Invasive alien species might benefit from phenotypic plasticity by being able to (i) maintain fitness in stressful environments ('robust'), (ii) increase fitness in favourable environments ('opportunistic'), or (iii) combine both abilities ('robust and opportunistic'). Here, we applied this framework, for the first time, to an animal, the invasive slug, Arion lusitanicus, and tested (i) whether...

BACKGROUND Chicks of virulent brood parasitic birds eliminate their nestmates and avoid costly competition for foster parental care. Yet, efforts to evict nest contents by the blind and naked common cuckoo Cuculus canorus hatchling are counterintuitive as both adult parasites and large older cuckoo chicks appear to be better suited to tossing the eggs and young of the foster parents. METHODOL...

in the present study the allelic polymorphisms of gh, ghr and tgfβ3 genes and its association with egg production traits were investigated. blood samples randomly were collected from breeder hens of mazandaran native fowls breeding station and transported to the laboratory in cold chain condition. dna was extracted using modified salting out method and the desired loci were amplified by specifi...

The first objective of this study on broiler breeders was to investigate the genetic basis of variability in hatchability over age using a longitudinal model. Weekly percentage hatch of fertile and hatch of set eggs were available for 23,250 dams mated to 3,106 sires of the same age between the 28th and 54th week of life. Hatch of set was very highly correlated with fertility and showed a simil...

With the Weihenstephan funnel nest box, 12 laying hen flocks were tested for their individual laying performance, egg quality, and nesting behavior in a noncage environment. During the whole observation period of 8 yr, a transponder-based data recording system was continuously improved and resulted in a recording accuracy of 97%. At peak production, heritabilities for the number of eggs laid ar...

Induced molting increases egg quality and egg production and extends the productive life of hens. Molting is accomplished by feed withdrawal, which has received criticism, and alternatives described thus far result in poor postmolt performance. Melengestrol acetate at a dosage of 4 or 8 mg/d, in a balanced diet, leads to reversible regression of the reproductive tract. However, this alternative...

Pheasant eggs evaluated in the first period of egg-laying did not differ significantly in their weight and shape index and the values of both traits were, respectively, 30.7 to 32.2 g and 76.1 to 78.1%. Over the laying season the thickness of the shell decreased and its capacity for deformation and crush strength were greatest at the end of the laying season. The share of yolk in the egg was hi...

It has been a common practice to place electrodes based on external landmarks, rather than locating the appropriate organ first by imaging techniques such as CT scan, ultrasonography, etc. Therefore, aside from abiding the cutaneous EGG (electrogastrography) electrodes placement rule, identification of its waveform should be performed to ease the validation of one’s EGG recording method. This r...

This study aimed to evaluate the productive performance of third-generation quails selected according color plumage produce a hybrid line distinguished by depending on plumage. 48 females different (Black, Golden, White and Brown) were compared transferred at age five weeks. To hall dedicated breeding containing rooms with dimensions 40 x cm numbered. The randomly distributed individually for e...