this experiment was designed to evaluate the effects of different levels of tomato pomace (dtp) with different multi enzymes on the performance and egg quality of laying hens at the first phase of production. in this experiment 432 hens were used in a completely randomized design in a factorial arrangement of 4×4, with four levels of tomato pomace (0, 4, 8 and 12) and different enzymes (without...

An experiment was conducted to investigate the effects of dietary supplementation of Rhodobacter capsulatus KCTC-2583 on egg-yolk and serum cholesterol, egg production and quality parameters during the late laying periods in hens. A total of 160 Hy-Line Brown layers (54 wk-old) were randomly allotted to 4 treatment groups on the basis of laying performance. Each treatment had 4 replicates with ...

Genetic studies of behavior in the nematode Caenorhabditis elegans have provided an effective approach to investigate the molecular and cellular basis of nervous system function and development. Among the best studied behaviors is egg-laying, the process by which hermaphrodites deposit developing embryos into the environment. Egg-laying involves a simple motor program involving a small network ...

—Bird species, including raptors, can often be categorized into two groups depending upon their response to alterations in clutch size while laying. For some, clutch size is predetermined prior to the start of laying (i.e., determinate species). In contrast, the clutch size of indeterminate layers can be influenced by external factors present at the time of laying. Using field experiments, our ...

The present study was designed (i) to assess the changes in the activity of 3beta-hydroxysteroid dehydrogenase (3beta-HSD) and cytochrome P450 aromatase (P450arom) in the ovaries of hens which are subjected to a pause in egg laying by fasting, and (ii) relate these changes with progesterone (P(4)) and estradiol (E(2)) production in the ovary. Hy-Line Brown laying hens (n=90) were fasted for 5 d...

this study was conducted to investigate performance of native chickens produced in the centre of production and breeding of native chicken of isfahan in rural areas of isfahan province by using 1440 native pullets with age of 45 days in 4 towns and 2 climate zone of warm and cold. this study employed by coworking 60 rural families that 24 pullets with age of 45 days with ratio of 5 hen to 1 roo...

this study was aimed to determine abundance and body distribution of prm in laying hens of arak. a total of 1400 laying hens were randomly examined from january to june 2008. of those, 26 (92.86%) layer farms were found to be infested with dermanyssus gallinae (39.3%). there was significant association between prevalence and climatic conditions of the region. the most common predilection site o...

Two experiments were conducted to determine whether taurine supplementation to laying hens would influence laying performance. In Experiment 1, a total of 120 White Leghorn hens were fed diets supplemented with 0, 0.25, or 0.5% taurine for 5 wk. Egg weight was reduced significantly by supplementing 0.25 and 0.5% taurine; however, taurine did not affect other laying performance variables. In Exp...

this experiment was carried out to study the effects of different levels of canola meal of different fat sources on the egg quality, performance as well egg yolk cholesterol during the first 12 weeks of age in laying hens (hy-line w-36). throughout the experiment a total of 432 hens were employed in a completely randomized design in a factorial arrangement of 3×4, with three levels of canola me...