Many avian species are considered sexually monomorphic. In monomorphic bird species, especially in young birds, sex is difficult to identify based on an analysis of their external morphology. For nestlings, sex identification is usually impossible by morphological examination. Sex identification in avian species is one of the key points of avian breeding and evolutionary studies. Through the knowledge of sex identification genes, poultry breeding programmes can be applied more successfully. Vent sexing, laparoscopy, steroid sexing and karyotyping are methods for sex identification used in monomorphic birds. However these methods are unreliable, time-consuming, and expensive while some of them could be painful and even lifethreatening for birds. The sex of an individual is established from the genes located on sex chromosomes. Female birds carry one copy of both Z and W, and male birds carry two copies of Z avian sex chromosomes. However, there are many DNA techniques, the most reliable one is amplifying sex specific CHD1 gene by P2 -P8 primer pairs.

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Inherited diseases are caused by recessive alleles proceed from increased inbreeding in Holstein cattle population. Bovine leucocyte adhesion deficiency (BLAD), deficiency of uridine monophosphate synthase enzyme (DUMPS), complex vertebral malformation (CVM), factor XI deficiency (FXID) and bovine citrulinaemia (BC) are the most frequent inherited diseases in Holstein cattle population. The prevalence for carriers of BLAD, DUMPS, CVM, FXID and BC diseases were reported highest in Denmark (21.5%), USA (1.2%), Japan (32.5%), Turkey (18%) and Australia (13%) respectively. Moreover the highest prevalence for carriers of BLAD, CVM and FXID were reported as 2.2%, 3.4% and 18% respectively in Turkey so far. Neither DUMPS nor BC carriers were identified in Turkey so far. However further studies are required in order to identify the provinces that have risks for mutant alleles of inherited diseases in Turkey. Determining the carrier animals and exclude them from breeding is the only solution for eradication studies of inherited diseases.

The aim of this study is to determine the genetic variability of CAST gene in native sheep breeds of Turkey by PCR-RFLP method. Six different native sheep breeds; Kivircik, Imroz, Karayaka, Hemsin, Red Karaman and Karakul were used in this study. This study was the first report about CAST gene variation in Karayaka, Red Karaman and Hemsin sheep breeds. After DNA isolation and PCR amplification, RFLP was performed with MspI enzyme. Two alleles M (336bp and 286bp) and N (622bp) were identified on 2% agarose gel electrophoresis. Allel and genotype frequencies, observed (Ho) and expected heterozygosity (He) and deviation from Hardy Weinberg Equilibrium were estimated by statistical analyses. The frequency of M allele was highest in Imroz (96%) and N allele was identified most frequently in Kivircik (30%) breed. Highest frequencies of MN genotype were identified in Kivircik (60%), MM in Imroz (92.6%) and NN in Red Karaman (7.1%) breeds respecitvely. Kivircik, Imroz, Karayaka and Karakul breeds were null from NN genotype. Kivircik sheep showed the highest heterozygosity (60%) and Imroz had the lowest (7.4%). The highest heterozygosity value was identified in Kıvırcık (60%), the lowest in Imroz (7.4%). All breeds except Kivircik and Hemsin were found in Hardy-Weinberg equilibrium. Absence of NN genotype in some breeds and high frequency of MN genotype in Kivircik breed might be resulted from the selection process of native sheep breeds in their breeding regions. Keywords: Calpastatin, Native sheep breeds, Genetic variation Türkiye Yerli Koyun Irklarında CAST Genine Ait Genetik Çeşitliliğin Belirlenmesi

The purpose of the present study was to examine the walking phases in horses using the OptoGait system, which works with optical sensors. In this pilot study, 52 healthy horses were used. For each horse, an average of 45 steps were examined. The stance phase, swing phase, step distance, and walking speeds of the horses were recorded. The stance phase of each step was examined in a separate manner in 3 steps: contact phase, foot flat, and propulsive phase. The contact phase and the propulsive phase of the forelimb and hind limb were significantly different. The propulsive phase was significantly shorter in the forelimb compared to in the hind limb, and the contact phase was significantly shorter in the hind limb. The fact that the propulsive phase of the European warmblood horses used in our study was longer than that of the British and Arabian horses was significant. It is considered that this technique might be used in the diagnosis of lameness in horses in the future with the reference measurements that were created with these data obtained from healthy horses.