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The aim of the study was to analyse the annual changes in the concentration of free triiodothyronine, progesterone and testosterone in the serum of prepubertal red deer males and females. Blood was collected monthly from 8 stags and 8 hinds for a period of one year, beginning in November. Hormone concentrations were determined using an immunofluorescence method (TR-FIA). Monitoring of the duration of the prepubertal period, based on the progesterone concentrations in females and testosterone concentrations in the males, suggested that the prepubertal period ended in September in both sexes. The experiment revealed the annual rhythm in free triiodothyronine (FT3) secretion, with significantly higher concentrations in the winter-spring period in comparison with summer-autumn in both, males (P < 0.01) and females (P < 0.05). The results showed that the season considerably influenced the intensity of FT3 secretion in prepubertal red deer and that the secretion dynamics in both sexes were similar, however, the concentrations in the males reached higher levels than in the females in each season and across the whole experiment
Oocytes attain developmental competence as a result of their maturation, which gives them nuclear and cytoplasm maturity. In physiological conditions the developmental competencies of oocytes are achieved in the environment of ovarian follicles before ovulation. In in vitro conditions, however, this occurs in a culture medium which, for porcine oocytes, is generally a TCM-199 and NCSU-23 medium supplemented in specific proportions of amino acids, proteins, hormones, growth factors and follicular fluid. The specific nature of porcine oocytes is that it takes them almost twice as long to obtain nuclear and cytoplasm maturity as in the case of other species of farm animals. Moreover, a common problem of in vitro maturation is the absence of normal cytoplasm maturity. Irregularities in translocation of mitochondria in the cytoplasm and transferring ions signals may also be observed. The absence of cytoplasm maturity of oocytes on the other hand reduces the possibility of male pronucleus (MPN) formation and development of zygotes to the blastocytes stage. Therefore, the latest studies concentrate on formulating methods of in vitro culture which enable normal development of porcine oocytes both in their nuclear as well as cytoplasm maturity.
The aim of this study was to determine circannual changes in the serum concentrations of thyroxine, calcitonin and parathormone in mature and immature red deer females. Blood samples from 8 hinds were collected monthly for 26 months. Secretions of thyroxine and calcitonin showed circannual rhythms with significantly higher levels in the immature hinds compared to the mature animals (p<0.05). For thyroxine, the concentration was higher in the winter/spring period than in summer/autumn (p<0.05), while for calcitonin the concentration profile was the opposite (p<0.05). The concentration of parathormone was significantly higher in summer/autumn that in the other months of the experiment (p<0.01). These results may indicate that the hormones investigated may be involved in the regulation of seasonal reproductive activity and in processes contributing to entering puberty in red deer females.
This study was designed to determine the degree and type of bacterial contamination in boar semen (79 ejaculates from Large White and Landrace boars) and its consequences for sperm quality during storage (27 extended semen samples, 16°C for five days) under practical conditions of artificial insemination (AI). The results revealed the presence of aerobic bacteria in 99% of the ejaculates (from 80 to 370 ×106 colony-forming units/mL). Most of the ejaculates contained two or three bacterial contaminants, while the Staphylococcus, Streptococcus, and Pseudomonas bacterial genera were most frequently isolated. Also detected were Enterobacter spp., Bacillus spp., Proteus spp., Escherichia coli, P. fluorescens, and P. aeruginosa. In general, the growth of certain bacterial types isolated prior to semen processing (Enterobacter spp., E. coli, P. fluorescens, and P. aeruginosa) was not discovered on different days of storage, but fluctuations (with a tendency towards increases) were found in the frequencies of Bacillus spp., Pseudomonas spp., and Staphylococcus spp. isolates up to the end of storage. Semen preserved for five days exhibited decreases in sperm motility and increases in the average number of total aerobic bacteria; this was associated with sperm agglutination, plasma membrane disruption, and acrosome damage. We inferred that, due to the different degrees and types of bacterial contaminants in the boar ejaculates, the inhibitory activity of some antimicrobial agents used in swine extenders (such as gentamicin sulfate) may be limited. Because such agents can contribute to the overgrowth of certain aerobic bacteria and a reduction in the quality of stored semen, procedures with high standards of hygiene and microbiological control should be used when processing boar semen.
The objective of the study was to determine selenium status and its distribution in the organs of free living foxes from selenium deficient areas of north-western Poland. Samples of organs harvested from 40 foxes shot during the 2008-2009 hunting seasons served as experimental material. Selenium concentration in the organs was determined spectrofluorometrically. Selenium distribution in tissues depends largely on its dietary content. Our study indicated that concentrations of selenium in the examined organs followed the order: kidney>liver>spleen>lung>heart and kidneys were the organ with the highest retention of this element. Mean selenium concentration in fox kidneys was 0.60 ± 0.15 μg/g wet weight. Several times less selenium on average was found in the liver (0.27 ± 0.09 μg/g w.w.), lungs (0.17 ± 0.06 μg/g w.w.), spleen (0.19 ± 0.06 μg/g w.w.) and heart (0.13 ± 0.05 μg/g w.w.). All the animals studied were deficient in selenium.
The aim of this study was to determine serum selenium concentrations in Polish Konik horses residing in the Odra Delta Nature Park (Poland) and to evaluate the activity of glutathione peroxidase and Se content in testes of this horse breed. In over 95% of cases, serum Se concentration was below the optimal range, and none of the horses examined was deficient in this trace element. The lack of Se deficiency in the animals examined suggests however, that the Polish Konik horses have a natural ability to the optimal use of nutrients available in their life area. Testicular content of Se and GSHPx activity in the colts was higher than those found in stallions, and a positive relationship between these antioxidants was demonstrated. The differences in Se contents and GSHPx activities in testes between colts and stallions suggest that selenoenzymes play important roles during the puberty of male horses.
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