The solicitation behaviours performed by dependent young are under selection from the environment created by their parents, as well as wider ecological conditions. Here we show how mechanisms acting before hatching enable canary offspring to adapt their begging behaviour to a variable post-hatching world. Cross-fostering experiments revealed that canary nestling begging intensity is positively ...

If a mother's nutritional status predicts the nutritional environment of the offspring, it would be adaptive for mothers experiencing nutritional stress to prime their offspring for a better tolerance to poor nutrition. We report that in Drosophila melanogaster, parents raised on poor larval food laid 3-6% heavier eggs than parents raised on standard food, despite being 30 per cent smaller. The...

Present study was conducted to evaluate the quality traits of poultry eggs collected from various sources i.e. market, commercial farm and backyard farming, in Karachi. A total of 250 eggs were analyzed for external and internal qualities. A significant difference (p <0.05) was recorded in quality parameters except percent shell, shell thickness, egg width, egg weight, shape index and Haugh uni...

Aim: In the present study, egg quality traits of endangered Nicobari fowl and its crosses (Nicorock and Nishibari) were evaluated under intensive (deep litter) as well as backyard system, in the regions of Andaman and Nicobar Islands, India. Materials and Methods: Fresh eggs (15) of all the three genetic groups of birds were collected randomly from institute farm (intensive system) and from far...

The present study aimed at evaluating the effect of the dietary inclusion of organic trace minerals selenium and zinc on the performance and internal and external egg quality of Japanese quails submitted to heat stress. Data on egg production, feed conversion (kg feed intake/ kg eggs and dozen eggs), egg weight, egg specific gravity, eggshell thickness and weight, Haugh unit, yolk index, albume...

Little is known about natural genetic variation for survival under oxidative stress conditions or whether genetic variation for oxidative stress survival is associated with that for life-history traits. We have investigated survival in a high-oxygen environment at 2 adult densities using a set of recombinant inbred lines (RILs) isolated from a natural population of Drosophila melanogaster. Fema...

Evolutionary theory of plant defences against herbivores predicts a trade-off between direct (anti-herbivore traits) and indirect defences (attraction of carnivores) when carnivore fitness is reduced. Such a trade-off is expected in plant species that kill herbivore eggs by exhibiting a hypersensitive response (HR)-like necrosis, which should then negatively affect carnivores. We used the black...

Fertilization in sea urchins, Strongylocentrotus purpuratus, is the result of a series of interactions between the egg and sperm. Microfilament formation has been implicated in both the acrosomal process formation and the entry of the sperm into the egg. Changes in internal calcium concentrations have been linked to exocytosis reactions that occur in both the egg and the sperm. Therefore, the d...

Records of a White Leghorn Line from three generations were used to evaluate the genetic parameters (heritabilities and breeding values) for production traits in laying hens based on individual and group mean records, taking into account mortality in the data structure. Three different data structures of group mean records, which were Hen Housed Production (HHP), Hen Housed Production corrected...