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...

the identification of different species of simuliidae, also called “black fly”, is based on particular structure of oral and terminal appendages of their larvae add also on the special morphology of adults and pupaes. because of their considerable flight range, the problem of finding their resting places, and also the difficulties of collecting the adult flies, breeding of this insect, in the l...

In 1971 we estimated that Schistosoma mansoni eggs in the tissues of mice were destroyed with an approximate half-life of four weeks. Our present results of five experiments suggest that egg destruction is not as rapid, and no significant destruction of eggs was detected for up to 26 weeks after treatment. However, in these experiments, a mean of 60% of the eggs in intestinal tissues were found...

Introduction: Feathers are important body structures that act as surface insulators to reduce maintenance energy requirements and also to protect skin against abrasions and infection. The purpose of this study is to investigate the effects of methionine injection into the yolk sac on development of feather follicle in chicken embryo. Methods: 50 fertilized eggs (weighting 50±0.4 gr) of Ross×...

This study was conducted to determine the effects of increasing lighting after peak production on eggs production and Hatchable Eggs in broiler breeder Hubbard F15. In this research we used from 4 growing saloons, that in per saloons were 5250 Hubbards broiler breeder hens. In this Experiment we used by Line design way of GLM for analysed data, that we considered the Effects of two parameters, ...

Control females of the twospotted stink bug, Perillus bioculatus (F.), and those given an artiÞcial diet mated repeatedly over their lifetimes when held with males. The average number of observed matings was 4 and 8.4 in the controls and those given the artiÞcial diet, respectively. Mating and an adequate diet are prerequisites for laying a full compliment of eggs in this insect. Virgins laid a...