scholarly journals Variation and significance of egg mass in a Pied Flycatcher Ficedula hypoleuca population in subalpine habitats in Swedish Lapland

Ornis Svecica ◽  
2015 ◽  
Vol 25 (3–4) ◽  
pp. 119-130
Author(s):  
N. Erik I. Nyholm

Newly laid eggs of Pied Flycatchers Ficedula hypoleuca breeding in subalpine birch forest in Swedish Lapland were weighed in the field in 1965–1976. The main objective of the study was to get knowledge of the egg production capacity and its relation to the environmental conditions in the northern periphery of the breeding range of the species. The eggs were on average smaller than what is known from other Pied Flycatcher populations. Egg mass was non-linearly related to ambient temperature, and smallest at temperatures <10°C. About 70% of the eggs were laid at those temperatures. Variation in temperatures during the egg formation contributed to a significant egg mass variation between years. Average egg mass was lowest in the biggest clutches (7 or 8 eggs). Egg mass did not vary significantly within clutches, was not significantly related to the female mass, and did not vary between years in the same female. Hatching and fledging success were non-significantly related to the mean egg masses, indicating that egg sizes were not decisive for the breeding output.

2010 ◽  
Vol 47 (4) ◽  
pp. 199-203 ◽  
Author(s):  
K. Taira ◽  
Y. Saitoh

AbstractEgg production capacity in Fasciola gigantica (Japanese strain) was estimated from egg count data obtained by the experimental infection of two goats. The goats were inoculated with a single dose of 50 metacercariae. The first goat was necropsied 132 days after infection (DAI) and the second goat 732 DAI. After patency, daily faecal production was collected and weighed and number of eggs per gram was counted. At necropsy, 23 flukes were recovered from the liver of the first goat, and five from the second goat. The mean number of eggs produced per day per worm (± 95 % confidence limits) was 9 477.9 (± 764.92) for the first goat at 106 to 132 DAI, and 8,064.1 (± 416.49) at 195 to 561 DAI for the second goat. The number of eggs produced per day per worm in F. gigantica (Japanese strain) has thus reached values ranged from approximately 8 000 to 10 000 eggs.


Author(s):  
A. A. Kretov

The primary cause of injuries and inflammation of the reproductive system in female quails in industrial quail farming is the process of egg formation and its passage through the oviduct. With technological injuries females aged from 42 to 55 days are involved into the risk zone, whose weight of laid eggs ranges from 11,6 to 13,7 g. In previous morphological and histological studies, the following patterns of development of the organs of the reproductive system of quails under conditions of intensive technology have been established. The development of the reproductive organs of female quails of Japanese breed proceeds sequentially in seven periods: the first (1–21 days) is the period of relative rest of the growth of organs, the second (21–35 days) is the period of intensive morphogenesis of the ovaries and oviduct departments, the third (35–45 days) is the period of preparation and the beginning of egg laying, the fourth (45–75 days) is the period of egg laying growth or functional formation of the oviduct departments, the fifth (75–185 days) is the period of intensive folliculogenesis and high secretory activity of the departments of the oviduct or the peak of egg production, the sixth (185–200 days) is the beginning of the involution of the reproductive organs and a decrease in the rate of egg production, the seventh (200 days and older) is the involution of the reproductive organs and the termination of egg laying. Taking into account these patterns of development of the reproductive organs of quails, the feeding scheme of female egg quails has been adjusted, which provides for the division of the productive period into 4 phases: phase 1 is the beginning of egg production (36–45 days), phase 2 is the growth of egg production (46–75 days), phase 3 is the peak of egg production (76–185 days) and phase 4 is the decline of egg production (185–200 days). The proposed scheme of phase feeding of female quails of Japanese breed during the productive period is the advantageous technological technique, since it allows to reduce the injuries of the poultry oviduct and improve the quality indicators of the quail egg, as a result of reducing the weight and size of eggs in the initial phase of egg production and the number of large eggs during the entire productive period. The use of the new scheme of phase feeding of female quails of Japanese breed allows us to get more egg mass by 67,5 kg, due to the increase in the gross harvest of commercial quail eggs by 4,5 % and the livability of the quails by 5,6 %.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Guzhen Cui ◽  
Saifeng Zhong ◽  
Tuquan Zheng ◽  
Zhangrui Li ◽  
Xu Zhang ◽  
...  

Abstract Background Environmental conditions affect the biology of mosquito vectors. Aedes albopictus is a major vector of many important diseases including dengue, Zika, and chikungunya in China. Understanding the development, fecundity, and survivorship of Ae. albopictus mosquitoes in different environmental conditions is beneficial for the implementation of effective vector control measures. Methods Aedes albopictus larval and adult life-table experiments were conducted under natural conditions in indoor, half-shaded, and fully shaded settings, simulating the three major habitat types in Hainan Province, a tropical island in the South China Sea. Temperature, humidity, and light intensity were recorded daily. Larval rearing used habitat water and tap water, with and without additional artificial food. Development time, survivorship, pupation rate, and adult emergence rates were monitored. Adult mosquito survivorship and fecundity were monitored daily and reproductive rates were determined, and age-dependent survivorship and reproduction were analyzed. Results The pupation time and male and female emergence times were significantly shorter in indoor conditions than in shaded and half-shaded conditions for both tap water with added food and habitat water with added food groups. For habitat water with added food, the shaded environment had the lowest pupation rate among the settings. For tap water with added food group, the shaded environment had the lowest pupation rate. The mean survival time of females was 27.3 ± 0.8 days in the indoor condition, which was significantly longer than that in the half-shaded (18.4 ± 0.6 days) and shaded (13.8 ± 1.2 days) conditions. Adult mortality was age-dependent, and the rate of change in mortality with age was not significantly different among different environmental conditions. The mean net replacement rate (R0) of female mosquitoes showed no significant difference among the three conditions, whereas the per capita intrinsic growth rate (r) in the shaded condition was 42.0% and 20.4% higher than that in the indoor and half-shaded conditions, respectively. Female daily egg mass was also age-dependent in all the settings, decaying exponentially with age. Conclusions Our results imply that half-shaded conditions are likely the best natural condition for adult emergence and female reproduction, and food supply is crucial for larval development and pupation. The results provide new avenues for integrated mosquito management in indoor and outdoor areas, especially in half-shaded areas. Graphical Abstract


Author(s):  
O. Merzlyakova ◽  
V. Rogachyev ◽  
V. Chegodaev

The efficiency of introducing probiotics based on strains of Bacillus subtilis, Bacillus licheniformis and their consortium in the amount of 150 g/t of feed into the diets of laying quails has been studied. The experiment lasting 182 days has been carried out on four groups of quails with 30 heads in each. The quails have been housed in the broiler battery in compliance with the required microclimate conditions. Quails of all groups have been received the main diet (compound feed) developed taking into account their age and physiological characteristics. The quails of the 1st, 2nd and 3rd experimental groups in addition to the main diet received probiotics (150 g/t compound feed) based on strains Bacillus subtilis, Bacillus licheniformis and their consortium, respectively. It has been found that feeding the laying quails of the consortium of strains Bacillus subtilis and Bacillus licheniformis had the most significant positive impact on their productive performance, it allowed to increase egg production by 7,81 %, egg laying intensity by 5,0 %, egg mass yield by 9,77 %, while reducing feed expenditures for 10 eggs by 13,35 %. The yield of hatching eggs has been increased by 7,03 %, hatchability of chickens from laid and fertilized eggs by 8,33 and 8,35 %, brooding waste decreased by 21,74 %. Hematological parameters of quails during the whole experiment were within the physiological norm. The economic effect calculated on the basis of data on the cost of compound feed, probiotics and the cost of sold eggs of quail laying was 14,56 % in the 3rd experimental group (in relation to the control group).


2020 ◽  
Author(s):  
Barry Taylor ◽  
David Christie

Fractals ◽  
1993 ◽  
Vol 01 (01) ◽  
pp. 11-19 ◽  
Author(s):  
SHU MATSUURA ◽  
SASUKE MIYAZIMA

A variety of colony shapes of the fungus Aspergillus oryzae under varying environmental conditions such as the nutrient concentration, medium stiffness and incubation temperature are obtained, ranging from a homogeneous Eden-like to a ramified DLA-like pattern. The roughness σ(l, h) of the growth front of the band-shaped colony, where h is the mean front height within l of the horizontal range, satisfies the self-affine fractal relation under favorable environmental conditions. In the most favorable condition of our experiments, its characteristic exponent is found to be a little larger than that of the 2-dimensional Eden model.


2006 ◽  
Vol 37 (6) ◽  
pp. 555-560 ◽  
Author(s):  
Juan Moreno ◽  
Judith Morales ◽  
Elisa Lobato ◽  
Santiago Merino ◽  
Gustavo Tomás ◽  
...  

1983 ◽  
Vol 61 (8) ◽  
pp. 2212-2223 ◽  
Author(s):  
Catherine Damerval

Seven foliar types were defined for the first leaf in the heteroblastic development of seven annual species of Medicago L. Among the species, M. aculeata and M. murex have a typical foliar form. There is no relation between the first leaf and the succeeding trifoliolate one. The shape changes of the middle foliole of the trifoliolate leaves during the development allowed to establish a foliar sequence whose mean length was used to suggest an evolutive hierarchy among the taxa. Five quantitative variables were analysed on the first and on the sixth leaf for stability according to environmental conditions; the two stable variables (L/l and L/Pl) have a best discriminant value for the first leaf than for the sixth one. However, intraspecific heterogeneity is high in both cases. A relation between the flowering precocity and the mean value of one of the sixth leaf's variables (that is, the ratio of the length to the width of the foliole limb) was demonstrated in four species only. The heteroblastic development not only allows to establish a relation between foliar stage and physiologic age, but it itself constitutes a very good taxonomic and systematic criterium; it allowed to identify the seven species studied.


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