نتایج جستجو برای: leghorn

تعداد نتایج: 1677  

Journal: :Poultry science 2006
P E Mozdziak R Wysocki J Angerman-Stewart S L Pardue J N Petitte

Modification of the chicken germline has been difficult, because it has been challenging to fractionate sufficient numbers of primordial germ cells for manipulation and implantation into developing embryos. A technique to enrich cell suspensions for primordial germ cells, using fluorescence-activated cell sorting (FACS), has recently been developed. The objective of the current study was to dem...

Journal: :Archives of ophthalmology 2006
Joel A D Javier Jae Bum Lee Hailton B Oliveira Jin-Hong Chang Dimitri T Azar

OBJECTIVE To evaluate corneal scar formation and new collagen deposition after laser subepithelial keratomileusis (LASEK) compared with photorefractive keratectomy (PRK) in the leghorn chick corneal model. METHODS Leghorn chick corneas treated with LASEK surgery (using 20% ethanol for 30 seconds) or PRK were evaluated by indirect confocal immunofluorescence and transmission electron microscop...

Journal: :Poultry science 2010
K J Navara S E Pinson

Maternal stress in birds can have permanent transgenerational effects through the transmission of stress hormones to offspring via the egg yolk. Previous studies have shown that White Leghorn hens show a heightened response to stress compared with Hy-Line Brown hens, producing significantly more corticosterone and displaying longer bouts of tonic immobility after handling, whereas baseline leve...

Journal: :Vision Research 2002
Jeremy A Guggenheim Jonathan T Erichsen Paul M Hocking Nicholas F Wright Rowanne Black

Myopia development in humans depends on a complex interplay between genetic and environmental factors. Many of those who become myopic when exposed to a myopigenic environment are likely to do so because of a genetic susceptibility, whereas others somehow remain immune. In the most intensively studied model of environmentally induced myopia, form-deprivation myopia in the chick, there is convin...

Journal: :The American journal of physiology 1969
J L Tummons P D Sturkie

TUMMONS,JOHN L., AND PAUL D. STURKIE. Nervous control of heart rate during excitement in the adult White Leghorn cock. Am. J. Physiol. 216(6): 1437-1440. 1969.-The control of heart rate by the sympathetics and parasympathetics during excitement has been studied in the adult White Leghorn cock. The data presented in this study demonstrate that at the basal resting heart rate (BRHR) of 280-290 be...

Journal: :Poultry science 2005
H Zhou A D Mitchell J P McMurtry C M Ashwell S J Lamont

Molecular genetic selection on individual genes is a promising method to genetically improve economically important traits in chickens. A resource population was developed to study the genetics of growth, body composition, skeletal integrity, and metabolism traits. Broiler sires were crossed to dams of 2 diverse, highly inbred lines (Leghorn and Fayoumi), and the F1 birds were intermated by dam...

M. Mazhari, Y. Badakhshan

An experiment was conducted to study the effect of Epinephrine (EP) and bromocriptine (BR) on productive traits of laying hens. Thirty White Leghorn hens, 50 weeks old, were divided into three equal treatments (with 10 hens for each treatment): control, physiological serum (0.5 mL/hen/week), EP (0.5 mL/hen/week) and BR (100 g/kg of body weight (BW); w/v in absolute alcohol). Hens were injected ...

Journal: :Poultry science 1997
A Yang E A Dunnington P B Siegel

The degree of asymmetry in bilateral morphological characters may reflect genetic and environmental stressors. Shank length and diameter, weight and length of the first primary wing feather, and distance between the junction of upper and lower mandibles and auditory canal (face length) were used to classify bilateral types and measure relative asymmetry (RA) in six genetic stocks. The stocks we...

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