afshari sheep

In this study, data from 1882 ewes, including 3351 lambs born, was used as litter size trait in Afshari sheep breed. The data were collected from 2000 to 2016 by the research station at Zanjan University. The data were analyzed by ASReml software via threshold model in six different models. Fixed effects of year and season, age of ewe, number of parturition and genetic group [at five levels including pure Afshari, 50% Afshari (F1), 75% Afshari (B1), 87.5% Afshari (B2) and 93.75% Afshari (B3)] were significant (P<0.05). Heritability and repeatability were estimated to be as 0.08 and 0.17, respectively. Genetic trends of this trait, in two periods between 2000 to 2006, before the gene introgression design as first period, and from 2007 to 2016, after the introgression as second period, were 0.004 (P>0.05) and 0.059 (P<0.05), respectively. Also, the phenotypic trends were 1.37 (P>0.05) and 1.69 (P<0.05) for two periods, respectively. The results showed that the FecB gene transfer increased the litter size. Consequently, because of the direct relationship between the more profitability of flock and the increase in the number of lambs born, the gene transfer design will be followed and more welcomed by sheep breeders. Therefore, genetic parameters and genetic trends estimation of litter size in this flock can be effective for developing continues genetic breeding strategy.

Selection of live animals with minimum carcass fat in animal breeding programs will lead to increase in meat production at national level. The ligands of Wnt genes are of the effective factors in adipocyte cell differentiation. This study was aimed to assess the association between polymorphisms in Wnt10a and Wnt10b genes and carcass traits in 96 Afshari – Booroola Merino male lambs. In this study, DNA was extracted from blood samples using phenol-chloroform extraction method and polymerase chain reaction was performed for amplification a 663 bp fragment of exon III and a part of the second intron of Wnt10a gene and a 512 bp fragment of exon III Wnt10b gene. The results showed a polymorphism and three monomorphisms (a different allele compared to reference sequence of the gene) in the Wnt10a gene but all the sequences of the Wnt10b fragment were the same in studied region of the gene. Results of the sequencing lead to identification of four single nucleotide changes in Wnt10a gene in the studied area when compared to the reference sequence. One of the monomorphisms was in the intron and among other three nucleotide changes identified in exon III one was a missense in codon 139. After digestion with restriction enzymes HpaII at this codon, it was observed that all sampled lambs had mutant homozygous genotype compared to the reference sequence. This site was also evaluated in a number of Afshari (fat- tailed) and Zell (with the least fat tail) but again the same results were observed. Therefore, it seems that in this position the G is the wild type allele in the studied population.

Introduction Leptin is a 16 kDa protein produced by adipocytes. This protein controls appetite, energy balance, efficiency of production and distribution of fat storage in the body and therefore plays an important role in regulating body weight and growth in mammals. LEP gene in sheep (NC_019461) located on 4th chromosomes and has 16275 bp in length and contains 3 exons and 2 introns. The resulting protein contains 193 amino acids (the length of coding region is 579 bp). So far in this gene, 17 single nucleotide polymorphisms in the coding region were reported that seven of them are synonyms and the rest are missense. The entire exon 3 is containing 357 bp in length that starts from nucleotide 13544 till nucleotide 13903. This exon comprise 119 (or 118) codons, seven missense and a synonymous SNPs from this area of the gene is reported till now. Different alleles of this gene may lead to different phenotypic effects.
Material and Methods The aim of this study was to identify alleles of the gene in exon 3. For this purpose, 133 lambs from a flock at almost the same age in three groups of Afshari pure breed and B1 and B4 of Afshari × Booroola Merino male lambs were used. Afshari sheep is one of the heavy weight sheep in Iran, which is important breed in terms of meat production. It has notable twinning rate and birth weight, growth rate and weaning weight is remarkable compared with other breeds of sheep in this country. Given the potential of this breed suitable for the production of meat, it can play an important role in production of red meat in the area. To increase productivity of this breed, FecB gene from Booroola Merino sheep was introgressed to this breed of sheep in University of Zanjan in 2007. Following the introgression of the gene (FecB) to Afshari breed Afshari- Booroola Merino crosses as a new genetic combinations was developed. This study aimed to identify single nucleotide polymorphisms (SNP) in exon 3 of Leptin gene and its association with carcass treats in male Afshari and cross lambs. First, blood samples of all the animals were taken and phenotypic measurements on live animals were done and then 85 lambs were slaughtered. After slaughter, carcass weight was measured and after 24 hours maintaining in cold, weight of carcass, thigh, shoulder, lion muscle, back fat and waste (tail, back and visceral fat) were measured. Estimation of the carcass traits in non-slaughtered lambs, were accomplished using regression coefficients achieved before. DNA was extracted using phenol-chloroform procedure from all the samples. Then, using designed primers, the target DNA was amplified and PCR products of a number of samples were directly sequenced to identify potential SNP(s). The sequencing data were analyzed and two SNPs were detected in samples. Thereafter, all the samples were genotyped by RFLP using two restriction enzymes Hpa II and AIwNI. The association of genotypes with phenotypic and carcass traits were studied.
Result and Discussion According to this study results, one of the polymorphism was identified in nucleotide position 13713. All three genotypes of this; GG, GA and AA were observed in studied samples. This missense polymorphism led to amino acid arginine/glutamine change at codon 142 and had a significant effect on the back fat thickness and withers height. The second polymorphism observed in the nucleotide (G> A13875) and two GG and GA genotypes were found in the samples. This polymorphism also had the same amino acid changes at codon 196 and associated with body length (with probability close to significant level). The frequency of GG genotype in both SNP was higher than other genotypes. This genotype is the genotype of the reference sequence in biological data bases. The alleles locating in 13713 bp in the studied population were not in Hardy-Weinberg equilibrium. But alleles of the 13875 location were in Hardy-Weinberg equilibrium. The allele frequency of each SNP was significantly different in genetic groups. In location of 13713, the most frequent mutation allele (A) and the lowest frequency of this allele was observed in genetic group B4 and Afshari group respectively. In location 13875, Afshari group had the highest frequency of the mutant allele and B1 had the lowest frequency.
Conclusion In general, in this study polymorphisms were found out in exon 3 of the leptin gene which has been found in previous studies and sheep SNP projects and have been reported previously in biological databases. Based on the results obtained and the variations observed in some previous studies, if the changes associated with these traits be confirmed in next studies, these polymorphisms could be used in marker-assisted selection in breeding programs.

Introduction One of the most important sources of the red meat in Iran is the meat produced from sheep. Increasing lamb per ewe considered as a strategy for improving the efficiency for sheep production, although reproduction traits have low heritability. Several genes associated with reproduction were investigated in the recent years. The BMP 15 gene and its paralog GDF 9 and receptor, BMPR-IB, are related to fecundity in sheep and attracted the interest of breeders recently. All these genes that are members of TGFβ super family are functionally closely related together and they affect expression and secretion of hormones affecting follicle growth and ovulation rate in mammals. BMP15 plays a key role in regulating many processes in granulosa cells and ovulation rate. Mutations in some candidate genes such as BMP 15 proved to affect the lambing rate. Since 2008, introgression of the BMP Receptor IB mutant (FecB) from Booroola Merino (from New Zealand) into Afshari sheep was initiated. Thereafter, several genes that proved to have an effect on reproductive traits were studied in this breed. This study was conducted to identify possible polymorphism(s) in BMP 15 and to compare its expression in ovaries of pregnant and non-pregnant ewes.
Materials and Methods To study these, blood samples were collected from 35 and 45 Afshari and Afshari × Booroola Merino ewes, respectively. DNA was extracted from all samples using phenol-chloroform procedure and Total RNA was extracted using the RNA extraction kit, CinnaPure RNA Kit (Cinnagen Inc®, Iran), extraction was performed according to the manufacturer’s instruction. To remove any possible residual DNA contamination, RNA samples were treated with 1 unit of DNase (Vivantis Inc®, Malaysia). The specific primers were designed for three areas of BMP 15, namely promotor (581 bp), exon one (325 bp) and exon two (857 bp) and the targets were amplified using PCR. The PCR products were sequenced using forward and reverse primer for all of the samples.
Result and discussion There was no difference among sequences of the promoter and the first exon among samples. But, a nucleotide in position 134 of the second exon, C was replaced by A, was observed in two samples with heterozygote genotypes AC instead of CC. Nonetheless, the codon of amino acid encoding proline is remained unchanged. This mutation occurred in two Afshari × Booroola Merino ewes. This mutation, to our knowledge, was not reported to date. Parents of these ewes were not available and also due to the low frequency of the mutation, detection and identification breed of the origin for the mutation was not possible. To date, such a mutation neither was reported in Afshari nor in Booroola Merino breeds. Obviously, the promoter of the gene is conserved and it shows high similarity amongst related species. Nevertheless, in our study sample size was limited to conclude this well. Considering conservation of the promoter of the gene within the species and closely related species, it appears that the regulatory regions were very protected and required for its sustained action. Given that a number of animals used in the study were twine bearing Afshari × Booroola Merino crosses, but there was no difference between them and Afshari pure breed in terms of BMP15 gene expression and gene sequences. Thereupon, the results of this study indicate that this gene plays no role in litter size of this new genetic component. In order to assess the expression of this gene in ovaries of the ewes, after slaughtering, ovary samples of 22 pregnant ewes and those of 8 none pregnant were collected. Total RNA was extracted from the samples and mRNA converted to cDNA using oligo d (T) primer and reverse transcriptase. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) was used as the endogenous control for normalization. Results of real time PCR using designed specific primers showed no difference in BMP 15 gene expression between pregnant and non-pregnant ewes.
Conclusion It is possible that this gene plays its role in relation to other genes include their receptors and its expression is needed in different steps of reproduction. This result and reports of other studies suggest that more data on BMP15 gene with a simultaneous expression of other genes in the ovary is needed to clarify the integral role of BMP 15 in reproduction.

Body Condition Score (BCS) is a subjective metod for evaluating the nutritional status of the flock that provided the profitable information of productive trait and body ingridients. OBGECTIVES: The Effect of BCS at lambing on ultrasounography, biometry measurement and productive traits of Afshari breeds were investigated. 169 Afshari ewes 2 to 7 years old were selected from experimental flock of Zanjan University. BCS of ewes at lambing were categorized to 5 groups of 2, 2.5, 3, 3.5 and 4. The numbers of each Group were 12, 50, 45, 27 and 35 respectively. Traits in this study included: ultrasounography and biometry measurements, body weight and body temperature, wool production and some productive traits. BCS have significant effect on Longissimus muscle depth, body length, chest circumference, length tail, middle and bottom of the tail and body weight, while skin thickness, fat thickness, withers height and depth of the chest have no significant difference (P<0.05). Average wool production in ewes with a score of 3.5 more than other groups, and ewes with BCS 2 was lower than other treatments (P<0.05). Birth weight of lamb from ewes with different BCS, have no significant. This study showed that type of birth and sex of lamb in birth weight was significant (P<0.05). Ewe Body condition score, sex, birth weight and type of birth were effective on weaning weight and average daily gain to weaning. The results showed that positive effect of BCS, ewes with BCS of 3 to 4 had better performance than other groups in the flock, therefore complementary feeding of ewes in late pregnancy is recommended.

This study was achieved to evaluation of some strategies and determination the best suitable selection index for Afshari sheep using simulated data. The relative importance of traits was determined based on the estimated economic values and consequently، the most benefit traits were applied to selection indexes construction. The interest indexes were different combination of traits including ewe body weight (EBW)، annual wools weight (AWW) and total weaning weight for each exposed ewe (TWWEE). The index 1 were included all three mentioned traits. The indexes 2، 3 and 4 were included (AWW، TWWEE)، (EBW، TWWEE) and (TWWEE)، respectively. The results indicated that the aggregate genotype، selection index and economic progress increased by increasing in the population size and decreasing in ram ratio، but made reduction in inbreeding average، in all indexes. In more cases، the aggregate genotype decreased by removing a trait in the index. The comparisons among indexes indicated that the most suitable selection index for this breed is index 1 which included EBW، AWW and TWWEE. This index had a maximum selection index average، aggregate genotype and economic progress.

To evaluate capability of sonography for estimation of carcass traits of live animals in Afshari sheep a study was conducted using 97 male lambs of Afshari breeds. Lambs were at age of 11 month before slaughtering. Muscle thickness, loin muscle area and back fat thickness, between 12th and 13th ribs was measured using the ultrasound. Back fat and muscle thickness was also measured directly using a metal ruler in same area on the carcasses. Carcasses were stored at cold room for 24 hours and afterward were divided into two halves of left and right. The right side of carcasses dissected into neck, leg, thigh, tail and waste. Ultrasound measurement of longissimous muscle showed a high accuracy and highly correlated with carcass weight (0.84), arm(0.8), flank area (0.78) and thigh (0.74) muscles with bone, respectively. Ultrasound muscle depth and its direct measurement on carcass were highly correlated (0.87). But its correlation with weight of carcass components was less than those of muscle area. Correlation between fat depth measured by ultrasound and fat depth measured on the carcass was 0.7. Regression equations for prediction of carcass traits using ultrasound and carcass measurements were calculated. The results of this study showed that measurement of loin muscle area and back fat by ultrasound has relatively good accuracy and can be used for estimation of some carcass traits.

In this research, economic value for production traits and reproduction traits of Afshari sheep were estimated using a deterministic bio-economic model. In production system of Afshari sheep, the variable costs comprised 99 % of total costs. Revenue sources consisted of meat, milk, wool and manure, where meat with 83.4 % of revenue had the highest effect. Economic value for a trait as the change in profit of production system by increasing one unit in the trait avrage, while avrage of other traits were constant was estimated.After that, milk, wool production and ewe survival were followed. Birth weight had negative economic value. The sensitivity of economic value of various traits to ±10 % changes in feed, non- feed costs and also to meat, wool and milk prices were examined, and the results showed the economic values of wool and milk productions were not sensitive to none of the costs. Also changes in the costs of rearing and marketing had no effect on the economic value for body weight in various ages of wool and milk production. By changing the price of meat, the economic values of all traits except birth weight, wool and milk production were changed, by increasing the price of meat results to increases in the economic values of those traits. Among various factors, meat price had the most effect on the economic value of traits.

The present study was attempted to produce MAS software. This software uses a combination of quantitative and molecular information for the prediction of breeding values. Some genes that control a trait have major effects comparing with others. These genes are called major genes which are located on QTLs (quantitative trait loci). Our understanding on inheritance pattern of QTL can be helpful in selection programs via marker assisted selection (MAS). This provides an opportunity to increase the genetic progress of domestic animals by MAS. The marker assisted selection performance are based on an index, consists of phenotypic and molecular markers data. The MAS software based on mixed model methods (MMM) was established with the C# programming language. This software designed based on animal models with matrix form for predicting breeding values. To identify polymorphism in promoter region of DGAT1 gene, DNA was extracted from blood samples, the PCR process performed on DNA samples. Allelic and genotypic frequencies of animals were characterized. MASS software was used for the prediction of breeding values for 80 male lambs of Afshari sheep in research-education farm of Zanjan University. To compare the results, analyses were also performed using SAS software. Comparing the predicted breeding values obtained from MAS software and SAS indicated the effect of molecular marker in selection based on the combination of molecular and phenotypic information.