Hatching performance of Japanese quails

A Khurshid, M Farooq, F R Durrani, K Sarbiland and A Manzoor

Department of Poultry Science, NWFP Agricultural University, Peshawar, Pakistan
durraniff@yahoo.com or durranif@hotmail.com 

Abstract

The present study was conducted on 500 eggs, selected from Japanese quails reared in cages at the Poultry Research Unit, NWFP, Agricultural University, Peshawar, Pakistan after discarding undesirable eggs to investigate overall hatching performance. All the eggs were collected on the same day from a 70-day-old flock maintained under similar environments to absorb the effect of flock age and management conditions.

Average early and late embryonic mortality was 14.5+2.01 and 11.9±1.96% on the basis of total eggs set and 17.8±2.26 and 14.6±2.09% on the basis of fertile eggs, respectively. Average fertility, loss in egg weight during incubation and weight of the newly hatched chick was 80.9±5.49%, 23.3±0.32% and 6.99±0.05 g, respectively. Hatching chick weight was found positively correlated with egg weight (r=0.77), length (r=0.31), width (r=0.33), eggshell weight (r=0.29) and shell thickness (r=0.12). Average hatchability on the basis of total eggs set and fertile eggs was 55.1±1.93 and 67.6±2.77%, respectively. Hatchability was found negatively correlated with eggshell weight (r=-0.27), shell thickness (r=-0.13) and egg shape index (r=-0.077) but positively correlated with egg weight (r=0.18).

Egg weight, shell weight, shell thickness and egg shape index affected hatching performance. Large-sized eggs resulted in better hatching performance as compared to small-sized eggs. Increase in eggshell weight and thickness resulted in deterioration in hatching performance of Japanese quails.

Key Words: Embryonic mortality, fertility, hatchability 

Introduction 

Egg weight, shell weight, shell thickness, fertility and embryonic mortality would influence overall hatching performance provided management conditions are not the limiting factors. Wilson (1991) and Kalita (1994) reported higher hatchability for intermediate than too small or too large eggs. Farooq et al (2001b) and Murad et al (2001) also reported significant influence of egg and shell weight on hatching performance. The authors reported lower hatchability of small-sized eggs and those with poor shell quality. Shanaway (1994) also reported better hatchability in large-sized eggs (9-11 g). Higher hatchability was found for thin and thicker shell eggs as compared to thickest (Ahmed et al 1983). The possible causes of higher hatchability in thicker shell eggs could be smaller embryonic mortality as has also been reported by Roque and Soares (1994).  

Hatchability is one of the pre-requisites for the better propagation of any breed. Farooq et al (2001a) reported 71.16% hatchability in quails on the basis of fertile eggs. Lower hatchability can be observed in a flock, if embryonic mortality is higher and fertility is lower. Embryonic mortality as high as 28.84% has also been observed in quails (Farooq et al 2001a). Variations in embryonic mortality may be due to poor egg holding period, imbalanced nutrition, stressful conditions the parent flock was exposed to, or any other fault in incubation and hatching requirements/equipments. Poor egg-shell weight has also been reported to result in higher embryonic mortality (Roque and Soares 1994). Loss in egg weight and hatching chick weight is mainly influenced by egg weight. Positive association of egg weight with hatching chick weight was also reported by Farooq et al (2001b). Hatching chick weight has been reported to be 62 to 76% (Wilson 1991) and 68.2% (Murad et al 2001) of the initial egg weight. Keeping in view the importance of egg parameters and hatchability, the present study was an effort to investigate hatching performance of Japanese quails and relative effect of egg weight, shell weight, shell thickness and egg length to width ratio on hatching performance. 
 

Materials and methods

The present study was conducted on 500 eggs, selected from Japanese quails reared in cages at the Poultry Research Unit, NWFP, Agricultural University, Peshawar, Pakistan after discarding undesirable eggs to investigate overall hatching performance. All the eggs were collected on the same day from a 70-day-old flock maintained under similar environments to absorb the effect of flock age and management conditions. Data on egg weight (g), length (cm) and width (cm) were recorded prior to setting eggs in the incubator. Each egg was given a unique number prior to putting it in incubator and for each egg a separate compartment was available to facilitate data on individual basis. All the eggs were put in one incubator on the same day. Data on shell weight, hatching chick weight and shell thickness of the eggs were recorded when hatching process was over. The un-hatched eggs were broken to investigate fertility, embryonic mortality (early and late), shell weight and shell thickness. Egg shape index was calculated using the following formula given by Panda (1996).

Egg shape index = (egg width/egg length)*100

Embryonic mortality and hatchability was calculated on the basis of total eggs set and fertile eggs as well. The mortality was then grouped as early and late depending upon the size of the dead embryos after opening un-hatched eggs. Loss in egg weight during incubation and hatching process was worked by deducting weight of eggshell and newborn chick from the initial egg weight. The data were analyzed using relevant statistical techniques. Correlations between egg weight, length, width, shell weight, shell thickness, loss in egg weight during incubation and hatching process, embryonic mortality (early and late), hatchability and hatching chick weight were worked out using the following formula:

                Cov (X, Y)
r_X,Y   =     ---------------
                 σ_xσ_Y

Results and discussion 

Embryonic mortality 

Farooq et al (2001a) reported higher early (20.25%) and lower late embryonic mortality (3.60%) in Japanese quails than the present findings (Table 1).  The higher embryonic mortality in the present study could probably be due to poor egg holding period as eggs were held for an irregular period. Early embryonic mortality was found negatively correlated with egg weight (r=-0.40; p<0.0001), shell weight (r=-0.009; p<0.883) and shell thickness (r=-0.056; p<0.346) but positively correlated with egg shape index (r=0.109; p<0.064; Table 2). On the other hand late embryonic mortality was found positively correlated with egg weight (r=0.199; p<0.001), shell weight (r=0.368; p<0.0001) and shell thickness (r=0.237; p<0.0001) but negatively correlated with egg shape index (r=-0.17; p<0.780; Table 2). Roque and Soares (1994) also reported higher embryonic mortality in eggs having poor shells. Findings of the present study suggested that increase in egg weight, shell weight and shell thickness will significantly result in an increase in late embryonic mortality.  

Fertility 

Shanaway (1994) and Farooq et al (2001a) reported higher fertility in Japanese quails than the present findings. The lower fertility in the present study could be attributed to unsuitability of rearing breeding quails in cages as the eggs were collected from caged quails. Cage rearing may have not ensured better mating as it could have been in case of floor rearing. 

Loss in egg weight during incubation and hatching 

Murad et al (2001) reported a little smaller (21.4%) loss in egg weight than the present findings (Table 2).  Loss in egg contents was found to be positively correlated with egg weight (r=0.038) but negatively correlated with egg length (r=-0.072), width (r=-0.163), eggshell weight (r=-0.27) and shell thickness (r=-0.096). The findings suggested that increase in egg weight would result in an increase in loss in egg weight during incubation and hatching process. On the other hand, the negative relationships among loss in egg weight and egg length, width, shell weight and shell thickness suggested that increase in the aforementioned variables would decrease the loss in egg weight during incubation and hatching process. 

Hatching chick weight 

Chick weight was 67.3% of the initial egg weight set for hatching. Wilson (1991) reported 62 to 76%;  whereas, Murad et al (2001) reported chick weight to be 68.2% of the initial egg weight set in incubator. Farooq et al (2001a) reported higher weight of the newborn chick (8.06 g) in Japanese Quails than the present findings. The smaller weight of the newly hatched chick in the present study is attributable to smaller egg weight than that reported by Farooq et al (2001a).  

Hatching chick weight was found significantly (P<0.01) and positively correlated with egg weight (r=0.77), length (r=0.31), width (r=0.33), eggshell weight (r=0.29) and shell thickness (r=0.36) but negatively and non-significantly correlated with egg shape index (r=-0.12). These findings suggested that increase in any of the aforementioned variables would result in an increase weight of the new born chick. But care should be exercised to select oblong eggs because longer eggs may create problems during incubation. 

Hatchability 

Farooq et al (2001a) reported higher hatchability on the basis of total eggs set (58.8%) and fertile eggs (71.2%). The lower hatchability in the present study could be due to poorer fertility in the present study than that reported by Farooq et al (2001a).    

The findings of the present study suggested an increase in hatchability with increase in egg weight whereas increase in eggshell weight and thickness resulted in a decrease in hatchability. Shanaway (1994) also reported improvement in hatchability with increase in egg weight of Japanese Quails.  

Table 2.  Correlation analyses among various traits
	Early embryonic mortality	Late embryonic mortality	Hatchability	Weight of the new-born chick
Egg weight	-0.404	0.199	0.179	0.772
Shell weight	-0.009	0.368	-0.270	0.296
Shell thickness	-0.056	0.237	-0.133	0.365
Egg shape index	0.109	-0.017	-0.077	-0.127

Conclusions and recommendations 

• Egg weight, shell weight, shell thickness and egg shape index affected hatching performance.

• Large-sized eggs resulted in better hatching performance as compared to small-sized eggs.

• Increase in eggshell weight and thickness resulted in deterioration in hatching performance of Japanese quails.

References

Ahmed M, Narahari D, Kothandaraman P and Khavi M A 1983 Effect of eggshell characteristics on hatchability of Rhode Island Red eggs. Journal of  Poultry Science 12: 148-153. 

Farooq M, Aneela K, Durrani F R, Muqarrab A K, Chand C and Khurshid A 2001a Egg and shell weight, hatching and production performance of Japanese broiler Quails. Sarhad Journal of Agriculture 17(3): 289-293. 

Farooq M, Mian M A, Murad A, Durrani F R, Asghar A and Muqarrab A K 2001b Egg traits of Fayumi birds under subtropical conditions. Sarhad Journal of Agriculture 17(2): 141-145. 

Kalita  N 1994 Effect of egg weight, storage period and position of egg on hatchability. Indian Journal of  Poultry Science  29(3): 281-283. 

Murad A, Farooq M, Mian M A and Muqarrab A K 2001 Hatching performance of Fayumi eggs. Sarhad Journal of Agriculture 17(1): 1-6. 

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Shanaway M M 1994 Quail production systems: A review. Animal Production and Health Division, FAO, Rome, Italy. 

Wilson H R 1991 Interrelationships of egg size, chick size, post-hatching growth and hatchability. World's Poultry Science Journal 47(1): 5‑20.