Environmental stressors impact physiology and behavior in many species of animals. These effects are partly mediated through changing concentrations of glucocorticoids, which also vary with reproductive state and social conditions. Prior research has focused largely on seasonal breeders, but the close temporal linkage between season and reproductive state in these species hinders ability to dis...

This study was conducted to determine the effect of photoperiod and feeding time on oviposition time and eggshell quality of broiler breeders. Five experiments were conducted in total. The effect of photoperiod on oviposition time was tested in Experiments '1 and 2. Experiment 1 involved 3200 33-week old broiler breeder hens housed in floor pens and subjected to photoperiods of 10, 11, 12, 13, ...

In this study, age-dependent changes of sperm quality parameters in Rutilus frisii were investigated. Also, fertilization capacity of breeders was tested using two age groups of males (3 and 4 year old breeders) and one female group (i.e. 4 year old breeders). For fertilization trials, the breeders were crossed randomly among age classes. Between the two age groups, spermatological parameters d...

Non-infectious infertility is particularly critical for sire rams/bucks, as seasonal breeders. This heavy use of males may lead to sexual exhaustion such that the regular semen production, libido, ejaculation, and litter yield can be seriously impaired. In severe cases, reproductive processes stop completely. For avoiding risk, management feeding should firstly arranged with a flock-based appro...

Behaviors associated with breeding can increase mortality risk. This increased risk be thought of as a cost reproduction. Increased movements prior to are common individuals search for food and sites. These entail greater predation risks travel through unfamiliar areas but few studies have looked at how these prebreeding affect survival, especially fine temporal resolution. Costs reproduction m...

Seedstock producers are interested in making as rapid genetic progress toward their defined breeding goals as is possible since this will enhance the profitability and long-term success of their breeding operations. These breeders need signals that will tell them how effective their breeding program has been and where problem areas might occur. PIGBLUP tries to provide these signals to breeders...

Long-lived animals typically exhibit several stages throughout their life cycle during which their distribution may vary substantially, which may challenge the relevance of protection measures. Here we surveyed individual movements of the Critically Endangered Amsterdam albatross from Amsterdam Island, southern Indian Ocean, throughout its life cycle. Our goal was to identify, from the areas vi...

Relationships between events in one period of the annual cycle and behaviour in subsequent seasons are key determinants of individual life histories and population dynamics. However, studying such associations is challenging, given the difficulties in following individuals across seasons, particularly in migratory species. Relationships between breeding performance and subsequent winter ecology...

A number of demographic factors, many of which related to human-driven encroachments, are predicted to decrease the effective population size (N(e)) relative to the census population size (N), but these have been little investigated. Yet, it is necessary to know which factors most strongly impact N(e), and how to mitigate these effects through sound management actions. In this study, we use par...

Animal societies are typically divided into those in which reproduction within a group is monopolized by a single female versus those in which it is shared among multiple females. It remains controversial, however, whether these two forms of social structure represent distinct evolutionary outcomes or endpoints along a continuum of reproductive options. To address this issue and to determine wh...