Changes of Selected Egg Quality Traits Depending on the Laying Period of Semi-Intensively Raised Guinea Fowl Hens

Abstract

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.

Prediction of Egg Weight from External Egg Traits of Guinea Fowl Using Multiple Linear Regression and Regression Tree Methods

“…The descriptive statistics of the evaluated external egg traits are shown in Table 1. The EW value determined in the present study (38.09 ± 3.21 g) was in contrast to the values determined in Guinea fowl raised in Nigeria (53.63 ± 0.15 g; Gwaza & Elkanah, 2017), Bosnia and Herzegovina (40.63 ± 0.27 g; Vekić et al, 2019), Turkey (40.14 ± 0.23 g; Alkan et al, 2013), and Poland (40.7 ± 0.54 g; Nowaczewski et al, 2008 and 40.8 ± 0.30 g; Bernacki et al, 2013). Previous studies reported that some factors such as age, body weight, and variety of birds (Oke et al, 2004;Kgwatalala et al, 2013), and laying management and intensity (Vekić et al, 2019), have important influence on the variation of egg weight in this poultry species; therefore, they should be considered in national programs to improve this trait.…”

“…The EW value determined in the present study (38.09 ± 3.21 g) was in contrast to the values determined in Guinea fowl raised in Nigeria (53.63 ± 0.15 g; Gwaza & Elkanah, 2017), Bosnia and Herzegovina (40.63 ± 0.27 g; Vekić et al, 2019), Turkey (40.14 ± 0.23 g; Alkan et al, 2013), and Poland (40.7 ± 0.54 g; Nowaczewski et al, 2008 and 40.8 ± 0.30 g; Bernacki et al, 2013). Previous studies reported that some factors such as age, body weight, and variety of birds (Oke et al, 2004;Kgwatalala et al, 2013), and laying management and intensity (Vekić et al, 2019), have important influence on the variation of egg weight in this poultry species; therefore, they should be considered in national programs to improve this trait. The recorded EPD value = 4.90 ± 0.18 cm was lower than the values reported by Kgwatalala et al (2013) in varieties: Pearl gray (5.09 ± 0.02 cm), Lavender (5.14 ± 0.02 cm), Royal purple (5.21 ± 0.03 cm), and White (5.01 ± 0.04 cm), while the reported EED values were similar to those found in this study (3.77 ± 0.13 cm), demonstrating that the length and width of the egg vary from the effect of the Guinea fowl variety used.…”