Developmental instability and light regime in chickens (Gallus gallus)

Møller, Anders Pape; Sanotra, G. S.; Vestergaard, K.

doi:10.1016/s0168-1591(98)00213-5

Cited by 72 publications

(41 citation statements)

References 21 publications

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“…Findings are consistent with previous reports that bodily FA is negatively associated with sex-typical facial structure (36,37) and that relative leg length correlates differently with attractiveness across the sexes (12). Body size and shape are important not only for aesthetic preferences but also have significant functional consequences (18)(19)(20)(21)(22)(23). For example relative leg length (38) and pelvis configuration (23) influence mobility in humans and thus could account in part for the previous associations found between human FA and locomotory performance (22,27).…”

Section: Resultssupporting

confidence: 89%

“…Higher FA is associated with increased morbidity and mortality, decreased fecundity, and other variables linked to natural and sexual selection (9,10). Higher FA also is associated with poorer locomotory trait design and performance in several species, including humans (18)(19)(20)(21)(22)(23). Finally, it has been reported that bodily FA is inversely associated with attractiveness based on a person's odor (24), voice (25), facial appearance (26), and dance (27).…”

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confidence: 99%

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Fluctuating asymmetry and preferences for sex-typical bodily characteristics

Brown

Price

Kang

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

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Body size and shape seem to have been sexually selected in a variety of species, including humans, but little is known about what attractive bodies signal about underlying genotypic or phenotypic quality. A widely used indicator of phenotypic quality in evolutionary analyses is degree of symmetry (i.e., fluctuating asymmetry, FA) because it is a marker of developmental stability, which is defined as an organism's ability to develop toward an adaptive end-point despite perturbations during its ontogeny. Here we sought to establish whether attractive bodies signal low FA to observers, and, if so, which aspects of attractive bodies are most predictive of lower FA. We used a 3D optical body scanner to measure FA and to isolate size and shape characteristics in a sample of 77 individuals (40 males and 37 females). From the 3D body scan data, 360°videos were created that separated body shape from other aspects of visual appearance (e.g., skin color and facial features). These videos then were presented to 87 evaluators for attractiveness ratings. We found strong negative correlations between FA and bodily attractiveness in both sexes. Further, sextypical body size and shape characteristics were rated as attractive and correlated negatively with FA. Finally, geometric morphometric analysis of joint configurations revealed that sex-typical joint configurations were associated with both perceived attractiveness and lower FA for male but not for female bodies. In sum, body size and shape seem to show evidence of sexual selection and indicate important information about the phenotypic quality of individuals.3D morphometrics ͉ body shape ͉ developmental stability ͉ sexual dimorphism ͉ sexual selection I n humans, as in other species, sex differences in size and shape are attributed to divergent effects of morphology on the survival or reproductive success of each sex (1-10). For human females, smaller waist relative to hips (WHR), larger breasts, and longer legs relative to height have been attributed to fecundity selection and are perceived as attractive by males (8,11,12). In human males, greater height, larger size, and shorter legs relative to height are believed to have arisen through sexual selection by enhancing success in male-male rivalry (6, 7) and by being more attractive to females (6, 12). In addition, pronounced secondary sex characteristics may be preferred because they are signals of a pathogen-resistant genotype (13). However, recent theoretical models suggest that high-quality signalers may be more resistant, equally resistant, or less resistant to pathogens, depending on life history trade-offs between reproductive effort, survival, and fecundity (14, 15). For example, high-quality males that produce costly signals may compromise their future survival but nonetheless be more fit than their low-quality competitors.If sex-typicality of body size and shape are attractive to the opposite sex because they indicate phenotypic quality, then these conspicuous sex-specific signals are expected to correlate negativ...

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Section: Resultssupporting

confidence: 89%

mentioning

confidence: 99%

Fluctuating asymmetry and preferences for sex-typical bodily characteristics

Brown

Price

Kang

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

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“…However, greater dorsal pelvic width asymmetry in one strain was associated with lower estimated fertility, but it is not clear how pelvic width was considered to be a bilateral trait. This is in contrast with other studies measuring morphological traits, which suggest that fluctuating asymmetry, as a measure of developmental stability, is a reflection of genetic or environmental stress, and has been suggested, and used, to measure genetic stress (Yang et al, 1997;Yang & Siegel, 1998) and welfare and environmental stress (Møller et al, 1999;Yalcin et al, 2001) The L and R testis weights were shown by the t-test to be significantly different for males on each treatment, except for those birds photostimulated at 161 d, where the L and R testis weights were the same. The other bilateral traits measured also showed directional asymmetry, except for HL, which showed a skew distribution.…”

Section: Left Minus Right Testis Weight (G)contrasting

confidence: 67%

The effect of age at photostimulation of male broiler breeders on testes growth and the attainment of sexual maturity

Tyler

Gous

2009

SA J. An. Sci.

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________________________________________________________________________________ AbstractMale broiler breeders were photostimulated at different ages (56, 77, 98, 119, 147 and 161 d) during the period of growth prior to achieving sexual maturity to observe their response to photoperiod stimulation. Birds were sampled at regular intervals to measure the average testis weight -these values responding curvilinearly to the age at photostimulation, similar to the attainment of sexual maturity observed previously in females. However, males reached sexual maturity at an earlier age than females, as measured by the start of semen production. Based on the age at first semen production, no differences in the mean age at sexual maturity (ranging from 164 to 172 d) resulted from the different ages at photostimulation. Testis weights from males on different photostimulation treatments showed that some males respond to early stimulation, but from 189 d of age some of these early photostimulated males still had an average testis weight of less than 10 g, while males photostimulated 98 d and later all had an average testis weight over 10 g. Serum testosterone concentration measured at 351 d also showed that early photostimulation resulted in two groups of birds that either responded or not. At 351 d the serum testosterone concentration was more evenly distributed in males photostimulated after 98 d, while males photostimulated before 98 d had either high or low serum testosterone concentrations. Directional asymmetry was observed in testis weights, with the left testis being bigger than the right. Other bilateral traits measured also showed directional asymmetry, an indication of developmental instability. However, the degree of relative asymmetry was not related to treatment. All males should respond to photostimulation by 98 d but some respond earlier, and these could be used by broiler breeding companies to eliminate seasonality in these birds. ________________________________________________________________________________

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“…This situation indicates that the animals in group FR2 show significant deviations from the perfect symmetry. The fact that the deviations from the symmetry are mostly in the form of DA also show that the growth at one side of the morphological character is lower or higher in comparison with the other side As deviations from bilateral symmetry increased, some abnormalities of developmental stability may appearance in animals (MOLLER and POMİANKOWSKİ, 1993;MOLLER and SWADDLE, 1997;MOLLER et al, 1999;MOLLER and MANNING, 2003). This may cause in negative changes in the performances of animals and thereby economic losses.…”

Section: Results Allometric Growth Curvesmentioning

confidence: 99%

“…Environmental stress may affect developmental stability, thus, increasing variation among individuals. In poultry, developmental instability mostly derive from the fact that more birds are kept in each m2 (stocking density), appropriate lighting program is not applied, feeding programs carried out (ad libitum and feed restriction) and some other negative conditions in the poultry house (MOLLER et al, 1995;YANG et al, 1997;AL-MAHROUS, 1997;MOLLER et al, 1999;YALÇIN et al, 2003). Developmental stability cannot be measured directly.…”

Section: Introductionmentioning

confidence: 99%

Asymmetry measures and allometric growth parameter estimates for investigate effect of early feed restriction on deviation from bilateral symmetry in broiler chickens

Mendeş

2008

Arch. Anim. Breed.

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The purpose of this study is to investigate the effect of different feeding programs such as ad libitum feeding (AD), 20 % feed restriction based on ad libitum group (FR1) and not fed between 9 a.m. and 3 p.m. (FR2) on deviation from bilateral symmetry or developmental stability in broiler chickens by means of two different approaches namely asymmetry measures and allometric growth model parameters. The weekly left and right sides of shank length, shank width, wing length and face width of chickens were collected from 7 days of age to 42 days of age. Results of this study showed that the deviations from the bilateral symmetry were mostly in fluctuating asymmetry (FA) in the FR1 group birds. On the other hand, the deviations from the bilateral symmetry in the birds in group AD and FR2 were mostly in the form of anti-symmetry (AS) and directional asymmetry (DA) respectively. In this study, the deviation from the bilateral symmetry was mostly in FA type for the measured morphological characters for the FR1 group, and the FA level was usually lower indicating higher welfare level and lower developmental instability for these animals than that of the AD and FR2 groups. Allometric growth coefficients for evaluating the effects of the feeding programs on the developmental stability were a little bit different from the findings obtained by the asymmetry measures' being taken into account. Allometric growth parameters, therefore, should be taken into consideration, along with asymmetry measures when investigating effect of rearing conditions or environmental conditions on developmental stability. As a conclusion, intensive feeding (AD) and long-term feed restriction (FR2) can be said as an important environmental factor affecting developmental stability and dependently the animal welfare and performance.

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Developmental instability and light regime in chickens (Gallus gallus)

Cited by 72 publications

References 21 publications

Fluctuating asymmetry and preferences for sex-typical bodily characteristics

Fluctuating asymmetry and preferences for sex-typical bodily characteristics

The effect of age at photostimulation of male broiler breeders on testes growth and the attainment of sexual maturity

Asymmetry measures and allometric growth parameter estimates for investigate effect of early feed restriction on deviation from bilateral symmetry in broiler chickens

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