Response to selection and genetic parameters of body and carcass weights in Japanese quail selected for 4-week body weight

Department of Animal Science, Faculty of Agriculture, University of Tehran, PO Box 4111, 31587-77871 Karaj, Iran.
Poultry Science (Impact Factor: 1.54). 09/2010; 89(9):1834-41. DOI: 10.3382/ps.2010-00725
Source: PubMed

ABSTRACT The current study was conducted to investigate the effect of short-term selection in Japanese quail for 4-wk BW and estimate genetic parameters of BW, carcass traits, and egg weight. A selected line and control line were randomly selected from a base population. In each generation, 39 sires and 78 dams were used as parents for the next generation. Data were collected over 2 consecutive hatches for 4 generations, and 1,554 records from 151 sires and 285 dams were used to estimate the genetic parameters. The genetic improvement of 4-wk BW was 9.6, 8.8, and 8.2 g in generations 2, 3, and 4, respectively. There was a significant effect of sex, generation, and line (P < 0.001). There was a significant difference for BW and carcass weights but not for carcass percentage components between sexes (P < 0.01). Females showed higher figures than males. The realized heritability for 4-wk BW was 0.55, reflecting the accuracy of selection. However the estimated heritability by using pedigree information was 0.26 +/- 0.05. The genetic correlation among BW and carcass traits was relatively high (ranging from 0.85 to 0.91). Inbreeding caused a decline in the mean for all of the traits, but its effect was only significant for 4-wk BW and carcass weight (P < 0.05). Selection for 4-wk BW improved feed conversion ratio 0.16 units over the selection period. Results showed there was a strong genetic correlation between 4-wk BW and carcass traits that suggests that early 4-wk BW can be used as a selection criterion to improve carcass traits. Also, intense selection resulting in high rates of inbreeding might result in decreased response to selection due to inbreeding depression.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Abstract 1. The objectives of the present study were to estimate heritability and genetic correlations for feed efficiency and body weight in Japanese quail. 2. Recorded tratis during different weeks of the growing period were body weight (BW) from hatch to 35 d, feed intake (FI), feed conversion ratio (FCR) and residual feed intake (RFI) from hatch to 28 d of age. 3. Genetic parameters were estimated by restricted maximum likelihood method using ASREML software. The results showed that heritability estimates for BW ranged from 0.11 to 0.22 and maternal permanent environmental effect was the highest at hatch (0.45). FCR, RFI and FI showed moderate heritabilities ranging from 0.13 to 0.40. 5. Genetic correlations of BW28 with FI0-28 (0.88) and RFI0-28 (0.1) and genetic correlation of FI0-28 with FCR0-28 (0.13) and RFI0-28 (0.52) were positive. A negative genetic correlation was found between BW28 and FCR0-28 (-0.49). There was a high positive genetic correlation (0.67) between RFI0-28 and FCR0-28. 6. In conclusion, selection for increased BW and reduced FI in a selection index could be recommended to improve feed efficiency traits including FCR and RFI in Japanese quail.
    British Poultry Science 05/2014; DOI:10.1080/00071668.2014.925088 · 0.78 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study was to evaluate the relationship between slaughter age and slaughter-carcass characteristics in 2 quail lines. With this aim, a Japanese quail flock subjected to mass selection to increase BW for 4 generations and a control flock that randomly mated for 4 generations were used. Birds of both lines were slaughtered at 4, 5, 6, 7, and 8 wk of age. Weights of carcass, breast, leg, wing, edible inner organs, and abdominal fat, and their percentages in BW were measured. Short-term mass selection for increased BW resulted in an increase for all slaughter and carcass traits, except edible inner organ percentage. Slaughter age had a significant effect on the studied traits, indicating that the BW and weight of carcass, carcass parts, abdominal fat, edible inner organs, and percentage of abdominal fat increased with increased slaughter age. Conversely, the carcass yield and percentages of carcass parts and edible inner organs were decreased with an increase in slaughter age. The present study showed that deterioration in carcass quality occurred with an increase in slaughter age. Furthermore, the differences between the carcass weights over the different ages ranged between 16.83 to 22.45% in favor of the selection line after a short-term mass selection.
    Poultry Science 03/2014; 93(3):762-9. DOI:10.3382/ps.2013-03506 · 1.54 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Preservation of genetic diversity in populations is an important task to ensure a possible long-term response to selection in animal breeding. The purpose of this study was to consider how pedigree analysis and gene dropping method could be used for management plans in order to maintain genetic variation in a population under selection of Japanese quail. Therefore, the distributions of alleles frequencies originated from founders were estimated using gene dropping simulation software on an actual pedigree. Then, genetic contribution of founders to current population, components such as the F-statistics and effective population sizer were estimated. The results show that from 156 founders there are only 64 of them (22 males and 42 females) in the last generation. The average genetic contribution of a founder male and female contributing to the last generation were 1.87 and 1.40%, respectively. A total of 87 and 95% of the genome in the last generation were constituted by 34 and 42 founders, respectively. The effective population size decreased as inbreeding increases. The allele frequency averaged over replicates agreed with the genetic contribution. Some useful information regarding to the management of genetic diversity such as the probability of allele extinction, the probability of alleles surviving at a critically low frequency, and risk of future allele extinction were derived by suing these distribution. Results show that pedigree analysis and gene dropping are valuable tools in optimizing decisions to preserve genetic variability.
    Archiv fur Tierzucht 04/2013; 56. DOI:10.7482/0003-9438-56-050 · 0.33 Impact Factor

Full-text (3 Sources)

Available from
May 21, 2014