Broiler chicks with high immune defense potential at hatching are of great value to the poultry industry. Heat stress can have immunosuppressive or immune stimulatory effect and Ascorbic Acid (AA) acts as anti-stressor and has important physiological functions in bird immune system development. This study aimed to assess the effect of intra egg injection of AA before incubation on development o...

Substratum quality and oxygen supply to the interstitial zone are crucial for the reproductive success of salmonid fishes. At present, degradation of spawning grounds due to fine sediment deposition and colmation are recognized as main factors for reproductive failure. In addition, changes in water temperatures due to climate change, damming, and cooling water inlets are predicted to reduce hat...

Avian eggs contain all the necessary materials for embryonic development except for oxygen, which diffuses in from the environment via pores in the hard, calcified eggshell to the chorioallantoic membrane (CAM), the respiratory organ, which is rich in blood vessels. An air cell is formed at the blunt pole of the egg between the two membranes of the eggshell and enlarges during incubation due to...

The aim of this study was to identify the optimal storage duration of incubated eggs of Dandarawi hens on embryonic mortality, hatchability, one-day chick weight and viability of chicks at 14 days of age. Eggs were collected 4 times daily for 15 consecutive days and stored at 16°C and 70% RH until sorted into treatments and then were incubated for 21 d under standard incubation conditions. The ...

________________________________________________________________________________ Abstract Eggs from a meat-type breeder flock at 29 and 35 weeks of age were used in two trials to investigate the effects of in ovo feeding of carbohydrates (CHO) and high incubation temperature (37.5 vs. 38.5 °C (HIT)) during days 16 to 21 of incubation on hatchability traits, chick weight at hatch as an absolute ...

The influence of membrane cholesterol content on 3-hydroxy-3-methylglutaryl CoA reductase (HMG-CoA reductase, EC 1.1.1.34) in rat liver microsomes was investigated. Microsomes were enriched in cholesterol by incubation with egg phosphatidylcholine-cholesterol vesicles and the nonspecific lipid transfer protein from rat liver. By this method, the microsomal cholesterol content was 2.5-fold enhan...

We used a recent passerine phylogeny and comparative method to evaluate the macroevolution of body and egg mass, incubation and fledging periods, time to independence and time with parents of the main passerine lineages. We hypothesised that passerine reproductive traits are affected by adaptation to both past and present environmental factors and phenotypic attributes such as body mass. Our re...

We developed an individual-based simulation model to explore the effects of harvesting eggs from a glaucous-winged gull (Larus glaucescens) colony that also experiences egg loss from avian predators. The model has direct application to Glacier Bay National Park, where resource managers are concerned about potential negative effects of traditional Native Alaskan harvesting of gull eggs at coloni...