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...

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+...

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...

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,...

This experiment was conducted, during a seven-week period to investigate, the effects of using various levels of garlic cloves and turmeric rhizome powders, on laying hens’ performance, egg quality characteristics and cholesterol content in yolk. Two hundred and sixteen, 27-weeks old Novogen white laying hens were assigned randomly into nine treatments with eight replicates of three birds each....

abstract  introduction: this experiment was conducted to study the effects of different levels of flaxseed (0, 5, 10 and 15% of diet) and copper (in the form of cupric sulfate pentahydrate, 0 and 250 ppm of diet) on fatty acids and cholesterol in egg yolk of laying hens. methods: a total of 128 white leghorn layers aged 50 weeks were used in a factorial design and randomly assigned to 8 treatme...

this study aimed to decrease the cholesterol content of egg yolk of laying hens through inclusion of barley malt rootlets in the diets. forty-two, 54-week-old, lohman laying hens were fed for a 12 weeks laying period on 3 iso-caloric and iso-nitrogenous diets contained 0 (control), 25.5 or 51.1g barley malt rootlets/kg. inclusion of barley malt rootlets at 25.5 or 51.1g/kg diet significantly de...

In avians, yolk synthesis is regulated by incorporation of portomicrons from the diet, transport of lipoproteins from the liver, and release of lipids from adipose tissue; however, the extent to which lipolysis in adipose tissue contributes to yolk synthesis and egg production has yet to be elucidated. G0/G1 switch gene 2 (G0S2) is known to bind and inhibit adipose triglyceride lipase (ATGL), t...

The population of great hornbills (Buceros bicornis) in the United States is rapidly aging, and captive breeding efforts have not met population managers’ expectations for a sustainable captive group. Little is known about the reproductive physiology of these birds. This study reports the first data on the reproductive endocrinology of the great hornbill. The hormone profiles of the only pair o...