Influence of temperature stimulation during the last 4 days of incubation on secondary sex ratio and later performance in male and female broiler chicks

2010 ◽  
Vol 51 (2) ◽  
pp. 308-308 ◽  
Author(s):  
B. Tzschentke ◽  
I. Halle
Keyword(s):  
Sex Ratio ◽  
Broiler Chicks ◽  
Male And Female ◽  
Influence Of Temperature ◽  
Secondary Sex Ratio ◽  
Temperature Stimulation

II.—Prenatal Death in the Pig and its Effect upon the Sex-Ratio

1927 ◽  
Vol 46 ◽  
pp. 9-14 ◽  
Author(s):  
F. A. E. Crew
Keyword(s):  
Sex Ratio ◽  
Sex Chromosome ◽  
Selective Mortality ◽  
Cytological Evidence ◽  
Male And Female ◽  
Primary Sex Ratio ◽  
The Future ◽  
Secondary Sex Ratio

The cytological evidence concerning the pig is that the sex of the future individual is determined at the time of fertilisation, and that in respect of the elements of the sex-chromosome sex-determining mechanism the male is digametic. If this is so, if the two sorts of sperm are produced in equal numbers, if each kind is equally viable and functional, and if fertilisation is at random, then a primary sex-ratio (that which obtains at the time of conception) of equality must follow. If male and female zygotes are equally viable, then the secondary sex-ratio (that which obtains at the time of gestation) will also be equality. A secondary sex-ratio other than equality must be the reflection of an unequal primary sex-ratio, the result of a differential production of the two sorts of gametes elaborated by the digametic sex, of a selective fertilisation by these, or of a sexually selective mortality among the embryos or/and fœtuses. A secondary sex-ratio of equality can follow a pronounced inequality in the primary sex-ratio if a sexually selective mortality operates prenatally.

Estimation of the Stillbirth Rate in Twin Pairs According to Zygosity

2007 ◽  
Vol 10 (3) ◽  
pp. 508-513 ◽  
Author(s):  
Johan Fellman ◽  
Aldur W. Eriksson
Keyword(s):  
Sex Ratio ◽  
Young Mothers ◽  
Stillbirth Rate ◽  
Male And Female ◽  
England And Wales ◽  
Common Opinion ◽  
Secondary Sex Ratio ◽  
The Difference ◽  
Mz Twins

AbstractIt is common opinion that the stillbirth rate is higher among monozygotic (MZ) than among dizygotic (DZ) twins. This is supported by the fact that stillbirth rates are higher among same-sexed than among opposite-sexed twins, and the relatively high stillbirth rates among twins of young mothers. In this study we present a method to estimate the stillbirth rates for MZ and DZ twins and identify the difference. We performed analyses based on the assumptions of (a) Weinberg's differential rule, including the assumption that the secondary sex ratio is 100, (b) the stillbirth rates among opposite-sexed twins hold for all DZ twins, and (c) the stillbirth rates estimated for MZ and DZ male and female twins yield for both sexes the observed total number of stillborn twins. Our methods are applied to data from Sweden, 1869–1967, the Åland Islands, 1750–1949, Saxony, 1881–1900, and England and Wales, 1996–2003. We observed that the ratio between the estimated stillbirth rates among MZ and DZ twins were on average 1.75, and the ratio among same-sexed and DZ (opposite-sexed) twins were on average 1.31. For Sweden and Saxony similar values were obtained, but for England and Wales the values were higher and for Åland lower. With exception of Åland, the estimated stillbirth rates were in all populations the lowest for DZ, medium for same-sexed and highest for MZ twins.

INFLUENCE OF THERMAL MANIPULATION DURING EMBRYONIC DEVELOPMENT ON HATCHABILITY TRAITS AND SECONDARY SEX RATIO OF BROILER CHICKS

2019 ◽  
Vol 39 (4) ◽  
pp. 825-833
Author(s):  
Ayat El-zeniny ◽  
Ahmed El-Kaiaty ◽  
Hewida El-Allawy ◽  
Hosam Safaa ◽  
Gamal Kamel ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Embryonic Development ◽  
Broiler Chicks ◽  
Secondary Sex Ratio ◽  
Thermal Manipulation

The DEVELOPMENT OF Elaeidobius kamerunicus FAUST POPULATION AFTER INTRODUCTION AND THE IMPROVEMENT OF OIL PALM FRUIT SET IN SERAM ISLAND, MOLLUCAS, INDONESIA

2016 ◽  
Vol 24 (1) ◽  
pp. 47-55
Author(s):  
Agus Eko Prasetyo ◽  
Agus Susanto
Keyword(s):  
Sex Ratio ◽  
Oil Palm ◽  
Fruit Set ◽  
Average Risk ◽  
Palm Fruit ◽  
Male And Female ◽  
Risk Of Death ◽  
North Sumatra ◽  
Female Flowers ◽  
Elaeidobius Kamerunicus

Elaeidobius kamerunicus is the main pollinating agent in oil palm plantations in Indonesia today. The development of oil palm plantations in new areas requires introduction of these insects, moreover the new areas are located on different islands. First introduction of Elaeidobius kamerunicus Faust had been done from North Sumatra to Seram Island on 23 September 2013. The introduction was performed on larva and pupa stadium in 4-5 days post anthesising of male inflorescences. The introduction of E. kamerunicus using plywood boxes has an average risk of death by 7.89% at 6 days delivery period. Observation before releasing of the weevils showed that this insect was not detected in both of oil palm male and female flowers and the oil palm fruit set was very low approximately 11.27%. For about 500 weevils/ha were released in Marnuhu estate and could be developed into 362,401 weevils/ha in 5 months with 97.86% of oil palm sex ratio. The oil palm fruit sets were increased after 1 and 2 months introduction, 53.70% and 75.56 %, respectively. The lower sex ratio of oil palm or the more availability of male inflorescences make growth of E. kamerunicus population became faster and the greater number of weevils that visiting anthesising of female flowers make the higher value of oil palm fruit set.

The DEVELOPMENT OF Elaeidobius kamerunicus FAUST POPULATION AFTER INTRODUCTION AND THE IMPROVEMENT OF OIL PALM FRUIT SET IN SERAM ISLAND, MOLLUCAS, INDONESIA

2018 ◽  
Vol 24 (1) ◽  
pp. 47-55
Author(s):  
Agus Eko Prasetyo ◽  
Agus Susanto
Keyword(s):  
Sex Ratio ◽  
Oil Palm ◽  
Fruit Set ◽  
Average Risk ◽  
Palm Fruit ◽  
Male And Female ◽  
Risk Of Death ◽  
North Sumatra ◽  
Female Flowers ◽  
Elaeidobius Kamerunicus

Elaeidobius kamerunicus is the main pollinating agent in oil palm plantations in Indonesia today. The development of oil palm plantations in new areas requires introduction of these insects, moreover the new areas are located on different islands. First introduction of Elaeidobius kamerunicus Faust had been done from North Sumatra to Seram Island on 23 September 2013. The introduction was performed on larva and pupa stadium in 4-5 days post anthesising of male inflorescences. The introduction of E. kamerunicus using plywood boxes has an average risk of death by 7.89% at 6 days delivery period. Observation before releasing of the weevils showed that this insect was not detected in both of oil palm male and female flowers and the oil palm fruit set was very low approximately 11.27%. For about 500 weevils/ha were released in Marnuhu estate and could be developed into 362,401 weevils/ha in 5 months with 97.86% of oil palm sex ratio. The oil palm fruit sets were increased after 1 and 2 months introduction, 53.70% and 75.56 %, respectively. The lower sex ratio of oil palm or the more availability of male inflorescences make growth of E. kamerunicus population became faster and the greater number of weevils that visiting anthesising of female flowers make the higher value of oil palm fruit set.

Sperm Competition and the Dynamics of X Chromosome Drive: Stability and Extinction

Genetics ◽  
2002 ◽  
Vol 160 (4) ◽  
pp. 1721-1731 ◽  
Author(s):  
Jesse E Taylor ◽  
John Jaenike
Keyword(s):  
Sex Ratio ◽  
Sperm Competition ◽  
X Chromosome ◽  
Sex Chromosome ◽  
Basin Of Attraction ◽  
Male Mating ◽  
Male And Female ◽  
Mating Rate ◽  
Female Mating ◽  
Balanced Polymorphism

AbstractSeveral empirical studies of sperm competition in populations polymorphic for a driving X chromosome have revealed that Sex-ratio males (those carrying a driving X) are at a disadvantage relative to Standard males. Because the frequency of the driving X chromosome determines the population-level sex ratio and thus alters male and female mating rates, the evolutionary consequences of sperm competition for sex chromosome meiotic drive are subtle. As the SR allele increases in frequency, the ratio of females to males also increases, causing an increase in the male mating rate and a decrease in the female mating rate. While the former change may exacerbate the disadvantage of Sex-ratio males during sperm competition, the latter change decreases the incidence of sperm competition within the population. We analyze a model of the effects of sperm competition on a driving X chromosome and show that these opposing trends in male and female mating rates can result in two coexisting locally stable equilibria, one corresponding to a balanced polymorphism of the SR and ST alleles and the second to fixation of the ST allele. Stochastic fluctuations of either the population sex ratio or the SR frequency can then drive the population away from the balanced polymorphism and into the basin of attraction for the second equilibrium, resulting in fixation of the SR allele and extinction of the population.

scholarly journals Maternal exposure to airborne polychlorinated biphenyls (PCBs) and risk of adverse birth outcomes

2021 ◽  
Author(s):  
Ane Bungum Kofoed ◽  
Laura Deen ◽  
Karin Sørig Hougaard ◽  
Kajsa Ugelvig Petersen ◽  
Harald William Meyer ◽  
...  
Keyword(s):  
Birth Weight ◽  
Preterm Birth ◽  
Sex Ratio ◽  
Polychlorinated Biphenyls ◽  
Birth Outcomes ◽  
Gestational Age ◽  
Small For Gestational Age ◽  
Maternal Exposure ◽  
Adverse Birth Outcomes ◽  
Secondary Sex Ratio

AbstractHuman health effects of airborne lower-chlorinated polychlorinated biphenyls (LC-PCBs) are largely unexplored. Since PCBs may cross the placenta, maternal exposure could potentially have negative consequences for fetal development. We aimed to determine if exposure to airborne PCB during pregnancy was associated with adverse birth outcomes. In this cohort study, exposed women had lived in PCB contaminated apartments at least one year during the 3.6 years before conception or the entire first trimester of pregnancy. The women and their children were followed for birth outcomes in Danish health registers. Logistic regression was performed to estimate odds ratios (OR) for changes in secondary sex ratio, preterm birth, major congenital malformations, cryptorchidism, and being born small for gestational age. We performed linear regression to estimate difference in birth weight among children of exposed and unexposed mothers. All models were adjusted for maternal age, educational level, ethnicity, and calendar time. We identified 885 exposed pregnancies and 3327 unexposed pregnancies. Relative to unexposed women, exposed women had OR 0.97 (95% CI 0.82, 1.15) for secondary sex ratio, OR 1.13 (95% CI 0.76, 1.67) for preterm birth, OR 1.28 (95% CI 0.81, 2.01) for having a child with major malformations, OR 1.73 (95% CI 1.01, 2.95) for cryptorchidism and OR 1.23 (95% CI 0.88, 1.72) for giving birth to a child born small for gestational age. The difference in birth weight for children of exposed compared to unexposed women was − 32 g (95% CI—79, 14). We observed an increased risk of cryptorchidism among boys after maternal airborne LC-PCB exposure, but due to the proxy measure of exposure, inability to perform dose–response analyses, and the lack of comparable literature, larger cohort studies with direct measures of exposure are needed to investigate the safety of airborne LC-PCB exposure during pregnancy

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