Yazar "Szara, Tomasz" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • [ X ]
    Öğe
    Size and shape of the neurocranium of laying chicken breeds
    (Elsevier, 2024) Guzel, Baris Can; Manuta, Nicoleta; Unal, Burak; Ruzhanova-Gospodinova, Iliana Stefanova; Duro, Sokol; Gundemir, Ozan; Szara, Tomasz
    The neurocranium in birds provides valuable insights into their morphological diversity, including adaptations related to brain size, facial shaping, and environmental factors. This study analyzes the neurocranial shape characteristics and size of chickens with similar genetic backgrounds. By examining the neurocranial shape variation in chickens of the same age and sex, the study aims to understand the factors contributing to morphological diversity within this specific group. 3D geometric morphometrics was used to analyze 235 neurocrania from four chicken breeds. The analysis revealed significant differences in centroid size among the chicken breeds. The largest neurocranium centroid size was found in Sasso chickens., which were statistically separated from Atak-S. Additionally, centroid size effectively differentiates between Lohmann Brown and Lohmann Sandy chicken breeds. The most significant shape variation concerned the width of the rostral part of the frontal bone. However, according to the PC1 value, the shape variation was observed within rather than between groups. Lohmann Sandy chickens exhibited higher variability in neurocranial shape, suggesting greater shape diversity within this breed than others. As for shape analysis, the breeds showed closer similarity to each other. Lohmann Sandy chickens are characterized by positive PC1 value, with the rostral end of the frontal region inclined more ventrally, and a more extensive basioccipital region. Sasso chickens have a more dome-shaped middle part of the frontal region than other breeds. The study also identified the most significant shape variation among the study samples, observed at the rostral part of the frontal bone. These findings contribute to understanding the genetic and environmental influences shaping neurocranial morphology in chickens. Similar studies in different bird species and subspecies offer valuable insights into avian biology and adaptation.
  • [ X ]
    Öğe
    Skull morphology in native and non-native cattle breeds in Türkiye.
    (2025-02-23) Gündemir, Ozan; Manuta, Nicoleta; Güzel, Barış Can; Bakıcı, Caner; Duro, Sokol; Ünal, Burak; Çakar, Buket; Szara, Tomasz
    This study aims to investigate morphological differences in the skulls of cattle breeds with different functional roles and geographical origins and to examine skull shape variations among breeds using geometric morphometrics methods. To this end, 95 skulls from Native (Eastern Anatolian Red and Southern Anatolian Red) and Non-native (Holstein and Simmental) breeds raised in Türkiye were analyzed. The results show a significant size difference between Native Breeds and Non-native Breeds, with the Non-native Breeds having larger skulls. The results also indicate considerable shape differences between Native and Non-native Breeds. No significant shape differences were observed between the two Native Breeds, which have shared the same geography for many years. Although no statistically substantial size difference was found between Simmental and Holstein, the nuchal region showed distinct shape differences. The nuchal part of the Simmental skull was more pronounced than other specimens. In native breeds, there was a more balanced proportion between the facial and neurocranial regions compared to the other two breeds. In Holstein skulls, the facial region was more pronounced in comparison to the neurocranial region, while in Simmental skulls, the neurocranial region was more prominent. This study provides valuable insights into the morphological characteristics of different cattle breeds, contributing to veterinary anatomy, biology, and paleontology.