Hrnčár C. et. al./Scientific Papers: Animal Science and Biotechnologies, 2013, 46 (2) 66 The Quality of Ejaculate in Cocks of Brown Leghorn, Oravka and Brahma Breeds Cyril Hrnčár* 1 , Lenka Barborová 1 , Jozef Bujko 2 1 Department of Poultry Science and Small Animal Husbandry, Faculty of Agrobiology and Food Resources, Slovak University of Agriculture, Nitra, Slovakia 2 Department of Genetics and Breeding Biology, Faculty of Agrobiology and Food Resources, Slovak University of Agriculture, Nitra, Slovakia Abstract In this experiment, ejaculates were sampled from cocks of three pure chicken breeds: Brown Leghorn, Oravka and Brahma. The 5 cocks from each breed were housed individually and the ejaculate was sampled regularly five times during the laying period of hens. We determined the volume, concentration of spermatozoids, total amount of produced spermatozoids, pH ejaculate, colour ejaculate and morphological changes of sperm cell. The motility of spermatozoa of the cocks was 64.48% (Brown Leghorn), 62.25% (Oravka) and 57.51% (Brahma). The highest volume of ejaculate was found in Brown Leghorn (0.72 cm 3 ), the lowest in Brahma (0.49 cm 3 ). The White Leghorn and Oravka had an intermediate colour between the opaque and the creamy-white, the Brahma had opaque colour. The ejaculate pH for all the breeds ranged from 7.01 for Oravka to 7.04 for Brahma. The highest sperm concentration was in Oravka (2.59x10 6 /mm 3 ), the lowest in Brahma (1.91x10 6 /mm 3 ). We found higher number of morphologically abnormal sperm cells in Brahma (46.32%), in Brown Leghorn and Oravka had similar value (42.75%, respectively 42.88%). Keywords: Brown Leghorn, cock, ejaculate quality, Oravka, Brahma. 1. Introduction  Semen qualities of cocks determine the fertility of the male chicken while the female contributes the eggs [1]. Semen qualities of cocks usually accessed for artificial insemination purposes [2]. The assessment of semen quality characteristics of poultry birds gives an excellent indicator of their reproductive potential and has been reported to be a major determinant of fertility and subsequent hatchability of eggs [3]. A morphological examination of spermatozoa is one of important qualitative parameters of ejaculates. An increased percentage of  * Corresponding author: Cyril Hrnčár, + 421 37 6414744, Cyril.Hrncar@uniag.sk morphologically modified sperm cells may result in impaired fertility [4]. A decrease in fertility and the occurrence of pathological sperm cells may be markedly influenced not only by chemical and physical factors but also, and above all, by stress and age of males [5]. The aim of this study was to compare qualitative and quantitative parameters of ejaculates collected from cocks of selected chicken breeds (Brown Leghorn, Oravka, Brahma). 2. Materials and methods Ejaculates were sampled from 5 cocks of three breeds: Brown Leghorn, Oravka and Brahma. Each adult cock was placed into one cage and fed a complete feed mixture. Nutritional value of diet