Egg is a miraculous food having all essentials of life. In the recent times, consumer
consciousness regarding egg and egg products is increasing and people prefer to eat eggs from
indigenous breeds over commercial breed, as they consider them of high nutritional value and
good quality. The present study was conducted with the objectives to compare egg quality,
proximate composition, macro minerals analysis, fatty acids profile, and organoleptic
evaluation of eggs from 6 different breeds of chicken in Pakistan. For this purpose, 5 bird of
each of the 6 breeds (White Leghorn, White Plymouth Rock, Naked Neck, Aseel, Rhode Island
Red and Fayoumi; 40-50 week of age) were kept under Completely Randomized Design on
litter floor. A total of 10 eggs from each breed were used for egg geometry (Egg Shape index,
surface area, volume) and quality analysis (Egg specific gravity, shell thickness, shell %,
albumen %, albumen index, haugh unit score, albumen pH, yolk pH, yolk %, yolk index, yolk
color, blood and meat spots), 3 from each breed were used for proximate analysis (Moisture
%, Crude Protein %, Lipids %, Ash %, Carbohydrates %), macro minerals (Calcium,
Magnesium, Sodium, Potassium, Iron) analysis, and fatty acid analysis, respectively. For
organoleptic evaluation, a semi trained panel of 20 people evaluated egg samples randomly
which were boiled at same time peeled and sliced into pieces. The panel evaluated Color,
Aroma, Flavor, Taste, mouth feel, and overall quality of Albumen and Yolk separately on 15-
point hedonic scale. The data were analyzed with Analysis of Variance (ANOVA) technique
under Completely Randomized Design. The significant means were compared using Duncan’s
Multiple Range (DMR) test using SAS 9.4. Results showed no difference among breeds for
egg geometry and shell quality parameter, however, egg specific gravity was significantly
higher in Fayoumi chicken. In albumen quality, Rhode Island Red eggs showed highest
albumen percentage, while Haugh unit score was best in eggs of Aseel, Fayoumi, Naked neck
and Rhode Island Red as compa red to other breeds. But, Albumen index and Albumen pH
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remained unaffected by different breeds. Similarly, in yolk quality traits, yolk percentage was
significantly higher in Aseel, Fayoumi and Naked neck, and yolk color in eggs of Fayoumi,
but yolk pH and yolk index remained unaffected by different breeds. Proximate analysis
showed significantly highest moisture and carbohydrate contents in White leghorn eggs while
Protein contents were highest in Aseel, Naked neck and White Plymouth rock. Moreover,
White Plymouth rock eggs also showed more lipid contents, while Ash percentage remained
comparable among different breeds. Macro minerals analysis showed higher Iron contents in
eggs of White leghorn breed, while Fayoumi eggs were higher in Magnesium, Potassium, and
Sodium contents. Naked neck eggs also showed higher Potassium and Calcium contents. Fatty
acid analysis showed higher Myristic acid (C14:0), DPA contents in eggs of White leghorn,
Stearic acid (C18:0) in eggs of Fayoumi and Aseel, Saturated Fatty acids in eggs of Fayoumi,
Palmitoleic acid (C16:1), Oleic acid (C18:1), Linoleic acid (C18:2), Arachidonic acid (C20:4),
EPA, DPA, DHA, MUFA, PUFA, and n-3 fatty acids in White Plymouth rock, n-6 fatty acids
in eggs of Rhode Island Red, While α-Linolenic acid (C18:3) was lowest in eggs of Naked
neck breed as compared to rest of the breeds. But, Naked neck showed higher total lipid
contents as compared to other breeds. During organoleptic evaluation, White Leghorn eggs
showed highest intensity for yolk taste, flavor and mouth feel, whilst, yolk color, aroma and
overall quality remained comparable among different breeds. Likewise, in albumen
organoleptic evaluation, Albumen color was least intense while Albumen Aroma was highest
in Aseel eggs. Albumen taste, flavor and overall quality was highly intense in White Leghorn
as compared to other breeds.
Conclusions
On the basis of the results of the present study it can be concluded that egg geometry was not
affected by genotype variation, however, very interestingly, huge variation was observed
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regarding internal egg quality traits, proximate and mineral composition, fatty acid profile as
well as sensory evaluation of the eggs from different chicken breeds.
Suggestions and Recommendations:
Based upon the findings of present study it is suggested for future researchers that:
1. There is a dire need to conduct thorough studies to investigate the genetic basis of
differences among different breeds regarding egg quality attributes.
2. In future breeding plans, egg quality and sensory properties of different breeds must be
kept in mind and incorporated accordingly.
3. Improvement in production performance of indigenous breeds through selection should
be made as these breeds have better egg characteristics and preference by the local
community.