This paper presents results of determination of certain quality parameters and its phenotypic correlation in eggs originated from extensively reared gray variety of Guinea fowl. A total of 150 egg collected by sampling 30 eggs in each of five analyzed laying months were used for egg quality evaluation and statistical analysis by methods of descriptive statistics and simple linear correlation. Average egg weight, shape index and shell thickness was 38.14 g, 76.03% and 0.49 mm, respectively.

Summary In order to determine phenotypic correlations between the quality traits of eggs from 41-week-old broiler breeder hens (Cobb 500), a total of 105 eggs suitable for incubation were analyzed using descriptive statistics and Pearson’s correlation coefficient. The average values of egg weight, egg length, egg width, egg shape index, shell thickness, shell weight, and shell ratio were 66.90 g, 60.00 mm, 44.81 mm, 74.70%, 0.37 mm, 6.07 g, and 9.07%, respectively. Moreover, the average values of yolk weight, albumen weight, yolk ratio, albumen ratio, Haugh units, yolk index, and yolk-to-albumen ratio were 20.04 g, 40.80 g, 29.97%, 60.95%, 82.12, 46.17%, and 0.49, respectively. A significant positive correlation (p < 0.01) was found between the egg weight and the egg length (0.75), egg width (0.80), shell (0.55), yolk (0.60), albumen weight (0.91), and albumen ratio (0.25). However, a significant negative correlation (p < 0.01) was found between the egg weight and both the yolk ratio (-0.20) and yolk-to-albumen ratio (-0.23). The egg shape index proved not to be significantly correlated with any of the internal egg quality traits considered. The shell thickness was in a significant positive correlation (p < 0.01) with the shell weight (0.83) and ratio (0.86), whereas a significant negative correlation (p < 0.05) was found between the shell thickness and yolk ratio (-0.23). The Haugh units were in a significant positive correlation (p < 0.05) with the albumen ratio (0.24) and yolk index (0.27), whereas a significant negative correlation (p<0.05) was found between the Haugh units and both the yolk ratio (-0.22) and yolk-to-albumen ratio (-0.23). The results obtained confirm significant phenotypic correlations not only between egg weight and the egg quality traits considered, but also between a number of external and internal quality traits of broiler hatching eggs.

The aim of this study was to evaluate selected egg quality traits depending on the laying period of pearl grey guinea fowl hens reared in semi-intensive system. In each of three evaluation terms (the second, fourth and sixth month of laying period) 40 eggs were collected, with the total of 120 eggs were used for quality evaluation. Methods of descriptive analysis and one-way ANOVA were used for data analysis. Overall values of three evaluation terms for egg weight, shell thickness, yolk to albumen ratio, Haugh units and yolk colour were 40.63 ± 0.27 g, 0.50 ± 0.01 mm, 0.58 ± 0.01, 75.37 ± 0.41 and 12.74 ± 0.11, respectively, whereas overall values of shell, albumen and yolk proportion were 15.32 ± 0.15, 53.75 ± 0.16 and 30.94 ± 0.17%, respectively. Significant differences were found for values of egg quality traits depending on the laying period, but the average value was generally comparable with literature data reported for similar rearing conditions for this Guinea fowl variety.

The aim of this study was to examine the effects of treatment with a single injection of GnRH and PGF2a on estrous response, fertility and service period. A total of 120 lactating Simmental cows were divided into four groups of 30 cows each: group PGF2a 40 was treated on the 40 th day post partum with a single injection of 2 mL prostaglandin analogue (Estrumate), group PGF2a 50 was treated in the same way on the 50 th day, group GnRH was treated on the 40 th day post partum with a single injection of 2 mL GnRH analogue (Receptal), and the fourth group (control) was not hormonally treated. Fertility of cows was not significantly different (p>0.05). The difference in the estrous response and service-period between the control group and experimental groups was statistically significant (p<0.01).

The aim of this paper is to present results achieved by adding dietary phytogenic additive (Biomin ® P.E.P. 125 poultry) on production and quality of table eggs in the early stages of laying period in commercial Hy Line Brown hens. The experiment was conducted from 16 to 28 weeks of hens age. During the experimental period the following parameters were determined every week : egg production, percentage of second grade eggs and egg weight. The examination of egg quality was conducted at 21, 24, 26 and 28 weeks of hens age. Based on the obtained results we can conclude that the addition of dietary phytogenic additive induced an increase in egg production and egg weight and reduced the percentage of second grade eggs. Significant effects of phytogenic additive on some egg quality parameters were not established.