Variability in Carcinus maenas Fecundity Along Lagoons and Estuaries of the Portuguese Coast

Although Carcinus maenas as a species is widely studied, research focusing on fecundity is still scarce. The main objective of this study was to evaluate size-fecundity relationships across different lagoons and estuaries, along the Portuguese coast, to understand how the local environment affects reproductive patterns. Between 2019 and 2020, ovigerous females were collected from the Southern (Ria Formosa and Ria de Alvor), Central (Rio Sado) and Northern regions (Ria de Aveiro) of Portugal, and the fecundity of each female was estimated by counting and weighing eggs. Morphometric relationships (carapace width–egg counting; egg counting–egg weight; body wet weight–egg weight; carapace width–body wet weight) were inferred from 180 egg-bearing females with a carapace width between 26.96 and 61.25 mm. A positive correlation between fecundity and the morphological parameters was observed. Differences in fecundity were found among all systems, from northern to southern Portugal, varying between 22121 and 408538 eggs per female. Furthermore, a regional gradient was observed across regions, with lower temperature estuaries (Ria de Aveiro) displaying an increase in fecundity. The fecundity in Rio Sado was also affected by salinity. Fecundity differences across regions were associated with hydrodynamics, temperature, and salinity differences among systems. No statistically significant differences were observed between Carapace Width—Body Wet Weight regressions performed in each studied system, indicating that, contrary to fecundity, the somatic growth of C. maenas is not affected by latitudinal or environmental conditions.

Interspecific variations in external and internal egg quality among various captive avian species from Punjab, Pakistan

Present study was planned to determine variations in external and internal quality egg parameters of different avian species including ostrich Struthio camelus, ducks Anas platyrhynchos, chicken Gallus gallus, turkeys Meleagris gallopavo and grey francolin Francolinus pondicerinus. All the birds were kept under similar rearing conditions. A total of 150 eggs were collected for each species to record external features of these eggs. Statistically significant (p<0.05) variations were recorded in egg weight, egg length and egg width between ostrich, ducks, chicken, turkey and quail eggs. Significantly (p<0.05) higher egg weight, egg length and egg width was observed for ostrich eggs while the same was lowest for grey francolin eggs. Similarly, significantly (p<0.05) greater shape index and egg volume values were observed for ostrich eggs while lowest shape index values were recorded for turkey eggs and egg volume was lowest for grey francolin. Significantly, higher (p<0.05) values of egg density were noted for eggs of the quail and the same were lowest for ostrich eggs. Non-significant variations in egg density values were observed between eggs of the ducks, chicken, turkey and grey francolin. It has been concluded that the positive correlations between the internal and external egg quality traits indicated that the traits can be improved through selection.

A Comprehensive Method for the Evaluation of Hermetia illucens Egg Quality Parameters: Implications and Influence Factors

The significant momentum received by Hermetia illucens as a worldwide species is due to its biological traits and large applicability in scientific research, environmental entomoremediation, insect meal production, and for biodiesel yield. The aim of this research is to develop a method for the preparation and precise egg counting of the H. illucens egg clutch, as well as an accurate technique for evaluating egg biometric parameters. The precise proposed method for egg preparation and counting consists in dispersing the eggs clutch under a stereo microscope and counting the eggs on a photographic capture using the Clickmaster software. Five solution types were used to disperse the egg clutches: glycerin 50%, ethanol 70%, ethanol 80%, physiological serum 0.9% and purified water. The efficiency of the estimation method for eggs number evaluation was also tested by using the estimated egg weight as a conversion factor. The biometric parameters of single eggs (length and width) were determined using the free Toupview software. The precise method of egg preparation and counting allows for the registration of the eggs number manually identified by the operator. The appropriate dispersion solutions were glycerin 50% and ethanol 70%. The method has an error of 1.4 eggs for each 500 counted eggs, thus an accuracy of over 99.4%. The eggs number estimation method is not applicable without significant errors, the accuracy being less than 32%, due to egg heterogeneity in the clutch. Biometric parameters (length and width) are positively correlated with egg weight (r = 0.759) and with the number of eggs in the clutch (r = 0.645). In conclusion, the results clearly suggest the method of egg preparation and precise counting for an accurate evaluation of quality parameters of the H. illucens clutches, as well as the technique for evaluating egg biometric parameters.

A market study on the quality characteristics of eggs from different establishments

Egg storage conditions, including sales locations, are a determining factor in maintaining the internal quality of eggs. Although eggs are an excellent protein source, they are a perishable product. The aim of this study is to investigate the quality of eggs acquired in different places (supermarkets, groceries stores, and fairs). A total of 300 eggs were obtained from three different kinds of marketing places (supermarkets, grocery stores, or local fairs) located in different areas of Porto Alegre, RS, Brazil, being 120 eggs from supermarkets and grocery stores each and 60 eggs from local fairs. Eggshell characteristics, egg weight, Haugh unit, albumen and yolk pH were determined for all individual eggs in each experimental group. Statistical procedures were performed using SAS statistical software (9.4, SAS Inst. Inc., Cary, NC, United States). The data were submitted to analysis of variance (ANOVA) and differences between means were evaluated with Tukey test (P<0.05) The results indicated that the point of sale led to a significant (p<0.05) decrease in egg weight, specific gravity, and Haugh unit. Eggs purchased from grocery stores had smaller Haugh units (P < 0.05) and higher albumen and yolk pH, while table eggs purchased from supermarkets showed better quality. Eggs marketed in supermarkets have better internal quality than eggs sold in other types of establishments, probably due to the greater flow of sales and product replacement on shelves in this type of establishment.

Laying performance of 5th generation of BLRI improved native duck

This research was aimed to improve the egg production performances and to estimate the selection response of fifth generation (G5) of deshi white (Rupali) and white breasted black (Nageswari) duck genotypes through an individual selection program. All the ducks were reared in an open sided duck house. Diet containing 17.5% CP and 2750 Kcal ME/kg and fresh water provided twice daily in the morning and evening. Individual egg production was recorded from each duck. After 40 weeks of age, female ducks were selected on the basis of selection index and selection differences, selection intensity and responses were also measured. Egg weight, egg production and feed intake were recorded and FCR, egg mass was calculated. All recorded data were analyzed by SAS and differences were determined by DMRT. The selection criteria of fifth generation (G5) of both duck genotypes were studied. As a result of selection, age at sexual maturity (day), egg weight (g) and egg production % were expected to improve by -1.63d, 0.60g, 1.01% and -0.85day, 0.39g, 0.47% for Rupali and Nageswari ducks, respectively. Egg mass was significantly (p<0.05) higher in Rupali (40.24g) than Nageswari (37.55g) duck whereas, egg weight was not significantly differ in both genotypes. Egg production in Rupali and Nageswari duck was 65.41% and 62.74%, respectively. Rupali ducks were significantly (p<0.05) consumed more feed (134.54 g) than Nagesswari ducks (126.23 g). The FCR was significantly (p<0.05) better in Rupali (3.34) than Nageswari (3.61) ducks. The egg quality results showed that egg shell thickness of Rupali duck was significantly (p<0.05) higher than Nageswari. Higher values for albumen width (p<0.05) was also found in Rupali (65.03mm) than Nageswari (59.11mm) duck egg. On the other hand shape index, albumen index, yolk index and haugh unit were not found significantly different in both genotypes but the yolk color score of Nageswari found highest score than Rupali duck egg. Proximate composition of eggs was not significantly different of both duck genotypes. Based on the results it is revealed that Rupali duck was better in terms of egg weight, egg mass and egg production, but starting lay egg is earlier in Nageswari than Rupali duck. Bang. J. Livs. Res. Vol. 27 (1&2), 2020: P. 15-23

The influence of the duration of the “subjective day” under intermittent LED lighting on the daily rhythm of oviposition and the productivity of hens

Lighting is the key factor affecting oviposition time. The oviposition time is directly related to ovulation, which occurs 5 hours after reaching the peak concentration of luteinizing hormone in the blood, which depends on the lighting regime. This paper studies the impact of the “subjective day” duration under intermittent LED lighting on the daily rhythm of oviposition and the productivity of hens of the productive flocks of cross SP-789. The “subjective day” lasted 16 hours per day for group 1, 15 h for group 2, 14 h for group 3 and 13 h for group 4. It was established that the shorter the duration of the “subjective day”, the earlier the hens begin and finish laying. So, in groups 1, 2, 3, and 4, hens began laying eggs at 4 a.m., 3 a.m., 2 a.m., and 1 a.m. and ended at 6 p.m., 4 p.m., 4 p.m., and 3 p.m. with an average time of laying eggs of 8.67; 7.36; 5.36 and 5.27 h, respectively. In groups 1, 2, 3, and 4 the livability of hens, weight of eggs, egg production and yield of egg weight per the initial laying hen, feed consumption for 10 eggs and 1 kg of egg weight were 98.0, 97.0, 99.0, 99.0%; 60.0, 59.9, 60.4, 59.7 g; 123.9, 124.1, 130.3, 126.1 pcs, 7.48, 7.47, 7.97, 7.63 kg; 1.37, 1.36, 1.32, 1.36, and 2.28, 2.26, 2.18, 2.26 kg, respectively.

A Study on Some Biological Parameters of Crayfish (Astacus leptodactylus Eschscholtz, 1823) in Ulugöl, Samsun, Turkey

The study aimed to investigate some morphometric traits, length-weight relationship, meat yield, fecundity and some biochemical compositions of Astacus leptodactylus, in one of the Bafra Fish Lakes named Ulugöl, Samsun, Turkey. A total of 378 A. leptodactylus (198 female and 180 male) were examined. The average carapace length was 50.96±0.46 mm for females, 51.31±0.66 mm for males and 51.13±0.40 mm for all sampled crayfish. Abdomen length was 52.36±0.49 mm for females, 49.26±0.62 mm for males and 50.87±0.40 mm for all sampled crayfish. Live weight was between 14.38 g and 105.03 g with an average of 38.26±0.73 g. The average weight of females was less than that of males. There was a strong relationship between length and weight. The weight of crayfish with pleopodal eggs ranged from 28.24 g, to 59.50 g with an average of 41.73±1.09g. The average number of eggs per individuals was 192.90±9.94 with an average number of 4.62±0.21 per unit of live weight. The average total egg weight was 3.35±0.19 g while the average egg diameter was 2.17±0.03 mm. Abdomen meat was lower for males comparing with females. Average moisture, crude ash, crude oil and crude protein of abdomen meat were 81.27%, 1.47%, 0.81% and 16.45%, respectively.

Fiber-optic light guides as secondary sources of light for hen keeping in cage batteries

The method of local illumination of cage batteries with LED lamps, previously developed by us, made it possible to increase the livability and productivity of hens in comparison with the traditional method. In this case, the placement of low-power LED sources directly in each cage requires a large number of rather complex electronic devices across the whole metal structure of the cage battery and extended power transmission lines. This work compares the efficiency of local LED lighting and fiber-optic light guides when keeping hens of the productive flocks of cross SP-789 in traditional cages. The 120-day-old hens were divided by the method of analogs in 2 groups of 100 heads. In the control group, LED lamps were used for local illumination of hens, and in the experimental group, fiber-optic light guides were used with LEDs as the primary source of illumination. The color temperature of light-emitting diodes was 3000 K. Up to 260 days of age, hens were kept in triple-tiered cage batteries, 5 animals per cage. The results of the study showed that in the control and experimental groups, the livability of the livestock was 95.0 and 99.0%, the egg production per initial hen was 99.2 and 102.5 pieces. The weight of eggs was 57.9 and 58.3 g, the yield of the egg weight per initial hen was 5.81 and 5.98 kg, feed consumption for 10 eggs and 1 kg of egg weight were 1.37, 2.35 and 1.30, 2.23 kg, respectively, without significant changes in the morphological and chemical qualities of eggs.