this trial was conducted to evaluate the effects of different dietary factors that affect egg cholesterol concentration in laying hens of 56 to 70 weeks of age. three hundred and ninety six hy-line w36 laying hens were subjected to 11 experimental treatments, each treatment consisting of 4 replicates, each replicate of 9 hens. dietary treatments included the control, made up of corn plus soy me...

Egg-laying behavior of free-living Willow Ptarmigan (Lagopus lagopus) was studied at Chilkat Pass, B.C. to learn if females were indeterminate egg-layers in natural conditions. Eggs were removed from clutches of experimental birds during laying, usually beginning with the third egg. All birds were determinate egg-layers and there was no difference in the number of eggs laid by control (K = 8.11...

Deformed wing virus is an important contributor to honey bee colony losses. Frequently queen failure is reported as a cause for colony loss. Here we examine whether sexual transmission during multiple matings of queens is a possible way of virus infection in queens. In an environment with high prevalence of deformed wing virus, queens (n = 30) were trapped upon their return from natural mating ...

Many factors can negatively affect honey bee (Apis mellifera L.) health including the pervasive use of systemic neonicotinoid insecticides. Through direct consumption of contaminated nectar and pollen from treated plants, neonicotinoids can affect foraging, learning, and memory in worker bees. Less well studied are the potential effects of neonicotinoids on queen bees, which may be exposed indi...

In a recent study, Amsalem, Orlova & Grozinger (2015) performed experiments with Bombus impatiens bumblebees to test the hypothesis that saturated cuticular hydrocarbons are evolutionarily conserved signals used to regulate reproductive division of labor in many Hymenopteran social insects. They concluded that the cuticular hydrocarbon pentacosane (C25), previously identified as a queen pheromo...

Th e aim of the present trial was to study the eff ect of two diff erent dietary phosphorus (P) levels on the laying performance in long-term (17 months) egg production and egg shell quality in terms of strength and thickness from the 7th to 17th month of laying. In case of eggshell quality parameters the time eff ect as well as the interaction between dietary P levels and time were also examin...

An experiment was conducted to evaluate the effects of bacteriophage supplementation on egg performance, egg quality, excreta microflora, and moisture content in laying hens. A total of 288 Hy-line brown commercial laying hens (36-wk-old) were randomly allotted to 4 treatments in this 6-wk trial and dietary treatments included: i) CON, basal diet; ii) T1, CON+0.020% bacteriophage; iii) T2, CON+...

During avian egg production, oestrogen mediates marked increases in hepatic lipid production and changes in the diameter of assembled very-low density lipoprotein (VLDL). A nearly complete shift from generic VLDL ( approximately 70 nm in diameter), which transports lipids to peripheral tissues, to yolk-targeted VLDL (VLDLy) ( approximately 30 nm), which supplies the yolk with energy-rich lipid,...

the aim of this study was to investigate the effects seaweeds gracilariopsis persica in diets on performance and tsh, t3 and t4 hormones in serum of laying quail. a total of 112 laying quails were randomly allocated into four dietary treatments (diets containing 0, 1, 3 and 5% seaweed) with 4 replicates of 7 birds each. the birds were fed on experimental diets for 12 weeks. eggs were collected ...