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A study was carried out to compare the efficiency of vaginal electrical impedance with serum progesterone profile, cytological examination and clinical findings. Vaginal electrical impedance values varied at the different stages of the estrous cycle, with the highest value during the transition into estrous and the lowest in diestrus (P < 0.05). There was a negative statistical correlation between serum progesterone values and the impedance values (36%) (P < 0.001). Vaginal electrical impedance was a faster and cheaper method than progesterone assessment. It was more reliable than vaginal cytology and clinical evaluation. In conclusion, a combination of vaginal electrical impedance measurements and progesterone evaluation was a more useful method for determination of the optimal breeding time in bitches.
The observation was carried out in a group of 70 female cattle in the course of two years. The animals were kept in suckler herds. They were provided with pasture grass and maize silage indoors during the grazing season and with forage ration (silage and hay) in winter. The aim of the study was to assess the effect of year (2001 and 2002), season (spring and autumn), breed (Aberdeen Angus AA, Beef Simmental BS, Blonde d'Aquitaine BA, Charolais CH, Hereford HE and Limousin LI) and reproduction cycle (pregnant heifers PH, non-pregnant heifers NPH, pregnant cows PC, non-pregnant cows NC and lactating cows with calves LCC) on some blood plasma parameters. Mean values of these parameters were following: Total protein 72.37 gl⁻¹ , glucose (Glu) 3.23 mmol∙l⁻¹, urea (Urea) 4.39 mmol∙l⁻¹, bilirubin (Bilir) 4.63 mmol∙l⁻¹, alkaline phosphatase (ALP) 1.02 µkat∙l⁻¹, asparate aminotransferase (AST) 1.29 µkat∙l⁻¹, gamma glutamyltransferase (GMT) 0.30 µkat∙l⁻¹, sodium (Na) 114.33 mmol∙l⁻¹, calcium (Ca) 2.30 mmol∙l⁻¹ and phosphorus (P) 1.99 mmolT1. Year affected TP, Glu, Bilir, ALP, AST (all p<0.01) and urea (p<0.05). Season affected TP, Glu, urea, Bilir, Ca, P (all p<0.01) . There were significant differences in urea, GMT, Ca and P between breeds. Reproduction cycle affected TP and Glu (p<0.05). It can be concluded that year and season affected the observed blood plasma parameters considerably more than breed or reproduction cycle.
To examine the changes in dentine microstructure in spotted souslik Spermophilus suslicus (Giildenstaedt, 1770) during pregnancy, parturition and lactation, we investi­gated 39 females from the Odessa region. Thirty females were dead-trapped in March­-July, 1987-1997, nine females (lactating or pregnant) were caught in April, 1996, injected with tetracycline as a time marker and kept in captivity during 14-47 days. Their litters survived from 1 to 29 days. We analyzed cross stained sections as well as cross ground sections of upper incisors. In the lactating sousliks both in nature and in captivity the daily layers formed in the course of pregnancy were followed by formation of a specific dentine pattern. The pattern consisted of alternating contrastive hypo- chromatic and hyperchromatic bands of about 30-50 n wide. The beginning of the pattern formation coincided approximately with parturition and the formation con­tinued during lactation. Therefore, the parturition-lactation zone could be the correct name for the pattern. In captured females no correlation between the duration of the pattern formation and the lifespan of their litters was found. The pattern was absent in immature and barren females. We found no changes in the dentine formation during pregnancy.
Salix myrtilloides L. is an endangered species whose western limit of range runs through Poland. The main aim of the study was to increase the knowledge on the ecology and biology of S. myrtilloides populations in the Polesie Lubelskie region (Eastern Poland) in order to create an effective protection program. An 80% decrease in its population was found in this area. Our study was conducted to identify the mechanisms responsible for the process of withdrawal of this species from its natural stands by determining whether the processes of generative reproduction (pollen viability and germinability, seed germination ability and dynamics) in the populations occur properly and by characterizing within- and among-population genetic diversity of S. myrtilloides, using ISSR (Inter-Simple Sequence Repeat) primers. The results confirmed that S. myrtilloides pollen viability was high (84.17±8.67), and so were the seed germination ability (76% of the total number of sown seeds/24 h) and dynamics. The within-population genetic diversity was quite high for this species and the inter-population genetic variation was of medium value (ΦPT=0.148). The condition of two populations, their genetic diversity and sex ratio as well as the correctness of the investigated reproductive cycle stages altogether give prospects for their survival. It seems to be very important to start conservation involving the reintroduction and reconstruction of S. myrtilloides populations in the Polesie Lubelskie region. The proposed method for restoration of S. myrtilloides resources would be possible if ex situ cultivation and in vitro methods were used.
The cycle of gonad development and related changes in the length structure and spatial-temporal distribution of ninespine sticklebacks (Pungitius pungitius L.) in Puck Bay were studied. Observations were carried out in the shallow shore zones, as well as in the deeper epipelagic zone of the Bay. Ninespine sticklebacks reproduce in the brackish environment of Puck Bay, breeding in its warmer, inshore zones. Reproduction takes place in the spring and summer months, from April to July. One female spawns several clutches of eggs during one breeding season. The average length of ninespine sticklebacks in Puck Bay was about 40 mm, and the sex ratio in the population was close to 1:1. However, both length structure and sex ratio were subject to local and periodic variations, resulting from possible breeding-related territorial divisions. Higher gonadosomatic indices in females in early spring represented the transition of fish to the advanced vitelligenous phase. The lowest GSI of males during the breeding season indicated the termination of spermatogenesis. The completion of spawning in August started a new process of gonad restoration to prepare the fish for the next breeding season.
The effects of the trematode Bucephalus polymorphus on the reproductive cycle of the zebra mussel Dreissena polymorpha were examined in mussel populations from the Drava River. The reproductive cycle was studied by histological examination of the gonads and quantified by an image analysing system to determine changes in volume of the entire visceral mass, gonads, digestive glands and in particular the volume of trematodes. Results confirmed that (1) gonads of D. polymorpha were affected by B. polymorphus infection more than any other organ and (2) development of cercariae in sporocysts of B. polymorphus coincides with host gonad maturation. This is the first study in which the image analysing system was used to determine the effect of trematodes on the reproductive cycle of D. polymorpha. Also, this is the first record of sporocysts of B. polymorphus in D. polymorpha in this part of Europe.
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