scholarly journals Maternal Lineage of Warmblood Mares Contributes to Variation of Gestation Length and Bias of Foal Sex Ratio

PLoS ONE ◽  
2015 ◽  
Vol 10 (10) ◽  
pp. e0139358 ◽  
Author(s):  
J. Kuhl ◽  
K. F. Stock ◽  
M. Wulf ◽  
C. Aurich
Keyword(s):  
Sex Ratio ◽  
Gestation Length ◽  
Maternal Lineage

Similarities between female meadow voles mating during post-partum oestrus and raising two concurrent litters and females raising only one litter

2006 ◽  
Vol 18 (7) ◽  
pp. 751 ◽  
Author(s):  
Javier delBarco-Trillo ◽  
Michael H. Ferkin
Keyword(s):  
Sex Ratio ◽  
Maternal Care ◽  
Post Partum ◽  
Microtus Pennsylvanicus ◽  
Meadow Vole ◽  
Gestation Length ◽  
Meadow Voles ◽  
Litter Weight ◽  
In The Wild ◽  
Males And Females

In many species of small mammals, females undergo post-partum oestrus soon after delivering a litter, becoming pregnant while suckling the previous litter. Females raising two concurrent litters need to allocate many more resources to reproduction than females raising only one litter. Consequently, there may be differences between litters raised concurrently or singly. We investigated this issue in the meadow vole, Microtus pennsylvanicus, a species in which most females in the wild reproduce during post-partum oestrus. Specifically, we tested the hypothesis that the development of pups in two concurrent litters differs from that of pups in a single litter. To test this hypothesis, we measured the following variables for concurrent and singly reared litters: gestation length; litter size; sex ratio; bodyweight of males and females at different ages; total litter weight at weaning; growth rates; and intra-litter variation in body mass. Except for bodyweight of males at 60 days of age, which was higher in the first of the concurrent litters, none of the variables differed among the litters. These results indicate that females are able to adjust to differing loads of maternal care to provide equivalent resources to concurrent litters and singly reared litters.

scholarly journals The effects of inbreeding on covering success, gestation length and foal sex ratio in Australian thoroughbred horses

BMC Genetics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Evelyn T. Todd ◽  
Natasha A. Hamilton ◽  
Brandon D. Velie ◽  
Peter C. Thomson
Keyword(s):  
Sex Ratio ◽  
Gestation Length ◽  
Thoroughbred Horses

scholarly journals Involuntary reduction in vigour of calves born from sexed semen

2016 ◽  
Vol 64 (2) ◽  
pp. 229-238 ◽  
Author(s):  
Radica Djedović ◽  
Vladan Bogdanović ◽  
Dragan Stanojević ◽  
Zsolt Nemes ◽  
András Gáspárdy ◽  
...  
Keyword(s):  
Birth Weight ◽  
Sex Ratio ◽  
Artificial Insemination ◽  
Reproductive Traits ◽  
Conception Rate ◽  
Gestation Length ◽  
Stillbirth Rate ◽  
Sexed Semen ◽  
The Mean ◽  
Fertility Traits

The objective of this study was to compare the reproductive traits of heifers and the development characteristics of their calves following artificial insemination (AI) with sexed and non-sexed semen. The analysed characteristics included conception rate, gestation length, calf birth weight, calf vigour, stillbirth rate, and twinning rate. Data of 530 calves produced with sexed and 1,163 calves produced with non-sexed semen were analysed. The General Linear Model (GLM) was applied to assess the influence of semen type, farm, season of insemination, the calf’s sex and the inseminating sire on gestation length and calf birth weight. With the exception of gestation length (P > 0.05), all other traits studied were significantly (P < 0.01) influenced by the type of semen. The conception rate was 55% for conventional and 44% for sexed semen, and the average gestation length was 274.6 and 274.9 days, respectively. The mean calf birth weight was 37.47 kg for non-sexed and 36.75 kg for sexed semen. The stillbirth rate was 6.19% for conventional and 7.54% for sexed semen, while the twinning rate was 3.78% for conventional and 1.13% for sexed semen. The calves produced with non-sexed and sexed semen differed significantly in viability (P < 0.001), the latter having a lower calf vigour score. The use of conventional semen did not affect the ratio of female and male calves (52.7:47.3%; P > 0.05); however, artificial insemination with X-sorted sexed semen significantly altered the sex ratio of calves (85.1:14.9%, P < 0.01). The results obtained in this investigation are in agreement with the majority of studies which compared the fertility traits, sex ratio and calf characteristics depending on the application of artificial insemination with sexed or conventional semen.

291 VARIOUS FACTORS INFLUENCING PREGNANCY RATES AND CALVING CHARACTERISTICS FOLLOWING TRANSFER OF OPU-IVP EMBRYOS PRODUCED IN A COMMERCIAL SYSTEM

2006 ◽  
Vol 18 (2) ◽  
pp. 253
Author(s):  
C. Ponsart ◽  
F. Aymar ◽  
B. Marquant-Le Guienne ◽  
C. Guyader-Joly ◽  
S. Ponchon ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Calf Serum ◽  
Blastocyst Stage ◽  
Pregnancy Rates ◽  
National Standards ◽  
Mean Deviation ◽  
Gestation Length ◽  
Assisted Reproduction Technique ◽  
Factors Influencing ◽  
The Mean

OPU-IVP is nowadays an assisted reproduction technique in which output for each step is variable. The aim of this work was to identify factors influencing calving rate and calf characteristics through a retrospective study conducted from 356 OPU sessions and 137 pregnancies on a farm. Donor females were stimulated with FSH in five decreasing doses (400 �g for cows and 250 �g for heifers). Collected oocytes were matured for 24 h in M199 plus fetal calf serum, FSH, epidermal growth factor (EGF), and estradiol. They were then fertilized in TALP with frozen-thawed semen and zygotes were cultured for 6 days on Vero cell monolayers in B2 medium. Embryos were transferred as fresh to recipients on Day 7; 137 pregnancies were followed up to calving. Gestation length, calving conditions and calf characteristics (sex and birth weight assessed by farmers) were recorded and compared to national standards (UPRAs data). The mean number of collected oocytes per session was 14; 11.6 were selected for IVM, 8.5 cleaved, and 3.9 developed to the blastocyst stage (40.4% of the embryos were Grade 1, 35.3% G2, and 20.5% G3). On average, 2.9 embryos were transferred into recipients, leading to an average of 1.6 pregnancies on Day 35 and 1.4 on Day 90 (76% of recipients were heifers). Pregnancy rates were higher in heifers than in cows (54.5% vs. 47.8%; P < 0.05). Pregnancies led to birth of a healthy calf in 81.9% of the OPU sessions (1.1 per session), the 18.1% losses being divided between 4.4% abortion (n = 6) and 13.7% perinatal mortality (n = 18). Gestation length from IVF pregnancies was longer than in national breeds standards (trial = 291 vs. national = 287 days). Moreover, 10% of calvings were induced. Calving conditions were mainly dependent on age of recipients: 70% of the heifers were assisted compared to 40.9% of the cows. No effect of gestation length or sex of calf was observed on calving difficulties. Sex ratio did not deviate in calves produced by OPU-IVF (52.3% of males and 47.7% of females). However, it was influenced by embryo quality, with the proportion of males decreasing from 56.3% to 44.4% for G1 to G3 embryos. The mean weight of healthy calves issued from IVP embryos averaged 47.1 kg � 10.1 and was not significantly higher than the national breed standards. The deviation (kg) from national breeds standards ranged from -20 kg to 0 in 68.8% (n = 90), from 1 to 15 kg in 16.0% (n = 29), and greater than 15 kg in 9.2% (n = 12) of the calves. Even if the mean deviation was not significant, those 12 calves in the >15 kg group should be considered as large. However, they were issued from two different donor females, so that this effect could also be attributed to a mother effect. To conclude, the effect of recipient parity on pregnancy rates was confirmed. The OPU-IVP system used in this trial did not seem to influence significantly sex ratio and weight of calves. Further studies are needed to investigate the sources of variation of gestation length.

scholarly journals 240 GESTATION LENGTH AND BIRTH WEIGHT OF IN VITRO PRODUCED EMBRYOS FROM ZEBU DAIRY CATTLE

2005 ◽  
Vol 17 (2) ◽  
pp. 270 ◽  
Author(s):  
L.S.A. Camargo ◽  
J.H.M. Viana ◽  
A.A. Ramos ◽  
W.F. de Sa ◽  
A.M. Ferreira ◽  
...  
Keyword(s):  
Birth Weight ◽  
Sex Ratio ◽  
Sao Paulo ◽  
Control Group ◽  
Gestation Length ◽  
São Paulo ◽  
Embryo Production ◽  
In Vitro Embryo Production ◽  
And Control

Gir cattle are a popular zebu dairy breed in tropical and subtropical regions because of their tolerance of heat stress and resistance to tick-borne disease. The use of in vitro embryo production (IVP) technology may help accelerate genetic improvement of this breed. However, in general, IVP systems have been implicated in the production of large offspring and a greater proportion of male calves. Natural breeding results in newborn Gir calves weighing around 25 kg despite the fact that dams may weigh over 500 kg. It is unknown whether in vitro-produced Gir embryos also result in large offspring. The aim of this work was to evaluate the effect of in vitro embryo production on gestation length, birth weight, and sex ratio in Gir cattle. COCs were harvested by oocyte pickup from mature non-lactating Gir cows and in vitro-matured in TCM 199 medium (Gibco, Sao Paulo, Brazil) with 10% inactivated estrous cow serum for 24 h under 5% CO2 at 38.5°C in air. Gir spermatozoa were obtained through the swim-up method and co-incubated with oocytes in Fert-TALP media (Parrish JJ et al. 1988 Biol. Reprod. 38, 1171–1180) with 10 μg/mL heparin (Sigma, Sao Paulo, Brazil) and 6 mg/mL fatty acid-free bovine albumin (Sigma) for 18 h in 5% CO2 at 38.5°C in air. Presumptive zygotes were co-cultured with their own cumulus cells in CR2aa medium (Wilkinson RF et al. 1996 Theriogenology 45, 41–49) with 10% fetal calf serum in humid atmosphere of 5% CO2 at 38.5°C in air. Fresh Day 7 blastocysts were transferred to synchronized B. indicus × B. taurus crossbred recipients. Data of gestation length, birth weight, and gender ratio from 26 IVP calves (IVP group) were recorded and compared to data obtained from Gir calves produced by artificial insemination or natural mating (n = 24; control group) using ANOVA or chi-square analysis. There was no difference (P > 0.05) in gestation length between pregnancies of the IVP and control groups (mean ± SEM, 285.4 ± 1.5 vs. 284.4 ± 1.1 days, respectively). IVP and control calves showed similar (P > 0.05) weight at calving (29.6 ± 0.9 vs. 26.9 ± 1.2 kg for IVP and control male calves, and 27.0 ± 2.5 vs. 25.2 ± 0.5 kg for IVP and control female calves, respectively). The percentage of male calves was greater (P < 0.05) in the IVP group than in the control group (76.9% vs. 43.4%, respectively). IVP calves did not show abnormalities associated with Large Offspring Syndrome, such as breathing difficulty and perinatal death. These data suggest that in vitro production may affect the development of Gir embryos, biasing the sex ratio in a manner similar to previously reported for in vitro-produced embryos from Bos taurus breeds. This work was supported by FAPEMIG and CNPq.

Genetic and environmental factors influencing litter size, sex ratio and gestation length in the pig

1978 ◽  
Vol 27 (1) ◽  
pp. 35-42 ◽  
Author(s):  
B. W. Kennedy ◽  
J. E. Moxley
Keyword(s):  
Sex Ratio ◽  
Litter Size ◽  
Gestation Length ◽  
Live Births ◽  
Factors Influencing ◽  
Size Number ◽  
Genetic And Environmental Factors ◽  
Sire Breed ◽  
Number Of Males ◽  
Length Of Gestation

ABSTRACTData from 675 litters were used to study the effects of type of service, number of services, parity, year, season, breed of sire, sire, type of dam (purebred or crossbred), breed of dam, dam, breed of sire × type of dam and breed of sire × breed of dam on litter size (live births), number of males, number of females, sex ratio (percentage of males) and length of gestation. Yorkshire, Landrace and Lacombe breeds and their crosses were represented. Artificial insemination significantly reduced litter size and the number of females and increased sex ratio. Parity had a significant effect on all traits except sex ratio. Lacombe-sired litters were approximately one-half pig smaller than Yorkshire- and Landrace-sired litters. Landrace-sired litters had gestations of one-third day shorter than Yorkshires. On average, crossbred dams farrowed 0·65 more pigs per litter than pure-bred dams. Litters from Yorkshire dams, however, were more than one pig larger than Landrace and Lacombes, and did not differ significantly from crossbred dams. Gestation length of Lacombe sows was 1·34 days shorter than Yorkshires. Repeatabilities of litter size, number of males, number of females, sex ratio and gestation length were 0·15, 0·08, 0·06, 0·05 and 0·32 respectively.

scholarly journals The sex ratio in farmed American mink (<i>Neovison</i> <i>vison</i>)

2018 ◽  
Vol 61 (3) ◽  
pp. 359-363
Author(s):  
Lidia Felska-Błaszczyk ◽  
Natalia Ławrów ◽  
Bogdan Lasota ◽  
Beata Seremak ◽  
Katarzyna Pęzińska-Kijak ◽  
...  
Keyword(s):  
Sex Ratio ◽  
American Mink ◽  
Male Offspring ◽  
Time Interval ◽  
Gestation Length ◽  
Northern Poland ◽  
Mating Interval ◽  
Mating Time

Abstract. The aim of the study was to analyse the sex ratio of American mink litters in relation to dam's age, gestation length, and time interval between the first and second mating. The observations were carried out on a mink farm located in northern Poland. The analysis involved litters of 207 females, aged 1 (n=107) and 2 years (n=100), which successfully raised all the born kits. The sex of the offspring was identified on weaning. The kits were assigned to groups according to their dam's gestation length, mating date, and first-to-second mating interval. It was found that female kits quantitatively predominated over male offspring. Longer pregnancies, delayed mating time, and greater interval between the first and second mating was accompanied by a higher number of female births in relation to male births.

Die unbehandelten Kranken: Ältere Männer mit Depression

2008 ◽  
Vol 27 (07) ◽  
pp. 617-619 ◽  
Author(s):  
M. Wittmann ◽  
E. Haen ◽  
H. Spießl ◽  
H. Hausner
Keyword(s):  
Sex Ratio ◽  
Epidemiologische Studien

ZusammenfassungZahlreiche epidemiologische Studien zeigen, dass sich das Geschlechterverhältnis der Prävalenz depressiver Erkrankungen ab der 6. Lebensdekade – also nach der weiblichen Menopause – wieder annähert. Wir haben untersucht, ob sich dieser epidemiologische Effekt auch in der stationären Versorgung abbildet. Unter Verwendung der AGATE-Stichtagsdaten der Jahre 2000 bis 2004, wurde der Zusammenhang zwischen Geschlecht und Alter bei stationär behandelten depressiven Patienten analysiert. Der Zusammenhang zwischen Geschlechterverhältnis und dem Alter wurde mithilfe des Korrelationskoeffizienten nach Spearman sowie mit χ2-Test untersucht. In der 5. und 6. Lebensdekade lag die Sex-Ratio F/M bei 1,7:1, sie stieg in der 7. Dekade auf 2,2:1 und in der 8. Dekade auf 2,6:1 an. Anders als aufgrund epidemiologischer Studien zu erwarten wäre, nähert sich in der stationär psychiatrischen Versorgung das Verhältnis depressiver Patienten im Alter nicht an. Depressive ältere Männer sind also im stationären Versorgungssystem unterrepräsentiert.

Sign in / Sign up

Export Citation Format

Share Document