Selecting for efficiency of egg production using food-consumption records in layer-type chickens.
1. The purpose of the experiment was to evaluate the use of food consumption records in selection to improve layer-type chickens. 2. Twelve subpopulations of Leghorns, including 5878 tested birds, were used in a selection experiment which lasted 5 generations. Four were selected using an index (I1) that combined information on body weight (BW), egg-mass output (EM), and individual food-consumption records (FC). Four were selected using an index (I2) that combined information just on BW and EM. The remaining 4 served as controls, with selection differentials set to zero in each generation. 3. Differences between the selected groups, control-corrected each generation, measured the "food-record effect". 4. Including food-consumption records in the selection criterion resulted in increased body weight (7%), reduction in food consumption (6 to 9%), increase in food efficiency (egg mass/food consumption) (2 to 5%), and increase in income over food costs (10%), relative to selection not involving food records.
Nordskog
A W
AW
Department of Animal Science, Iowa State University, Ames 50011.
Hou
Y H
YH
Singh
H
H
Cheng
S
S
D000818:Animals; D001947:Breeding; D002645:Chickens / Q000235:genetics / Q000502:physiology*; D004435:Eating / Q000235:genetics*; D005260:Female; D008957:Models, Genetic; D010058:Oviposition / Q000235:genetics*; D012044:Regression Analysis; D015430:Weight Gain / Q000235:genetics