The effect of broiler breeder ages on the qualitive and quantitive properties of the egg

Abstract: Broiler breeder age is one of the most important factors that affects on egg properties. However by increasing the age of broiler breeder flock, the quality of eggs and consequently the quality of their chick products would be changed. In order to study the effect of broiler breeder flock age on the various aspects of chick products, 300 fertilizable eggs were selected randomly, from 3 broiler breeder farms. Selected eggs were collected from broilers that were 30 (young), 36 (peak), 43(after peak), 53 (old), 60 (very old) and 82 (molted) weeks old. Collected eggs were stored during 3 to 4 days in the ambient temperature. Qualitive and quantitive aspects of eggs including egg weight, albumen height yolk, height thickness of egg shell, yolk color, Albumen and yolk PH and Hugh unit were studied. Trait Analysis was done by ANOVA procedure of SAS statistical software. To compare the means, Duncan test was used. The effects of age and breeder farms on the egg weight, yolk color, yolk and albumen PH, yolk and albumen height, shell egg thickness and Hugh unit were significant (p<0.05). The lowest difference was seen between the age of 53, 60 and 82 week old (p<0.05). Albumen PH and alkaline is increased by increase of age, but yolk PH is the variance. Influence of age on the traits including yolk and albumen height and Hugh unit was decreased and the color of yolk was faded by increasing age. According to obtained results from this research performances of ages of 53, 60 and 82 weeks are close together. We could conclude that older broiler breeder flocks are produce the better qualitive and quantitive properties of egg products. Since most poultry enough information about the quality of breeder chickens and the best age to have chickens, using the results of this study can be answered many questions.

INTRODUCTION

        Bird’s age is one of the natural effective factors on the daily product and quality of egg in a flock the size of eggs is elated not only to the weight, but also to the age. In the start of laying period, eggs hell thickness is very more than he end of product. By increasing age of broiler, eggs shell thickness is more thinned. Weak quality of the egg shell influences on the inner quality of eggs during laying or hatchery period. The most information about quality of egg shell, has achieved during last 50 years. In the meantime, poultry genetics, ration, installation and management have changed and improved significantly. Not only a factor causes to crack and weakness of eggs, but also, today, more factors have been known which affects on the quality of eggs. Some of the mentioned factors are included nutrient levels, diseases, managements, environment and modification of spices.

MATERIAL AND METHODS

        In order to perform experiments, concerning to egg properties, 300 fertilizable eggs selected randomly, from 3 boiler breeder farms. Farms included Dorna Jouje Shomal, Dorna Jouje Delijan and Zarbal broiler breeder. In the Dorna Jouje Shomal farms elected eggs were collected from weeks 30 (young), 36 (peak) and 43 (after peak) chick. The average of the product in Dorna Jouje Shomal farm was 84, 85.1 and 75.5%, respectively.

        In Dorna Jouje elijan, The sampled eggs which were in the age of week 82 (molt) in the Zarbal Company, selected egg were sampled from chicks which were 53 (old) And 60 (very old) weeks. Averages of product at mentioned age were 67.29 and 59.65% collected eggs per 3-4 day, at room temperature. Then some of the normal eggs that must be set to hatchery were sending to Hatchery Company. Some of the eggs were sent to nutrition laboratory of the Islamic Azad University- Qaemshahr branch, in order to perform experiments related to the study of qualitive and quantitive properties of eggs. Total sampled eggs were measured by digital scale Sartorius (Model CPC 153) with 0.001gram accuracy and then recorded. The content of all eggs was emptied, individually, in the trays. Then egg inner characteristics including yolk and albumen height were weighted for trait of albumen height, most of upper of albumen was weighted that was located near of yolk and their yolk height from most upper part of yolk which were in the middle of yolk by caliper.

        Accuracy of caliper were 2% millimeter. while testing, in some cases during breaking eggs, their yolk were cracked or their albumen was thin. These observations prove that some of the eggs were dated. After recording albumen height and egg weight by following formula, Hugh unit was calculated and recorded for each egg:

HU=100log (H+7.57-1.7W^0.37)

Where; HU, Hugh unit; H, Height of dense albumen to millimeter and w, Egg weight to gram

        After breaking the eggs, their shells were separated. Then they were measured and recorded at 3 arts of head (thing part), intermediate and end of eggs (width part), by micrometer. The micrometers were more accurate than caliper. this investigation was done by micrometer (Model CMC) with 1% millimeter accuracy. After eggs were cracked and their inner content was spread over a smooth surface (tray), yolk colors were measured by color of yolk (By kit of identifying yolk color Roche).

        These kits were graded from number 1 to 15 and have linear relation with the amount of Xenophile (Dibazar 2009). Colors of cart were adapted to yolk color and then nearest number to color of kit were recorded. Yolk and albumen PH, after emptying contents of eggs on the tray were measured and recorded by PH meter. Recorded data were transferred to Excel software (2003), normal distribution test of data was done by SAS statistical software (2003) and then initial statistical information (Descriptive Statistic) was calculated.

        Traits analysis was done by following statistical model and ANOVA procedure of SAS statistical software (with 95% precision).

Y_ij = m+H_i +A_j +e_ij

       Where; y_ij,  amount of each observation for per trait; m, mean; H_i, effect of breeder farm; A_j, effect of boiler breeder age and e_ij, effect of errors.

       To compare the means, Duncan test was used.

RESULTS

        Descriptive statistics of studied traits are presented at Table 1.

        According to Table 2, there is no significant difference between the average of egg weight product in the Dorna Jouje Delijan and Zarbal broiler breeder farms (p>0.05), but the difference between the average of egg weight product in these farms are significant (p<0.05). The effect of the difference between the average of egg weight product by broiler breeders with age of 53, 60 and 82 weeks is not significant (p>0.05). There is a significant difference between egg weights of 30, 36 and 43 week (p<0.05). The difference between the average of egg weight, broiler breeder of this 3 ages and the other ages is significant (p<0.05). According to Table 2, there is no significant difference between mean albumen height of egg product at Dorna Jouje Shomal and Delijan (p>0.05), also the difference between mean albumen height of egg product at Dorna Jouje Deiljon and Zarbal is significant (p>0.05). But inversely, difference between mean albumen height of egg product at Dorna Jouje Shomal and Delijan with Zarbal is significant (p<0.05). Effect of difference between mean albumen height of egg product by broiler breeder age of 36, 53, 60 and 82 week old is not significant (p>0.05). There is also a significant difference between albumen height, broiler breeders at to latter age and another age (p<0.05).

        As shown in Table 2, the difference between average of yolk height of egg product at Dorna Jouje Shomal and Zarbal is not significant (p>0.05), but the difference of this at Dorna Jouje Shomel and Zarbal farms with Delijan farm is significant (p<0.05).

        At Table 2, there is no difference between mean of Hugh unit and egg product at Dorna Jouje Delijan and Zarbal farms (p>0.05), but the difference of them at Dorna Jouje Delijan and Zarbal with Dorna Shomel is significant (p<0.05). The effect of the difference between these factors by broiler breeder at age 53,60 and 82 week and also between the age of 36 and 82 week is not significant (p>0.05).

Table 1: Descriptive statistic of the traits

Egg weight               300                    64.697                 4.828

Albumen height       270                    6.453                   16.810

Yolk height              272                    18.450                 5.181

Hugh unit                 270                    77.339                 10.614

Egg shell 1               300                    0.342                   8.100

Egg shell 2               300                    0.333                   7.602

Egg shell 3               300                    0.336                   7.466

Color of yolk           300                    7.120                   8.208

Yolk PH                   279                    9.165                   0

Table 2: study the  effect of breeder farms and various ages of broiler breeder on metric traits

(1)                               61.310^b ± 0.255                         6 .600^a ±0.092                 18.060 ^b ±0.081                                        79.350^a±0.701

(2)                               67.880^a ±0.441                          6.510 ^ab ± 0.161               19.930^a ±0.142                                         76.410 ^b ± 1.223

(3)                               68.160^a±0.312                           6.190^a±0.115                   18.290^a±0.100                                          74.670^b ±0.875

Age (week)

30                                57.970^d ±0.441                          7.620^a±0/153                   18.730^b ±0.135                                    87.290^a±1.160

36                                61.320^c±0/441                           6.510^b±0/163                   18.030^c±0.144                                     79.470^b±1.230

43                                64.660^b± 0.441                          5.490^c±0/165                   17.300^d±0.145                                     69.990^d±1.251

53                                68.440^a± 0.441                          6.250^b±0/169                   18.720^b±0.144                                     75.190^c±1.282

60                                67.890^a±0.441                           6.140^b±0/158                   17.890^c±0.140                                     74.210^c±1.197

82                                67.880^a±0.441                           6.510^b±0/161                   19.930^a±0.142                                     76.410^cb±1.223

MSE                            9.750                                         1.170                               0.910                                                   67.380

(1): Dorna Jouje Shomal, (2): Dorna Jouje Delijan, (3): Zarbal company, *similar letters at each column show statistical in difference at %5 level

Table 3: The effect of chick farm and various ages of broiler breeder on the trait of shell thickness

(1)                                            0.350^b±0.002                                             0.342^a±0.002                                                0.347^a±0.002

(2)                                            0.359^a±0.004                                              0.349^a±0.004                                                0.350^a±0.004

(3)                                            0.320^c±0.002                                              0.310^b±0.003                                               0.310^b±0.003

Age (week)

30                                             0.371^a±0.004                                              0.366^a±0.004                                                0.374^a±0.004

36                                             0.350^b±0.004                                             0.345^b±0.004                                               0.35^b±0.004

43                                             0.331^c±0.004                                              0.314^c±0.004                                                0.319^c±0.004

53                                             0.320^d±0.004                                             0.314^c±0.004                                                0.309^c±0.004

60                                             0.320^c±0.004                                              0.307^c±0.004                                                0.310^c±0.004

82                                             0.360^ab±0.004                                            0.349^b±0.004                                               0.35^b±0.004

MSE                                         0.001                                                          0.001                                                            0.001

(1): Dorna Jouje Shomal, (2): Dorna Jouje Delijan, (3): Zarbal Company, *Similar letters at each column show lack of statistical difference at %5 level