The objective of this study was to compare genetic gain, aggregate genotype and change of inbreeding in closed nucleus, open nucleus and sire referencing strategies with computer simulation. Four traits of litter size (LS), weaning weight (WW), average daily gain from weaning to 6 months of age (ADG) and greasy fleece weight (GFW) were included in selection index and breeding goal. Relative economic values of these traits were 240, 8, 0.424 and 1, respectively. The genetic gain, aggregate genotype and inbreeding for three strategies were calculated for 10 years selection. Average and standard errors of 20 repeats were reported. Results of simulation showed that cumulative genetic gain in closed nucleus after 10 years selection was 0.190, 1.342 kg, 44.96 g and 0.125 kg for LS, WW, ADG and GFW, respectively. These estimates were 0.193, 1.355 kg, 46.50 g and 0.128 kg in open nucleus and 0.197; 1.492 kg, 52.48 g and 0.138 kg in sire referencing strategies, respectively. For all traits, genetic gain resulted from sire referencing strategy were higher than closed and open nucleus strategies. Average yearly increase of inbreeding coefficient were 0.247, 0.095 and 0.175 percentage for closed nucleus, open nucleus and sire referencing strategies, respectively. Inbreeding coefficient in open nucleus was lower than closed nucleus and sire referencing strategies. In general, based on genetic gain and aggregate genotype value, sire referencing strategy is more suitable than open and closed nucleus strategies for Baluchi sheep breeding.

Estimation of cytoplasmic effects of Baluchi sheep breed for production traits were studied. The data used in the present study were collected from flocks at the Abbasabad sheep breeding research station in north east of Iran included 13625 animals descended from 275 sire and 3863 dam.Traits were birth weight, waning weight, 6-month weight, 12-month weight and greasy fleece weight at 18 month. Cytoplasmic origin was found by tracing the individual progeny to the earliest ancestor in the pedigree. Genetic Parameters were estimated by Derivative Free Restricted Maximum Likelihood (DFREML) using univariate animal models. For all traits cytoplasmic effects were not important. The evidence is broadly consist with 4% for BW and 2% for GFW of variation in performance due to cytoplasmic effects. However effects in genetic evaluations are likely to be small. Maternal genetic effect contribution on greasy fleece weight was very low.

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.

In order to identify polymorphic microsatellite markers and evaluae genetic variation within Baluchi sheep population, nineteen microsatellite loci were studied. Whole Blood samples were collected from 156 sheep at north eastern animal breeding station of Iran (Abbasabad-Mashhad). DNA was extracted by salting-out procedure with some modifications. Polymerase chain reactions were successfully done except for UNC5C locus. PCR products were electrophoresed on 8% denaturing polyacrylamide gels stained according to rapid silver staining procedure. The genotype and allelic frequencies were calculated by direct counting and used for estimating of different polymorphism and genetic variation criteria. This population wasn't at Hardy-Weinberg equilibrium except for OarAE101 locus (P<0.005). Heterozygosity (gene variation) ranged from 0.1 to 0.93. BULGE5E and BM1329 loci were monomorphic. In conclusion, this investigation showed high polymorphism at the studied loci, so they could be used in future studies.

Myogenin gene (MYoG) affects the synthesis of muscle myofibrillar growth and increase of meat produc-tion. The myostatin (MSTN) gene is identified as a specific negative regulator of skeletal muscle growth. Reduction of the expression level of MSTN through mutation in the sequence of this gene leads to an in-crease of myogenesis and regeneration of muscle cells during the postnatal growing period of sheep. The Baluchi sheep are among the most popular breeds of sheep for breeding in Iran and have an important por-tion in meat production industry of the country. In present work the relative expression level of the two candidate genes have been studied at two age intervals (9 and 12 months) in male and female Baluchi sheep. In order to analyze the relative expression level of MYoG and MSTN gene in Baluchi sheep’s long-issimus muscles, quantitative real-time polymerase chain reaction (qRT-PCR) reaction has been applied. Results of RT-PCR for sex effect showed MSTN and MYoG expression were not highly expressed in ram’ longissimus dorsi compared to ewe at the same age stages (P>0.05) and there were no significant differ-ences between male 12 months comparing to female 12 months (P>0.05) and male 9 months with female 9 months (P>0.05). For the effect of age, relative expression of MYoG and MSTN genes on Baluchi sheep longissimus muscles did not show significant differences between males or females (P>0.05).

Baluchi sheep is the most dominating sheep breed in Iran, its breeding station being located in Abbas Abad, Mashad. In this study, genetic diversity was attended to through a study of polymorphism in 17 microsatellite loci in its population. Each of the loci was investigated using 145 DNA samples. Polymeroze Chan Reaction (PCR) conditions for all loci were optimized and PCR products run on polyacrylamide gels, bands being revealed by a silver staining procedure. Based on the results, all loci, except BMS4000 and OarAE54, were amplified and showed polymorphism. MCM120 (0.9232) and TGLA387 (0.6839) carried the highest and lowest Polymotphic Information Content (PIC) values respectively. The highest number of actual alleles were observed in MCM 120 (21 alleles) and the least number of actual allele in MCM494 and MCM541L (9 alleles). Also it was shown that the highest and the lowest number of effective alleles belonged to CSRD144 (14.9664) and TGLA387 (3.6255), respectively. Average heterozygosity over all loci in this population was found as 0.8764. All loci, based on X2 and G2 tests, were out of Hardy-Winberg Equilibrium (HWE) while only MCM120 by G2 test stood in HWE. High genetic diversity in the population of Baluchi sheep, based on the studied loci, can be concluded from the results obtained from the present investigation.

Land use capability for a type of range utilization with considering the sustainable land use is called range suitability, nowadays which is a priority in the science of range management. The objective of this study is evaluation of range suitability for sheep grazing through FAO method (Condition limitation) in Sarayan-South Khorasan province in 1990. For the purpose of this study, at first, the map of vegetation types was determined in each region and in each vegetation type, the status and tendency of rangeland and the amount of plant species were determined by cutting and weighing method and the suitability map was produced. Then, using EPM method, soil erosion susceptibility map was prepared. Also, to study the watershed suitability of the area, the drinking water resources of livestock area and sampling of each water source was done, the quantification of water was determined and water samples were transferred to the laboratory and TDS, EC and Mg + 2 parameters were measured for each sample and by integrating layers of quantity, quality and equal distant points from water sources, the water resource suitability map was adjusted. Finally, by finalizing production suitability maps, soil susceptibility to erosion and water, the final model of range suitability classification was prepared. The results indicated that there was no class of suitability (no vegetation type) (S1) in the region and the suitability classes S2, S3 and N (no grazing suitability) were 12. 1%, 50. 7% and 37%, respectively. Based on the research results, overgrazing, early grazing, formation susceptible to erosion, slope, allowable use limits and available forage, poor condition, negative trend of ranges and inappropriate distribution of water sources for livestock are the most considerable limiting factors in area for sheep grazing. In general, with regard to the obtained results using the livestock grazing suitability model in the study area, it is suggested to use this model as the basis for preparing rangeland plans with emphasis on removing the limiting factors as far as possible to improve rangeland status and Shepherds' income.

The study was designed to investigate the relationship between growth trait and biometric traitsin Baluchi sheep. This study was conducted to estimate the genetic and phenotypic biometric traitsincluding daily gain (ADG) and height at withers (HW), height at back (HB), body length (BL),heart girth (HG), leg girth (LG) and testis girth (TG) in Baluchi sheep. Total data of 4542 recordsfrom six experimental herds of Jahad Organization Research Centre of Mashhad County werecollected since 2001 to 2011. Data were analyzed using General Linear Model (GLM) of SAS. Forthe estimation of genetic parameters and genetic correlation between traits, animal model uni andmulti-trait by restricted maximum likelihood (REML) of WOMBAT 32 (Meyer 2007) have beenused. The mean heritability of ADG, BL, HG, HW, HB, TG and LG traits was estimated 0.13±0.01,0.11±0.06, 0.21±0.07, 0.17±0.06, 0.32±0.1 and 0.2±0.06 respectively. The results of the currentstudy showed that the TG trait has the highest heritability. The estimations shows geneticimprovement will be predictable in biometric traits of Baluchi sheep. The genetic correlationbetween traits was positive, ranged between 0.15-0.97. Moreover, phenotypic correlation waspositive and was estimated in range of 0.32 to 0.94.

This experiment was carried out based on 5913 records of Baluchi sheep from Abas Abad Animal Breeding Station in North East of Iran. The under study traits were, birth weight, three months, six months, nine months and yearling weights. Six different models of DFREML software were used. Genetic parameters were estimated by REML method with the animal model. Age of dam, sex of animal, birth type, year and month of birth was regarded as fixed factors in analysis data and traits. Number of days between birthday and time of obtaining each trait were used as a covariate for correcting the real data. The estimated heritability for birth weight, three, six, nine and twelve (yearling) months were 0.14 (0.033), 0.28 (0.045), 0.25 (0.05), 0.28 (0.052) and 0.33 (0.055) respectively. It was conduced that increasing the age of animal, direct genetic effects on weight traits also increased significantly.