Egg Quality

ABSTRACT

A study was carried out in the department of Poultry Science, Kerala Veterinary and Animal Sciences University to determine the egg qualities of farm fresh kuttanad and white pekin duck eggs in comparison with eggs collected from various shops in and around Thrissur district, Kerala. A total of 42 eggs were Subjected to evaluate the internal and external quality parameters. The results revealed that there is no significant difference among mean egg weight, shape index and specific gravity. Kuttanad and White Pekin farm fresh eggs showed significantly (P<0.05) superior quality in shell thickness, shell percentage and yolk index. Albumen index and Haugh unit score of kuttanad duck eggs were significantly (P<0.05) superior to white pekin eggs and market eggs showed the least. Mean shell weight value of white pekin eggs were significantly higher than market eggs while there is no significant difference between  kuttanad and white pekin eggs. Yolk score of market egg (8.67 ±0.31) was significantly higher than the farm fresh eggs (6.0 ±0.24).

KEY WORDS: Duck egg, Egg quality traits, Breeds.

INTRODUCTION

Duck egg and meat have become an important source of nutrients in human diet and these are gaining momentum as a food item in modern life. Ducks are reared mainly for eggs and meat, even though some might consider them as ornamental birds. In Europe and USA, ducks are reared for meat, where as in Asian countries they are primarily meant for egg production. Duck production gets along well with paddy cultivation in an integrated farming system. Duck farming is not only eco friendly, but also plays a vital role in increasing soil fertility. Ducks are also helpful in the biological control of pests in agricultural fields. They are valued for their versatility and adaptability and they exhibit rapid growth rates and produce heavier table eggs in comparison to chicken. In India indigenous ducks contribute about 90% of the total duck population and total egg population in India holds 6.13% of total poultry production in the country. Duck eggs contain nutrients in a well balanced ratio; it also contains unsaturated fatty acids which help in the control of cholesterol. In addition to its nutritional qualities, people have a belief that it is inherent medicinal properties.  Maintaining fresh egg quality from producer to consumer is one of the major problems facing those engaged in marketing eggs. Temperature, humidity, air movement and storage time can all have adverse effects on interior quality. These factors, if not controlled, can cause loss of moisture in eggs. Loss of water through the porous shell will mean loss of weight. A loss of weight of two to three percent is common in marketing eggs and is hardly noticeable to consumers. Proper attention to production, distribution and point-of-sale phases are of vital importance in maintaining egg quality. In this connection, a study was designed to assess the external and internal quality characteristics of market duck eggs from Thrissur district and farm fresh Kuttanad and White Pekin eggs.

Eighteen duck eggs were procured from various retail shops in and around Thrissur district and 12 eggs each of Farm fresh Kuttanad and White Pekin ducks were used for the study. On the same day of collection, these eggs were subjected to external and internal quality assessments in Department of Poultry Science, College of Veterinary and Animal Sciences, Mannuthy, Thrissur. In the external quality parameters, egg weight, length, width of the egg were recorded and shape index and specific gravity were calculated. In internal quality characteristics, height of albumen and yolk, length and width of albumen and yolk, yolk colour score, egg shell thickness were recorded and Albumen index, Yolk index, Haugh unit score also were calculated.

The external and internal quality parameters of the three groups of egg were presented in the following Table.

The results revealed that there is no significant difference among mean egg weight, shape index and specific gravity among the three different group of eggs. The mean egg weight of market egg and white pekin duck egg recorded in the present study is in close agreement with the findings of Abraham and Ravindran (2009) who reported that retail mean duck egg weight is 66.10±0.98g however the kuttanad duck eggs from the farm were recorded the least value of 64.03±2.01 where as shape index of all the three groups values were slightly lower than their finding, 76.20±0.97. Specific gravity values of all three groups were slightly lower than the values reported by Mahanta et al (1993) for indigenous ducks of Assam (1.11±0.006) and Sangilimadan (2009) for retail eggs at Chennai metro, 1.13±0.01.

Kuttanad and White pekin farm fresh eggs showed significantly (P<0.05) superior quality in shell thickness, shell percentage and yolk index than retail eggs which is in accordance with Abraham and Ravindran (2009) who reported yolk index value of 0.31±0.02 for retail eggs however the yolk index values of farm fresh eggs are very high.  Shell thickness values for white pekin, kuttanad and market eggs were 0.385±0.02, 0.357±0.01 and 0.33±0.01 respectively. Shell thickness value of white Pekin duck egg is similar to the findings of Kokoszynski (2007) who observed the shell thickness values of white pekin duck eggs at different stages of production.

 Albumen index and Haugh unit score of kuttanad duck eggs were significantly (P<0.05) superior to white pekin eggs and market eggs showed significantly (P<0.05) the least value. These values for market eggs were in agreement with Sangilimadan (2009) for retail eggs however farm fresh eggs had extremely high values.

Mean shell weight value of white pekin (6.93 ±0.27g) eggs were significantly higher than market eggs (6.12 ±0.12g) while there is no significant difference between kuttanad (6.47 ±0.17g) and white pekin eggs. Yolk score of market egg (8.67 ±0.31) was significantly higher than the farm fresh eggs (6.0 ±0.24) and this may be due to the scavenging feeding habits of the free range ducks in the paddy fields of Kerala. Feeding of prawn waste incorporates a salmon red colour to the yolk due to the pigment Xanthene (Elizabeth et al, 1982). These types of feeding practices are common in free range reared ducks in Kerala which substantiates the result.

The study inferred that the duck eggs sold at market level in and around Thrissur dictrict, Kerala are sufficiently poor in their qualities in comparison to the farm fresh eggs.

Elizabeth,V.K., Ramakrishnan, A and Reghunathan Nair, G.(1982) Kerala J. Vet. Sci., 13: 95-98.

John Abraham and Ravindran, R. (2009) Intern.J.Poult.Sci. 8(8):804-07

Kokoszynski. D., Bernacki, Z. and Korytkowska, H. (2007) Poland. J. Cent.Eur.Agric.8(1):9-16

Mahanta, J.D., Dutta,D.J and Rahman,H. (1993) Indian .J. Poult. Sci. 28(2):147-49

Sangilimadan,K., Murugan,M., Asha,R.R and Sheriff, F.R.(2009) IV water fowl conference, proceedings. 514-517