Alterations in gonadotropin, prolactin, androgen and estrogen receptor and steroidogenesis-associated gene expression in gander testes in relation to the annual period.

Physiological mechanisms of seasonal changes in testicular function in birds are not fully elucidated. The balance between androgens and estrogens and testis sensitivity for gonadotropin and gonadal steroids are still unclear. The aim of the study was to examine: (1) the changes in circulating and intra-testicular steroid hormone levels and their relationship; (2) the mRNA expression of testicular gonadotropin, prolactin (PRL), progesterone (P4), androgen, and estrogen receptors, and (3) key steroidogenesis processes-related genes with immunofluorescent localization of aromatase in gander testes during the annual period.

Annual changes in cell proliferation and apoptosis and expression of connexin 43 in the testes of domestic seasonal breeding ganders.

Molecular mechanisms of seasonal changes in testicular morphology, histoarchitecture, and functions in birds have not been fully elucidated. The aim of the study was to examine the alternations in cell proliferation and apoptosis, these processes-related gene expressions, and gap junction protein (GJA1gene, connexin 43 protein; Cx43) expression and localization in gander testes during annual stages. Testes from domestic ganders (n = 28) in the first reproduction season were obtained at five stages, i.

Research Note: The nutritional value of eggs from native Polish Crested chickens and commercial hybrids that have been stored in various conditions.

The aim of the study was to compare the nutritive value of eggs from Polish Crested chickens (PCr) to that of eggs from commercial hybrid Hy-Line Brown (HLB) and to examine the effect of storage conditions on physical quality parameters. In total, 135 PCr (9 pens) and 75 (5 pens) HLB chickens were kept on litter and fed commercial feed. At laying peak (36 wk), all eggs (n = 66/ genotype) were collected on the same day and divided into 3 groups (n = 20): group I was assessed on the day after laying; group II was analyzed after 28 d of storage in a fridge; group III, after 28 d in storeroom conditions of 19.

Determination of Annual Plasma Hormone Levels Associated with Reproduction in Long-Day Breeding Domestic Geese.

This paper examines the dynamics of circulating hormone changes connected with reproduction in geese during the annual period related to gonad morphometry. One hundred geese were examined. The levels of prolactin (PRL), triiodothyronine (T3), thyroxine (T4), testosterone (T), progesterone (P4) and estradiol (E2) were estimated.

Targeted differential monochromatic lighting improves broiler breeder reproductive performance.

Light perception in birds is composed of the retina and extraretinal sites, located in the brain. Previous studies indicate that selective photostimulation of the eye decreased reproductive performance, whereas extraretinal photostimulation increases it. Differential photostimulation of the retina and extraretinal sites is based on the retina's sensitivity to green wavelengths and on the red wavelengths' ability to penetrate body tissues.

The effect of parachlorophenylalanine treatment on the activity of gonadal and lactotrophic axes in native Polish crested chickens stimulated to broodiness.

Brooding behavior, a common characteristic of native breeds of the domestic chicken, is marked by elevated prolactin (PRL) levels, which is necessary for incubation and connected with changes in hypothalamic-pituitary-gonadal axis activity. Evidence indicates the serotoninergic system is a potent modulator of PRL secretion. The objective of this study is to investigate whether blocking serotonin synthesis with parachlorophenylalanine (PCPA) prevents incubation behavior in native Polish crested chickens.

Comparison of carcass traits and meat quality of intensively reared geese from a Polish genetic resource flock to those of commercial hybrids.

The aim of the study was to determine slaughter yield and meat quality of native Zatorska (ZG) goose and compare them to those of commercial hybrid White Koluda® goose (WKG) after fattening in an intensive production system. The experiment was carried out on 500 birds of each group and lasted up to 10 wk of age. The birds were kept on deep litter with access to free range and were fed with the same complete feed mixtures, according to dietary requirements for broiler geese.

Effect of Repeated Gathering and Age on the Quality of Zatorska Goose Feathers.

We investigated a reproductive flock of Zatorska geese. The birds were divided into four groups: three-year-old ganders (=10), and one-, two-, and three-year-old layers (=30). Mature feathers were collected from the birds between July and September (, after breeding).

Mating activity and sperm penetration assay in prediction of the reproduction potential of domestic goose ganders in a harem system.

In a natural mating system, the sexual behavior of birds has an important role in fertility success. Non-competitive mating system provides special conditions to study gander-goose interactions. Behavioral and physiological data from a domestic geese breeding flock was used to determine interrelationships between mating activity (MA) parameters, sperm penetration assay (SPA), plasma testosterone (T) concentration, and fertility (F).

Effect of breeding stage and photoperiod on gonadal and serotonergic axes in domestic ganders.

Reduction in reproductive potential of ganders with progress in seasonal breeding is a known problem in commercial geese production. The role of changes in hypothalamic-pituitary-gondal axis and testis functions in this process is not clear. This article presents studies on the hypothalamic (GnRH-I, vasoactive intestinal peptide), pituitary (LHβ, prolactin [PRL], PRL receptor [PRLR]), testis (PRLR) axis messenger RNA (mRNA) expression during different stages of the breeding period and photoperiodic conditions.

Breeding period-associated changes in semen quality, concentrations of LH, PRL, gonadal steroid and thyroid hormones in domestic goose ganders (Anser anser f. domesticus).

In flocks of geese fertility decreases in the second half of the breeding season. The reasons for this reduction in reproduction ability are still unclear. This study measured changes in semen quality variables throughout the period of intensive breeding in relation to hormonal concentrations associated with the sexual activity of ganders.

Mating activity of domestic geese ganders (Anser anser f. domesticus) during breeding period in relation to age, testosterone and thyroid hormones.

In breeding geese, natural mating applies. The objective of this study was to determine seasonal- and age-related changes in the sexual activity of ganders. Moreover, T, T4 and T3 plasma levels were evaluated.

Age effect of broiler breeders on fertility and sperm penetration of the perivitelline layer of the ovum.

The objective of this study was to determine the age effect of a broiler breeder flock on duration of fertility and number of spermatozoa penetrating the perivitelline layer overlying the germinal disc (SP/mm(2) GDIPVL). Moreover, in the second half of the flock's reproductive life, the effect of using ejaculates of young roosters (CA2) in artificial insemination (AI) on the above parameters of fertility was estimated. The commercial flock of broiler breeder hens (n = 100) was inseminated six times from 31 to 62 weeks of age.