Evaluation of sperm chromatin structure in boar semen

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

Comparative analysis of the external and internal egg quality in different pure chicken breeds

The present study was conducted to evaluate some parameters of external and internal egg quality of some pure dual chicken breeds.  A total of 500 eggs (100 eggs from each breed) were collected to study for egg (weight, shape index), albumen (weight, percentage), yolk (weight, percentage) and shell (weight, percentage, thickness, strength) quality. The eggs were analysed in the laboratory of Department of Poultry Science and Small Animal Husbandry of Slovak University of Agriculture in Nitra. The results showed that the egg weight and egg length of New Hampshire were significantly higher (P0.05). Differences in albumen weight, albumen percentage, yolk weight and yolk percentage of tested dual chicken breeds were statistically no significant (P>0.05). Albumen height was significantly higher (P0.05) in egg shell thickness and strength

Development of Chicken Embryos in Double-Yolk Eggs: Fertility, Hatchability, Embryo Malposition and Time of Embryonic Mortality

Fertility rate and hatchability rate are low for all types of double-yolk (DY) eggs in comparison to single-yolk eggs (SY), but these parameters also depend on the number of developing embryos in the egg. The hatchability rate of double-yolk eggs containing two developing embryos (DY2F) is vastly lower than in the case of double-yolk eggs containing only one embryo (DY1F). The aim of the study was to determine the differences between egg fertility rate, hatchability rate, time of embryonic mortality, and embryo malposition during incubation in three types of eggs from Hy-Line Brown hens: SY, DY1F and DY2F. In addition, the quality of the hatched chicks was assessed using the Pasgar©score. Following a 21-day incubation, chicks were obtained from DY1F and SY eggs. No chicks were obtained from DY2F eggs, although the embryos in these eggs developed up to the late stage of incubation. Early (≤7 d of incubation), middle (8–14 d), and late (≥15 d) embryonic mortality was significantly higher in DY eggs than in SY eggs. The embryonic mortality rate during early incubation was the same for DY1F and DY2F eggs, but middle and late embryonic mortality were significantly higher for DY2F eggs. Based on evaluation of embryo position according to Landauer, only three types of malposition that could potentially lead to embryonic death were noted. There were fewer malpositioned embryos in double-yolk eggs containing one embryo. Quality assessment of chicks (Pasgar©score) showed no differences between chicks hatched from eggs containing one yolk and those hatched from double-yolk eggs with one developing embryo, but chicks from double-yolk eggs were significantly heavier. The results of the research will contribute to a better understanding of the development and mortality of embryos in double-yolk eggs

Wpływ warunków przechowywania na wybrane cechy jaj pochodzących od kur rasy zielononóżka kuropatwiana

Celem pracy było porównanie wybranych cech jaj pochodzących od kur rasy Zielononóżka kuropatwiana w zależności od czasu i temperatury ich przechowywania. Materiałem doświadczalnym były jaja uzyskane od 50-tygodniowych kur tej rasy. Badania przeprowadzono na próbie 60 jaj, podzielonych losowo na trzy grupy doświadczalne. Grupę pierwszą oceniano jako jaja świeże, drugą grupę stanowiły jaja przechowywane w chłodziarce w temperaturze 6 °C przez 20 dni, a trzecią grupę jaja przechowywane przez 20 dni w temperaturze 24 °C. Oceniano jaja w całości, a następnie po ich wybiciu na szklaną płytkę. Przechowywanie jaj przez 20 dni w temperaturze 24 °C znacznie zintensyfikowało procesy ich starzenia się. Zwiększone parowanie wody z treści jaj w tej temperaturze wpłynęło na zwiększenie wysokości ko-mory powietrznej, istotne zmniejszenie masy jaj (z 32,55 do 27,93 g), zmniejszenie zawartości białka ogólnego (z 32,55 do 27,93 g) oraz obniżenie jednostek Hougha (JH) białka i wzrost zasadowości białka. Zaobserwowano istotnie większą (p ≤ 0,05) masę żółtka w jajach przechowywanych przez 20 dni w temperaturze 24 °C w porównaniu z masą żółtka jaj przechowywanych w temperaturze 6 °C, co było spowodowane przenikaniem wody z białka. Jednocześnie zaobserwowano istotne (p ≤ 0,01) zwiększenie indeksu żółtka oraz nieznaczny wzrost wartości pH – z 6,01 do 6,62. Temperatura 24 °C i wydłużony czas przechowywania jaj wywarły niekorzystny wpływ na dynamikę zmian zachodzących w ocenianych jajach, co przyczyniło się do utraty ich świeżości.The objective of the research study was to compare some selected characteristics of eggs derived from hens of the Green-legged Partridge species depending on the time and temperature of storage. The experi-mental material comprised the eggs derived from 50 weeks old hens of this species. A sample of 60 eggs were analyzed; the eggs were divided randomly into three experimental groups. The eggs in the first group were assessed as fresh eggs, the eggs in the second group were stored in a refrigerator at a temperature of 6 °C for 20 days, and the eggs in the third group were stored at a temperature of 24 °C for 20 days. At first, the whole eggs were assessed; next, the eggs were spilled onto a glass plate and, then, assessed. The storing of eggs for 20 days at a temperature of 24 °C significantly intensified the processes of their ageing. An increased evaporation of water from the eggs caused the height of air cell to increase, the weight of eggs to significantly decrease (from 32.55 to 27.93 g), the content of total white to decrease (from 32.55 to 27.93 g), the IH of white to drop, and the alkalinity of white to grow. Significantly (p ≤ 0.05) greater yolk weight was observed in the eggs stored for 20 days at 24 °C than in the eggs stored at 6 °C, which was due to penetration of water from the albumen. At the same time, it was reported a significant increase (p ≤ 0,01) in the yolk index and a slight increase in the value of pH from 6.01 to 6.62. The temperature of 24 °C and the extended time of storing the eggs negatively affected the dynamics of changes occurring in the eggs assessed and this fact caused that the eggs lost their freshnes