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. In both sexes, PRL level patterns fit a quadratic trend with elevations in the post-breeding and the second half of the breeding–laying periods. During these periods, differences in the PRL level between sexes were noted. In ganders, increased PRL levels during the laying period occurred earlier compared to in female geese. Cubic trends for T and E2 in ganders and quadratic for T, P4, and E2 in female geese were observed. PRL was negatively correlated with T in both sexes and with P4 and E2 in female geese. A higher level of T3 and variation in T4 in ganders with a quartic trend in ganders vs. a quadratic in female geese were noted. Patterns of PRL, T, and E2 suggested that the breeding–laying period in ganders may be shorter than in female geese. These findings will be used to explore experimental manipulations of the endocrine axis to increase synchronisation of both sexes.

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 19.5 to 20.5°C. For group I, vitamin A and E content (n = 3 samples) and fatty acid (FA) profiles (n = 6 samples) were determined. For all groups, the physical quality parameters of the eggs were assessed. The vitamin E content was higher (P < 0.05) for PCr than HLB. The PUFA n-6 FA content was higher and the amount of MUFA was lower (P < 0.05) for PCr when compared to HLB. All physical parameters changed after storage, with more negative changes recorded for group III than for group II. Concerning egg weight, albumen height, Haugh unit score and the pH of the yolk and albumen, interaction between genotype and storage conditions (P < 0.001 – P < 0.05) was demonstrated. The lightest eggs with the lowest albumen height and the highest pH were recorded from PCr in group III. The lowest Haugh unit score was recorded from HLB eggs stored in the same conditions. Moreover, the eggs of PCr were characterized by a higher (P < 0.001) yolk content and yolk color (P < 0.05), whereas the weight of the yolk and content of albumen were lower (P < 0.001) for HLB. Eggs from PCr that are stored in appropriate conditions could possibly be offered as a niche product.

The variation in egg quality parameters of traditional/native hen breeds with good freshness and antibacterial properties of egg albumen may determine the attractiveness of these eggs for modern consumers looking for high quality products. The objective of this study was to evaluate external and internal physical quality parameters and enzymatic activity of lysozyme of eggs from three traditional hens bred in Poland and to compare these egg quality parameters to those obtained from commercial hybrids kept under the same management conditions in extensive farming production system. The study was carried out on eggs collected from 4 genetic groups of hens, i.e. Polish Liliputy Bantams (PLB), native Polish Crested Chickens (PCr, CP-22 strain), Gold Laced Polish Chickens (GLP) and from Hy–Line Brown hybrids (HLB). In total 135 PLB, 75 PCr, 75 GLP and 75 HLB hens were kept on litter (3 pens) and fed commercial feed. The eggs (n = 33/genotype/age) were collected at the 33 and 55 weeks of age. The study concluded that with the age of the hens, there was an increase (P<0.05) in the weight of the egg and the proportion of its main fractions, as well as a decrease (P<0.05) in the quality parameters of the albumen and the eggshell. However the eggs from traditional breeds retain good parameters of albumen quality even at the end of production period. The eggs of traditional hens were characterized by higher (P<0.05) yolk proportion and its color and albumen lysozyme parameters, and a lower (P<0.05) eggshell and albumen height and Haugh unit score in relation to commercial hybrids. The highest (P<0.05) content of lysozyme and enzymatic activity of lysozyme were found in eggs from Gold Laced Polish Chickens. Thus, eggs obtained from traditional hens may meet requirements of modern consumers because of specific physical characteristics, good albumen lysozyme activity and freshness parameters. Particularly noteworthy are Polish Liliputy Bantams eggs, characterized by the low weight and a high proportion of more intensely colored yolk and good Haugh unit score at the end of production period.

Hrabia A., Wolak D., Frydrych K., Gumułka M., S aito N., Sechman A. 2024. Is selected aquaporin expression in the chicken adrenal gland affected by disturbed sex steroid action? Folia Biologica (Kraków) 72: 118-129. In our earlier study, we demonstrated changes in the aquaporin 4 (AQP4) abundance in the reproductive system of hens following a fasting or tamoxifen (TMX; estrogen receptor modulator) treatment. In the present study, we examine the hypothesis that the expression of selected aquaporins (AQPs) changes in the avian adrenal gland under reduced circulating sex steroid hormone concentrations or a blockage of estrogen receptors. Accordingly, our aim was to examine the AQP1, AQP2, AQP4, AQP5 and AQP9 mRNA and/or protein expression and immunolocalisation in the adrenal glands of chickens after several days of fasting or TMX treatment. The hens were fasted or treated with TMX every day, until a pause in egg laying occurred in all the hens. Control hens were fed ad libitum or were treated with a vehicle, respectively. The hens were euthanised on Day 6 or 8 of the experiment, respectively, and the adrenal glands were collected. Subsequently, the gene and protein expressions of AQPs in the tissues were examined by quantitative real-time PCR and Western blotting, respectively. The fasting, which is accompanied by dimi- nished plasma concentrations of sex steroids, caused a decrease in the relative abundance of AQP1, AQP2, and AQP9 mRNA transcripts, while the TMX treatment lowered the AQP2 and AQP4 mRNA transcript levels. However, the abundances of AQP proteins were not changed by the fasting and TMX treatment. Immunoreactivity for AQP1, AQP2, and AQP9 protein was localised to the adrenal gland chromaffin cells and adrenocortical cells; whereas for AQP4 it was localised exclusively to chromaffin cells. In summary, the selected AQPs seem to be important for the regulation of the water/glycerol transport required for the functioning of the hen's adrenal gland cells. An involvement of ovarian steroids, especially estradiol, in the regulation of the AQP expression is also suggested.

Liquid storage of semen is of practical interest in the management of native chickens kept under biodiversity conservation programs. The objective of this study was to examine semen quality from native Polish Crested (PCr) in comparison to Hy-Line Brown (HLB) roosters, and to assess the effect of short-term storage on semen quality. The evaluation of semen collected from 12 roosters (5 times) was performed at 0, 24 and 48 h of storage using CASA and a flow cytometer. Fresh PCr semen was characterized by good quality, with the proportions of total motility (MOT) and viable sperm greater than 93.0%, while the proportion of sperm with apoptotic and chromatin changes (DFI) was below 5.0%. The proportion of PCr apoptotic sperm, with chromatin and membrane damage was lower after storage than that of HLB. Thus, the gradual increase in DFI (%) after 24 and 48 h compared to 0 h was about half as large in PCr as in HLB. However, semen storage resulted in a similar gradual reduction in MOT and similar moderate changes in sperm kinetic motility parameters in both genetic groups. The PCA analysis of sperm parameters revealed three principal components, explaining more than 80.0% of the cumulative variance. On the basis of the relationship between sperm parameters, it is possible to reduce the semen dataset, thereby possibly improving the assessment of future fertility. In summary, MOT, motility parameters and DNA integrity were more affected than other sperm functions during storage of PCr semen. The results can be used to create guidelines to support breeding programs for native poultry breeds worldwide.