Maternal social status and birth sex ratio in domestic pigs: an analysis of mechanisms

  title={Maternal social status and birth sex ratio in domestic pigs: an analysis of mechanisms},
  author={Michael T. Mendl and Adroaldo Jos{\'e} Zanella and Donald M. Broom and Colin Trengove Whittemore},
  journal={Animal Behaviour},

Sex ratio in litters of domestic pigs (Sus scrofa f. domestica Linnaeus, 1758)

It was found that paternal breed and litter size significantly affected the offspring sex ratio (fewer males in larger litters) and maternal month of birth had a significant influence on offspring sex ratios.

Sex ratio in litters of domestic pigs [Sus scrofa f.domestica Linnaeus, 1758]

It was found that paternal breed and litter size significantly affected the offspring sex ratio (fewer males in larger litters) and maternal month of birth had a significant influence on offspring sex ratios.

Dominance Rank and Parental Investment in Swine (Sus scrofa domesticus)

Using domestic swine, we tested the general prediction from life history theory that females increase their investment in offspring with increasing age and parity. Because increased investment may

The Weaker Sex? The Propensity for Male-Biased Piglet Mortality

Life history strategies are being displayed by a domestic population of pigs with sows in this study displaying a form of parental optimism by allocating greater resources at birth to males and providing an over-supply of this more vulnerable sex in expectation of sex-biased mortality.

Seasonal Variation in Sex Ratios Provides Developmental Advantages in White-tailed Deer, Odocoileus virginianus

It is found that maternal condition did not affect offspring sex ratio in a captive population of White-tailed Deer in Michigan; however, birth date did, and it was found that more males tended to be Born during the second and fourth birthing periods, while more females were born during the first, third and fifth periods.

The sex ratio of a gilt’s birth litter can affect her fitness as a breeding female

There is cause to investigate the effect of the birth litter sex ratio of a gilt on her suitability for selection into the breeding herd, and existing evidence of masculinisation in rodents and sheep is covered.

Sex Ratio Variation in Iberian Pigs

Analysis of sex ratio data of 56,807 piglets coming from 550 boars and 1893 dams and analyses fitting linear and threshold animal models in a Bayesian framework using Gibbs sampling techniques found no trend in sex ratio related to maternal age.

Testing models of adaptive adjustment of secondary sex ratio in domestic swine

It is argued here that the design of the original study by Mendl et al. (1992) was not appropriate for testing whether female swine adjust secondary sex ratios in relation to social dominance ranks, and that the evidence presented does not support the Local Resource Competition model.

Programming of offspring sex ratios by maternal stress in humans: assessment of physiological mechanisms using a comparative approach

  • K. Navara
  • Biology, Psychology
    Journal of Comparative Physiology B
  • 2010
The evidence that stressful events induce sex ratio adjustment in humans is reviewed and the possibility for glucocorticoid mediation ofsex ratio adjustment is discussed and the potential reproductive stages during which stress-induced sex ratio adjusted may occur in humans and other mammals are discussed.

Sex allocation in a polygynous mammal with large litters: the wild boar

Maternal expenditure per individual offspring was higher for male than female fetuses, and mother quality appeared to be related to litter size but not to the sex ratio of the litter, thus supporting Williams' hypothesis that mothers should adjust both litter size and offspring sex.



Maternal dominance rank and secondary sex ratio in domestic swine

Abstract Abstract. Maternal dominance rank may influence the reproductive potential of male and female offspring differently. Recent models of adaptive variation in secondary sex ratio (offspring sex

Maternal dominance, breeding success and birth sex ratios in red deer

It is shown that, in polygynous red deer (Cervus elaphus), dominant mothers produce significantly more sons than subordinates and that maternal rank has a greater effect on the breeding success of males than females.

Sex Ratio Variation in Mammals

Valid evidence that sex ratio trends are adaptive must be based on the overall distribution of trends or on cases in which the sex ratio can be shown to vary with the relative fitness of producing sons and daughters.

Birth sex ratios and social rank in rhesus monkey mothers

High ranking rhesus monkey mothers in the authors' captive colony were more likely to give birth to daughters than sons, while the remaining mothers were morelikely to bear sons than daughters, and a mechanism for adjusting birth sex ratios in macaques is suggested.

Role of the Hypothalamic Paraventricular Nucleus in Mediating Stress‐Related Litter Deficits in the Golden Hamster

It is suggested that subordinate dams produce smaller litters via selective resorption of males in utero and that the paraventricular nucleus of the hypothalamus may be a relay center for the mediation of this response.

Sex ratio variation in relation to maternal condition and parental investment in wild reindeer Rangifer t. tarandus

Along small-sized, resource-limited females with high mortality of progeny during parental investment, the prenatal sex ratio favoured males. After weaning, at the end of juvenile male dispersal, the

Dominance Rank, Secondary Sex Ratio, and Reproduction of Offspring in Polygynous Primates

A model proposed by Trivers and Willard (1973), however, specified how deviations from equal PI may be favored by natural selection according to the influence of maternal condition on the reproduction of offspring.