Heritabilities and phenotypic correlations of growth performance traits in Japanese quails

I O Adeogun and A A Adeoye

Animal Science Department, Obafemi Awolowo University, Ile-Ife, Nigeria
adeomoh@yahoo.com

Abstract

A research was conducted at the National Veterinary Research Institute Vom, Plateau State to estimate means, heritabilities and phenotypic correlations of growth performance in Japanese quails. Data were collected from first generation birds hatched from 400 eggs randomly collected from a breeder stock and the second generation birds resulted from mating of the first generation birds.

Heritabilities of the two performances were estimated from sire and dam component of variance and they had medium to high estimates, indicating that they could be improved through individual selection. Phenotypic correlations were estimated from sib-analysis of variance and covariance, and ranged from -0.06 to 0.85.

Keywords: growth performance, heritability, Japanese quails, phenotypic correlations.

Introduction

 

Diversification into production of livestock with short generation interval will be a viable tool in ameliorating shortage of protein among the populace in developing countries as reported by NVRI (1994).

 

Japanese quail is the smallest avian species farmed for meat and egg production (Panda and Singh 1990) and it has also assumed world-wide importance as a laboratory animal (Baumgarther 1990). Distinct characteristics include rapid growth - enabling quail to be marketed for consumption at 5 - 6 weeks of age, early sexual maturity - resulting in short generation interval, high rate of lay and much lower feed and space requirements than domestic fowl.

 

Genetic studies on quail in Nigeria will enable breeders to design suitable improvement programme for the bird. Therefore, reliable estimates of genetic parameters (heritabilities and correlations) are necessary to predict response to direct or indirect selection.

 

Materials and Methods

 

The data used for this study were collected from 1st generation birds hatched from 400 eggs randomly collected from a breeders stock and 2nd generation birds resulted from mating of the 1st generation birds at the Veterinary Research Institute, Vom Plateau State. The mating ratio was 1 sire to 3 dams. At the end of incubation, chicks were taken to the brooding pen and reared according to routine management procedures. Body weight and shank length measurements were taken at day old and thereafter weekly for six weeks.

 

The data were analysed using the Mixed Model Least Square and Maximum Likelihood procedure (Harvey 1990). Heritability was estimated from sire and dam components of variance (Becker 1984).

 

 

Standard errors for the heritability estimates were approximated in accordance to Dickerson (1965).

 

 

Where:

            MS_D    =          Mean Square dam

            MS_s       =             Mean square sire

            d²_T      =          Total variance

            d          =          Number of dams

            s          =          number of sires

                        K₃        =          number of progeny per sire

 

The phenotypic correlations among the traits were estimated from sib analyses of variance and covariance (Becker 1984) as follows:

 

 

Results and Discussion

 

The body weights and the shank lengths increased as the birds increased in age (Table 1). The heritability estimates of body weights ranged between 0.43 + 0.18 to 1.08 + 0.17, and that of shank lengths between 0.08 + 0.15 to 0.61 + 0.18. It is evident that most of the traits have medium to high heritability values. This suggests that the traits can be improved through individual selection.
 

Table 1. Means and heritabilities of growth performance of quail from full sib analysis
Traits	Means + SD	Heritability + SE
Day old body weight	7.74 + 0.55 g	1.08 + 0.17
1st week body weight	22.3 + 3.23 g	0.58 + 0.18
2nd week body weight	47.2 + 4.77 g	0.43 + 0.18
3rd week body weight	89.5 + 6.16 g	0.52 + 0.18
4th week body weight	123 + 7.60 g	0.69 + 0.19
5th week body weight	161 + 9.90 g	0.89 + 0.18
6th week body weight	197 + 12.16 g	0.95 + 0.18
Day old shank length	1.47 + 0.08 cm	0.61 + 0.18
1st week shank length	1.76 + 0.07 cm	0.08 + 0.15
2nd week shank length	2.18 + 0.13 cm	0.67 + 0.19
3rd week shank length	2.67 + 0.17	0.44 + 0.18
4th week shank length	3.05 + 0.18 cm	0.35 + 0.17
5th week shank length	3.35 + 0.15	0.24 + 0.16
6th week shank length	3.66 + 0.15 cm	0.41 + 0.18
+ SD = Standard deviation ;   +  SE = Standard error

The phenotypic correlations (Table 2) ranged from -0.06 to 0.85. Most of the traits were positively correlated, which indicates that they can be simultaneously improved while the negatively related ones show that improving one will be at the detriment of the other.
 

Table 2. Phenotypic and Environmental Correlations of Growth performance Traits from sire and dam (full –sub) variance components

Traits (r + SL)

Wto

St1

Wt2

Wt2

Wt3

Wt4

Wt5

Wt

Wt7

Wt2

Wt3

Sl1

Sl2

Sl3

Day old body weight (Wto)

Day old shank length (Slo)

0.48***

1st week body weight (Wt1)

0.20*

0.20*

2nd week body weight (wt2)

0.25**

0..19

0.80***

3rd week body weight (wt3)

0.15

0.17

0.68***

0.80***

4th week body weight (wt4)

0.03

0.07

0.43***

0.58***

0.75***

5th week body weight (wt5)

0.14

0.04

0.26**

0.47***

0.61***

0.74***

6th week body weight (wt6)

0.10

0.11

0.28**

0.47***

0.62***

0.72***

0.81***

1st week shank length (SL1)

0.22*

0.43***

0.29**

0.23*

0.27***

0.21*

0.41***

0.16

2nd week shank length SL2)

-0.06

0.03

0.60***

0.54***

0.49***

0.37***

0.26**

0.30**

0.47***

3rd week shank length (SL3)

-0.05

0.08

0.62***

0.57***

0.57***

0.44***

0.32***

0.36**

0.45***

0.85***

4th week shank length (SL4)

-0.02

0.07

0.61***

0.57***

0.55***

0.45***

0.29**

0.29**

0.32***

0.70***

0.78***

5th week shank length (SL5)

-0.03

0.04

0.52***

0.52***

0.55***

0.49***

0.37***

0.42***

0.28***

0.65***

0.76***

0.79***

6th week shank length (SL6)

-0.06

0.01

0.49***

0.49***

0.51***

0.47***

0.37***

0.45***

0.26***

0.56***

0.63***

0.65***

0.84***

Egg weight (EW)

0.57***

0.40***

0.22***

0.21***

0.11

0.04

0.02

0.02

0.24

0.03

0.13

0.12

0.10

0.08

* = (p< 0..05);   ** = (p<0.01);   *** = (p,0.001)

Discussion

 

The heritability values obtained for body weights are in line with the report of Baumgartner (1993) who recorded a range of 0.20 - 0.80, but defer from the findings of Aggrey and Cheng (1994). Heritability value (1.08) for day-old body weight is above the normal range of heritability values. This may be due to uncontrolled effects of lines, sex and generation (Michaska 1992) in addition to method of analysis.

 

Shank length heritability estimates are also high, except for 1st and 5th week which are particularly low. This suggests that shank length should not be selected for in the 1st and 5th week.

 

Phenotypic correlation of body weight and shank length are mostly positive, indicating that an improvement in body weight will likely lead to improvement in shank length and vice versa. Selection based on shank length (Ibe 1995) may not be useful in improving overall body growth of an animal unless selection is designed to improve specific body areas of prime economic value.

Conclusion

• Individual selection will be effective in improving the growth performance of Japanese quails.

References

 

Aggrey S E and Cheng K M 1994 Animal model analysis of genetic (Co) variances for growth traits in Japanese quails. Poultry Science, 73 (12): 1822 - 1828.

 

Baumgartner J 1993 Japanese quail production, breeding and genetics: proceedings of the 10th international symposium on current problems of Avian Genetics, Nitra, Solvakia. pp 101 - 103.

 

Becker W A 1984 Manual of Quantitative Genetics 4th edition, Academic Enterprises, Pullman, Washington, pp. 188.

 

Brah G S, Chaudary M L and Sandhu J S 1992 Distribution statistics of body weights in two stocks of Japanese quails. Poultry Abstracts 19 (10): 298.

Dickerson G E 1965  Experimental evaluation of selection theory in poultry.  Genetics Today, Vol. 3.

Harvey W R 1990 Mixed model least squares and maximum likelihood computer program, PC-2(LSMLMW). Ohio State University.

 

Ibe S N 1995 Repeatability of growth traits of Nigerian local chickens using early records. Nigerian Journal of Animal Production, 22 (1 and 2): 5 - 8.

 

Michalska E 1992 Genetic parameters of body weight and shank length of Japanese quails from four lines over 3 generations. Animal science Papers and Reports. Polish Academy of Science, Institute of Genetics and Animal Breeding, Jastrezebeic, 10: 27 - 34.

 

NVRI 1994  National Veterinary Research Institute, Vom: Farmer Training and Quail Production and Health Management. Pp44

 

Panda B and Singh R P 1990 Development in processing quail. World's Poultry Science Journal 46: 219 - 234.