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Dromedary camel fibers have long been utilized to make clothes, tents, ropes, mats, and carpets, however, only a minority of these fibers are currently used to produce textiles. Dromedary fiber classification based on quality traits is essential to investigate its textile potential. Therefore, the objectives of this study were to (1) develop a classification protocol for dromedary camel fibers based on crimp (i.e., shape), (2) investigate the characteristics of each fiber class using length, diameter, and medulla (i.e., the innermost hair layer) and (3) determine which fiber class is most suitable for the textile industry. Fiber samples were obtained from the mid-torso of 32 Arabian Peninsula camels of different types. Five crimp categories were identified (straight, C-shaped, wavy, ringed, and kinky). Across all crimp categories, the average length ranged from 20.20 – 43.93 mm whereas the mean fiber diameter ranged from 29.74 – 72.11 μm. Percent medullation extended from 68% to 100% with noticeable variation between crimp categories. Overall, fiber traits significantly differed between the crimp categories. Kinky hair was particularly distinct from the other crimp categories. The kinky crimp category is the most suitable dromedary fiber for the textile industry because its fibers are long, fine, and has the lowest percentage of medullated fibers. Hence, we recommend that selective breeding programs and genetic studies focus on the production of dromedaries with kinky hair fibers. • Quality assessment of dromedary camel fiber and classification are essential for assessing its textile potential. • Dromedary fiber crimps can be categorized into: straight, C-shaped, wavy, ringed, and kinky. • Overall, dromedary crimp categories differed significantly with respect to length, fiber diameter and medullation. • Kinky camel fibers are long, fine, and with very low medullation, which renders it comparable to that of cashmere fibers. • Crimp-type can assist in selective breeding programs for superior fibers and provide measurable phenotypes genetic studies. [ABSTRACT FROM AUTHOR]

Dromedary camels are outstanding livestock that developed efficient abilities to tolerate desert conditions. Many dromedary camel-types (i.e., named populations) exist but lack defined specific breed standards, registries, and breeders' governing organizations. The breed status of dromedary camel-types can partly be assessed by exploring mitochondrial DNA (mtDNA) variation. Accordingly, this study aimed to examine the breed status and the inter-population relationships of dromedary camel-types by analyzing sequence variation in the mtDNA control region and in three coding genes [ cytochrome b , threonine, and proline tRNA , and part of the displacement loop (D-loop)] (867 bp region). Tail hair samples (n = 119) that represent six camel-types from Kuwait were collected, extracted, sequenced, and compared to other publicly available sequences (n = 853). Within the sequenced mitochondrial region, 48 polymorphic sites were identified that contributed to 82 unique haplotypes across 37 camel-types. Haplotype names and identities were updated to avoid previous discrepancies. When all sequences were combined (n = 972), a nucleotide diversity of 0.0026 and a haplotype diversity of 0.725 was observed across the dromedary-types. Two major haplogroups (A and B) were identified and the B1 haplotype was predominant and found in almost all dromedary-types whereas the A haplotypes were more abundant in African regions. Non-metric multidimensional scaling revealed an increased similarity among Arabian Peninsula "Mezayen" camel-types, despite their defining coat colors. The relationships among dromedary camel-types can partly be explained by mtDNA. Future work aimed at a deeper understanding of camel-type breed status should focus on a high number of nuclear markers. [ABSTRACT FROM AUTHOR]

The dromedary camel is a unique livestock for its adaptations to arid-hot environments and its ability to provide goods under extreme conditions. There are no registries or breed standards for camels. Thus, named camel populations (i.e. camel-types) were examined for genetic uniqueness and breed status. Camel populations are generally named based on shared phenotype, country or region of origin, tribal ownership, or the ecology of their habitat. A dataset of 10 Short-Tandem Repeat markers genotyped for 701 individual camels from 27 camel-types was used to quantify genetic diversity within camel-types, compare genetic diversity across camel-types, determine the population genetic structure of camel-types, and identify camel-types that may represent true breeds. Summary statistics (genotyping call rate, heterozygosity, inbreeding coefficient F IS, and allelic frequencies) were calculated and population-specific analyses (pairwise F ST, neighbor-joining tree, relatedness, Nei's genetic distance, principal coordinate analysis [PCoA], and STRUCTURE) were performed. The most notable findings were 1) little variation in genetic diversity was found across the camel-types, 2) the highest genetic diversity measure was detected in Targui and the lowest was in Awarik, 3) camel-types from Asia (especially the Arabian Peninsula) exhibited higher genetic diversity than their counterparts in Africa, 4) the highest DeltaK value of population structure separated camel-types based on geography (Asia vs. Africa), 5) the most distinct camel-types were the Omani, Awarik, and the Gabbra, 6) camel-types originating from the same country did not necessarily share high genetic similarity (e.g. camel-types from Oman), and 7) camel-type names were not consistently indicative of breed status. [ABSTRACT FROM AUTHOR]

• We use geometric morphometrics to classify camel breeds • We differentiated between two predefined breed groups using torso size and shape • Geometric morphometrics provided an alternative source of data for breed discrimination In this study, we examine the utility of image-based geometric morphometrics in classifying camel breeds. As a case study, we explore morphometric variation of six common Arabian Peninsula camel breeds ("Mezayen" breeds), traditionally named according to their coat color: Homor (red), Majaheem (black), Shaele (brown), Shageh (wheat), Sofor (smoky brown), and Waddeh (white). According to prior research, Mezayen breeds are often divided into two main groups: (1) the Majaheem breed alone and (2) the "Malaween" breeds, encompassing Homor, Shaele, Shageh, Sofor, and Waddeh breeds. Our main aim is to determine if we can find support for these two groups based on geometric morphometric analysis. We quantified the shape and size of each camel's torso based on landmarks and semilandmarks spanning their dorsolateral surface, from the root of the tail to the base of the neck. Landmarks and semilandmarks were digitized on photographs of 514 camels, sampled from > 23 breeders from various regions in Kuwait. The division of the Majaheem breed from the Malaween breeds was strongly supported. The Majaheem breed showed marked group homogeneity and significantly differed from all the Malaween breeds, while the Malaween breeds were largely heterogeneous, and did not significantly differ from each other. These results were supported by Procrustes ANOVA, between-group PCA, UPGMA cluster analysis, and Type-II ANOVA. Based on the TPS deformation grids, the Majaheem breed mainly differed from the Malaween breeds in the shape of the posterior part of the torso (the curvature from the tail root to the hump apex). We detected no significant allometry in shape variation, indicating no correlated variation of torso shape with size. This study demonstrates the usefulness of geometric morphometric analysis in camel breed classification. To utilize this method for camel breeding, further work is needed to determine whether our results could be generalized to other breeds, and to discover the combination of morphometric traits that best delineate breeds based on predefined breeding goals. [ABSTRACT FROM AUTHOR]