Characterization in the Egg Quality of Three Species of Phasianidae Birds

Putra


INTRODUCTION
Egg production is an essential trait in poultry because of its high economic value.Generally, two poultry species of chicken (Gallus domesticus) and Japanese quail (Coturnix japonica) were kept for meat and egg production in most countries.Despite chicken and quail, two other poultry species, Rock partridge (Alectoris graeca) and Common pheasant (Phasianus colchicus), were kept for meat and egg production in the Republic of Turkey.According to the IUCN Red List, Common pheasants have the conservation status of Least Concern (Braasch et al. 2011).Meanwhile, the Rock partridge has the conservation status of Near Threatened globally and Vulnerable in Italy (Fontaneto et al. 2022).Despite habitat loss, the decrease in the Rock partridge population can be caused by parasitic helminths of Cheilospirura hamulosa (Fanelli et al. 2020).Hence, the breeding program for both bird species for economic purposes is vital to protect them in the wild habitat from extinction.
Rock partridge and Common pheasants are classified as Phasianidae family birds (Shen et al. 2014).The average body weight in mixed-sex Rock partridge at 12 weeks of age was 421.57±4.88g (Putra & Kırıkçı 2021).Meanwhile, the average body weight in Common pheasant at 13 weeks of age was 1053.00±58.97g in males and 825.00±74.25 g in females (Kokoszynski et al. 2012).Compared to Rock partridge and Common pheasant, the average body weight of Japanese quail was shown to be lowest, i.e., 203.48±25.21g in males and 228.21±26.44g in females (Khalil et al. 2006).Therefore, Rock partridge and Common pheasant can be kept for meat production (Hofbauer et al. 2010;Franco & Lorenzo 2013;Wen et al. 2020).
Interestingly, the quality of milk and eggs can be used to characterize the livestock breed (Haygert-Velho 2018; Putra et al. 2021).A Canonical Discriminant Analysis (CDA) and Hierarchical Cluster Analysis (HCA) are two statistical methods that are used to evaluate livestock animals (Ali et al. 2013).Both statistical analyses represent a valid method to simplify the considerable amount of information available regarding the poultry Farms' routines.An example is cluster analysis, which allows grouping and discriminating between groups, where the Euclidean distances, a measure of similarity, define that the means of nearer observations are in the same group, while the most distant are in separate groups (Todde et al. 2016).In addition, both statistical methods have been used to characterize eggs in poultry (Michalczyk & Kurczab 2018;Putra et al. 2021;Ariza et al. 2021).Presently, a study to discriminate many Phasianidae birds based on egg quality traits has yet to be reported.The egg characteristics can be used for avian species identification (Buss & Keiss 2009) and for determining the Euclidean genetic distance (Putra et al. 2021).Unfortunately, there are few studies on egg characterization in Phasianidae birds.Alaşahan & Günlü (2012) have worked to observe the egg quality traits in partridge, pheasant, quail, and chicken without characterization analysis.Hence, this study aimed to characterize the egg quality of three Phasianidae birds (Rock partridge, Common pheasant, and Japanese quail) and determine the Euclidean genetic distance with their egg quality.The results of this study can be used as early information to observe the similarity of egg characteristics in three species of Phasianidae birds.

Egg sample and research site
Three species of Phasianidae birds, i.e., Rock partridge (Alectoris graeca), Common pheasant (Phasianus colchicus), and Japanese quail (Coturnix japonica), were involved in this study, as shown in Figure 1.A total of 372 eggs consisting of 100 eggs of Rock partridge (RP), 200 eggs of Common pheasant (CP), and 72 eggs of Japanese quail (JQ) were used in this study for the egg quality analysis.All Phasianidae birds were kept at the Selçuk University Faculty of Veterinary Science Hümeyra Özgen Research and Application Center Farm, Republic of Turkey.The egg collection was performed during the laying period of RP (40-44 weeks of age), CP (44-48 weeks of age), and JQ (10-14 weeks of age).

Management of bird
Typical pheasant eggs were used from matings of 90 females and 15 male pheasants of 44 wk of age.The pheasants were mated inside four semi-open shelters (a 4 × 5 m open section and a 4 × 4 m closed section) as one male: 6 female ratio.Artificial lighting was used 16 hours light in a day.Birds were fed with ration ad libitum, including 18% HP and 2,850 MJ/kg of ME, and water was provided from automatic nipples.Rock partridge eggs were used from mating 72 rock partridges (24 male and 48 female) of 44 wk of age.The partridges were mated as one male and two females in open cages (1.2 m x 6.0 m x 1.2 m).Artificial lighting was used 16 hours a day.An ad libitum ration, including 24% CP and 2,850 MJ/kg of ME was provided, and water was supplied via automatic nipples.Quail eggs were used from matings of 120 quails (40 male and 80 female) at 15 weeks of age.Quails were housed in battery cages with 130 cm 2 space per bird as one male and two females and exposed to a 16 h light daily.Commercial quail layer rations containing 17% crude protein (CP) and 2800 kcal/kg metabolizable energy (ME) were provided for quails.The ration and water were available ad libitum.

Data analysis
The descriptive statistics of egg quality traits were computed with General Linear Model (GLM) using a mathematical model as follows: Where Yij is the response variable of the jth observation in the group, µj is the overall mean, σi is the effect of the ith group, and eij is random for the jth error.Thus, a Canonical Discriminant Analysis (CDA) was performed to calculate Mahalanobis distance (D 2 ), tolerance (T), Wilk's lambda (λ) values, and the discriminator variables.
After that, the CDA was applied with the backwardstepping automatic elimination method for the variables, with F value entry = 3.84 and F value removal = 2.71 (Depison et al. 2021).The T value (0 to 1) was computed to detect the level of correlation among variables in the discriminant function.Suppose a variable is highly correlated with one or more of the others.In that case, the T value is minimal, and the resulting estimates of the discriminant function coefficients may be unstable (Asamoah-Boaheng & Sam 2016).The Hierarchical Cluster Analysis (HCA) was used for clustering in each breed with the squared Mahalonobis (D 2 ) distance (Oliveira et al. 2018).The HCA in this study was performed using the morphometric measurements with the nearest-neighbor method and computed using the SPSS 16.0 computer program.

Egg quality
The egg qualities of three Phasianidae poultries in the present study are presented in Table 1   (olive green), respectively.Hence, the HU value of CP birds was higher than in a previous study reported by Kırıkçı et al. (2005).Despite this, the EW of CP birds in the present study was close to the eggs of CP with brown and olive green colors.The egg quality in birds can be affected by nutrient, environmental, and genetic factors.

Canonical discriminant analysis
In this study, the egg quality traits were described as the discriminant variable (Table 2).In addition, ten discriminant variables were able to discriminate three Phasianidae poultries with the canonical correlation (R) of 0.98 (function 1) and 0.79 (function 2), as shown in Figure 2. Hence, ten discriminant variables were able to classify RP (100%), CP (98%), and JQ (100%) birds into their original Phasianidae poultry group (

CONCLUSION
The egg quality traits can be used to differentiate three species of Phasianidae birds, i.e., Rock partridge (Alectoris chukar), Common pheasant (Phasianus colchicus) and Japanese quail (Coturnix japonica).The egg quality traits of Rock Partridge and Common Pheasant were closed.However, a study with the mitogenome DNA revealed that Japanese quail and partridge have a similar maternal lineage.Hence, genetically, Japanese Quails are the closest kinship to Rock partridge.Nonetheless, the egg quality of Rock partridges was close to that of Common pheasant.In the future, Rock partridge and Common pheasant can be managed in poultry farming for meat and egg production.

Table 1 .
Means (±SD) of egg quality in three species of Phasianidae birds a,b,c = superscript of differ significantly (P<0.05);N= Number of bird; SD= Standard deviation

Table 2 .
Factor selected by stepwise discriminant analysis to discriminate three species of Phasianidae birds

Table 3 .
Percentage (%) of individual classification per bird species based on discriminant analysis

Table 3 )
Kimball et al. (1999) Phasianidae poultries was 15.28(RP and  CP birds), 22.79 (RP and JQ birds), and 27.94 (CP and  JQ birds), as shown in Table4.Hence, RP and CP birds were grouped into a similar cluster based on HCA with egg quality, as shown in Figure3.Meanwhile, the JQ Coturnix japonica (GenBank: NC003408) was performed to evaluate the findings in the present study.According to the mitogenome DNA sequence, partridge and quail have a close genetic relationship and are grouped into a similar cluster, as shown in Figure4.Meanwhile, the pheasant was grouped into a separate cluster.Kimball et al. (1999)obtained a similar finding that Coturnix coturnix and Alectoris sp. have a close genetic relationship based on the mitochondrial Cytochrome-b (Cyt-b) gene.
bird was grouped into a separate cluster.Putra et al.  (2021)reported that three egg qualities of yolk diameter, volume, and surface area were the discriminant variables