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Strategie oplozování u ryb s vnějším oplozením
SIDDIQUE, Mohammad Abdul Momin
Morphological properties, species specific differences, development, and function of egg envelopes are of importance for a better understanding of fertilization strategies as well as for captive reproduction. We reviewed morphology and the developmental stages of egg envelopes, mechanism of polyspermy block, and also the role of micropyle and cortical granules in polyspermy block for acipenserid eggs. The structure of the egg envelope is similar among the acipenserids, comprising an external envelope (thecal cells, basal lamina, and follicular epithelium), a five-layered oocyte envelope (adhesive layer, alveolar layer, epilayer, and zona radiata externa and interna) and a layer of oocyte matrix and cortical granules. The development of acipenserid egg envelope within the ovary comprises five stages, with further changes following fertilization. Moreover, we standardized the terminology used to describe the egg membranes which can minimize the confusions and be helpful for future work on acipenserids eggs as well as for other fish species. The sperm to egg ratio (required to fertilize eggs) and effects of pre-incubation of eggs in freshwater before fertilization were studied to standardized fertilization protocols for sterlet Acipenser ruthenus. Pre-incubation time had no effect on fertilization success at 430,000:1 and 43,000:1 sperm to egg ratios, while it was significant at the 4300:1 and 430:1 ratios. The use of adequate experimental suboptimal sperm to egg ratio revealed a positive effect of pre-incubation time, such that at the 430:1 ratio, 0.5 min pre-incubation increased the fertilization rate than 10 min. Transmission electron microscopy showed that pre-incubation of eggs in water for <10 min did not trigger a cortical reaction, suggesting that a low sperm to egg ratio 0.5 to 1 min pre-incubation of eggs in freshwater prior to fertilization can enhance fertilization rate of sterlet (minimally do not change fertilization). The effects of pre-incubation in seawater and the duration of egg receptivity were determined for fresh and over-ripe sea bass eggs. Our results revealed a significant effect of pre-incubation time for both the fresh (P < 0.01) and over-ripe eggs (P < 0.01). The fresh eggs had a higher fertilization success than over-ripe eggs. Fertilization success of eggs significantly declined for both of these treatments after 3 min of pre-incubation clearly indicated that sea bass eggs are able to be fertilized by sperm for up to 3 min after release into seawater. Effects of pre-incubation of eggs and activation medium on the percentage of eyed embryos for Ide Leuciscus idus were examined. At the eyed-egg stage, pre-incubation time was significant for the freshwater activation medium (P < 0.001), such that the percentage of eyed embryos declined across the pre-incubation time gradient. Activating medium had a significant effect on the percentage of eyed embryos for each pre-incubation time (P < 0.05). More precisely, freshwater produced the lowest percentage of eyed embryos at all pre-incubation times, whereas saline water and Woynarovich solution produced the highest percentage of eyed embryos at 0 s and 30 s before incubation. Examination of sperm traits showed no impact of activating medium on computer assisted sperm analysis parameters. Our results suggested that saline water or Woynarovich solution improve fertilization rate in Ide during fertilization. In conclusion, this thesis provides basic knowledge on gamete biology, role of egg receptivity period, effects of pre-incubation of eggs and different activating medium which can be useful to understand the fertilization strategies of different externally fertilizing fishes as well as standardize their fertilization protocol for captive reproduction.
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Effects of hormonal treatment during artificial reproduction to produce to fingerlings of weatherfish (Misgurnus fossilis)
HOUDA, Ondřej
In this M. Sc. thesis, the influence of selected commercially available hormonal preparations based on hCG (Pregnyl, Chorulon) and GnRH-a with dopamin inhibitor (Ovopel, Dagin, Ovaprim) and their benefits were studied, compared with homogenate of carp pituitary (CPE), during controlled reproduction of weatherfish (Misgurnus fossilis, Linnaeus, 1758) in artificial conditions on the quality of the produced fry. The goal of this thesis was assess the suitability of individual commercially produced hormonal preparations for controlled reproduction of weatherfish and the possibility to replace with them unstandardized use of homogenate of carp pituitary. It was found that use of various hormonal preparations and dosage may to in some extent affect hatchability and survival rate of larvae (fry), the size of the yolk sac of larvae, and the amount of energy deposited in body tissues of larvae. However, demonstrable difference in studied parameters for the application of different preparations on the different hormonal basis (hCG versus GnRH) was not reported. The highest rate of hatching larvae (93.3 ? 3.8%) was observed in the groups treated with preparation Pregnyl 3000 IU - kg-1. In terms of overall survival of the larvae (from deployment of hatched eggs until the end of the experiment) have proven to be the most effective medication Pregnyl 3000 IU - kg-1 (69.9 ? 12.1 %) and Dagin (60.56 ? 11.71 %). Within the thesis has been demonstrated no relationship between hormonal treatment used and the growth of larvae (in terms of achieved total length of body and dry weight). The amount of energy deposited into the body tissues of larvae (gross calorific value) was comparable in all groups, except Dagin preparation, which was recorded impairment losses. For the best, most effective and commendable for control of reproductive hormone preparation carp pituitary homogenate replacing the terms of the assessed indicators can be seen the preparation based on hCG and that is Pregnyl at a dose of 3000 IU - kg-1.
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Fertility assesment of sows after cervical insemination and intrauterine insemination
BRÁZDOVÁ, Ivana
The objective of the thesis was to analyse the reproductive traits of sows on a particular farm with regard to the method used, as observed during the period of one year. The highest rate of live-born piglets per the first litter (12.4) was reached in nucleus breeding. Regarding the mating method, the highest number of piglets born in the first litter (12.7) was reached through natural mating, followed by intrauterine insemination (12.3) and cervical insemination (11.6). During the one-year period, the rate of successful conception at first service was 83.3 per cent of sows in case of intrauterine insemination, 80.6 per cent of sows in case of natural mating and 79.2 per cent of sows in case of cervical insemination. When calculating the number of all born piglets per 100 inseminations, it was found out that 1 028 piglets were born in case of intrauterine insemination, 1 026 piglets in case of natural mating and only 921 piglets were born in case of cervical insemination, that is 107 (or 105) less. The highest number of born piglets (11.8) was reached in sows serviced when they were 256270 days old, followed by sows serviced when 241255 days old (11.1 piglets). With the gestation length under 114 days, the sows farrowed 1.2 piglets more than when the gestation length was over 115 days. With the weaning-to-conception interval under 5 days, the sows farrowed more (12.4) piglets than with the weaning-to-conception interval lasting over 6 days, which resulted in only 11.9 piglets being born.
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Analysis of influences on reproduction of sows
BRÁZDOVÁ, Ivana
The aim of the bachelor thesis is to analyse the reproductive traits of sows, namely their fertility, the lactation performance as well as the influences that affect them. The reproductive traits are in particular influenced by the animals? breeding affiliation, heterosis, the age and weight of the sow, the litter size and number, the farrowing index, the heritability of the boar, nutrition and the technology of stabling. The thesis deals with these aspects and clarifies them. Furthermore, it provides a description of the pig maternal breeds in which these reproductive traits were monitored, and focuses on controlled reproduction as well.
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