statistical differences (p<0. 05) were found just for ewes at the treatment 3 and the control ewes (118 vs. 102). The gestation length for ewe-lambs and mature ewes at all treatments, were similar. The multiple lambing rate was higher (p<0. 01) in ewe-lambs at the treatment 3 (29 %) than two other treatments. But, differences between mature ewes at the treatments 3 and 2 for multiple lambing rates (23 and 18 % respectively), were not statistically significant. It seems therefore that, in Lori-Bakhtiari sheep, flushing of mature ewes with barley grain (with or without fat) and flushing of ewe-lambs with barley grain and fat supplement, will increase their reproductive performance.

The present study was carried out to estimate (co)variance components and genetic parameters for some productivity traits of Baluchi ewes. The data were collected during a 31 year period (1984-2014) at the ex-perimental breeding station of Baluchi sheep, which is located in north-east of Mashhad, Iran. The analysis was based on 14030 records of lambs and 4371 records of ewes. Investigated traits were litter size at birth (LSB), litter size at weaning (LSW), litter mean weight per lamb born (LMWLB) and litter mean weight per lamb weaned (LMWLW) as basic traits, total litter weight at birth (TLWB) and total litter weight at weaning (TLWW) as composite traits. Genetic analysis of the studied traits was performed applying re-stricted maximum likelihood (REML) procedure by fitting a linear mixed animal model. Direct heritability estimate for LSB, LSW, LMWLB, LMWLW, TLWB and TLWW were 0. 10, 0. 08, 0. 13, 0. 07, 0. 12 and 0. 05, respectively. Corresponding values for repeatability estimates were 0. 18, 0. 17, 0. 19, 0. 15, 0. 18 and 0. 15, respectively. Direct genetic correlation estimates among the studied traits varied from-0. 52 for LSW and LMWLB to 0. 99 for TLWB and TLWW. Phenotypic and environmental correlation estimates were generally lower than those of genetic ones. Although low direct heritability’ s were estimated for the repro-ductive traits, as these traits are of interest then they used as the primary selection criterion to bring about genetic improvement in ewe productivity traits.

An investigation was under taken to evaluate the out of season reproduction performance of ewe. A flock consisting 119 ewes was synchronized via implementation CIDR over a period of 12 days, following by injection of PMSG (400 IU). The ewes inseminated and divided to three experimental groups. Group1: Injection of GnRH (5ml) at day 12 post insemination, group 2: Received CIDR for 5 to 15 days post insemination and group 3(control): ewes did not receive any treatment. Data were analyzed in Chi- Square method by SAS soft were. Fertility in group1, 2 and 3 were 40, 30 and 30.76 percent and fecundity were 65.0, 37.5 and 43.5 percent and twining rate were 62.5, 25.0 and 41.6 percent, respectively. Results reveal that supplementation of progesterone or GnRH would not enhance reproductive performance in the ewe in out of season.

A selection program is being implemented to improve meat production in Makooei sheep. Increasing litter size per ewe is the main objective, but possible repercussions on weight traits of lambs should be considered. The aim of this study was to estimate heritability along with genetic and phenotypic correlations between ewe's reproductive vs. weight traits in Makooei ewes. Data were comprised of 5,364 records of body weight of lambs from 289 sires and 1,726 dams, plus 3,418 records of reproductive traits from 1,429 ewes collected from 1996 to 2009 from a Makooei flock at Makoo Station in West-Azerbaijan Province. The ewe reproductive traits investigated were Conception Rate (CR), Litter Size at Birth (LSB), Litter Size at Weaning (LSW), Litter Weight at Birth (LWB) and Litter Weight at Weaning (LWW). The lamb traits investigated were Weights at Birth (BW) and at Weaning (WW). Genetic parameters were estimated through REML procedure using ASReml program. The estimates of direct heritability for lamb body weights were 0.15±0.04 at birth and 0.16±0.03 at weaning. The estimates of heritability for reproductive traits varied from 0.05±0.02 for CR to 0.17±0.03 for LWB. Additive genetic correlations between BW and ewe's reproductive traits varied from small to moderate, ranging between –0.14 and 0.22. Additive genetic correlations between WW and ewe reproduction traits varied from moderate to high, positively ranging between 0.21 and 0.67. In conclusion, WW could be considered as a selection criterion in indirectly improving the ewe's reproductive traits in Makooei sheep.

In this study phenotypic and genetic factors affecting the reproductive efficiency of Lori-Bakhtiari ewes were determined using 8202 reproductive records of 2478 ewes collected at Shooli research station in the southwestern part of Iran (Shahrekord) during 1989 to 2012. Reproductive efficiency over all consecutive lambing opportunities were calculated by adding the total reproductive efficiency traits per ewe joined for all of the parturition opportunities. Reproductive traits included in the current study were: number of parity (NP), total number of lambs born (TNLB), total number of lambs weaned (TNLW), total of lambs birth weight (TLBW), total of lambs weaning weight (TLWW), total of lambs weaning weight per kg ewe body weight (TLWW/EBW) and total of lambs weaning weight per kg metabolic ewe body weight (TLWW/MEBW). The data set analyzed with multi-trait animal model included the fixed effects of birth year of ewe, number of parturition in ewe's lifetime, ewe body weight as covariate and random effects direct additive genetic and residual. The overall mean of NP, TNLB, TNLW, TLBW, TLWW, TLWW/EBW and TLWW/MEBW were 3.31, 3.31, 3.21, 16.51 kg, 87.31 kg, 1.51 and 4.16, respectively. The effect of non-genetic factors were significant for all investigated traits in this study (P<0.01). The heritability estimates were medium (0.30) for NP and low (0.08 to 0.11) for other reproductive efficiency traits. The estimates of genetic and phenotypic correlations between the traits were high (0.72 to 0.99) or medium to high (0.57 to 0.99). Thus, improving environmental effects could make significant improvements in reproductive efficiency traits at first. The low to medium heritability estimate and high genetic correlations obtained be-tween reproductive efficiency traits in ewe's lifetime and high phenotypic standard deviation from them indicated that improvement by selection of all of traits, especially NP can be improved TLWW as net re-productive efficiency trait in Lori-Bakhtiari ewes.

The phenotypic and genetic characteristics of ewe traits were studied using multitrait animal model analysis with DFREML procedure on the data of 5025 ewe trait records, collected during 1989 to 2003 in Rearing and Improvement of Lori-Sakhtiari Sheep Station (Sholi) in Shahrekord. The model included fixed effects (year, age of ewe and according to trait sex of lamb, and days of weaning as covariate) and random effects additive genetic of ewe, permanent environmental of ewe as well as residual. The overall mean (s.d) of traits were 56.21 (7.33) kg for ewe body weight, 1.91 (0.54) kg for greasy fleece weight, 0.91 (0.28) for conception rate, 1.20 (0.43) for number of lambs born per ewe lambing, 1.12 (0.45) for number of lambs weaned per ewe lambing, 1.06 (0.56) for number of lambs born per ewe joined, 1.00 (0.55) for number of lambs weaned per ewe joined, 5.65 (1.48) kg for total birth weight per ewe lambing, 31.34 (8.26) kg for total weaned weight per ewe lambing, 5.01 (2.28) kg for total birth weight per ewe joined, and 26.77 (13.44) for total weaned weight per ewe joined. The heritability coefficient of ewe body weight and greasy fleece weight were estimated as 0.42±0.02 and 0.55±0.02. For reproduction traits the corresponding estimates ranged from 0.04±0.02 for number of lambs weaned per ewe joined to 0.14±0.02 for number of lambs born per ewe lambing.The repeatability coefficient of ewe body weight (0.60) and greasy fleece weight (0.66) were high while for reproduction traits low (0.11) to moderate (0.26). The phenotypic and genetic correlations between body weight and other traits were low to moderate, between greasy fleece weight and reproduction traits were low, between conception rate and other reproduction traits, they were low whereas among the rest of reproduction traits moderate to high.