scholarly journals Direct and Correlated Responses from Selection for Lately Sexual Maturity in Japanese Quail

2021 ◽  
Vol 12 (9) ◽  
pp. 299-303
Author(s):  
M. Aboul-Hassan ◽  
D. Aboul-Seoud ◽  
Ahmed Abd-Allah
Keyword(s):  
Japanese Quail ◽  
Sexual Maturity ◽  
Correlated Responses ◽  
Selection For

Correlated responses to selection for cow fertility in a tropical beef herd

1990 ◽  
Vol 50 (3) ◽  
pp. 417-424 ◽  
Author(s):  
M. J. Mackinnon ◽  
D. J. S. Hetzel ◽  
N. J. Corbet ◽  
R. P. Bryan ◽  
R. Dixon
Keyword(s):  
Growth Rate ◽  
Sexual Maturity ◽  
Live Weight ◽  
Breeding Value ◽  
Correlated Responses ◽  
Scrotal Circumference ◽  
Beef Herd ◽  
Selection For ◽  
Significant Line ◽  
Tick Resistance

ABSTRACTCorrelated responses to selection in a tropical beef herd for high (H) and low (L) estimated breeding value for pregnancy rate were measured over three calf crops. The H line calves were proportionately 0·04 lighter at weaning but during the ensuing dry season they lost less weight than L line animals, so that between the ages of 12 and 18 months there were no significant line differences in live weight. It was concluded that selection for cow fertility had not directly altered the progeny's growth rate. Tick resistance and heat tolerance also did not differ between the lines. However, resistance to worms was lower (P < 0·05) in the H line indicating genetic antagonism between cow fertility and worm resistance. Scrotal circumference and scrotal circumference adjusted for live weight were significantly higher in H line bulls between 9 and 18 months of age. Pregnancy rates of heifers in the H line were 0·12 higher than in the L line despite similar average live weights at mating. It is suggested that accelerated sexual maturity in both heifers and bulls has occurred as a result of selection for lifelong cow fertility.

scholarly journals Effect of selection for growth on onset of sexual maturity in randombred and growth-selected lines of Japanese quail

2003 ◽  
Vol 82 (2) ◽  
pp. 187-191 ◽  
Author(s):  
JM Reddish ◽  
KE Nestor ◽  
MS Lilburn
Keyword(s):  
Japanese Quail ◽  
Sexual Maturity ◽  
Selected Lines ◽  
Selection For
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