• فهرس المقالات Sistani cattle

      • حرية الوصول المقاله

        1 - Effect of Using Reproductive Technologies on Genetic Progress in Sistani Native Cattle of Iran: A Simulation Study
        ه. فرجی-آروق م. رکوعی ع. مقصودی م. مهری س. انصاری مهیاری ا. کریستین سورنسن
        The effect of artificial insemination (AI), embryo transfer (ET) to bull dams (BD), and sexed semen (SS) to cow dams (CD) with and without controlling inbreeding were studied using stochastic simulation. Three levels of embryo transfer (no ET, ET on all BD, and ET on 20 أکثر
        The effect of artificial insemination (AI), embryo transfer (ET) to bull dams (BD), and sexed semen (SS) to cow dams (CD) with and without controlling inbreeding were studied using stochastic simulation. Three levels of embryo transfer (no ET, ET on all BD, and ET on 20% of BD), five levels of sexed semen (no SS: control, SS-X on all CD, SS-X on 20% CD, SS-Y on all CD, and SS-Y on 20% CD), three levels of artificial insemination (no AI, AI on 50% cows, and AI on 90% cows), two levels of mating system (random and minimum consistory) were combined together to make 66 scenarios in which the combination of no ET, no SS, and no AI are assigned as a control. The simulated population consisted of 40 herds with 50 cows each was monitored for 30 years. The results showed that the use of AI, ET, and SS techniques increased the annual change of total merit index (TMI), inbreeding, and selection accuracy. Compared to control, the rate of annual change in TMI and inbreeding were increased as 41.95, 36.91 and 83.91%; and 192, 57 and 207%, for using of AI, ET and combination of SS + AI + ET, respectively. The minimum consistory mating decreased inbreeding, but not affected other parameters. The results suggested that using of ET on 20% BD, SS-Y for all CD, and 90% AI alone or in combination with each other along with minimum consistory mating might resulted in high genetic progress and low inbreeding rate. These technologies and inbreeding control strategies may increase the ratio of annual change of TMI to inbreeding. تفاصيل المقالة
      • حرية الوصول المقاله

        2 - Lack of Association between Somatotropin Receptor Gene Polymorphism and Birth Weight of Iranian Indigenous Sistani Cattle
        آ. جوانمرد س. ر. میرایی آشتیانی آ. ترکمن زهی م. مرادی شهر بابک
        The objective of the present study was to determine polymorphism within the promoter region of somatotropin receptor genes in indigenous Sistani cattle (Bos indicus) and associations between this polymorphism and breeding value of birth weight. The pedigree structure wa أکثر
        The objective of the present study was to determine polymorphism within the promoter region of somatotropin receptor genes in indigenous Sistani cattle (Bos indicus) and associations between this polymorphism and breeding value of birth weight. The pedigree structure was included by considering 1173 animals with 600 progeny birth weight data obtained from a Zhark breeding station in Sistan and Baluchistan. Heritability was estimated for birth weight using different univariate models with the derivative-free approach of restricted maximum likelihood algorithm (DFREML). The average weight of each birth was 23.9 ± 3.16 kg. The effects of non-genetic factors were significant (P<0.01) for birth weight. Direct heritabilities (h2) in single trait analyses were 0.31 ± 0.06. Genomic DNA was isolated from blood and semen using conventional methods. Polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) assays were used to genotype this candidate gene in 72 individuals with the birth weight record. The observed allele size was similar to that reported in the literature. The Sistani cattle showed higher frequency of alleles ALuI (+) than ALuI (-) in population. Statistical analysis was conducted to test the association of this polymorphism with the breeding value of birth weight data. There was not significant association between producing genotypes and birth weight trait. Future research on another candidate gene and growth trait strongly is encouraged to deep in the understanding of growth pattern in this breed. تفاصيل المقالة