Many of the methods used to stain semen result in very pronounced coloring of the sperm, but unfortunately they do not distinguish their individual s

Hatching results depend on the biological value of the eggs and on factors affecting the development of the embryo during incubation, as well as the conditions in which the eggs are kept between being laid and being placed in the incubator. Numerous studies conducted in Poland and other countries indicate that the suitability of eggs for hatching and their biological value are determined by genetic factors (mainly the origin of the birds) as well as environmental factors. Hatching eggs are primarily subject to assessment of external characteristics. The most important characteristics determining whether eggs are suitable for incubation are their weight, shape, structure and eggshell condition, as proper structure is a fundamental condition of satisfactory hatching results. Egg weight is highly dependent on genetic factors, as evidenced by the high heritability coefficients of this trait. Assessment of the hatching eggs weight is important because the weight of the hatchling is positively correlated with the egg weight. Works clearly confirm the effect of genotype on the physicochemical features of eggs, including the weight of the egg, yolk and eggshell. The eggshell plays an extremely important role in eggs used for reproduction. Eggshell quality traits are determined by both genotype and non-genetic factors, including the layer hen age and the diet, particularly the amount, form and availability of calcium. An important factor affecting the hatching process and quality of chicks is egg storage.

This study was an attempt to evaluate sperm chromatin structure in the semen of insemination boars. Preparations of semen were stained with acridine orange, aniline blue, and chromomycin A3. Abnormal protamination occurred more frequently in young individuals whose sexual development was not yet complete, but may also be an individual trait. This possibility is important to factor into the decision regarding further exploitation of insemination boars. Thus a precise assessment of abnormalities in the protamination process would seem to be expedient as a tool supplementing morphological and molecular evaluation of semen. Disruptions in nucleoprotein structure can be treated as indicators of the biological value of sperm cells.

Introduction The fertilisation capacity of semen can be evaluated in a number of ways, including analysis of sperm motility (Froman and Feltmann, 1998), live/dead analysis and morphological evaluation (Łukaszewicz et al., 2008). However, it is