This article contains a review of some genes involved in respective stages of gonadal development in mammals: formation of gonadal ridge and then differentiation of testis and ovaries. The newest research gives evidence that many genes take part in these processes, except SRY – switch of development, also: LHX1, LHX9, SF1, GATA4, WT1, SOX8, SOX9, DAX1, WNT4, FOXL2, DMRT1. The article presents actions and interactions between them.

The experiments have been carried out with 7 dairy cows (of the lowland black-white race, 3-6 years old and body weights 490-580 kg) in two groups. The animals in experimental group [4 cows] and control group [3 cows] was in 1-2 days after calving. The uterus motility was recorded with balloon method by way of air transmission. After registration initial curve (30 min.) in cows the experimental group was intrauterine administrated 50 mg of beta – adrenergic blocker – propranolol (Uterotonic – Polfa) in 50 ml 0,9% NaCl and have been determined uterus contractions during 90 min. In this time was intravenous application of adrenaline (1 ml 0,1%). Similar investigations have been carried out also in second group (control), with has not received propranolol – intrauterine administrated only 50 ml 0,9% NaCl. It has been found that in cows of the experimental group after intrauterine infusion propranolol was improved motility of uterus – amplitude, frequency of contractions and tonus of myometrium increased. Any changes in control group were not observed.

The purpose of a study was to compare the water activity of selected chocolate assortments stored at different temperatures, in order to determine if the factor analyzed affects the microbiological stability of the products. The experiment was performed on six chocolate assortments obtained directly form the commercial production line. The products were stored for 7 months at three different temperatures: 2-4, 20 and 30 ºC. Their water activities and microbiological parameters were monitored in course of the experiment. Significant, proportional to the storage temperature, decrease of water activity was noted in course of the study. At the end of experiment however, all the products followed the legislated microbiological criteria and did not contained the detectable levels of microorganisms. The results suggest that suitable level of water activity has higher impact on microbiological stability of the chocolate products than as potent extrinsic factor as temperature of storage.

The studies on the effect of cut-up degree on the microbiological status of herring products were not performed as far. The purpose of a study was the comparison of the microbiological stability of commercial herring assortments with variable cut-up degree: „Fantazja” salad (high degree), 2) herring fillet in oriental sauce (low degree), 3) home-made herrings with lemon (non cut). The products examined were stored under refrigeration (temperature 4 ± 1°C) for 8 weeks. Their microbiological estimators, as well as water activity and pH values were controlled at weeks 0, 2, 4, 6 and 8. The significant variation of microbiological parameters was noted in the material studied in course of storage. The aforementioned variability seemed to reflect the raw material composition (percentage of herring meat, kind of organic acid applied) and the physico-chemical properties of products, and particularly their water activity. However, there was no evident effect of cut-up degree on the microbiological stability of herring assortments.

The current study was designed to evaluate the counts of selected caecal microbial populations after addition of humic and fatty dietary supplement Humobentofet (HBF). Ten California White rabbits aged 6 months each were slaughtered. Their caecal contents diluted with buffer were the control samples of the study, and to the second part of the samples was added HBF(1g per sample). The samples were incubated in anaerobic conditions in the shaking water. The total bacterial counts, the counts of cellulolytic bacteria, Escherichia coli, Clostridium perfringens, moulds and yeasts in the caecal content were established at the beginning, 6^th and 24^th hours of fermentation. The decrease of the total bacterial counts, moulds and yeasts was observed in the samples with HBF (6,739 log x g^-1 and 4,637 log x g^-1 caecal content, respectively) in comparison with control (8,187 log x g^-1 and 5,050 log x g^-1) at 6^th hours (P≤0,05). Only small, non insignificant statistically decrease of the number of the cellulolytic bacteria, which are the predominant bacteria in caecal fibre digestion, and E. coli, was observed in comparison with control. The presence of Cl. perfringens was not observed during the experiment.

The purpose of the study was to determine the influence of various types of water environment and hydrostatic pressure in various temperatures and with or without participation of daylight on embryogenesis and hatching of miracidiums of liver fluke. The study materials were the eggs of Fasciola hepatica. The influence of temperature (21±1 ^oC, 24±1 ^oC, 30±1 ^oC), daylight and darkness on embryogenesis in eggs situated in physiological liquid, tap water, puddle water, in 1% water solution of ammonium phosphate and potassium oxide mixture, which is use for fertilization of meadows, was observed. For determination of developmental stages was used the Kowalska’s embryogenesis key [1990]. The principial influence of temperature on development of eggs of Fasciola hepatica was observed. With the temperature growth, decrease the time differences, which results from influence of another factors on embryogenesis. The results of trial obtained in vitro suggest, that agrotechnical operations (fertilization of meadows and pastures) probably have an effect on embryogenesis and population of miracidiums of Fasciola hepatica. It needs a verification in further field trials.

The purpose of the study was to examine the influence of ditiocarb sodium (DTC) at a dose of 20 or 200 mg/kg on lead distribution injected once in sub-toxic dose (2 mg Pb/kg i.v.), as a solution of lead acetate. The study was conducted on clinically healthy, mongrel rabbits, divided into 7 groups. Two groups were administered lead acetate; four groups lead acetate and DTC in low or high dose. Control group was intravenously injected with 0.9% saline solution. After euthanasia, at 4^th or 72^nd hour after injection of DTC samples of brain, fat, muscles, liver, kidneys, urine and blood were taken and mineralized dry in a muffle furnace at 450 ºC. Lead was determined by the atomic spectrophotometry on a Pye Unicam apparatus. Clinical observation and histo- and anatomopathological examination simultaneously there were performed. It was proved that intravenously injected DTC simultaneously with lead acetate makes relevant changes in lead distribution in rabbit’s organism. As an effect of DTC-metal interaction brain, adipose and muscles tissue levels of lead raise which are reflected in the increase of toxicity, what was proved by clinical and histo- and anatomopathological examination.

Cocaine- and amphetamine-regulated transcript (CART) is recently discovered peptide that has been involved in the control of appetite in mammals. The majority of peptides have been found in the brain, but CART was also demonstrated in gut and some endocrine glands like pituitary, pancreas and adrenals. In the present study we examined the effects of CART, using CART (55-102), on the structure and function of the thyroid gland. Single administration of CART caused dose dependent decrease of T4. In prolonged experiment we observed inhibition of pituitary-thyroid axis on the level of pituitary (rTSH concentration decrease), as well as, on the thyroid level (T4 and T3 concentration decrease). Stereometric analysis shows dose dependent decrease in epithelium volume associated with decrease in colloid volume. Our results suggest important role of CART in regulation of pituitary-thyroid axis function and thyroid gland structure.

9 pigs underwent the experiment. The animals were all sexually mature. In the group of the experimental animals - in 6 pigs – the experimental procedure was performed which depended on lateral extirpation of the specific complexes of the mammary gland with leaving the skin. The remaining pigs constituted the control group. All animals were kept alive for 21 days, after which they were put to sleep and the following material was taken for further examination: the brain stem, the thoracic-lumbar-sacral part of the spinal cord with adequate nerve ganglia and the following ganglia and plexuses of abdominal and pelvic cavity: celiac and pelvic. The material was elaborated on histologically. The experiments conducted on experimental and control animals caused the occurrence of deep degenerative lesions in the nerve cells of the central and the peripheral nervous system, which gave rise to establishing of the localization of the parasympathetic nerve cells innervating the mammary gland in pig. The results of the study and the localization of the retrograde changes allow stating that the parasympathetic nerve cells reaching the mammary gland are of multi-source origin. They come both from the central and peripheral nervous system.

Activity of aspartate aminotransferase, alkaline and acid phosphatase of wild boar/domestic pigs hybrids semen in annual cycle. The object of the study was to determine the biochemical properties of the semen of wild boar/domestic pig hybrids, as well as changes in these properties over the annual cycle. Over the 14 months study period in 257 ejaculates sampled from 4 fertile hybrids aspartate aminotransferase (AspAT), alkaline and acid phosphatase were determined. Generally activity of this enzyme are similar to those of domestic boars and wild boar. It was found no effect of the duration of light period on the activity of AspAT and alkaline phosphatase, but activity of acid phosphatase was significantly correlated with the duration of light period.