SHORT-TERM SELECTION FOR BODY WEIGHT AND GROWTH RATE IN JAPANESE QUAIL 2. CORRELATED RESPONSES

Farahat, Gihan, S.; El Full, Ensaf, A.; Abdel Fattah, Mohamed, H.; Hataba, Nabel, A.; Khalifa, Mohamed, A.

doi:10.21608/fjard.2007.197534

SHORT-TERM SELECTION FOR BODY WEIGHT AND GROWTH RATE IN JAPANESE QUAIL 2. CORRELATED RESPONSES

Document Type : Research articles.

Authors

¹ Poultry Production Dept., Faculty of Agriculture, Fayoum Univ., Egypt.

² Animal Production Research Institute, ARC, Dokki, Egypt.

10.21608/fjard.2007.197534

Abstract

Three quail lines were used in this work to evaluate the correlated
responses of growth and some fitness traits in Japanese quail after mass
selection for increased either weight or growth rate: HBW42 line was
selected for high body weight at 42 days of age, HGR1-42 line was selected
for high growth rate during the period from one-day to 42 days of age and
randombred control line RBC was used as non-selected pedigreed
population. The results obtained can be summarized as follows:
The highest correlated responses of body weights were attained in the
1st generation for BW1 and BW35 associated with faster GR21-42. The highest
fertility and hatchability percentages either calculated from total egg set
(HTE%) or fertile eggs (HFE%) were obtained after one generation of
selection. Asymmetrical correlated responses between the two sexes were
found and were not stable throughout the three generations. Selection for
HBW42 resulted in increases in body weights at 14, 21, 28 and 35 days of
age and faster growth rate during the period from 1-21 days than other lines.
However, the HGR1-42 line had heavier body weights at 7 and 42 days of age
than other lines. Significant line differences favoring HGR1-42 followed by
HBW42 were attained for fertility%, HTE% and HFE%. Correlated
responses in the line HGR1-42 were higher but insignificant than that for the
HBW42 line for males and females. However, females had higher correlated
response in BW7 with significant sex differences in the HBW42 and HGR1-42
lines. Generally, the realized correlated responses of all studied growth traits
in males were positive and higher than their expected correlated responses.
The highest realized correlated responses were 4.97 in BW35 of the HBW42
line and 4.76 in BW42 of the HGR1-42 line. Realized correlated responses in
all body weights from 7 up to 42 days of age for the HGR1-42 line, except
BW1 were significantly higher and positive than their expected estimates,
whereas the realized correlated responses in growth rate traits of this line
were insignificantly different than their expected estimates. The highest
correlated responses for females were 7.21 and 5.86 for BW21 in the HBW42
and HGR1-42 lines, respectively. The realized correlated responses were
insignificantly lower than expected estimates for all fitness traits in the line
selected for HBW42. Similar trend was observed for fitness traits except
HTE%, which indicated highly significant differences favoring realized
correlated responses as a result of selection for HGR1-42 . It can be
concluded that selection for high growth rate is more effective than
selection for body weight because both insignificantly differed from each
other for all growth traits and the survivability during the periods from 1-21
and 1-42 days of age. Besides, there are significant differences favoring
HGR1-42 line for fertility% and hatchability% which calculated as a
percentage of total eggs or as a percentage of fertile eggs, which can be used
as additional indirect goals from selection in that line.

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