The quality of parts produced by a composite tape-laying process is sensitive to the contact force exerted and the abutment of adjacent tape courses kept when the tapes are laid. Thus, a prerequisite for a high performance laying process automated by means of industrial manipulators is the ability to regulate laying force and position precisely in the presence of robot motion inaccuracies and l...

There has been growing social and scientific interest in recent years in laying hen welfare. Stress is an animal welfare parameter that has been found to alter laying hens’ physiology and social behaviour. Our study aims to test the effects of the different housing systems (laying cage, barn and free range) on the laying hens’ welfare. In this study we have taken a new approach to determine str...

this experiment was conducted to evaluate the effects using of different levels of rosemary hydro-alcoholic extract (rosmarinus officinalis l.) on productive performance and egg quality indicators, in laying hens. the levels of rosemary hydro-alcoholic extract in this experiment were 0, 500, 1000 and 1500ppm. this experiment was conducted in a blok completely randomized design with 160 “hy-line...

Seasonal decline in clutch size is common in birds, but the proximate mechanisms for this phenomenon have not been elucidated. The most credible model to date posits that late-laying females lay fewer eggs due to a seasonal increase in the tendency to incubate during laying, which inhibits egg production. We tested this model with free-living and laboratory American Kestrels (Falco sparverius) ...

The effects of housing systems on the calcium requirement for eggshell production, eggshell quality and on the breaking strength of the hen’s tibia were evaluated. Unenriched cages (UN) (24 laying hens), enriched cages (EN) (16 laying hens) and floor system (FS) (24 laying hens) were used in this experiment. The eggshell production of laying hens from 19 to 66 weeks of age was higher (P < 0.01)...

Exploration of causal components of plasticity is important for insight into evolutionary dynamics and an organism's ability to respond to climate change. Among individuals, variation in plasticity can be due to genotype-environment interaction (GxE) or a result from environmental effects associated with an individual. We investigated plasticity for laying date in the common gulls Larus canus, ...

A major question for conservationists and evolutionary biologists is whether natural populations can adapt to rapid environmental change through micro-evolution or phenotypic plasticity. Making use of 17 years of data from a colony of a long-distant migratory seabird, the common tern (Sterna hirundo), we examined phenotypic plasticity and the evolutionary potential of breeding phenology, a key ...

Numerous studies have demonstrated influences of hybrid, feed, and housing on prevalence of keel bone fractures, but influences of behavior and production on an individual level are less known. In this longitudinal study, 80 white and brown laying hens were regularly checked for keel bone deviations and fractures while egg production was individually monitored using Radio Frequency Identificati...

The development of selected haematological and biochemical parameters during the laying period was monitored in common pheasant hens housed in an enhanced cage system. The cages were enhanced by the addition of two perches and a shelter formed by strips of cloth hanging in the corner of the cage. The results showed significant changes in the haematological and biochemical parameters monitored d...

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...