Mean Ovary Weights Research Articles

Morphometric Assessment of the Bovine Ovary for in vitro Matured Oocyte Quality to Determine Developmental Competence

Background: Embryo production in vitro requires three steps: in vitro maturation (IVM), in vitro fertilization (IVF) and in vitro culture (IVC). The first step in the in vitro maturation of oocytes is germinal vesicle breakdown (GVBD), followed by completion of the 1st meiotic division and formation of the 1st polar body. These parameters are critical during ovary and oocyte selection. This study aimed to evaluate bovine ovary and oocyte collection for IVM. Methods: Ovaries collected from cows in a 0.9% NaCl saline solution at the central slaughterhouse were divided into two normal and abnormal ovaries according to their morphological appearance. The morphometric dimensions of bovine ovaries, such as weight and deamination (length, width and volume), were recorded. The oocyte was extruded and its deamination occurred before and after culture in maturation medium. Result: The mean ovary weight, volume, length and width were not significantly different between the two ovary types. Additionally, the dominant and subordinate follicle diameters in both ovary types showed no significant differences. Furthermore, the oocyte number per ovary of the normal and abnormal oocytes showed no significant differences. The mean cumulus oocyte complex before maturation showed no significant difference (52.73±7.23 mm for the normal ovary vs. 43.015±5.41 mm for the abnormal ovary). However, after maturation, a highly significant difference was found (P less than 0.001) between the normal ovaries before and after maturation (178.10±15.36 µm) and abnormal ovaries (10.45±7.99 µm). Additionally, data analysis of oocytes with or without 1st polar bodies revealed a highly significant difference (P less than 0.001) between oocytes of the normal ovary with (32.15±4.19) and without (10.95±1.59) 1st polar bodies and oocytes of the abnormal ovary with (7.0±078) and without 1st polar bodies (3.3±0.32). Thus, the critical point at which the normal ovary produces better in vitro matured follicles with good oocyte quality and produces the 1st polar body determines developmental competence. Therefore, the best selection of normal ovaries will enhance in vitro maturation for subsequent experiments, such as in vitro fertilization or cloning and in vitro embryo development.

Estimation of the Fecundity of Threatened Pethia ticto

In order to estimate fecundity of threatened small indigenous fish species, tit punti (Pethia ticto), an investigation was done at the Field Laboratory Complex, Faculty of Fisheries, Bangladesh Agricultural University, Mymensingh during June to August, 2017. The mean total lengths were 5.39 ±0.58, 5.20 ± 0.43, 5.79 ± 0.97 cm and mean ovary weights were 0.45 ± 0.20, 0.38 ± 0.15, 0.53 ± 0.26 g for the month of June, July and August, respectively. The fecundity of P. ticto for the month of June was estimated to be 1120-13892 with a mean of 5319.62 ± 3169.16, for the month of July it was 1071-12325 with a mean of 5407.68 ± 3186.82 and for the month of August it was 2268-14328 with a mean of 5919.92 ± 3436.29. The gonadosomatic index (GSI) were 16.62 ± 3.35, 19.01± 4.55 and 14.75± 2.53 for the month of June, July and August, respectively. The highest GSI was observed in July (25.77) and the lowest was 10.53 in June. Information of fecundity and GSI of P. ticto will be helpful for artificial propagation, conservation, and management of this fish species.

Use of an anti-GnRF vaccine to suppress estrus in crossbred Iberian female pigs

Antibodies against GnRF elicited by vaccination with Improvac are expected to have the same effects on the gonads of female pigs as those observed in males and thus suppress estrus. The objective of this study was to evaluate whether a 3- or a 4-dose regimen of Improvac was effective in inducing and maintaining suppression of estrus in intact Iberian female pigs through 14 months of age. Sixty 18-week-old gilts were randomly assigned to one of the following three treatment groups: control (PBS injected), V3 (3-dose Improvac regimen), and V4 (4-dose Improvac regimen). Animals were tested for the presence of standing estrus in the presence of a boar three times per week until study completion at 60 weeks of age. Blood samples were regularly collected to determine the serum levels of anti-GnRF antibodies and progesterone. The weight and size of the uterus and the weight and activity of the ovaries were assessed at the time of euthanasia. For both treatment groups V3 and V4, a large reduction in the incidence of standing estrus was observed when compared to the control group (P < 0.0001). No significant differences between the V3 and V4 groups were observed. Both V3 and V4 groups had higher serum anti-GnRF antibody levels than the control group from 28 days after the first vaccination until the end of the study. In addition, both V3 and V4 groups had lower levels of progesterone than the control group from Day 112 until the end of the study (P < 0.0001 in all cases). Mean ovary weights at study end in treatment groups V3 and V4 were significantly lower (P < 0.0001) than those for the control group and not significantly different between the V3 and V4 groups. An onset of immunity of 2 weeks after the second vaccination and a long-lasting immunity of at least 20 weeks after the third vaccination were observed. In summary, both the 3-and 4-dose Improvac regimens were efficacious in reducing the incidence of standing estrus, serum progesterone levels, and the development of the uterus and ovaries.

Use of portable ultrasonography to determine ovary size and fecundity non-lethally in northern pike (Esox lucius) and white sucker (Catostomus commersoni)

The objective of this study was to investigate the feasibility of using field-based portable ultrasonography to accurately estimate ovary weight, gonadosomatic index (GSI) and fecundity in large-bodied fish species. These reproductive endpoints were estimated using ultrasound on prespawning female northern pike (Esox lucius) and white sucker (Catostomus commersoni) and compared with actual measured values determined post mortem. Using five cross-sectional ultrasound images in pike, estimated ovary weight and fecundity, but not GSI, were significantly correlated with measured values. All endpoints were overestimated by 21 to 23% using ultrasound in pike. In a subsequent experiment using 20 cross-sectional ovary images, estimated ovary weight, GSI and fecundity were significantly correlated with measured values in white sucker. Although underestimated by 5 to 12% using 20 cross-sectional images, there were no statistical differences among estimated and measured mean ovary weight, GSI and fecundity in white sucker using this approach. Based on the variances for GSI estimations in both species, power analysis indicated that the ultrasound technique could detect a 25% change in GSI using sample sizes of &amp;lt;20 fish. This study illustrates the utility of portable ultrasonography as a promising non-lethal technique for assessing reproductive endpoints in the field.

The influence of feeding regime on sexual maturation, fecundity and atresia in first‐time spawning turbot

Exposure of adolescent turbot Scophthalmus maximus to low rations during vitellogenesis, covering the 4 months immediately prior to spawning, led to a drop of 70% in mean ovary weight, and was associated with poor growth of the vitellogenic oocytes or, in a third of cases, the absence of vitellogenic oocytes. Exposure to low rations during the recruitment of vitellogenic oocytes, 4–8 months prior to spawning, produced a more variable response. A few of these females produced well‐developed vitellogenic oocytes, but in most, vitellogenic oocytes were absent or only poorly developed and in some cases there was a high incidence of atresia. Exposure to intermediate rations throughout oocyte recritment and vitellogenesis also depressed oocyte development. In maturing females the number of non‐atretic vitellogenic oocytes (relative potential fecundity) averaged 998 per g of somatic body weight of fish at the start of the spawning season in mid‐June. Maturation of the males was not significantly influenced by the dietary regime. The small size of the testes and the low levels of milt production, even in fish fed high rations immediately prior to spawning, showed that reproductive investment in males was much lower than in females.

Contents and organ distribution of pantothenic acid in maturing turbot (Psetta maxima )

Contents and organ distribution of pantothenic acid in maturing turbot (<i>Psetta maxima</i> )

Ecomorphological correlates of interspecific plasticity in reproductive investment and egg production of some cichlid fishes (Cichlidae) of a Nigerian rainforest stream

Interspecific variability and trends in the reproductive investment and fecundity of four sympatric cichlid species (Thysochromis ansorgii (BOULENGER 1901), Chromidotilapia guntheri (SAUVAGE 1882), Hemichromis fasciatus PETERS 1852, Tilapia mariae BOULENGER 1899) were studied in Ikpa River vis-a-vis certain ecological and morphological attributes. There was a positive allometric functional relationship between mean total length and total weight; mean body condition increased with mean length; mean ovary weight and egg weight increased with mean fish length and weight (minimum in T. ansorgii and maximum in T. mariae in each case). Gonadosomatic index increased only slightly with mean fish length. The hierarchy of mean absolute fecundity was: C. guntheri>T. ansorgii>H. fasciatus>T. mariae. Mean absolute fecundity increased with mean length and weight among the substrate-spawners (T. ansorgii>H. fasciatus>T. mariae) while C. guntheri, a paternal mouth-brooder, was an outlier in these relationships. Interspecific divergence in reproductive investment, fecundity and morphometric attributes of the cichlids (CV = 10.1-149.5 %) may enhance reproductive niche partitioning, a phenomenon which provides the fundamental biomechanism for the evolution of their distinct reproductive strategies. This explains in part, the coexistence of these cichlids in the vegetated marginal water biotope.

The effects of feeding triiodothyronine on reproductively inhibited prairie deermice ( Peromyscus maniculatus bairdii) from laboratory populations

1. 1. Two reproductively inhibited populations were given 250 ng triiodothyronine (T3) per gram of food for 35 days to elevate the reduced serum thyroid hormone concentration previously demonstrated in reproductively inhibited animals and to determine if the treatment would promote recovery. 2. 2. Per capita food intake was significantly increased but per cent body fat tended to decrease and body weight did not significantly increase during T3 treatment. 3. 3. Mean testis and seminal vesicle weights of T3-treated males were significantly increased and testis histology indicated some increase in spermatogenesis. 4. 4. Mean ovary weights of T3-treated females only tended to increase although the uterine weights were significantly increased and ovarian histology revealed a significant increase in preovulatory follicles. 5. 5. The limited recovery of reproductively inhibited animals may indicate that thyroid activity per se is related to, but not the direct cause of, the reproductive inhibition observed in populations.

The influence of prostaglandin E 2 and the steroid hormones, 17α-hydroxyprogesterone and 17β-estradiol on moulting and ovarian development in the tiger prawn, Penaeus esculentus Haswell, 1879 (Crustacea: Decapoda)

1. 1. During trials of 5 weeks duration, nine groups of adult female tiger prawns, Penaeus esculentus (carapace length >28 mm), were treated with prostaglandin E 2 (PGE 2) (0.1 μg/g body weight), 17α-hydroxyprogesterone (0.01 μg/g body weight), 17β-estradiol (0.01 μg/g body weight), or a combination of these. Both ovarian development and moulting were individually monitored during this time, and upon completion, ovaries were weighed and histologically examined. 2. 2. Those groups treated with PGE 2, whether alone or in unison with a steroid hormone, displayed significantly shorter moult cycles than did either the control or steroid treated groups ( P < 0.0001, two-way ANOVA; mean moult cycle duration for all PGE 2 treated groups, 14.46 ± 0.29 days). 3. 3. Neither 17α-hydroxyprogesterone or 17β-estradiol, whether alone or in combination with PGE 2, significantly effected moult cycle duration ( P > 0.05, two-way ANOVA; mean moult cycle duration of all non-PGE 2 treated groups, 17.30 ± 0.39 days). 4. 4. Histological examination showed that no treatment significantly stimulated ovarian development. There was also no significant increase in mean ovary weight relative to body weight. This result questions a body of opinion which suggests that both 17α-hydroxyprogesterone and 17β-estradiol are vitellogenin stimulating hormones.

Female reproductive biology and spawning periodicity of two species of king prawns, Penaeus longistylus Kubo and Penaeus latisulcatus Kishinouye, form Queensland's East Coast Fishery

In the coastal region of central Queensland female red-spot king prawns, P. longistylus, and the western or blue-leg king prawns, P. latisulcatus, had high mean ovary weights and high proportions of advanced ovary development during the winter months of July and August of 1985 and 1986. On the basis of insemination, both species began copulating at the size of 26-27 mm CL, but P. longistylus matured and spawned at a smaller size than P. latisulcatus. Abundance of P. longistylus was generally three to four times greater than that of P. latisulcatus but the latter was subject to greater variation in abundance. Low mean ovary weight and low proportions of females with advanced ovaries were associated with the maximum mean bottom sea-water temperature (28.5�C) for both species. Population fecundity indices indicated that peaks in yolk or egg production (a) displayed a similar pattern for both species, (b) varied in timing from year to year for both species and (c) were strongly influenced by abundance. Generally, sample estimates of abundance and commercial catch rates (CPUE) showed similar trends. Differences between the two may have been due to changes in targeted commercial effort in this multi-species fishery.

Patterns of reproduction in two populations of pumpkinseed sunfish,Lepomis gibbosus, with differing food resources

The influence of available food resources on growth and patterns of reproduction was studied in two populations of pumpkinseed sunfish in adjacent lakes in southeastern Ontario. Ideally, mature individuals should be long-lived, attain a large size, and maintain a high reproductive effort. However, rarely are environmental conditions ideal and compromises are necessary. In the present study, there were smaller quantities of preferred prey items (gastropods), and total benthos available in one lake. Pumpkinseed in this population ate less in general, and were smaller in body size in the older age classes. These fish matured at a younger age and a smaller size than individuals in the other lake studied, and in populations in this geographic area reported in the literature. In addition, the relationships of both fecundity and ovary weight to total weight were different between lakes. Mean ovary weight, ripe egg size and lifetime fecundity were less in the population of small-bodies fish. Variation in patterns of reproduction between populations suggests that fish may be able to fine-tune responses to local environmental conditions.

Food Discrimination and Ovarian Development in Burying Beetles (Coleoptera: Silphidae: Nicrophorus)

Burying beetles are carrion feeders that reproduce on small carcasses, but adults are also attracted to large carcasses to feed themselves. Beetles captured at large carcasses (baits in pitfall traps) and small carcasses (mice placed singly on the forest floor) differ in their mean ovary weights. Beetles with mature ovaries tend to favor the mice, whereas newly emerged adults with immature ovaries tend to favor the pitfall traps. The ovaries of all beetles develop only to a certain point; final oocyte development proceeds only after a small carcass is secured. Because our baited pitfall traps represent an adult food source, they capture a biased sample of the community, a sample that underrepresents the most reproductively active individuals.

Contribution to the biology of the redbanded perch, Ellerkeldia huntii (Hector), with a discussion on hermaphroditism

The presence of oocytes in the testes of several males indicates that the redbanded perch Ellerkeldia huntii exhibits protogynous hermaphroditism. All males appear to be secondary in origin; however the structure of the testes differ from most other protogynous serranids. In samples collected from the Poor Knights Is., New Zealand, males outnumbered females 2.7: 1 (n= 52). The numbers in each sex were equal until a length of 100–110 mm, after which the male proportion increased to 100%. The oldest female was aged 2+ years, whereas males were found as old as 5+ years. There were no colour differences associated with sex. The mean testes weight was only 7% of the mean ovary weight. Both sexes grew at the same rate. Observations during December indicated that although many individuals were solitary, some were paired. The larger individuals of pairs were males, the smaller females. Individuals foraged in the algal canopy on gammarid amphipods and mysid shrimps. The average range of movements was only 2·2 m2.