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Indigenous Iranian horse breeds were evolutionarily affected by natural and artificial selection in distinct phylogeographic clades, which shaped their genomes in several unique ways. The aims of this study were to evaluate the genetic diversity and genomewide selection signatures in four indigenous Iranian horse breeds. We evaluated 169 horses from Caspian (n = 21), Turkmen (n = 29), Kurdish (n = 67), and Persian Arabian (n = 52) populations, using genomewide genotyping data. The contemporary effective population sizes were 59, 98, 102, and 113 for Turkmen, Caspian, Persian Arabian, and Kurdish breeds, respectively. By analysis of the population genetic structure, we classified the north breeds (Caspian and Turkmen) and west/southwest breeds (Persian Arabian and Kurdish) into two phylogeographic clades reflecting their geographic origin. Using the de-correlated composite of multiple selection signal statistics based on pairwise comparisons, we detected a different number of significant SNPs under putative selection from 13 to 28 for the six pairwise comparisons (FDR < 0.05). The identified SNPs under putative selection coincided with genes previously associated with known QTLs for morphological, adaptation, and fitness traits. Our results showed HMGA2 and LLPH as strong candidate genes for height variation between Caspian horses with a small size and the other studied breeds with a medium size. Using the results of studies on human height retrieved from the GWAS catalog, we suggested 38 new putative candidate genes under selection. These results provide a genomewide map of selection signatures in the studied breeds, which represent valuable information for formulating genetic conservation and improved breeding strategies for the breeds.

Background Kurdish horse is one of the most valuable horse genetic resources in the Middle East. Objectives To assess the genetic diversity of Kurdish horses, Mitochondrial DNA D‐loop hyper‐variable region1 (HVR1) was sequenced in 29 non‐related Kurdish horses which were sampled from diverse geographic regions of Iran. Methods Total DNA was extracted from the collected blood samples by modified salting out method. The HVR1 was amplified by PCR and then sequenced using ABI PRISM BigDyeTM Terminator Cycle Sequencing Ready Reaction Kit. Consequently, the sequences were trimmed to 294 bp using BIOEDIT to become comparable with other reported HVR1 sequences in GeneBank. Sequence alignment was performed using CLUSTALW package. Haplotype and nucleotide diversity were estimated using DNASP5.10 and phylogenetic tree was constructed by neighbour joining method. Results Fourteen different haplotypes and 22 polymorphic sites were detected. Haplotype diversity, nucleotide diversity and Tajima D values were 0.901 ± 0.001, 0.01153 ± 0.0020 and −1.378, respectively. Kurdish horse showed a high haplotype and low nucleotide diversity. The compositional frequency of consensus sequences for base A was the highest (29.93%) compared to other three nucleotides (C = 28.91%, T = 26.53% and G = 14.63%). As expected, all of the detected Kurdish horse haplotypes belonged to haplogroup K (i.e., Kurdish horses). Conclusions According to the phylogenetic analysis, Kurdish horses were genetically more closely related to Tibetan, Chinese, Bulgarian and Iranian native horse breeds, compared to other Asian horse breeds, but some traces of European horse breeds were detected in their maternal lines. Mitochondrial DNA D‐loop hyper‐variable region 1 (HVR1) variability in Kurdish horse breed Milad Nikbakhsh, Sheida Varkoohi* and Hamid Reza Seyedabadi Kurdish horse is one of the most valuable horse breed in the Middle East. Kurdish horse has high haplotype and low nucleotide diversity and its haplotypes were belonged to haplogroup K. This breed was genetically more closely related to Tibetan, Chinese, Bulgarian and Iranian native horse breeds, also some traces of European horse breeds were detected in their maternal lines.

Background Development of exogenous enzymes is one of the most important discoveries in animal nutrition. The supplementation of exogenous enzymes in broiler diets allows for supplying nutrient deficiencies and to decrease endogenous losses. Objectives The effects of phytase (Hostazym and Phyzyme) and xylanase (Ronozyme) enzymes were investigated on growth performance and Mucin2 gene expression in broilers. Methods A completely randomized design was applied, including 7 treatments, 4 replicates and 25 birds per replicates. A total of 700 male Ross (308) broiler chickens were fed with similar diets supplemented by Hostazym and Phyzyme (500 and 1000 FTU/kg) and Ronozyme (100 and 200 EXU/kg). Weight gain (WG), feed intake (FI) and feed conversion ratio (FCR) were determined for three phases and entire rearing period. On 42 days of age, four birds per replicate were slaughtered. Total RNA was extracted from jejunum samples, and Mucin2 gene expression was measured by real‐time PCR. Results Phytase and xylanase enzymes had a significant effect (p < 0.05) on traits (WG and FCR) in grower and finisher phases and whole rearing period, but FI was not affected by enzymes (p > 0.05). Carcass (74.13 g) and breast (27.76 g) weights by Hostazym (1000 FTU/kg) were higher than other treatments (p < 0.05). Weight of liver, bursa and spleen were significantly influenced by enzymes (p < 0.05). Likewise, bursa and spleen weights in Hostazym (1000 FTU/kg feed) and Ronozyme (200 EXU/kg feed) were significantly higher than other treatments (p < 0.05). Mucin2 gene expression was affected by enzymes in whole treatments. The lowest amount of Mucin2 gene expression belonged to Ronozyme (200 and 100 EXU/kg), and the highest was belonging to Hostazym (1000 FTU/kg). Conclusions Phytase enzymes have higher effect on broiler performance and Mucin2 gene expression compared to xylanase. High doses of Hostazym (1000 FTU/kg feed) could be supplemented in broiler chicken diets to improve optimum growth and feed efficiency. Phytase and xylanase enzymes had positive effect on growth performance in broiler chickens and improve carcass yield, as well as relative weights of internal organs. Phytase enzymes have higher effect on broiler performance and Mucin2 gene expression compared to xylanase. It seems that phytase enzyme had significant effect on immune response in broilers. High dose of Hostazym could be supplemented in broiler chicken diets to improve optimum growth and feed efficiency.

This study was to determine phylogenetic relationships and genetic variation in Iranian Afshari sheep breed. For this reason, phylogenetic relationships and genetic variation were analyzed by using 12S rRNA and 16S rRNA gene sequences. The genomic DNA was isolated by salting out method and amplified 12S rRNA and 16S rRNA genes using PCR method. PCR amplification of 12S and 16S rRNA generated PCR amplicons at 859 and 1053bp lengths, respectively. Sequence analysis was performed using Bio–Edit software. Phylogenetic tree was constructed using MEGA software. Phylogenetic analysis of haplotype in the combination with the sheep from Gen–Bank showed that Iranian Afshari sheep made a close to the Australian sheep cluster. There was found informative for establishing relationships between breeds from different parts of the world. This may facilitate the future researchers and breeders for better understanding the genetic interactions and breed differentiation for devising future breeding and conservation strategies to preserve the rich animal genetic reservoir of the country.