منابع مشابه
Lutear Cells and Hen-feathering
The experimental evidence had made clear that some substance is produced in the testis of the male Sebright that suppresses in him the development of the secondary sexual plumage of the cock of his species. The detection in his testis of lutear cells like those in hens makes the conclusion highly probable that it is these cells that cause the suppression of cock-feathering in both the Sebright ...
متن کاملGroup selection for adaptation to multiple-hen cages: beak-related mortality, feathering, and body weight responses.
The hypothesis was tested that selection on the basis of family means for increased survival and hen-housed egg production, when sisters with intact beaks were kept together in multiple-bird cage, would cause adaptive changes in behavior. Specifically, it was posited that beak-inflicted injuries causing cannibalistic mortality and feather loss and damage would be reduced. Body weight effects we...
متن کاملSpurs and feathering in spiral galaxies
We present Smoothed Particle Hydrodynamics (SPH) simulations of the response of gas discs to a spiral potential. These simulations show that the commonly observed spurs and feathering in spiral galaxies can be understood as being due to structures present in the spiral arms that are sheared by the divergent orbits in a spiral potential. Thus, dense molecular cloud-like structures generate the p...
متن کاملAltered feathering of chicks caused by T-2 toxin.
Dietary T-2 toxin (0, 1, 2, 4, 8, and 16 mug./g.) was fed to 4 groups of 10 chickens at each treatment level from hatching until 3 weeks of age. Growth inhibitory levels (4, 8, and 16 mug./g.) caused abnormal feathering which appeared dose related. The chickens were sparsely covered with short feathers protruding at odd angles in comparison to controls. There were few feathers on the base of th...
متن کاملA new Eocene swift-like bird with a peculiar feathering
A new taxon of swift-like birds is described from the Middle Eocene of Messel (Germany). It is tentatively assigned to the extinct family Jungornithidae and exhibits a completely unexpected feathering, which contrasts sharply with that of recent swifts. The short and rounded wings clearly show that it was not adapted to gliding, but might have caught its prey by sallying flights from a perch. T...
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ژورنال
عنوان ژورنال: Journal of the American Association of Instructors and Investigators of Poultry Husbandry
سال: 1920
ISSN: 2666-3651
DOI: 10.3382/ps.0070014