Duration Of Insemination Research Articles

Биотехнология воспроизводства и выращивания рыбопосадочного материала балхашской маринки (Schizothrax argentatus) в индустриальных условиях

Artificial reproduction is one of the most popular ways to preserve rare fish species. Researchers of the Balkhash branch of the Research and Production Center for Fisheries of the Republic of Kazakhstan carried out the reproduction and cultivation of Balkhash marinka at their own fish farm using a recirculating water supply system. There have been considered the technological methods of removing the marinka spawners from the natural environment, their pre-spawning maintenance in fish tanks, hormonal stimulation of spawning, intravital methods for selecting reproductive products, artificial insemination, incubation of eggs, growing viable material for stocking a native reservoir. The catch of the required number of spawners was carried out from the river Tokyraun (Northern Balkhash). After adaptation and quarantine, female species were exposed to 2x and 3x hormonal stimulation with acetonated carp pituitary. Males were injected once. Reproductive products were obtained from a female injected 3 times, after 15 hours; from a female 2x injected – after 21 hours. Duration of insemination for marinka was 2 minutes. The degluing process lasted 40 minutes with constant stirring and partial replacement of the solution. The eggs were incubated in Weiss apparatus, completely protected from light. With a high quality of reproductive products, the fertilization of eggs was 90%. The incubation time at a water temperature of 19.5-20.0 °C continued 3-4 days (60-78 degree days). The yield of prelarvae made 19-20%. Under industrial conditions, keeping the larvae lasted 4-5 days. When feeding marinka larvae, in order to increase their survival, it is advisable to use only decapsulated Artemia eggs. The juvenile period of development of Balkhash marinka began on the 30-35th day. Aller Aqua dry food was gradually introduced into the diet of fry. Under optimal abiotic and biotic conditions, the fry growth rate reached 0.075 and 7.32%/day. At the end of September marinka underyearlings with an average weight of 11.0 g were released into Lake Balkhash. The research results will serve as a theoretical and practical basis for the development of adapted technologies for the artificial reproduction of rare and endemic fish species and their introduction at fish farms.

Time-lapse monitoring of fertilized human oocytes focused on the incidence of 0PN embryos in conventional in vitro fertilization cycles

We aimed to investigate why the incidence of embryos derived from oocytes with no pronuclei (0PN) decreases using time-lapse monitoring (TLM) versus fixed-point assessment in conventional IVF cycles. We analyzed 514 embryos monitored with TLM 6–9 h after insemination and 144 embryos monitored using microscopic assessment 18–21 h after insemination. The primary endpoint of this study was the incidence of 0PN-derived embryos in short insemination followed by TLM. The secondary endpoint was the duration of insemination. As exploratory endpoints, we analyzed the blastulation rate and cryo-warmed blastocyst transfer outcome of embryos with early PN fading, whereby PN disappeared within < 20 h following the initiation of insemination. The incidence of 0PN-derived embryo reduced more significantly through TLM than through fixed-point observation. The microscopic assessment time was more significantly delayed in the 0PN-derived embryo than that in the 2PN-derived embryo. The embryo with early PN fading formed good-quality blastocysts, and their pregnancy outcomes were similar to those of other embryos. Most 0PN-derived embryos in the fixed-point assessment might have resulted from missed observation of PN appearance in the early-cleaved embryos. TLM or strict laboratory schedule management may reduce 0PN-derived embryos by reducing missed PN observations.

153 The effects of parity and oxytocin or prostaglandin F2α added to insemination doses on reproductive performance of pigs bred in summer

Summer is the least favourable season for swine reproduction, mainly due to long photoperiods and heat stress. Such conditions negatively impinge on the reproductive system of sows and boars, manifesting in debilitated uterine and gonadal function. This situation is exacerbated by the dilution of ejaculates in semen extender before AI. Consequently, there is a noticeable decline in piglet productivity of summer-breeding gilts and sows. The main goal of this study was to determine the effect of oxytocin (OX) or prostaglandin F2α analogue (PG) added to boar semen extender on the duration of insemination and reproductive performance of pigs bred in July and August. A total of 144 females (80 gilts and second-parity sows (G+SP) and 64 multiparous sows (M)) were divided into three groups (n=48 per group). The OX (11 G+SP and 37M) and PG (20 G+SP and 28M) groups were inseminated twice (at the onset of behavioural oestrus and 22-24h later) using semen supplemented with 20IU of OX or 5mg of PG, respectively; the controls (33 G+SP and 15M) were artificially inseminated with non-supplemented inseminate doses. Pregnancy was detected ultrasonographically on gestational day 42, and the number and viability of piglets were recorded at farrowing. Proportions were analysed using chi-square test (Brandt and Snedecor formula), and other numerical data were analysed using two-way analysis of variance and least significant difference test to determine the differences between individual mean values (SigmaPlot, Systat Software Inc.). The mean duration of first insemination was shorter (P&amp;lt;0.05) in M females (80±22s) compared with G+SP females (191±26s) inseminated with PG-supplemented semen, whereas the second insemination was shorter (P&amp;lt;0.05) in M females than in G+SP females artificially inseminated with OX-supplemented semen (93±15s compared with 192±28s). The mean pregnancy rate was lower (P&amp;lt;0.05) in control G+SP females (26/33; 85%) than in OX G+SP females (11/11; 100%). The farrowing rate was less (P&amp;lt;0.05) in control females (36/48; 75%) than in OX females (44/48; 92%), and it was less (P&amp;lt;0.05) in PG G+SP females (14/20; 70%) compared with PG M females (26/28; 93%). The M females in the OX group had more (P&amp;lt;0.05) stillborn piglets per litter compared with their G+SP counterparts (0.6±0.1 vs. 0.1±0.1). Overall, PG females had more (P&amp;lt;0.05) weak piglets per litter (1.2±0.2) compared with the control (0.5±0.2) and OX (0.6±0.2) groups. The present results reveal the occurrence of both beneficial and undesirable effects of PG and OX added to boar semen extender on reproductive performance of breeding pigs in summer. Addition of PG was associated with shorter first-insemination times in older sows compared with G+SP animals but also with lower farrowing rates in younger animals and an overall increase in the number of weak piglets at farrowing. Supplementation of OX was in turn associated with a shorter second insemination and higher pregnancy rates in young females but more stillborn piglets per litter in multiparous sows. The specific causative mechanisms of these associations remain to be elucidated.

EFFECT OF SPERM INSEMINATION DURATION ON IN VITRO FERTILISATION (IVF) PERFORMANCE IN GOATS

The objective of this study was to evaluate the effect of sperm insemination duration during in vitro fertilisation (IVF) on the cleavage rate of goat embryos. Goat oocytes were retrieved through the slicing of ovaries obtained from abattoir and laparoscopic oocyte pick-up (LOPU). For in vitro maturation (IVM), the collected cumulus oocyte complexes (COCs) were matured and then incubated overnight in CO2 (5%) incubator at 38.5°C for 24-27 hr (abattoir source) or 18-21 hr (LOPU source). Oocytes were partially denuded and co-incubated with post-thawed sperm with concentration of 1x106 sperm/ml. After 8-14 hr or 18- 24 hr of insemination, in vitro culture (IVC) of presumptive zygotes were further incubated in CO2 (5%) incubator at 38.5°C for preimplantation embryonic development. The cleavage of the embryos was observed and recorded daily under inverted microscope. The fertilisation rate with insemination duration of 8-14 hr (39.82%) was higher than that with 18-24 hr (33.59%); however, there was no significant difference (P&gt;0.05) between 2 groups of insemination durations. There was significant (P&lt;0.05) decrease as the embryo developmental stages increased. Generally, the embryo developmental rates of all stages for insemination durations of 8-14 hr were higher than that of 18-24 hr, which were 49.36 vs. 27.92%; 33.77 vs. 22.29%; 7.32 vs. 2.08% and 0.56 vs. 0.00% for 2-, 4-, 8-cell and morula, respectively. In conclusion, shorter insemination duration may be needed to improve the IVF performance in goats.

Size-dependent mating and gender choice in a simultaneous hermaphrodite, Bulla gouldiana

Simultaneous hermaphrodites are predicted to optimally divide resources between male and female function, which can result in both size-dependent mating behaviors and conflict between potential mates. Predicted strategies include size-assortative mating, conditional exchange of gametes, and mating patterns where relative size affects investment in each sexual role. This study investigated the effect of body size on the mating strategies of a hermaphroditic opisthobranch, Bulla gouldiana. Although individuals were spatially aggregated in the field with high levels of movement and size variation, there was little evidence for predictions. Laboratory experiments, however, revealed complicated effects of mass on the probability and duration of mating, as well as gender choice. Pairs were more likely to mate if they included at least one large animal, with the larger animal typically inseminating the smaller. When both individuals were large, they were more likely to each mate in both sexual roles by switching roles once. Although B. gouldiana did not usually alternate between sexual roles multiple times within mating events, paired individuals behaved similarly (neither or both mating as sperm donors) more often than expected by chance. This suggests some level of reciprocity, which is unlikely to be conditional given rates of unilateral mating. When the larger member of the mating pair inseminated the smaller, the duration of insemination increased with the size of the smaller sperm recipient. Copulations lasted longer in pairs that switched sexual roles than in those that did not switch roles. This study suggests that variation in body size can lead to size-dependent mating patterns, but only some of the patterns in B. gouldiana support theoretical predictions. We review other studies that have addressed similar issues, providing inconsistent mating patterns in sperm-storing hermaphrodites.

Female Choice and the Consistency of Courtship Feeding in Black‐horned Tree Crickets Oecanthus nigricornis Walker (Orthoptera: Gryllidae: Oecanthinae)

Courtship feeding in insects is often strongly correlated with insemination duration and therefore provides a potential postcopulatory episode of sexual selection. We tested whether courtship feeding and other courtship traits in the black‐horned tree cricket Oecanthus nigricornis showed sufficient consistency potentially to respond to sexual selection by testing whether they differed significantly among males. Duration of courtship feeding differed among males when measured repeatedly and this caused significant differences in the duration of spermatophore attachment, a trait that determines the maximum duration of insemination and thus has important fitness consequences in crickets. We also partitioned variance in courtship behaviour between the sexes to test whether differences in courtship behaviour were attributable primarily to males, females or both sexes. Duration of spermatophore attachment was controlled by females and therefore represents a mechanism of female mate choice. Significant variation in duration of spermatophore attachment was associated with differences between individuals of both sexes. Differences among males indicate that females agree in their preference of certain males whereas differences among females indicate that females differ in their receptivity to postcopulatory courtship and insemination. The fact that differences among males in duration of spermatophore attachment were due to significant differences solely in the period of courtship feeding indicates that postcopulatory female choice was mediated through courtship feeding. Whether males manipulate female choices by allocating more or fewer resources requires further testing, but we found that males court some females more vigorously than others after females dismount. The number of previous mates had opposite effects on the duration of courtship feeding for the sexes, decreasing it for males but increasing it for females, and we discuss the possible causes of these results.

Courtship feeding in tree crickets increases insemination and female reproductive life span

Courtship feeding in the majority of insects may influence female reproductive patterns either directly, through effects of the gift material, or indirectly, through correlated effects of prolonged copulation and larger ejaculates. This distinction is important because the cause of changes in fecundity may influence patterns of the allocation of resources between the sexes, with implications for the intensity of sexual selection and magnitude of sexual conflict. I show that post-copulatory feeding on the secretions of a gland on the metanotum of maleOecanthus nigricornis. Walker correlates with oviposition and affects the number of sperm remaining within the spermatophore. Manipulations of gland feeding and insemination duration showed that changes in fecundity are due to the gift rather than the ejaculate. Metanotal gland feeding increased female fecundity by increasing reproductive life span without significantly increasing oviposition rate. These changes in reproduction were directly due to the gift itself. Although gland feeding was positively correlated with the duration of insemination and thus the number of sperm transferred from the spermatophore to the female, experimentally prolonging or reducing insemination had no significant effect on reproductive life span. Male phenotype was also associated with female fecundity but in this case the effect was caused by an increase in the oviposition rate of females that mated with relatively large males. Male size had no significant effect on female reproductive life span, suggesting that its effect is not simply due to a quantitative increase in gift size. Three other measures of male phenotype, fluctuating asymmetry, condition (i.e. size-standardized wet body mass) and age, had no significant effects on female reproduction.

Effect of Hypotaurine in Fertilization Medium on Fertilization of In Vitro Matured Bovine Oocytes and Their Subsequent Development

In Experimental 1, when in vitro matured (IVM) bovine oocytes were inseminated with frozen-thawed spermatozoa in in-vitro fertilization (IVF) medium (BO solution containing 5 μg/ml heparin) (Control) and IVF medium supplemented with 5 mM caffeine (Caf) or 10 mM hypotaurine (HT) for 1, 3 and 5 h, significantly higher percentages of oocytes were penetrated in Caf and HT groups than Control group after 3 h of insemination. Then the rates showed no difference between groups after 5 h of insemination. However, a significantly lower percentage of monospermic oocytes was obtained in Caf group than Control and HT groups. In Experimental 2, IVM oocytes were inseminated with spermatozoa in IVF medium supplememted with 0, 1, 5 and 10 mM HT, and then co-cultured with cumulus cells in TCM 199 with 5% calf serum. There was no difference in the ability of spermatozoa to penetrate oocytes between groups but significantly higher rates of fusion of male and female pro nuclei in monospermic oocytes were obtained in the medium supplemented with 10 mM HT than no addition.The addition of HT in IVF medium significantly improved percentages of embryos developed to the stage of blastocyst. In Experimental 3, IVM oocytes were inseminated in IVF medium supplemented with 10 mM HT or 5 mM Caf and then co-cultured as described in Exp.2. significantly higher percentages of monospermic oocytes and embryos developed to the stage of blastocyst were obtained with HT groups than Caf group. In monospermic oocytes significantly higher rates of fusion of male and female pro nuclei were obtained in HT group than Caf group. These results indicate that addition of HT in the ferti lization medium promotes monospermic fertilization compared with Caf and shortens the duration of insemination needed for spermatozoa to penetrate oocytes resulting in higher percentages of IVM/IVF oocytes develop to the stage of blastocyst than those of no addition.