Comparative Evaluation of Dietary Oregano , Anise and Olive Leaves in Laying Japanese Quails

Aim of the present study was the comparative evaluation of the effect of ground oregano, anise and olive leaves as feed additives on performance and some egg quality characteristics of laying Japanese quails. A total of 189 Coturnix japonica quails (126 females and 63 males), 149 days old, were randomly allocated into seven equal groups with three subgroups of 9 birds each (6 females and 3 males). A commercial laying diet was fed to the control group. The remaining six groups were fed the same diet supplemented with oregano at 10 g/kg or 20 g/kg, anise at 10 g/kg or 20 g/kg and olive leaves at 10 g/ kg or at 20 g/kg. The birds were offered feed and water ad libitum for a period of 29 days, while being kept under commercial conditions. During the experiment, egg production, feed intake and mortality were recorded daily. At the end of the feeding period egg weight, egg yolk, albumen and eggshell weight percentages, egg yolk color (using the L*a*b* color space) and blood serum triglycerides were determined. The diets supplemented with olive leaves (10 g/kg or 20 g/kg) resulted in a tendency (p = 0.054) for higher egg production percentage. Also, the color parameter a* was significantly (p = 0.001) higher in the eggs of quails that consumed oregano (10g/kg or 20 g/kg) or olive leaves (10g/kg or 20 g/kg).


INTRODUCTION
Herbs and spices have a traditional history of use in the nutrition of humans and animals.Today, in the search for natural feed additives in animal diets, many studies focus on the antioxidant (Botsoglou et al., 2002;Giannenas et al., 2005;Florou-Paneri et al., 2006), anticoccidial (Christaki et al., 2004;Florou-Paneri et al., 2004) or antimicrobial (Govaris et al., 2007;Botsoglou et al., 2010) properties of the plants.Consequently, such plants have attracted increasing interest as an alternative feeding strategy to replace antibiotic growth promoters.
Anise (Pimpinella anisum L.) is an annual aromatic plant belonging to the Apiaceae family.It is cultivated mainly in Southern Europe and Southeast Asia.Anise fruits or the so-called seeds are the used parts of the plant (Al-Beitawi et al., 2009).According to Franz et al. (2005) they contain 2-6% essential oils, phenolic acids, eugenol, estragole and trans-anethole -a powerful phytoestrogen which is the main component of the oil (80-95%).Anise has been used over the years for its antioxidant (Gulcin et al., 2003), antimicrobial (Al-Kassie, 2008), antibacterial (Tabanca et al., 2003) and antifungal (Soliman & Badea, 2002) properties.
This study was designed to evaluate and compare the effects of the dietary use of oregano, anise and olive leaves in natural form on the performance and some egg quality characteristics of laying quails.

Plant material collection
In this study, oregano consisted of flower tops and leaves of the plant.Moreover, from the anise plant, the seeds were used, whereas the olive leaves were collected from trees that were not treated with any chemicals for the last six months.All above plants of Greek origin were dried and ground before inclusion in the diets.Proximate analysis of oregano, anise and olive leaves, performed according to the guidelines of AOAC (2005), is presented in Table 1.

Birds and diets
A total of 189 Coturnix japonica quails (126 females and 63 males), 149 days old, were randomly allocated into seven equal groups with three subgroups of 9 birds each (6 females and 3 males).All quails were individually weighed when placed in the cages, and their average weight did not differ (p > 0.100) between the seven groups.Quails were allowed to acclimatize for a period of 10 days, consuming a commercial laying diet in mash form ad libitum (Table 2).The same diet was fed to the control group (CONTR) during the experimental period.The remaining six groups were fed the above diet supplemented with 10 g oregano/kg (OREGA10), 20 g oregano/kg (OREGA20), 10 g anise/kg (ANISE10), 20 g anise/kg (ANISE20), 10 g olive leaves/kg (OLIVE10), or 20 g olive leaves/kg (OLIVE20).Birds were offered feed and water ad libitum for a period of 29 days, while being kept under commercial conditions.Quails were handled according to the principles of the Greek Directorate General of Veterinary Services for the care of animals in experimentation.Throughout the experimental period, egg production, feed intake and mortality were recorded daily.At the end of the study, egg weight and egg yolk, albumen and eggshell (with shell membrane) weight percentages were determined in ten eggs per subgroup.Moreover, the egg yolk color was measured in a mixture of ten egg yolks from each subgroup using the L*a*b* color space (L = lightness, a = redness, b = yellowness), according to Herber-McNeill & Van Elswyk (1998), with the aid of a Konica Minolta Chroma Meter CR-410 (Japan).Florou-Paneri PC Comparative Evaluation of Dietary Oregano, Anise and Olive Leaves in Laying Japanese Quails At the end of the feeding period, blood serum triglycerides were measured in six quail per group (two quail from each subgroup), according to Fossati & Prencipe (1982), using a biochemical analyser Flexor E, Vital Scientific N.V. (Holland).

Statistical analysis
The statistical analysis was performed using the SPSS 16.0.1 statistical package (SPSS Inc., Chicago, IL, USA).The one-way analysis of variance (ANOVA) for the seven groups of the experimentation was performed using the general linear model function of SPSS.Pearson's chi square test was used to analyze mortality.A value of p ≤ 0.050 was considered significant and a value of 0.050 < p ≤ 0.100 was considered a tendency.Levene's test was applied to test the homogeneity of the variances.Duncan's test was applied to determine statistical differences between the means.

RESULTS AND DISCUSSION
The effect of oregano, anise and olive leaves on egg production, daily feed intake and mortality of quails at the last day of the experimentation are presented in Table 3.A beneficial effect (p = 0.054) was noticed on egg production of the groups OLIVE10 and OLIVE20 as compared to the remaining groups, except for the group OREGA10.Moreover, there was no egg production difference (p > 0.100) among OREGA10, OREGA20, ANISE10, ANISE20 and CONTR groups .There are no published data concerning the comparative use of oregano, anise and olive leaves in laying quail diets.As far as the use of olive leaves in quail nutrition is concerned, direct comparison with other studies cannot be made due to lack of pertinent reports.However, similar results were reported in laying hens fed olive pulp (Christaki et al., 1994).The benefits of dietary olive leaves are possibly due to the presence of polyphenols and particularly oleuropein, the main active component in this material (Malik & Brandford, 2008).In previous studies relative to the supplementation of quail feeds with oregano only, no effect on egg production was found (Cetingul et al., 2007(Cetingul et al., , 2009)), whereas El-Deeb et al. (2007) reported that dietary anise decreased quail egg production.
As indicated in Table 3, there were no differences (p > 0.100) in daily feed intake between the dietary treatments over the experimental period.According to other researchers (Cetingul et al., 2007(Cetingul et al., , 2009;;Handl et al., 2008), oregano did not affect the daily feed intake in quails.On the other hand, Bayram et al. (2007) found that when anise was added to quail diets, feed intake increased.Moreover, there were no significant (p > 0.100) changes in mortality between the experimental groups, which is in agreement with Cetingul et al. (2009), who examined the dietary use of oregano in laying quails.0.054 0.319 0.668 1 -Groups: CONTR = control; OREGA10 = 10 g oregano/kg; OREGA20 = 20 g oregano/kg; ANISE10 = 10 g anise/kg; ANISE20 = 20 g anise/kg; OLIVE10 = 10 g olive leaves/kg; OLIVE20 = 20 g olive leaves/kg.2Values in the same column with a superscript in common do not differ significantly at P≤0.100.
The effect of dietary treatments on some egg quality traits is shown in Table 4.There were no significant (p > 0.100) differences in egg weight and yolk, albumen and shell weight percentage between the seven groups.Cetingul et al. (2007Cetingul et al. ( , 2009) ) also reported no significant effect on egg weight when oregano was incorporated in quail diets.Bayram et al. (2007) observed that egg weight was reduced when anise was used as dietary supplement in laying quails.Eggs from quails fed either oregano or olive leaves at levels of 10 g/kg and 20 g/kg presented significantly (p = 0.001) different yolk color as compared to the other groups, since a* color value was higher, shifting towards red.This increase in yolk a* values might be due to the passage of pigments contained in the plants included in the diet into the egg yolk.No significant (p > 0.100) differences on L* and b* values were observed between all the dietary treatments.There is little information published on the effect of dietary oregano, on yolk color index of quail eggs.Cetingul et al. (2009) mentioned that the addition of oregano in quail feeds had no influence on yolk color.Moreover, there are no literature data relative to the effect dietary anise and olive leaves on yolk color of laying quails.

CONCLUSIONS
Results of this study showed that there were no adverse effects from the dietary inclusion of oregano, anise and olive leaves in laying quail feeds.However, dietary olive leaves (10 g/kg and 20 g/kg) improved egg production and increased the a* value of the yolk colour.Also, dietary oregano (10 g/kg and 20 g/kg) increased the a* value of the yolk colour.Therefore, the use of herbal natural feed additives to benefit laying quail performance and egg quality seems to be promising.
in Laying Japanese Quails and did not differ significantly (p > 0.100) between the groups.

Table 1 -
Chemical analysis of oregano, anise and olive leaves.

Table 2 -
Composition of basal diet.