The objective of this study was to compare fattening performance, carcass traits, and egg quality of Japanese quails with different feather colors (white, dark brown, golden, and wild-type). In the study, 360 one-day-old quail chicks with 4 different feather colors were used as animal material. Quails were fed ad libitum for 42 days to determine fattening performance and carcass traits. To dete...

Obligate brood parasitic birds lay their eggs in nests of other species and parasite eggs typically have evolved greater structural strength relative to host eggs. Increased mechanical strength of the parasite eggshell is an adaptation that can interfere with puncture ejection behaviours of discriminating hosts. We investigated whether hardness of eggshells is related to differences between phy...

This study deals with the effects of different hatcher temperatures on hatching traits in modern commercial broiler eggs during the last five days of incubation. The hatching eggs were obtained from a 52wk old (Ross 308) flock. All eggs were distributed randomly into one incubator and incubated for 17 d using uniform conditions (37.6 ± 0.5 °C and 58% relative humidity). At the start of 18 days ...

this study was conducted to investigate direct and maternal effects on some economic traits in north iranian native fowls. traits considered were body weight at 1 day of age (bw1), body weight at 8 weeks of age (bw8), body weight at 12 weeks of age (bw12), egg number (en) during the first 12 weeks of laying period, egg weight at 1st day of laying (ew1), mean egg weight at 28th, 30th and 32nd we...

Drosophila melanogaster is able to thrive in harsh northern climates through adaptations in life-history traits and physiological mechanisms that allow for survival through the winter. We examined the genetic basis of natural variation in one such trait, female virgin egg retention, which was previously shown to vary clinally and seasonally. To further our understanding of the genetic basis and...

Phenotypic measurements of chicken egg character and production traits are restricted to mature females only. Marker assisted selection of immature chickens using quantitative trait loci (QTL) has the potential to accelerate the genetic improvement of these traits in the chicken population. The QTL for 12 traits (i.e. body weight (BW), six for egg character, three for egg shell colour and two f...

Mango (Mangifera indica) is an economically and nutritionally important tropical/subtropical tree fruit crop. Most of the current commercial cultivars are selections rather than the products of breeding programs. To improve the efficiency of mango breeding, molecular markers have been used to create a consensus genetic map that identifies all 20 linkage groups in seven mapping populations. Poly...

Sexual selection has been suggested to be an important driver of speciation in cichlid fishes of the Great Lakes of Africa, and the presence of male egg dummies is proposed to have played a key role. Here, we investigate how mouthbrooding and egg dummies have evolved in Tanganyikan cichlids, the lineage which seeded the other African radiations, with a special emphasis on the egg dummies. Using...

Hosts of brood-parasitic birds must distinguish their own eggs from parasitic mimics, or pay the cost of mistakenly raising a foreign chick. Egg discrimination is easier when different host females of the same species each lay visually distinctive eggs (egg 'signatures'), which helps to foil mimicry by parasites. Here, we ask whether brood parasitism is associated with lower levels of correlati...

Many life-history traits are expressed interactively in life, but to a varying extent on different occasions. Changes in trait expression can be accounted for by differences in the quality of the environment ('environmental constraint' hypothesis) or by strategic adjustments, if the relative contribution of the trait to fitness varies with time ('strategic allocation' hypothesis). In birds, egg...