Volume 20(2), 2021

Abstract. Domestic cattle descend from the aurochs, a species of wild animals, inhabiting forests of Europe and Asia in the past. The results of genetic studies allow concluding that the world cattle population originate from 80 female aurochs domesticated in today's southeastern Turkey. After 10,500 years the worldwide bovine population has exceeded 1.4 billion, with two subspecies: taurus cattle (Bos taurus) and zebu cattle (Bos indicus). The former was first scientifically described by Linnaeus, who in 1758 proposed its name, used until now. The processes of cattle domestication and improvement have led to more than 1000 distinct breeds. During the last two centuries several kinds of classification have been developed in order to identify cattle breeds. Several criteria have been used, such as basic cranial type, length of the horns, skull shape, degree of domestication, production purpose, type of ancestral aurochs, geographic distribution, place of breed origin, population size, growth performance, biochemical polymorphisms and molecular-genetic methods. At present the attention of cattle farmers around the world has focused on the most productive improved breeds at the expense of less productive local ones. Modern methods, such as artificial insemination and embryo transfer, have allowed unlimited spread of breeding material around the world. This way, it has become possible to use reproductive material of different cattle breeds on an unprecedented scale in many countries. At present, many of the latter have disappeared, or their population is on the verge of extinction.

Abstract. The aim of this study, conducted under identical environmental conditions and the stanchion barn housing system, was to compare milking performance traits and somatic cell count in milk of daughters sired by Holstein-Friesian Black-and-White bulls from various origin groups. Cows were divided into three groups depending on the region of sire's origin, i.e. Polish bulls, bulls from other European countries (the Czech Republic, France and Germany) and bulls from the USA. Analyses were conducted applying the following experimental conditions: the age group of cows (primiparous vs. multiparous), stage of lactation (≤ 40 days, from 41 to 100 days, from 101 to 200 days and > 200 days) and season of the year (spring, summer, autumn and winter). Results of this study indicate that at the stanchion barn housing system of dairy cows in order to increase milk yields the use of semen from bulls of imported Holstein-Friesian Black-and-White bulls seems to be beneficial. However, daughters of US bulls may be prone to elevated somatic cell counts in milk. In turn, cows sired by Polish bulls can be characterised by favourable milk solids contents.

Abstract. Folic acid has multi-faceted effects on the body. Its biological activity ensures genome stability and the normal course of the cell cycle. A deficiency of this acid can lead to serious consequences for health and life. Folic acid is the most oxidized form of folates taken with food. Folic acid is not produced in horses and must be ingested with food. Its bioavailability is also affected by environmental factors. The aim of the study was to analyse the content of folic acid in the blood serum of Polish Konik horses kept in a free-roaming herd system and a stable system. The folic acid concentrations in all horses were within the normal range of reference values for the species. Higher folic acid concentrations were noted in the free-roaming horses. Variation in the content of folic acid in the serum of stabled horses was higher than in the free-roaming horses. The management system was not found to significantly affect the serum content of folic acid in the horses.

Abstract. Acipenser gueldenstaedtii is recorded for the first time from the Euphrates River, west of Iraq. The species has not previously been mentioned as introduced to the Tigris-Euphrates River basin. There are two possibilities for this occurrence, first, the natural dispersal from adjacent Turkey and second, the aquaculture introduction. Both possibilities were discussed. Confirmation for the origin of the sporadic appearance of individuals of this species will wait for the appearance of more specimens in the inland waters of Iraq.

Abstract. The aim of this study was to analyse the effect of pepper (Capsicum annuum L.) oleoresin (PO) and rosemary (Rosmarinus officinalis L.) extract (RE) on the quality of ground pork (m. longissimus dorsi). Vacuum-packaged pork samples were cold-stored for 4 weeks. The quality of meat without additives and with the addition of PO (0.4 and 0.2 g · kg^–1 meat) and 4% RE (0.6 and 0.3 g · kg^–1 meat) was evaluated. The pH of vacuum-packaged ground pork decreased during 4 weeks of storage in all experimental groups. The rate of lipid oxidation and changes in the colour and sensory properties of stored meat were determined by the type and quantity of natural antioxidants. Rosemary extract added at 0.6 g · kg^–1 meat was the most potent inhibitor of lipid oxidation. Pepper oleoresin added at 0.4 g · kg^–1 meat had the most beneficial influence on colour intensity evaluated instrumentally and colour desirability evaluated visually. Pork containing RE added at 0.3 g · kg^–1 meat was characterised by the most desirable aroma and taste after storage.

Abstract. The aim of the study was to analyze the body weight of different color varieties of breeding mink and to assess the relationship between the body weight of females and the reproductive indexes obtained. The research material consisted of 3499 one-year-old American mink females of five color varieties: White Regal, Standard Black, Pearl, Silverblue and Black Cross. Six body-weight ranges of female mink were distinguished. The following were analyzed within each range: pregnancy length, fertility, average number of kits born in a litter, average number of kits born alive in a litter. It was also examined whether there was a relationship between the color variety and the average body weight of females attained during the pre-mating body condition adjustment. There were statistically significant differences in the body weight of the analyzed color varieties of mink. It was also found that the body weight of females obtained in the period of breeding preparation influences the resulting reproductive performance. Higher body weight positively influences fertility, while animals of an average body weight produce larger litters of kits.